UNCLASSIFIED

AD NUMBER

AD450975

NEW LIMITATION CHANGE

TOApproved for public release, distributionunlimited

FROMDistribution authorized to U.S. Gov't.agencies and their contractors;Administrative and Operational Use; Jun1964. Other requests shall be referred tothe Navy Weather Research Facility, NavalAir Station, Norfolk, VA 23511.

AUTHORITY

USNRS, per ltr dtd 18 Sep 1972

THIS PAGE IS UNCLASSIFIED

NOTICE: When government or other drawings, speci-fications or other data are used for any purposeother than in connection with a definitely relatedgovernment procurement operation, the U. S.Government thereby incurs no responsibility, nor anyoblig3.tion whatsoever; and the fact that the Govern-ment may have formulated, furnished, or in any waysupplied the said drawings, specifications, or otherdata is not to be regarded by implication or other-wise as in any manner licensing the holder or anyother person or corporation, or conveying any rightsor permission to manufacture, use or sell anypatented invention that may in any way be relatedthereto.

CLIMATOLOGY AND LOW-LEVELAIR POLLUTION POTENTIAL

i F•OM SHIPS IN THE HAMPTON ROADS

ad.

QUALIFIED REQUESTERS MAY OBTAIN COPIES OF THIS REPURT DIRECT FROM DDC

Location C)o rre

Page Column Paragraph Line

6 -6 2 x10'

i - 6 3 clima-

1 2 2 15 plume

5 2 1 17 a

9 1 4 11 28.a x 10e

10 1 2 3 2 x 10'

15 2 3 9 gravitational

16 1 2 4 e....

17 1 1 Equation 2.2: ...-.--

52 - " Figure 3.29 is upside down

S.....

FORE WORD

'lhim rep~ort waerj111( TidriMEk 3t1 which woioofi4gnild oth" Niivy Wontlirr ltue-!wtrrhPriclilty for thu Ipt pIOSC Of etViniiriiiiig the, r.ticorologiiuaj "rfet tpon It pitlP1rwiIH1U iii'ci.4142noiic into the attmophn'r' veithin portm and ho rbo rn of Inteon uiatt the NR~vy,.

T liI IVpUbliIt i(t i o I iiVuet1 igao rm I' It' pIlUtIQ I tit IOnP~~tli ( V u?I I AhljrýI I, [A 1Jirinipt Is Wi I ( , A AL~tiInr pub~liusittio ror Sswi 1Ingo tisishol' h1as proviounly butin publi,,ifint howovtVe', thst prvput eun

part Villodic'rm eumo incu Ilrtu' rcoa do velopinpentio in the crilcuistions olf antfionphoii ri rifu p~itil,

A gote nns I om t I it itic or thir iq rn ' L I III Iniite of IIathe HaInpton Hod oal I, n i14 p uuoI I It ed, o Lw., do (1'tailed data fire not :Ava Iilabi on Lith, mnicruclirnetle itra La. A confipilet enh u utinvelisv -grai~on un the, titt. and 51poce va clnt ion Of w ind, f 1tipe rattilre grmdir it, imdlirtwc pittAtiun withinthist rIgiof Would by4 v~rot~ii'Iv u lt it 'anOI)O id #!" t Ilbtt buN it tank fozt flis' pstlipow' jr oijrs s~t- ul't.Consequently, thouigh.essr'h n eittdy miay hrdsieraiblo, It nAM n~A hpwn MA-t 'mptsd. Avis ihbli, rnoterc-t'ologi.'it recurJI(hM rthoeS linnhihstot Itultid tegomf hAvv born sirlliý4d, ati froms thtPo dti, parutni-oters have been cianaon which fireti onsido#'t'd 'itUnt unarfil III c'Vfluatifir the I povel finch dispersionof airborne meterinl i. hue vffvctiM of thvP* primtunnOLV'a ares ditilumiaga, and Iorwraes; oummnrbivsof thoir diurnal, sefaoonal, and muinthly chnngom have been ijueparted

The astimAtca of the dispersion of pollutant materials, rc'loused to the lower' atmosphere(to approximatealy 2,1100 foot), are prosented within the limnitN of our current knowledge on this4%calo. However, the general niature of this estimates of extent and ground-lovel concentrAtionof the@ contaminant leave, roomi for improvoment, posiribly by more detailed motitorological in-formation or research Into thr dippermion of miaterialo on thili 'Mcalo of interemt,

The order oi presentation of the work differs from the usual and ihould be explained. Itis customary In motoorologicni studies to bogin with it dotAiled description of the site and itmclimatology, and then to show the significance of these featurois In terms uf the problem, ThiApresupposes conmiderable familiarity with the mubject anrd is the actual order of the originaldevelopment of the work. However, the% processes describod are not especially fnmiliar, andthe significance of the climatological variations III much clearer, if reviewed tifter An uinder-standing of tu. problem is assured,

Chapter l is intended to give the reader an Introduction to and hopefully an underatainding ofthe basic concepts In diffusion meteorology, Chapter 2 deala with calouletions of the variousdiffusion patternsf using A hypotheticali release of 2 x 10' unitsa. Chapter' 3 presents the climtology of the 11hampton Rocds area, stresising the meteorological puarsmet irm rioot importtiwfrom an atmospheric pollution standpoint. Chapter 4, the concluding section, specifically dia-cusses the pollution potential of Hampton Hoads from the theory ijiscuussod in chapter 1 find thecalculations and the data Precented in chapters 2 wnd 3i.

The~ roporl, waistasemblod from current lhters'tu se, and vximLt ng (Itut find wats written byMr. lienic V.* Cormit'r, Astiltrint Taak L~endvr, mritlor tiltsMpc svibi-viim of Ow Tfun LcdMr. John M. Morcer, who Iffri edhitedh this plirtlir~tiion,

This report htie been reviOW&d And approveud on Myl I P0f"4 by the undorsmigned.

LCf)lOUmianer U.r S. NaivyUrrhics' ift c Isis rjeU. S. Ntivy Wc'nthtsr- U censrch, Pnc'lity

Bes Aailable Copy

TABLE OF CONTESTS

TABLE or uCONTN TS . . . . .. . . . , . . . s . . . . . . . . . . . . HNI

LS OF 1.3.2tr 1ANDil Tand11 . .d . . . .. . . . . . . . . . . VLST M HIL( AN) 01 iADIFFUSI ,ON ...... ....... ... .1.1 Transport nl Dilution . ........ . ......... . .. I.1, S d ) Smoe iam . . . . . . I# . .nI . . . . . .. . 11 .3 rheoretical Sttdina .. . . . . . . . . . . . . . . . . . . . . . . 3

1,3.1 sution I a I . a . . . , .. 0 . . a . I

1.3.U PA mqui ll and M d . I 9 . . . . . . . . . I. . . . 52.1 Basic Assumptin lo ,. . a . 0 S . . * . . . .. . . . 5(b) ThD oth forct Modification . . . . I 1 . . . . . . . . .. . . .. p(c) Compared with Cutton, . I . .. . .. . . .. . . . I I . I .n(d) UnC ertaintih s . . . .. . . . . . . .. . . . . . .. .. . . . 1(2I Puresent VIuo . . . . . ....... .

1.3.3 Transitlonai States, . ...1, .1a., , .*

.CALCULATIONS . . . . . . . . , . . . . . . . ... i2.1 Initial Behavior of the Cloud ....... . .,2.b Diffusion of th n Cloud , % * . . .. ,,, .,. ,)

2.2,1 Cen otaltne DosWalues, Cold RelWao e ,02.2.2 Centerline Dosages, Hot Release . ,III

3.2.3 Cloud Width . . . I I I . , 1 1 1 , 132.3 Deposition from the Cloud ........ 0. . . ....

2.32 1 General Considerations , s*s. t. 13

2. 3 , D Wpe sion lmt olg .. . . o . . s . v . . . *, . . . .. . ,. . 103.3.1 Winstrutur..., ..... .. ...99 9 9. ... .. .,

W,) Modification of Diffusion Curve. .... . . . I(

(b) Pollutrnt D.posted ... ............. 2 I7(c) Total .nstantanou. Washout .. . . . .. ... .. . . . . .I

3. CLIMATOLOGY OV THlE HIAMPTON ROADS ARS•A . . In•

3.1 Location And Topograph...... .... .. .. 9 ...... :it32 General Climate .. ....... .83.3 Dispersion Climatology ............ 20

(3.3 Wind Structure ......... ..... ... .... . 20(a) Winter ......... . s ...... 122

(b) Sprin r. . A . . 1, 1 . . I t. . . . . . . ... 27(0) Summer . .I 3 2(( ) Faill . . . . . . . . . . . ... ... . . . . . . . . . .. 32

(e) Aloft . . . ................ ....... .. . .. .. .. .... 01.3.2 Inverxions . ......... .... .... 3 9

(a) Surface Hased ... . .. . .42(b) Abnve Surface: ),; h t "At B'-I' I•o :,0 Fiý o o - t ... . 42•

3.3.3 FElement..i of Weathe . . .. .. .. .. .. .I. . . .. .. .... 43

(ra) Precipitation ..... ....... ................ ...... .. 3(h) ThunderstormE...... . ... ... ... ............... ...... 47

(0) Fog .......... ... ... ............................... ...4

(d) Sky Covcr and Ctoud.% ............................. .

3ccst Available Copy

TABLE OF CONTENTS (CONTINUED)

4, THE POLLUTION POTENh'T!A!, 'O HAMPTON ROADS . ...... . , ... 4

4,1 Under Southwest Flow . . . . . .. . . . .. . . .4

4.2 Under Northeast Flow . .. . , . . . . . . . s . . ..... .

4.3 Other Wind Flow& and Conditions . . . . . . . . . . . . . . . .4.4 Conclusion .. . . . . . , . . . . . . . . . . .. .. . . . u7

RFFFHR .NCES . . . . . . . . . ., . a . . e . . * . * , . r... n

APPENDIX - EXAMPLE OF DIFFUSION CALCULA'rION USING THE OI0FtORD

MODIFICATION OF THE PAS3UILL FORMULA. . ..... . . . . . .. . A-1

i~v

esAt w

LIST OF FIOURES AND fARLES

Figure. (511):

1.1 Configuration of A Smoke Plume . . . . .. ,

1.2 The Average Shape of the Plume , , t . 1 . . S . . . .. . . 2

1.3 Examples of Vertical Wind Fluctuion . . . , . ............. 3

1.4 Model lUfcts of Vortical Stability on Dlfu•sto .. . . . . . . . . . . . I . . 4

1,5 Normal Distribution of Alr Pollution, o . o. @a. o. . .......

1. Horisontal Dispermun Prameter, 4, (metorm), As a Function ofDownwind Distance. x (metors), for Various Wrathor Type. . ....

1.7 Vertical Dispersion Parameter, tq (meters), •'s a Function of

Downwind Distanc@, x (motor.) for Vartout Weather TypoIs . . . . . . .

2,1 Downwind Centerline Dosages, Ground Lavol Cloud, Wind Spood,4 2 M./sec. (0 m./so. for examphlo) 9 . .6. . . , . . I . . . . . . . 10

2.2 Downwind Centrrline Dosages, Ground Level Cloud, Wind Slpeed,S2 ,t560 . I . . .. a 0.. .. a.. 1.. . . .. . .. a . 9... 10

2,3 Downwind Centerline Dosages. Ground Loyal Cloud, Wind Speed,

4 n ,i/s ec. .9 9 * , 9 9 9 9 9 9 9 9 9 9 9 9 9 , , .0

2.A Downwind Cerotrline Dosages, Ground Level Cloud, Wind 8pred,8 rn.Isec 999999999999999999999999999999999, I I

2.5 Downwind Contorline Dosages, Ground Level Cloud, Wind Speed,

0 6 ./sec. (10 m./se., for example), ... ,11

2.6 Downwind Conterline Dosages, Hot Cloud Aloft, Wind Speeds,S2 m./sec. (1 m,./seo.) and 2 m./seo . .. . . . 0 0 6 1 . . . 11

2.7 Downwind Centerline Dosages, Hot Cloud Aloft, Wind Speed,4 r/fl9 ece .9999999999 .99999999 12

2.8 Dcownwind Centerline Doseges, Hot Cloud Aloft, Wind Speed,6 -.10/6eO4 1 1 , , a a ,, . , , .$ I .. 1 6 . 1 , 1 1 1 1 . . 12

2.0 DMwnwind Ceoterdlne Dosages, Hut Cloud Aloft, Wind Spced,6 m./see. (0 m./se, for example) ....... . . . ... . . . 2

2. .0 Cloud Width - Isopletho of A Contam~nant, Ground Lývel Cio id,Daytime, Wind Speeds;< 2 m.rsee. (1 m,/sec, for vxample),2 m./qec.,an.4 Md./sect ...... 1.....1.... .. ...... I3

2.1,1 Cloue, Width Inopleths of a Contam"iant, Gi ound Lv'vel Cloid,Daytime, Wind Speeds: 6 m./see. and 1#6 m., sec. (10 m./sec.

for example). . . . . . I . .. 9. . . . . . . .................. 142.12 Cloud Width - Isopleths of a Contaminant, Ground Level Cloud,

Nighttime, Wind Speeds: 4 2 m,/aec. (0 m./sec, for example)and 2 m./sec,. . ,., .,., .... .99,9.. ........ 14

2.13 CCloudl Width - 1.oplvths of n Cuntnminant, Ground Level Cloud,

Nighttime, Wind Speeds.: 4 ia./.wec., 8 m./sec., nnd n .d)o . .(10 m./sac, for example) . .. .. .. .. .. . . .. .. •. .h

2.14 l)owilwind Centerline Doalges. Gr-,ind Level Cloud, Corrercted forWaihout, Wind Speed, < 2 ki)./iec. (0 m./n .., for exnmple) ....... ...

2.15 Downwind Conterllne Domngv., Ground Level Cloud, Corrected forWashout, Wind Speed, > 6 m./ /ec. (10 m. /ec, for nxnmple) ...... . .

2.11; )ownwind ContvrLinr- Deposition (unitm4/ tn ) from R dt., ('.rt:undi,•.vl or Ctomd Aloft ............... ........................... .7

2.17 D)ownwlnd Conticrllne Deposition (unlit/ m! ) from Totnl Instantanoeu.t-

Waxhoit, Ground Level or Cloud Aloft. ......................

V

LIST OF FIGURE. AND TABLES (CONTINUEDW

:1. (1loionpht(ni locatiun Mall . . . . . . . . . .. . . . . . . 11):.2 Annm.-:; Vitr'iatiun of Monthly romeqmraturep and iPreoipitthtton

for Norfolk, Vo. (0.Ali)). . . . .. . . I I * * 0 . 0 . I . I . . .03.3! Anlntlni"l I'IPIIU~FltY ('Mi) ofl Wind tp,-!ed Iirnd Dirovtionlr for IP5vI•

3.4 Wnimnt l11rPeussnuy (V) of Wind Spiad and Direction for V~ivoItamplton Iloniia SNt tioll . . . . . . . . . . I I .. . . . . . . . 213.4 Winteemr requntny (%) of Wind M1ped and Direction for IFive

Hampton Htonda tatiltOn" .I # . I 1 0 9 0 1 1. . . 1 1 0 . . . . 0 . 233.5 1Jaernber Frequenry (%) of Wind !ljjod andi Direction for Five

Hampton HoAdx Stations . . . . . I .I 1 .a 1 0 .0 , . . . . . 243.6r January Froquency (%) of Wind Sp.4d And D)irection for Five

Hampton Hoads Stationa , q , , , a a a a 6 6 1 1 . t . . ... 2*3., February Frequency (%) of Wind Spe ed and Direction for Five

Hampton Roado Stations .,..1 * . ., 1 . 2S3,0 Sprinh Frequency (%) of Wind Speed and Direction for Five

Hampton Roads Stations. v ,... ., 6.a.a, 283.10 March Frequency (%) of WVind Speed and Direction for Five

Hampton Roads Station . 2n3.10 April Frequency (%) of Wind Speed and Direction for Five

Hampton Roada Stations , . I I 1 0 , 1 0 . . .a , 6 0 * . , 1 , , 30

3,11 mmy Frequency (%) of Wind Speed and Direction for FiveHampton Roads Stations ,., 33

3.13 Summer Frequency (%) of Wind Speed and Direction for FiveHampton Roads Stations . ,.. .. ,. .. .III1. ,. 33

3.13 June Frequency (%) of Wind Speed and Direction for FiveHampton Roads Stations. . o . %off. $ . . . . .4 . . . . . . 3

3.1 uJuly Frequency (%) of Wind Speed and Direction for FiveHampton Roads Stations . 1 0 P 1 . . 0 . I . I . 1 1 . . . . . 35

3.15 Auut Frequency (%) of Wind Speed and Directio n for FiveHampton Roads Stationst. " .1..#, s ,, . 37

3.10 Fiet Frequzency (%) of Wh,d Speod and Direction for FivuHampton Roads Stationa . I . 0 * 4 . . . a . . . . ... 373.1 7 September Frequency (%) of Wind Sp 4ed aind Direction for FiveHampton Roads Stations, I.... II .611 . 0 . . . . . 3B

3.18 October Frequency (%) of Wind Speed and Direc'ion for FiveHampton Roads Stations .I.. . I,, . . ...... 40

3.19 November Frequency (%) of Wind Speed and Diroction for FiveHampton Hoads Stations ............................................. 41

:1.20 Annual and Seasonal Wind Directionm Durirg Surface' laed. .Inversions at Norfolk (OH F), Wind Spcedti 5 10 knots, And

>1 0knots ................... ..... . ....... ... 43,21 Annual and Seasonal Wind Directions During Invernions be",veen

the Surface and 1,5f' feet at Norfolk (01PF), Wind Speo,'c.:J10 knots and > 10 koots... . ................................ .. 43

A.22 Annunl Variation at Norfolk (O01F) of : (a) Nunnber of Daym 1Each

Month With Precipitation, 'animdoritorn•, and TIeavy F,'og;(b) Average Monthly livlntivT, sumnidity (",) - Day and Night .4... .14

:1.23 Annual Frequency (') of Wind Speod and Direction for Fl."vHampton I-onedi Stntinnsi Whomn l'reipitation Is Occurring ......... ..

't,2,l Winter Frequency (%) of Wind Speed and Directior for Vivo'lIampton ] oada Stnti ons When ]rrcl: pitntion i1 Orcur ring ...... .. .

I, r u: '" '4 , . W hl S(".'1,I 'nJ I)1 , on firr ri•' l 1 V,',

V A

SotA ~~3Copy

a~~~~AaP VA aL's aaa"To ~ ~I~ ...a I I'VoI

3o20 •Summot' l'r•.q•omny (%) of Wind Siveid nnd D)ir.'tion fur I'iveHlampton Ie'vda Stationx Whon Prowipitntlon im Oceurrin .. . . . . . .a

3.27 reipt Prequorwy (%) or' Witl Spsod 4nd Direction for FiveHampton i4ondrA Stntionm Whon Provipitation is Occurrna . ... a.. , )

3.40 Annual Vnriation of Monthly Sky Conditiont nt Norfolk (OURF) . . . . . . . .

3,20 Stratuo Withan Lu.itarly to Northeastrly Circulation a . a . . . . .a. . 523.30 StrAtus With a Scuth to Southwomt CIr.ulation . . .. a . . . . . . . 63

4,1 Probabia E~xtent t4? Co'nd-Leva! remoninant~ Dura.ing -yia

Summer Day At tifnipton Rolads . . . a...a a.. a

4.3 Probable E•xtent a' Oround-Levol Contaminant During a TypicalNight at Hampton Roads , . .a a a a a5a5a.. .. .. aa

4.3 Probable E~xtmnt of Ground-Level Contaminant With an AfternoonSea Brease In the Hampton Roads. , . a a.a.a.. a.a..a..a. 50

4A• Probmble Extent of Ground-Level Contaminant With Strong Northeastnlow in the Hampton Rtoads .aa. aa a a , a a a a 56

rn~bles (2)

1.t Meteorologicaml Categories '

3,1 Annual and Seasonal Fr'equency of Low-Level Inver'sions A..... •3

Vti

Best v l-

1. PRINCIPLES OF DIFPUIO?'

III TI'rapett end Dilution fig] another. 'I'hoa ddles which give rtrme to thetrvelocity fluctuations cover ain almoat infinite

'fhrt diffusivoi capacity of the a, insphere is range of sim@ and the diffusive acetion of ti par'-superimposed on the general air motions and tioular eddy dopendsl mainly on its uixe. A sm~all.will affect Any foreign matter injec'ted Into the parcel ofti contaminant may be merely transpor-air, whether it is a smoke, gas, mist, or dust, ted as a whole by a large eddy whereo a £ smallIn order to understand the role of the Atmos- eddy would be an effective diffusing agent. Inphere in moving pollutants it to neceissary to the cast of continuous discharge of efflk,ent, bomerecognize that the two processes, trv~nsport and eddies promote diffusion of the piume, And there -dilution, operate simultaneously. l'io generml fore mixing with the surrounding atmopharv,direction tha~t a pollutant will take after being while other eddies move the plume in n berpon-introduced into the atmosphere can be estimated tine fashion horizontaily anti vve' Icaiiy; iii gi~ii-with some precision from the genermi flow pat. oral the p-,ff of pollutant will movo in the dir-terns indicated on a synoptic chart. I he direc- action dictated by those motion. larger than thetion, at any point, will change with tirne as the puff, while the diffuslonof the puff will be causedlarge scale weather systems move and change by those motions smaller than the' puff,their intensity. If, however, we scrutinize theweather map In deatai,through a microscope as 1.2 SIudYlRQ Smoeke Plum~es j181it were, smaller irregularities in the flow be-coine evident: not only has the acale been in. 'rho relationship between Atmospheric mo-creased hut more observations have been used tions and diffusion may be further invesatigatedto deliniate some of the irregularities, The by studying the patterns noommond by smokesharp discontinuities in the wind field and the plumes (which may be thought of As a continu-small so called I"meso' AtgAm and law# , too ous string of puffs) from, a chimney and r~l;;týsmall to be seon on the map of the entire United Ing these plumnes to concurrent wind fluctuationsStates, now become visible, The systems ob- as observed by a recording wind vane and Ant-servad onthis scale have life spana on the order mrnomter, Figure l.la shows An Instantaneousof a few hours to loes than a day. It we now in. snapshot from about a chimney emitting stioke,crease the magnification *van further, may look- If we were to measure the percentage concen-ing at a cigarette, we would see that in the space tration of the smoke across the plume at theof just a toot or less, the smoke from the c iga- slice A-A we might well' have a pattern similarrette wouldtwist and turn in response to atirros- to that In figure l,lb, We would find that thepheric motions as small as an inch, or if we had concentration values varyerratically acrossitheunusual visual acuity, even loes, Perturbations Plume And drop to zero at the edge of the i. no.of such small size probably disappear in a mat. Now InstQad of an Instantaneous picture, if weter of it few secondsi This above progressior, were to take a 5-minute time exposure of theserves to illustrate the increasing complexity smok* plume (fig, 1.20), %yo would note someof the atmosphere as we regard it in incroasing. substantial changes, The irregular edge of theiy grentttr detail, Instantaneious plume would be replaced by

smoother, regulai edges. TIho croitswind con-The mixing of materiml with the atmosphert., cantration curve through A-A would alsao be

in caused almost entirolý jy what in called eddy more regular and would be distinctly higher atinotion Iwhich may be mechanical or thermal. the center than at either dige, 'rho concentra-ItA origin or due to both effects in combination. tion along the axis of the plume wouild docromilc.\rriilomtcr r orordii show that In jgontirtl, and Inverseoly as the croms-bectiorml arva of the

ojc;I ly tn the iowtir layers if the atmurphtrre, jptirne in('rcocd, Had we plaved n wind waverthe~ wind in highly turbulont willth th velocity or.- near'the, mouth of the chimney anin mensurcd th(eti lletIng with pe'rlodm varying front a fIDctmiol wind direction we might find 'hat the jrecot~r(1--'i st-nd II) severlV mtnintvl' andi %vth tn stll trnc looked like thiat in figure 1.2c . Th, fflr1-

11itld'. \jhjrhl irm ortc'11 t tiubm rilitinI froctioll (lf ectlon Is rllrcly, If ever, krtvfdy evvn Over athi eAV%.r11Fng hinori. siirnlurrly, dil-reeton Indicn - ieoriodl t him short.*r itt'ur ~eoe re

vvcltor 1--i vo~nvlnly chainging tiot only froin oni. otI intervalm is shown in ftrur'c I.2cd. IfT nuh) lolh I. 1)(1 oki froni e)nv poin 1r ; br ty hb wetwenfiu 1 *2h -nti !¶,!f

A, INITANTANNOUS SNAPSHOT FROM 5. INSTANTANEOUS GROGSUWNABOVE A SMOKE fLUMS. PIfMINK CONCENTRATION

AT 890TION A-A,

dontal. If the wind at a given instarit io from, bean devoted to this subject.aiay, 280" then the smoke from the c himnay Inthat instant Will move, generally, with the wind For out present purposes, however, it ioand intersect A-A at 2004. At each succeeding only necessary to recognise that the result ofsecond the emitted smoke will move with the overeglng the data over a few minutes has beertowind direction at that second. Thus, curves smooth out the irregularities in bcth smoke con-l.2b and 1.2d will be similar. This relation- centration arnd wind direction frequency distri-ship to not quite as Simple an stated here. A butions.particle of smoke need not maintain its initial

direction indefinitely, Much recent study has Vertical as well ais horizontal windnfuctia-

ISO

A. FIVE MINUTE TIME EXPOSURE FROM 5. FIVE MINUTE CROSSIWIWOABOVE A SMOKE PLUME PSPOENTASE CONOINTRATION

AT SSOTI(fE A-A.

30013

aw"s

2400 L -IV MINUl S.. -J 20..,0. ME! MINUTE WINO DIRECTION

C .;o DIRECTION RECORD PtRCENTAGK FREQUENCY.ThP A -' 4v.r.A, 5Pvar. -1 eb.' P).. -' 11- SIIr i'sr 181

Figuts 1.. Examples of V tfioal Wind Pluefuaftion, rlwm Sfad., I8

ations are of importance in asseassing diffusion. solation conditions and more stable during in-Fig¶ire 1.3 Ciowe how the vertical wind fluctu- versions.ittions might appear. Their effect on plume shapeand concentration is also shown. 1.3 Tkeoretlial Studies

The faotthat the apparently chaotic atmos- A number of theoretical studieo have pro-pheric motions maybe shown to tall into smooth duced fairly straight forward methods for eati-and regular patterns by the application of suit- mating the history of contaminants introducedable averagingliechniques has enabled meteoro- into the atmosphere. However, it is necessarylogist to forecast, with some accuracy, the ex- to keep in mind that these theoretical treat-tent to which an atmospheric contaminant will ments are so highly idealized that their limita-be diffused. The magnitude of the fluctuations tions must be understood if serious errors armmay be related tothe Nerticalatmosphsric tem- not to be made.perature structure, which in turn is related tothe intensity of solar radiation (or the lack of L3.1 S (21, 22, and 23]it) and the speed of the wind. When the inso-lation is intense and the wind is light (convec-two instability), as might bh the case on a clear The well-known theory developed by Sutton,summer day, atmospheric motions, both vertical along semiemparical lines, provides a satisfac-and horizontal, will be initiated or enhanced, tory means of estimating concentrations in aWhrn solar insolation is weak or absent and the cloud or plume of effluent for distances of travelwind speed low, as on a clear night, tempers- of about I kilometer and for atmospheric con-ture d•fcreases slowly or even increases with ditions corresponding to neutral equilibrium.hoigE (invoerson condition) tending to inhibit Sutton's theory is formally complete in that itturbulent motions. Neutral conditions common- investigates the affect@ of wtnd #poed, turbu-lyo ccur when the sky is overcast or in the pres- lence, and atmospheric Ptability; however, it isonce of strong windM which mix the air very too rentrictivv for real-life appli,•tion, wherethoroughly. 1ligh wind xpo!ds tend to redwv. atmoipheric conditions are more often otherthe fluctuationm during sirorig hnsoIntion coo- than neutraland where interest lico beyond dIs-H!.!.nn iknd incr'eaw fluctuntionA • Whn tho, in- tances of : kilometer. Eý,tendtd Rppltcntionnof-iolution in stnall, Figutir 1.4 xervwt &• i guild tho theory (treating Suttor.'m d(ffliaon parn-for depicting, schvmat iclly, mode', effvcls of rnetor' more ta adjutohi.e unitantm thim an

i ic;6 stamlity on dtefper~kon. N'tar the ground, fundamental quontitieM) to vnaytnng dogrucc ofthw otaLn of the atmnosphore can dl'fer markedly atmompheric atnbility, to grenie-' dlit;rneio, andfrom thot depitmd by radlomonde 1( ,srvntlon-; to all kindis of terrarin huve. bercn wittmptefd hl:t

i. y- rf', i durkill hl'. hilve boon et st ""-

W Imi N Dl ~mI ii

TEMPERATURE

STRONG LAPSE CONDITION (LOOPING)

N _ _ _ _ _ ____ _ _ _ _

SUR TEMPIRATURE

WEAK LAPSE CONDITION (CONING)

t % %

SUR, . ,.'Ar RSMTEMPERATURE

INVERSION CONDITION (FANNING)

URTEMPERATURE

INVERSION BELOW, LAPSE ALOFT (LOFTING)

"- ' -_ . -" -- .- - - -.r..

SUR,TEMPERATURE

LAPSE BELOW, I,'JVERSiON ALOFT (FUMIGATION)

Fiijire 1.4, Mdodal I..!t,'ctm of Vrrczicl Snbiitiy on Diffauion.

Bo~A~v~b:~cs

1.3.2 PAmqUIll and Moado t12, 13, and 141 mu

In light of the above consider&rtions it is , 'clearly deoirable to takW a more dirct account (11of conditions Actually prevailing in tie atmor- where:phsre over thedtstancoandheight for Nhich con- a (depending on the units of Q) groundcontrations are to be estimated. In Englrand, loevl air;Pasquill and Mead@, along these lines, recentlyproposed a simple system of estimating stmos- (1) concentrAtion (unite per c-iic moter)

pherio dispersion from a continuous point source orthat seems likely to find widespread acceptanceamong workers n the field of diffusion. It ea- (3) dosage (units-seondo s per cubicbodies the main principle of Sutton's work but motor)applies the sppropriati elnosphorie ooiidiUioiFidirectly. Q • source strength, either,

These investigations have shown that a fair- (1) continuous source (units par second)ly rational allowance can be made for the effects orof much of the wide variation in atmospheric tur-bulence which occur In reality over a particular (2) instantaneous source (units)distance from a pollutant source, Although mmyaspects of the problem require further attention, R a 3.14these recent developments, supported also byexperimental studies in this country, form a o, m lateral disper.!on coefficiont (meterm)basis for a tentative system of estimating dif-fusion within a wide range of meteorological a, - vorticaldispearion coofficont (rnpt.wr-,conditions and over distances of up to 100 kilo-meters. 'a mean wind speed (meters per oocond)

(a) ca(e A,•=#mxmps a theoexponential

A cloud of smoke or other airborne sub- g a crosswind(lateral)distance from ),umostance, continuously generated at ground lowvl, axis (meters)drifts downwind as a long plume; its width andheight increasing with distance travelled in at -cordance with the degree of turbulence present.If measuring instruments are placed at varyingdistances and at varying heights downwind andacross wind, it is found that for any plane per-pendicular to the direction of the wind, the con- AX OF PLuW9centration decays horizontally and verticallywith a distribution that closely resembles aGaussian error curve (a'normal" distribution),This means that the coneen tion drops off sym-motrenally in any two directions from the line ofmaxixnum concentration according to a normalerror law, as Illustrated in figure 1.fl. Thisampiumption formr the banIa for au(cceadling de-voecpmonti.I

p.,) The. ?;iffor.d fadivlfiona.r(101

Tho work of Pansquill and Montle ePxpremsodin :n slghtly modified farm itfgcsted by Gifford HEIO T ur Y

(100 I) yields tho ,io -c Ild dgenerai zed Gaussian

ht•:;• kiaWnk onL fi (;i?:tlltiv inturColyti fu'-,

- Ii -

A heiglt' of the source abovo thp grouwid(meters)

The modification consists of expressing V,

the dispersion coefricienta in the y and z di -rections as standard deviations of the plume dis- Itribution, a, and l,, rather than the points a!which the concentration falls to 10 percent ofits axial value (a figure representing the visualextent of most smoke plumes). The right-hand Oside of equation 1.1 contains a multiplicativefactor of 2, which is a conventional device toaccount for the assumed reflection of the plumeby the ground plane.

P111w 1.,', Veil fel Dlipuef e Pwam•r •, (oet), ae a

In order to solve the equation, Paequill 1131 Pme)l a-,l. s of ftvnl"iutanoO, X (me•w.) ANproposed families of curves of disperaiio cc= Wom Is UO, ryp".

ffi'eient* .r;urs distance from the aource; these distances beyond about 10 kilometers, Down-are based both on recent concentration measure- wind ground concentrations computed for a typements and on theoretical expections, In terms P condition, at greater distances, are higherof e, and e, the values are given in figure 1.5 than concentrations computed using stable dif-and figure 1.7, from Gifford 1101. Table 1.1 fusion coefficient values in Sutton's formula.[10 and I1I should be used in conjunction with This point has significance in connection withthese figures; it shows how the stability cats- environmental studies of hararda associatedgories A through O are related to wind speed, with newer power systems for which concentra-insolation, and the state of sky. mom inso- tions have commonly been computed for down-lation, for example, refers to sunny conditions wind distances far in excess of I kilometer, toaround midday in midsummer, while lI1,Ao in- which Button's formula was originally Intendedsiolation refers to the corresponding conditions to apply.in midwinter. Using equation 1.1, figures 1,6and 1.7, and table 1.1, graphs of downwind con- (4) UVRen.MUd.A [121centrations may be prepared.

The method proposed above Involves a num -(0) COMPEd with311 bar of uncertainties, for example in the esti-

mates of vertical spreading, and so it should beGenerally speaking, concentration patterns regarded as giving only approximate but realis-

computed with equation 1.1 will closely resem- tic estimates of the magnitudes of the coneen-ble those computed by Sutton's traditional math- trations at various dtstances from the source.od, The chiof difference les in the behavior for In mcam of the more difficult cases involving

stable and unstable conditions, errors of sev-eral told in vertical spread could be made. Thinshould he kept in mind when applying this tech-nique to the assessment of hasarda. On theother hand, there will be relatively straight for-ward cases where estimates of vertical spreadmay be expected to he correct within a factor of2, for example:

(1) All stnbilities, except extremes, fordistanres of travel of A frw hundredrmeters in epen country.

(2) Notvtral conditions for distannes of o"few dilonmeterr.

F'iatrr, !.6. Horixontal Di.rwrsin Prmptor (Y, (mcfea, t).axv

a Prncr..n of,, wnwirid DiatAnce, x (meter)J, (3) UnstnL to co-ditinn.a in the firs;t I ,0()oi'. Various. W.mshr Typox. in4r hovc .rornd, witlia~ rnnrrk;-d hi -

L-LKJ~~ 4"AUY c>

TWOl II. i. cwI~iilCtome

S/ C 1) S11A0-3 IM4 Y''IIA' IN'1, A VION NIGH 11TIME 7M./morvr (6noim) SIppp&g )Iodertisi Slight Thim Oe oreit of I

2 (4) 8 c E4 ( B) nr c P

6 (12) C C.D D D D68 C(U, 12D D D

A: k ofielm~y "RAiable~ votnitcutio A- Neutral sainditttrnx 2

m:&odstratey uristnhIo contsi~o"i K: Slightly fit111p conditioum

V: Sl11sdy UNA106,t' orlditiomm F., Rudenueb' stablo vorldisiopi

ilihw Adwalg M~ oinwdinp-mm Im le.Is,I1o tiw Ihil Ir"lomfI "'f tIhw *ký ont, ilia lou. i 11opmov i,9sm,,.,i hP iltf'I WI*II O."YoVtitby cilenude, (M~lt~tl iti nurliln.' MA~~4~lt WI , ,'Il,.tttInr N (71h "d,, II uilmptih I ý1II, U, 0. MA~vpqlimmo 1i l lrIitll011100., Washingtein, Juily I41.

ApjthnobI. in heavy mwou~qt, dofy IPl mflsht It Ie.Ll,,q In looo 1i,,i, 7,10MI lao.I

Nolai ftot A- ink l~ia Iho voriq* ,il cutypo A wtI.i i piti,

-Solar Altiludii ((f) Inolation

2. ii(r6 rUl hrt*1

S(I. ) Codingi b~elow 70,001), Ve(MINOt A u) C. I to IV ) C to A.

1'. ) C..tl$ 7,00 (1(X abt'r filtt below M, 0, cda~m~r: A ta Ii, P ) toC, C' it, 1),

r.) rilig I),(,k) ir aour nd vikri, o chu-r

versim i dne iatily above, for diM- the beat current o t4orvational w'wlul airtancea of travel of 10 kilometors or concentrationdowrwind from an iralotcd eotrc-cmore,

The ganorallemd Guasian rtliritl,n ro -

For the mout-pp rt, uncertainties In the lat- mula is, briefly, bothadjustable nnl' nompatable,oral spread of the plume are ifkely to be less and thua provides an approprlateframework intoimportant than in tho came of vertical spread, which we can fit existinglatmospheric diepersionexcept whia the wind field is indefinite. In such knowledge, both theoretical and obeorvational, n,circumstances, a more important source of er- well as anticipated futvr ivie inanim,ror is that involved In estimating the positionof the plume, and it .ij bost to allow for A wide 1,3.3 Taelional Statosrange of poasible diro~tions of the plume.

Another concept which hap A dirort be~aring(.) P•41i vPjW, on the concentration of a pollutant irotm ships,

or any source, aiid about which littlo la knownThe curves presented in figures 1,8 and 1, is that of diffusion in "transitional stmtes",

will, in all likelihood, have to be modified as air This limply reans that the atmospheric turbu-concentration measuremuents, partioularly at the Woneo often displays a marked variation in timegreater distance, become available, A recent or space, or in both, The variation of turbu-series of diffusion observations n111 has, how- lenes in the horimontal plane along a line pnr-ever, verified the above method out to distances pendicular to a shoreline can be slngtfiennt,of D kilometers from the ocurce, Nevertheless, Those horisontal variations can be due to tam-use of theme disperolon estimates in connection perature differences in the underlying surface,with ship pollution potential studies, as well as or they can be due to roughness differences inother air pollution problems, particularlyin the the underlying terrain, Boththermaland mech-form of the plume standard deviation presented anical turbulence can be initiated or suppressedhere, seems to be very desirable. It is a depending on whether the air flows over waterstraightforward approach that directly reflects or over land first,

L-

2. CALCULATIION

The cql•,0*tion of the offectM of i release height to whirh the cloud roprosentig the na.mvof decaying p.oducts is hindered by look of release would rise at night. The button for-knowledge of t"e nature of the source, in parti- mula gives a negative resultwith .4tampcrMturc

culsr the souri-i strength, the distribution of inversion and the Holland modification [2.1 hemparticle siaes, and the height of rise of the been substituted, An would be anticiptaed, thisaloud, 1escognising these difficulties the moth- Hollardl modification Rives a amnisler rise, ANO0ods described may be used to calculate the meters. Both calculations apply only to uloudcappeop Iwoi of the air concentration near ground consisting essentially of dry air at 3000%F, Itleval, is doubtful whether any refinementa inthe above

treatment would have yielded ary greator pre-2.1 Initial Weheavwi of Cleud cision.

The initial conditions of release would h•ive It is proper to question, however, the erroran Important beat ing on the fate of a pollutant in these estimates, since the ground level con-cloud, which might consist of a #as or a vapor centrations calculated in later work are strong-or very smal solid particles. In additionte the 'ly dependent upon them. This is difflrult withamount of pollutant, the cloud temperature and the available data, but it seems doubtful that athe time period over which the release occurs cloud would reach a height more than twice thatwould both be significant. A rapid relearn of calculatod,warm effluentwillform a rough sphere that willtend to rise until it reaches the density of the Itto easier to define the other (lower) limit,surrounding air. A slower release of the same since a release of the pollutant material mightamountof warm effluent will give a much lower 'ccur slowly at essentially the teoiperature ofcloud height, Variations in the existing atmos- the surrounding atmosphere, This implies nopheric temperature, lapse rate, and turllence asoant of the cloud, and is treated as such, Inwill also havv an important influence upon this this case the contaminant ib postulated to be re-process, leased without a 1".rge source of heat and may

be approximated as a cloud at ground levl.Both the rapid and the slow (cold) releases Thistype of release would be the more hazard-

are considered in this report. The upward ov-4, and P solution using this assormption wouldmotion ofthe warm clood muetbetaken into ac- be pessimistic since a cloud in all probabilitycount, and the cloud is represented lnitially as would have some rise.a sphere having a uniform temperature. This"bubble", of lower density than its surround- 2.2 Dlffuslon 4 the Cloudtngs, will rise and move Aownwind simultaneous-ly. The temperature differential is continuous- The generalized Oaudsian dispersion equs-ly reduced by entrainment, by adiabatic expan- tion (previously presented) applies when erti-*ion as it rises to regions of lower pressure, mating ground concentrations, with the x-axisand bythermal radiation untilit attains the den- oriented downwind and the y-axis crosswind,sity of the surrounding air, Wheaithe source is atthe nut-face (cold releane),

A is equal to zero and the ter..r containing AS., selection of a mathematical model for drops out of the equation, For determining the

thia process and the choice of appropriate val, line of maximum downwind ground Accumulationues for the parameters presents a difficult prob- (x-axia), Y would also be equalto zorn. There-l1m. In leu of anything ouperior, a height rise fore, when both h And Y are equal to zero (our-formula developed by Butto- (20, 211 has been face nouree, x-axis accumulatlon), the entirtichosen to represent daytime (lapse) conditions exponential term would be equal to tnm' and thein this study. It in relatively conservative in equation r'duo.es to:ter-nm of low-level behavior, in the sense thatit predicts R modest riMe. 'o-" a release suf- (2.1)fictent to rupture a heavy rr,'tnl container(%8.6 x 104 cal.), the equation pr'ýdict~s a cloud X14 1411

~hvi r~f 860 mfeturm.In the r'a r. of tht' hot roilt.ntr, tilt ter irn r(m ~

A Onillar rontrnaent i umed to roimatt, the tnining A rernainm ii thow equstnon.

Becst -

It it difficult to opscify both ti.c r-to and thetime interval civor which ýho roleastn would o(-cur, but if the total release, is substituted forthe rate of release, the result can be given interms of dosagen (that is unlts-sec./mrl) in-stead of concentration (units/m,! ). Dosage re-fare to the total integratud amount of pollutingagent for a given pollution incident, while con-centration refers only to an instr.ntaneou- amountof pollutant. i

The result, of the diffusion computationsare mummarized in figures 2.1 through 2.16, A LIsomewhat arbitrary release of 2 x 10' units isassumed for the Calculation, This figure io ipessimistic one derived for a power sourcemuch larger than is probably in existence orcontemplated for naval ships; ,hus, the diffusionpatterns which will result frem the use ut this toifigure are on the cautious, side, Dosages for a I Io 41 00smaller release may be derived as a direct pe.- ITsANvC 1I4,)

aenta#e of those given in the figures since only il~ue" 2,P. Vownonod Comtlin, Desd.a, Omod Levul Cloud,the Q will differ Ln the equation, Wind spsed, 2M./Swe.,

2.2.1 Cantwillne Dosages, Cold Pt.sImsp

Figuren s,l through 2.5 refer tathe cold re-lease in which the cloud centerline begins andremains at the ground. This approximation is^btained by settingy mA h,. in equation 1.1. Thecentorline dosages Are preaented for both day l,nd niglqht threo degree ', of insolation Pre con-sidered for t Lffusiotv during ,.ie day ;&nd two Con-

SDI • fVANCFr 4M.,,

Pdieo 23., Dewnwlnad Cntowlin, Doa.Ve, round Lev.' Cloud,Wind Spe.d, 45!,/1:o,.

ditions of cloudine.s for night patterns, The dayend night Laopleths are presented for wind .%poednranoLng from 2 knots (I m./sec.) to 20 knots (to

L mrn./ie'.). The calculatione Oxtund to 100 kilo-61 1 10 42 100 meters(U2 miles),which in aliit nuggested by

t,•I'TAMC~,• Pasquill in the application of his techniqueg. Inthe wornt case of diffuion, that of n nighttime

Fi4:m, 2.!. v',nwind Ce•tmene Doifrrn, Ground LvvolCfoud, inversion condition and a wind snpocl of I meterWin c. S .t !of r nxampiv). p er s fe ond, a poa ltItnnt w ould travel approxi-

The very great diffvrstiw ba4 tgihIu and day, In the lower speed ea.zriez, i. Imn-

mediately evidont, A dosage of lOunitn (bottomOt the ordinate scale) for a day with stroms In-solation and a wind spoed of I meter por secondextends to a distance on the order of 5 kilo-meteras whereas on a clear lam ritght the e•modosage would theorritioally eyxind (if conditionsremained unchanged) to hundreds, if not thou-sands of kilometers, Thin great difference ba-tween night and day, is due mainly to differencesin the v~a1tn diffuainm tinaffitinto ta tea fie.1M7), As wind speed Increases, however, thedifference betwenn night and day decreases, so

that for wind spoeds gre &tvrtshw. 1 !tt'As (A-,Ssea) both day and Mi•nt are mimiia-, exw pt iordays of very strong Insolatim,. Tihe higher wind

steeds tend to create deep layerm of neutralstability, Along these same lineos, the effect ofoloudinesii en dispersion at night and insolation

CIeTANCIse ,t during windier days tends to disappear as windspeed increases, However, In the lower wind

Pidwo 2.4, Downwind Caew!lne Doeeg, Omoimd Level Clou, speeds, significant differences In the dispersionWind ISp*d, ft/so,, distance of a pollutant exist for varying degrees

of insolation by day and cloudiness tit night.

I~~us(~m ogs ff one" Ie 2.2.2 Cuoiterline DceapAc, Jlim nesiaae

trigures a2,through 2. rsprosentthe samedosage information derived rom Ath assump-tion of & rapid, hot release owrfole nt to rup-ture the cont ainear, but including the same amouniof pollu.ant. In these cases, the contaminant

DISTAP4O a•"t. •

'Flgtwi 2,5. Downwind Caitsw~fte D0449u4 Oround Level Cloud,Wind S!p..d, tý 6u,/sc(fta./Pec. lot exumplo),'. M

mately 42 kilometers in a 12-hoior prriod; thiscondition would, in moat csasý bo followed byi'ome sort of lapse condition which would dis-parno a pollutant in a dintance of about 10 kilo- 4C 100

motiwrs. Thiis, the 100 kilometer limit. el-though at flrat glunce reatrickivo, its nore real-letic than, any, extending tho calculations to Pýduro 2.6. IXoawn nd C ei,'rtwn o rrrý., Uz :I ut Al-,,

Be :t AvCa ."'a.

12

101ait ol~t groiut(i,torn of a maimum at z disa.: fre:m th•his valid, proVided thO pQrtiClQ5 Are FrnaMl,

t beThos•, figere so haveo the ems heonta i•,Aitance scale used or the cold -eleasv, how•nw ,O

S4the do.age scale M2 beoen bcr~onad b1two ,Ž'ders of magnitudo(101 ). Calculatcionsfo ta.'jtime hot redossed inolving woltd ~eC 2emetrs per second or lreo have nut bnon l•r-

at the clssulatsd rise heightof h8d metoiro ;lotbe rare. F'igure 2,6 coom Irh oth the I mmeorper second and 2 motors per second nhoightime-patternh; the efopleths for night conditions of0S/8 cloudiness are off of the graph, since they*ouldth~eretioally begin beyond 100 kilometersand, as d iscussed before this, would be unreal-istic. The fact that the distance botwzvn the

S44 CO0 source and the first ground dosages in rightcases 8 meotrs per second or greater (fig 2.hand 3.0) is lose than some of the day isoplfths,

Fidw2. Downwind C•_.t•lite DOWu4i Mal CloudAtlot Is due to the different cloud ris e hoeghts em-Win~djp SPA401. ployed In the calculations (day, 860 in,; ni~ht,

400 in.), The effects of insolation, cloudiness,andi ind speed discussed for vhe col releaseaao also in evidence here. Of greatest impor-tan~e, however, in the fact that ouly !an the 4meters per second category (fig, 2.7) does thedosage get above the suggested harmful limit of10 units; and then the *xtreme case reachesav~1taofonly'2d units for a distance on the ardwrof 2 kilometers and maintains a value of at least11 units for a distance of 11 kilometers. Thus

011 TANC 1 'lA.)

Neurtor,.8. Jownwind CwVfrIIn, Dore~., Not Clnuil AMIr,WInd Soto, 6m.lIr.,• .!0 ...°

iz not contntmnuly prempnt nt th-. ermoniwcxuae of the fact that the cloud firmt ri!',m nnethen diffuse, back towardthm surface. Thin ro-%,.:15 hin whAt might bf described &a i mklp-dlm-toi•.e betwoo.n th4 source and the bulk of the

.ron-i cot nirnation, In practice there 'vumdonorn'" pollutant present in thi., region, bo-

"the an ed the orea pred1otcd hy thi cit. 2,9. 10f.'iwnnd 1ontorflnc 1ken, Uot CloI ,•4Io,

-"!; n, ;1xcC :?nrrne f .tthý? cloud wollud Initiully Wirnd Spnrd, 6.•./•c.(Om,/.,o, ,r

Ecot A~ ~l: )yy

for all practical cons it,4rgi tioni tha hot itlaa diffuion arali by d.~y 4-ncan be discounted from a putential ha•ard dnnly- innolation or cloudiness, and wind spee(l, Thesis, lrteral limit of s•gnificant doinges %> 10 unitA),

in most caOne, does not exceed (6 kilomntern22,,3 W',loud •l.th ( x 3 kIm,) and of lethal donagon (400 utnit), :

Figures 2ol through 2.5 show the grounld kilometers (9 x 1,5 km,),conditions alon'the clcud venterline. Obvious-ly, the width of the cloud must be defined, if its No urillr calculations havo beon made fortrue relation to the contaminated area is to be the corresponding hot releane, fov the obviouAevaluated. This hug been accomplished in tig- reason that the dosages derived thorefrom nre,u•,m•140 th.ough X•. !•r the eele ,.aitean by in most e*ses, not significant.computing dosage lolines o! 400, 90, and 10dosage units, Let us arbitrarily say that t do*- 2.3 Depealtlon fom the Claudago of 400 unilz per cubic meter represents thelower limit for I lethal dose; between 400 and 2,3, o.ai Consld.rntlona90 illness Is likely; between 90 and 10 injury isunlikely but come expense may be incurred! and The diffusion studies have provided a basilsbelow 10 no injury or expense is conteim- or evaluating tha direct effects of the cloud asplated 123, 291, To facilitate comparison, the it passes over the countryside, but they give nosame scale has been used for both axial and indication of the particular residue that may becross-axial distances and for all patterns; this, transferred to ground surfaces, vegetation, randdue to spce limitations, has necessitated a buildings. The term "transferred" is used in-nhopped off appearance (at 42 km,) for the night itiallyto suggest the lack of knowledge concern-patterns; however, as previously discussed this ing the physical processes actually involvod.is more in keeping with reality, As a gross The question of what occurs at the boundary ofcomparison the numerical Pxial concentration interaction between an ae.rozol cloud and thedistance limit#, for any of the three categories underlying ground surface is clearly a very(400, 90, 10) that .xtendi beyond 42 kilometers, complicated one, Material i deposited on sur-are included on figures 2.12 and 2.13. These faces by A variety of physical processes, few ofhorizontal plots emphois._ the differences in which are well understood, Gravitational set-

VMS,4 I..t,Il*a I tm .i Pt IO,~ *SI" SLllI 1.I11tsl, I1 • ,gge

' , ? r- .,.

Pi•• .,. C~t,)ijd Width - Ne¢,pl.,lhm nt n CI)ntfalino"I, Gr('11:r1 U -1 v [Cloud, Myl;i,•r, :Nnr. ' Prt r dw~c•,, .'' *r

Best Aa!kýnC ,

-14

-$TAW14 IN~I.A1Ie II#0t # M M 14

I1 A1 #0 it 1 if 10

14? It t, 11 ll S

IVII

0II00 ink

L ±r--~-~- ~ k

r ~ ~ ~ ~ ~ ~ ~ 0 0411L Y03hr~'~lJf~)nd2r.I.

-, &fil Nf

Tom~~~~~~~ 0"0610 or4o" M 1.01,1

...............

HO

ila Ofi hoi&e IN I &N 5M 01O C

P14w# 2. 13, Cloud Width -lepilohe ofla Contnsinet, Ginsnd LOW~ Cloud Hidhttim., wind spoeluit li/.oc-,on/sec.. d~a/eJm/e low .asple01).

tling, adsorption, particle intetraction, molecular it seems beat to utillme simple approximationsand turbulent diffusion, and various chemical for such effects rather than to become involvedand electrostatic effects no doubt must be con- in a complex treatment which may not fit theed.C.... Ra= =dc Y.hn:.c.m... pi lI L...- '04..-..Qr

that impaction, electrostatic, and thermal forcesmay be equally Important for luA particles, which The first problem to to ontablish a physicalare of importance In this particular sttdy, Simi- aivocr~ption of the particles. It seems most pro-larly, a simple treatment probably does not de- bable that a pollutant release would occur as Ascribe scavenging by rain, in which the hydro- result of or in combination with combustion,scopic nature of the particles may bel as tim- with the particles havingthe general character-portant as the size and %hpape Forms of pre- istics of a fume. The size distribution fittingcipitation other than rain prosentia even mere thin description would involve very t~mall piir-complicated problems, ticles. However, the possibility cannot ba POOa

out that a much larger particle size dit~ribuition.Unfortunately, scientific knowledge of the could be caused by a pollutilnt relealie of F% 0if-

right type for this study is even moro In~dequato forent niaturo or by unknowni procesitit,.thanthat Rpiplyingto diffusion. Tho mnain reasonis tha~t complete field exp~erimentsJ In deposition A straightforward approach to r~oponition,nod rainout are extremely diffloult to condluct, presented by Chambrnbt'ain [4] ;and well PuibcidsPnd there has bven little need for them until rc- to the' study, 1% usod witbouit altotratiots. The cal -cent yeaors. Theoretical wortk and Most labora- cuinlontio have been performned for only twotory studies have dealt with Idealized ispherical special cases of deposition, wnrshout ordt totalp.urtivlese undes; conditions very diffmi-ent fron'. in:;tantnneoul% wwihout. For' IrnuFt of tho !rthone in tht! atrnosplwrto. Field expe-ritmcvo Is ticle Mizeo aa -umtcd hcrci, olt'y dq lo:-ULiI, hOi

.0t FilffI•'1r',i!1Y crmytic' to hiive rin itrnj,)t:-t.'. is ~o Iindrn~nej'~p~ o '~"'~

~inf1't-tc, .-n thiA vi-inl yn.iO. PotOi'tG'ev -o'sor noi', duo' to1 grnvit udirIId Ptutt Nig r t ypd iTOI);o'tion, wouo~id

---- --- ---

be negligible. In a cas@ of larger pcrticlom, how-ever, the patterns computed for washout ctould 0soerve an a guide to the ariors of mnagniitudeii n-valved, and according to 0ifford [91 maximumdry deposition would be one order of magnitudesmaller than total Instantaneous washout,

2.3.2 Wenhoutto

To account for the cloud depletion fromwashout, that to removal ot cloud material by

tial factor *DLinthe numerator ottho Gauasian

dispersion formula, It is reasoned that since 10rain removes material fronm the whole clouddepth, the process (oan be likened to radioactivedecay, because the entire cloud is affected uni-formky rather than preferentially near theground, and the shape of the cloud -distributionfunction is not, slteredl thus, rain modifies and adecreases dispersion distanceis by the above -40exponential factor. P10we 2.14, Downwind Camtff line Dee4. Ge.,ound Level

Claude Comclsd Iow Washout, Wind SpeeThe it end the I in the exponential have been k3,ao~,aelt eXaM,:.).)

previously identified, the A, is known as thewashout coefficient and is mainly related to (b) Polls&"# DPOee11ii [11Orainfall rate and particle stae; a figure of lxl07'has been used in this investigation and repre- The amount of pollutant deposited by wash-sent rainfall of the order of O.l Lnchee per hour out is obtained by integrating the diffuston equa-and particle sites of the order of I to 3 microns. tion containing the washout term, with respect

to height; for centerline deposition thia yields,A proper description of natural rainfall

would reflect its, inconlstant nature, for it ts al-most certain that for any given period a rapid-ly varying rate would be found, Therefore,sharp departures above and below the washoutcurves should be expected.itn an actual case.Heavier rainfall rates would hae" the effsect ofincreasirg deposition alas* to the source, butdecreasing It furlher away because mof morerapid depletion of the total available pollutant.

(a) NHdfteseten of Diffeslos Comve

Figures 2.14 and 2.15 show the changes Iwhich can occur In dosage rates due to deple-tion of the cloud by the exponential term chmr-acterizing the washout process. Only two windspeeds are pres~nted, 1 meter por se-cund and10 netter per second, the heavy linom are thecurves corrected for deposition and the thinimw%' reprecent uncorrected done-a anhd artýsimlipw to curves prosented in figures 2.1 snna2.5. The figures show that washout ifs much Fl'gur 2.13, Downwind Co.,intl Dea.i4.., Ground Levegl!rorn effective at wind speed decreases atnd Cloud, Canrectod lor WNashut, Wind Spazrd!rtability >nr~SA >dM./0C.(10M. /foe., for egnrmpI.).

j

zou zurullni~ III frm gr-trthn

- 17-

9 un~tt per square meters where GV~mEm u 41~iwt-(I I t ,701 in 12 houre is necessnryto lose than '0I' mnitb

(2.2) per square metor, whtre no expense in cri'tTir-plated (241) and thtt the higher Ppoot inop~otha

Certain implications of this equation arc very cross 'he lower speed isopleths as dirctace In-important. The vectical diffusion parameter creascs.( o, ) disappears from the equation in the same ) o Imi4Adm e u(, 3, 2,11way that , does. No advantage is gained fromthe rise of a hot cloudi therefore, all releases Totslinstantaneous deposition is tht limit-are effectively treated as cold. The rise of the ing case of the complete deposition of an entirehot u ri l onE;; .. , ... ..... iir,-- - -- 'l leasening 1n-ud or nlume of an air-borne tmaterial, such

pollution concoentrations (compared to the cur- am the highly improbable occurrence of a r1oluface cold cloud) as it had been in cases of dif- under a sudden heavy rain showers The follow,-fuston; in fact, the highest deposition rates at in# equation depicts the situation,great distances are now found with the fast- Qmoving clouds aloft (fig. 3.16). - -1)(a _ _ . (213)

Figure 2.16 represents cold cloud center- Figure 3,17 is derived f•rom the equiation; sinceline deposition in terms of units per square intense showery precipitation is due to pro-meter for wind speeds ranging from I meter nounced instability, atmosphere stability cri-per second to 10 meters per second. The teria A (see table 1.1) has been ,:aed for the so-curves were computed using the above equation lution; also, because of associated increasedassuming neutral stability, a condition common wind speeds, the wind speeds ha'/• boon ciosenduring overozit and rainy days or nights, Note to be 4 moters per second or greater. As canthat the curves do indicate possible serious be seen from figure 2,17, the isopleths for theseground-level deposition (the suggested rango for conditions do not cross, and significant deposi-

tion values extend from the source to 100 kilo-. .. . .. -,,,, motors.

RAINPLl. MIT| IN

Jet.- ---- --- ---

&.00

I logJJIl5 O~ A C • , i 5 0• •00) 0lTA MC • u•. 2,

Figur 2. I7. Downwin d C~mted/n Dop.oi lon (s.znir=n/,nA Irons

tgoror. 2.26. fl'1wnwind Cnt'.tltrlfn'. DVp.o on lui rntn/mrn Jlrurn Total Inallmiant m• Wn p •'.lt, C:(.; nd [.-%,I or

Rnin. Ground Lt.vnl or Clot•d Aloft. Cloud Aloft.

-10 -

3. CLIMATOL0Y OP THE HAMPTON ROADS AREA.

3.1 Location ai Toparophy ,ings even approach 100 feet, the lalir at:•c-turems re located in the southwestern part of

the city of Norfolk.

3.2 Goeorel CtimateHampton Roads, one of the largest natural

harbor areas in the world,'is the name given to The Hampton Roads aras (approximatolythe nearly enclosed body of water formed by the 368,3 N. and 76.4' W.), located in mid-_atittdeeconfluence of the James, Nansemond, Elisabeth, on the east coast of a continent, ha. a climateand Lafayette Rivers, prior to a.-iptying to the whiah is tepeate, rainty without 4 dry saVSn,eust-norftsaet into Chesapeake Bay, Norfolk and has warm summers, In addition, wint@rsand Portsmouth, Virginia are located on the are usually mild since the circulation of a coldeast and southeast sides of the area, and New- air maiss moving towards the area will usuallyport News and Hampton, Virginia are on the have a&trajectory over the warmer ocean watersnorthwest and north sides, (see figure 3.1), within 24 to 48 hours, Figure 3.2 presents theDocking facilities a&e located in various areas monthly temperatures, extremes of tempera-of the port,' The Norfolk Naval Station piers ture, and monthly precipitation for Norfolk Mu-are located on the. eaateor side of the harbor nicipal Airport (ORF),and extend from fewell's Point to the mouth ofthe Lafayette River, Ships of different types The sea position of the unoccluded polarand siese (among which are submarines, des- front lies to the southeast of the area. Bo'.ngtroyers, cruisers, and carriers as large as the situated in midlatitudem, there is conm~derablenuclear-powere4 Enterprise) may be berthed variation in wind direction and speed, both alofthere. Oftenvesxela mayalsobe foundat anchor and at the surface. The pevliN uahid has ain the Roads proper. Another possible ship lo- steadiness of only 16 percent and, on the ever-cation, the Newport News Shipbuilding and Dry- age, blows from the north during the cold seasondock Company, is looated on the northwestern and the southwest during the warm season,side of the Roads, in the city of Newport News,Includedinthe Ham.pton Roads Area for the pur- The weather encountered in the area re-poses of this study are the ship docking facili- suIts almost exclusively from two air massesties along the Elizabeth River from Lambert's and the front which dividos them, being alter-Point to the Norfolk Naval Shipyard via the natively influenced by polar continental (c P) andSouthern Branch of the Elisabeth River. maritime tropical (mT) air, with the transition

being heralded by the pass-are of the polar front.The northeast, and moutheast sides of Hamp- In the winter season frontal activity in the area

ton Roads containthe larger population centers, is pronounced, while in summer the area iswhereas the western and ad'acent southern sides frequently a region of frontolysis (front decay-are relatively sparsely populated, The most Ing), in which fronts which were well defined Indensely populated sections in the area are lo- the eastern continental United States become on-cuted southeast of the Roads along the Southern treamly diffuse and are difficult to locate andand Eastern Branohes of the Elizabeth Rliver. forecast accurately. The flow, in summer, is"rhis river separates Portsmouth, Norfolk, and generally governed by the western extenaion of(homapeake from each other, the Bermuda semipermanent hig! pressure

coll. During the transition seasons, spring andThe topography of the region t.L low And fall, the polar front it often quaui--stationnry

flat; am t,.n ¢xample, the oclevation above roenn and oriented east-wost, either just north oii.ustimp levtA of Nofflk Naval Air St-ths in I 5 'ot, south of the region. Stationz to the north of the

T'o' the iouthwext of the region lire th" Dimsmal front will usually experience fog, xtratuq, driz-S,.vitrnp, which extends into North Caeolina, As le, or rain; whereas stationa to the 14otlh w1l1li•,Ml•l wentward the terrain nlopen imper- generally bc clear. Forecasting the locationuptibl''y uopwar'd to a diatanco approximately of the front it difficult, for the front m='.y have aMi Intic woet of the area; here the land rises north-pouth oscillation ranging from a f.rw milo,,;

-h;arpIy into the Appalachians, with elevations to a few hundred miles; in rnary cac•c, r, ntto)nVI 3,f00 to 4,000 fugt above mean sea in the path of these oscillations will cyperrien(,.'. MItim h:•5 not altcrvd the regiin',i lopog- ropeated clenring and cloudln,, over in tho sarntI

I W ! ,'•rit-'} Iii h, II , I. •V'Z)r , rvw hi11- doy. Tothe :ioutheast of tho are.,% Lle th.1 wollO -

AJ

k

.7.,

~MCAN DAILY MIN, %CAL

-~70_1

IIT

Figure 3.2. Affltml Wad~ofl of Monethly TempwerauoemE anodprcpitation, top lorfelk, V& (Olt).

k~nown cyclogenests region, in which the not -in- Hampton Roads area drawn on a bare chart offrequent Ildistraa low to spawned, the region, The wind breakdown proc@Ltcs from

an annual presentation to a seasonal a id finallyThe Hampton Roads region can be influene - to a monthly presentation; day (0800-l1 OD EST)

the beginning of the hurricane season, How- for each grouping. In general the five stationsever, It tit usually the middle of August before show similar wind regimes; Cape Henry, beingt~iu *:_ azoJbility of hurricane occurrence in this a cape locatioti In the transition zone h~stwoonregion reaches a point of concern. Theon do- bay and ocean, ahowa the. moat departure fromsMructiva storms usually develop north of the the other' ntationa; Oc*Ana, beoing clooser to theLotisser Antilles and move erratically along thoi open Qocen, AAlO AhOWs some departure.Gulf %roeam current, September Is the monthwith motit hurricanes; the official hurricane A look at thý annual, day wind ro~ari (fig.,

s t'nioonvn on Novemnber If5th. 3.3) will show th.- cant const, middle-latitudecharacter of this region. A prounagioi u'Midcal-

3.3 Dispersion Climatology vulottir'n on an annual basis is less monning-N1i than on ni astosonal or mocnthly basis; how-

I. I.I W rid Sn~rtiqo vor, the warm seseon influence of thle wem'-vrn extension of the Raena&da high Ise evidout,

In tho study of disliorsion wind k~truciitrr, iso an thei freoltency of southweat winds is. %'ome -ýnqvOrt[Imt, for it no~t only dettyr'mintv Aviv what higher than the general distribution. 1t'r.e-

fai; Io~llUtont Will he dissperbod hut almo w&!rri quencles of north through northeast wtndot tireit will tit dItspet-sed to. Iligures 3.3 through 3.0 also nomewhat higher due, In part, to Ithe'-prt,,svrat wino rosvs foir five stationn lrn .he virc-alation or the offshore, north -notrthca~nt

U-ctmi

lei.¶

4 1"

W IAN -C

Wi",S!.... *Il , ~ I- Npo

-22

moving, buovam lowa and afternoen warm-seamon wind. CApe Henry an I Oceanc, Although xhow-sea brcemee. Thz 1aat prevkwini wind li- Ing aonc oi th; abovi aingtIlritier piot it

rection is from the southoaxt; with the eucep- nore: uniform aouthweitthrough nvortheiarlbu-tion of Cape Henry, for which a southeast wind tion. As in the winter distributions, the fre-is the most frequent. Oceans shows the most quenoy of winds with ttn easterly componqnt tauniform annual wind distribution of all the eta- small, The diurnal ch'kngea in evidence fortions. Annualday wind speeds average II knots winter, may aloo be ec•rin the Decembernight-at Cape Henry and 10 knots at the remaining lo- time wind roses (fig. 3,5), Other differencescations, Although strong winds are possible are also noticeable, maitly a nighttime docreasofrom any direction, northwest winds (when they in west winds, and for the three Roads neighbor-occur) tend to be strong and gusty, ing stations, an increase In northwest wind,. A

nighttime increase in southwest winds at CapeThe night annual wind roses (fig. 3M,), In Henry and Oceenais also perceivable. Dlecem-

contrast to the day roses, do show that the pro- ber wind speeds are somenwhat less than the twovailing wind directions at all stations are south other winter months, ant. sver6&ge knots; thethrough southwest. This direction preference average diurnal wind speed decreaso iL on theis a result of the already discussed aeosmds order of 1 knot, Cape He.try shows the singu-higA and a night land brase which flows toward larity of having higher avorags wind speeds atthe relatively warmse, waters of Chesapeake night than in the day (II kn-ts vs. iI knots),Say. The oLhor wind directions are relativelyuncommon, with an east wind being thv most In January (fig. 3.6),the daytime southwestuncommon, Wind spieds at night are, on the wind is not as frequent as in December (exemptaveraqe, 3 knots les than diring the day, with Cape Henry), As the storm track in midwinterCape Henry showing the least diurnal change. becomes displaced further southward, this re-Langley APB has the highest frequency of calms gion comes more and more tinder the influence(1.0%) and Cape Henry the lowest (0.0%). of northwest cyclonic flow following the passage

of a cold front, Evidences of this can be seen(a) serae. tDosembe, i.u.iey, P6,os.py) in the increasing frequency of northwest winds

which oc•crs between December and Janiuary.The days, winter wind regime (fig. 34) shows In addition to eart winds, south winds also Lo-

the influence of the increased frequency of fron- come rare in January. A look at the Januarytal passage• .- windr from the southwest thrnugh night wind regime (fig. 3.6) shows a noticeable,oarthdirectiont prevail, with a north wind being nightly increase in south winds at adl stations.the most prevalent. Winds from an saw, or Easterly winds, as in the dytime, are infe-soutrheast dU -action are noticeably rbsent. The quent. January wind speeds are higher than De -winter, night roesa (fig. 3.4) indicate some di- comber's, and average 10 knoes; the diurnalurnal changes in wind direction, as north winds wind speed change is small rnd f-)r Cape Henrydecrease in frequen-y and south winds iaicreas4. is nonexistent.Langley APB %howa the least diurnal wind d!.r--tional ohanmo. Its diurnal variation I. due February finds .he polar front south o' themainly to a significant drop-off in wind speed. Hampton Roads region, and in a position to fa-

vor east coast cyclogenesis. These offshore de-The waning influence of the RepwadohigAh is volopments are responsible for tho increase in

evtdent du! lIg the daytime in December (fig. north through northeast winds so aren in figureM.&) •.r the three stations closest to Hampton 3.7, which depicts the ,ebrusry wind "-lit lhu-itoads (LFI, NOU,ORF), as southwest winds are tion. The ' Adronaesfor thib last month of win-st'll common. One would expect northwest tor show a mcre unifrm distribution than thowinds to b! more prevalent than indicated dur- two provi"o winter months. As in thte season-ing this time of year, when cold front passages al winter roses, winds from the southeapt arebt.come more numerous; however, it Appears rare in the immediate vicinity of Hamptonthat the Hampton Rtoads region, in Ducerrber, Roads. Northwest winds at Oceans .nd CapeIn tar enough mouth of the track of lawo, asso- Henry are generally stronger and mcre fre--ihted withcold air outbreaks, sothat post cold- quent than nt the other stations. In FebruIryfrontal imobars begin assuming Anticyclonic diurnal wind changes (fig. 1.7) oro tho. sn'nftloimtcurvature in this region, The typical northwe.t of tho winter months and consist escenttiniy ofwind, which usually follows cold fronts, is thus a nightly increase in south winds. Wind sp, cdsveererd to Ihe mnrn frequently indicnted north in February are, in gr'neral, s[milvr to thmt of

~33tAv.a;!l:, C C1.i,

#AeAN

MNf

511

.OVA

MUI~~~~~~ f s PC A Ah4IC7

I t mt

A'r9

k~K.

Fr j"w rdSý ' '" i, 1r "- ,Y Cd

L

eA- *djI

1 00 >

# .04,

NVA NAe*R

5/K -_

CM*~IAcopy

Jt

.. 06v .....

IlAY4~ Af~l

JA I.A>

Wfk ( I.

Kx

Iht)UM AYlt

aaW tpu 1. 6 C.r i1 4 nd " i

'ED Nl

e4/-.~~ fl -,l

w-

.II

W0 1 of, POO P.1;1

pr14

A4W~tP?~ 0

"Pt~v 0

wow

*o9

I ~ ~ C40 *CJNA

* ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~04 IOIU!'Cy()*f ''l *IIf ~ILtdlh~pv'IA 4rw~~' ,...

Jlfla try, both fretj nlcy ri1l ri2 -,, Cii. e lk ,?nv2 n , i r' 2 i

(b) Spr~m fMoiveA April, M4 t) Rend qule rcn; he ho' w'i A1z~and its minimum frequency froarn ootilholy

Since spring marjim the transition time ba- winds, The nighttime regime L,' -no-ki unizormtween winter with its 'epolattd cyclonic distur- than the duy dhatribution (fig. 3,0) "n- genoraIlybances, and summer % ith itx porsintent hemavo raembles the spr-Ing nighttime roarmi; the di-AlxA the spring, day wiid rosve mhow fewer pro- urnal changes in V"Tch, however, are rot natdominating directions tian the winter roses (fig. pronounced asthose fits aeancn. n3othday and3,8). The northeasterly and easterly flow ap- night wind speeds are at their yearly maximumparent in the figure is indiuativw of offshore in March. The diurnal decrease in wind tpmednortnoaitsrly-moving Naioms low found in early is at a minimum, which, in part, aeeount." forspring, and anticyclonic flow resulting from the small diurnal wind directional changes inbeing on the north side of an east-west oriiln- March winds,tated front in the latter part of *pring. Also,towards the end of spring, southwest flow In- The daytime winds of April (fig. 3.10) ex-creases as the N.wudi AWi# builda and extends hibit the rapid change from the cold teasoto toitself Into the east coast of the United States, the warm season which takes place during thisThe flow in the vicinity t f Cape Henry departs month of the year. Southwest winds are on thefrom the above, as strong northwest through increase and northwest winds on the decreade.north and weak southeast winds are most pre- The northeast winds of April are due more tovalent, Oceana shows the most uniform dis- anticyclonic flow around a Alph rather than thetribution in terms of both wind speed and di- cyclonic flow of offhorv lowA . Oceans andrection, Minor wind directions for the three Cape Henry salow considerable doparture fromstations closest to the Roads are northwest and the other stations, with Oceana (as before) ex-southeast; a northwest wind, when it occurs, hibiting more uniformity in wind distributionis usually stronger than winds from other di- and Cape HonryindicatingA southeast maximumrections. The least predominant wind direo. and a south minimum. A limited sea breese istions for Ocean& and Cape Henry differ from in evidence at the Norfolk Naval Air Stationthe other statione and are west and south, Fig- (NOU) in April as the 1400 LST (the time ofure 3.8 represents the nighttime spring winds; maximum heatsng) wind rose (not included as asome departure from the more uniform day figure) shows anincrease over the 0800 to 1800distribution may be seen. The most significant LST composite rose (fig. 3.10) in northeasterlyfeature iS the marked increase in weak south- winds, The proximity of the Air Station to theerly windsj it appears that a weak local dir- relatively colder waters of Chesapeake Bay isculation is established under a nighttime in- responsible for this development. It is doubtful,version, producing general southerly flow in the however, that this sea breese oftsen extends veryregion. The tendency for northwest winds to in- far inland, as the Weather Bureau station atcrease or remain constant at night either in- Municipal Airport doesnot show one. The maindihate. an absence of diurnal change whenever diurnal changes in April (fig. 3.10 night) is athis ares is under the influence of northwest reduction in the frequency of winds coming fromflow, or a nighttime preference for the passage the west clockwise to the east, and an increaseof northwest wind-producing cold fronts. Wind in winds from the south. A land breeze is, also,apeeds are at their highest in spring and for the somewhat in evidence at Norfolk Municipal andarea average 11 to 12 knots during the day and Cape Henry as the 0400 1.ST (near the time of0 to 10 knott. : night: calms also are at a mini- maximum cooling) wind rose Indicates at moremum in spring, frequent southwest wind than is evidenced in

figure 3.10 (night), which Is a eo6rnposite of allMarch dnytime winds are prezented in fig- night hourn (O900-0700 LST), April, day wind

ure 3.0. Winds from n soothwest clockwlis speeds are similarto those of March, wh!e the,through northeast are well reprvtinl!,d (except night wind Fpeed& Are slightly lower.Cape Henry). The passage of cold fronts, stillc'ommont in March, account for the frequency of May, day wind roses (fig, 3,1i) are charec-northwest through north winds; northrant winds terizeci by the presence of a sea lweeze 4t allire due, to the already discussed, pasiagc of mtntions; Its orientation ie ensierly for Langley,(oCfshor'e lows , Southeast winds, with ti'- ex- Cape Henry. mid Omuann, and northea•ctrly for

jption of Ca pe Henry, lrt, at it minimuini in the Air Station and Municipil Airport. 8outh-

A 7nM p i .oBest "-',

f4-

1,e 4

"112 ý*(IPfN Ei 4".

A 0MAW

to44ft-*.1 4

AAM~ifrl iif'fWgfI

fri~~~~~ ffr ,'frq, C py

Ilk

PO fl.o

0A9 fNvl

AAM1

A)"I.~~~I It/ I- I;Wnp~d"' ,1 ,rF% If,,

Best Avaiz,,t IA,

MI to=014'N.J. ~ ~~ ~ ~ ~ tit ti, ou, d, 94

RI A,/ P- v f

71J 1 WCr,,

-31

AV519 A AttA V o

4,44' L

*~~ ~~~ I ,s,.*WES S i

**~~C bl--' C OPYSS~ S'4 95' ~ S. 5

Ll9*£IS:13, cs't

wame,*rl,; winds~ rr tr:c-.:n4 at 411 KtM1011n ., rx- roset. TV nionth tf Jully dtviiAtc,ý irit't t.L~ept Camp. Henry, where the wind 1A houttheast. riot grentiy? from the two other murnino !nonths.Northwea. winds tare (argain, with aeuroption of In July the RAnm~da A1#A is strongeat and produ~eorCape ffrnry) plainly Infrequent. The Psea breecse K higher frequency of tiny anti night ntoutiswe'Aeut the Air Station anti Caipe Hfenry iahown up eni- winds than June or August. gea bre'aces areapocnally wfll at 1400) LST. A look at tho May, Also slightly reduced in Jluly sinee tho warmingnight windb (fig. 3.11) Indicate@ a diurnal vhunge coastal writers, along with the clofor locatior.niot only similor but of grvntkr mrignitudo thnn of the Gulf Streim , ruduces§ the lanid-water,that of April; as winds with northerly ivompo- niid'dAy temperaturv contrantm, The frequecyvnent. becoine infrequent and south winds be- of northwest winds, although low in June andvome predominant. In partioulAr the rantl or August, is even more reduced during JTuly -

northeast fa'eqtiencies, nassociated with seran the month of highost temperature. July haribreorem and evident during the day, are can- the lowest wind speeds both daty and night ofsiderably di.,ninishod, The nightly predomi- Any month ot the year. Tho Juno and Augustnance of mouth winds in spring shifts somnewhot wind distributions are quite almilarin both dir-to the southwest during May. Tho provnIonco ection and speed and show some apring and fallof south or aotithwast winds, at this time ct year, influence#, respectively.If attributable' to a land breeze circulation,should show i, maximum around the time of (4) Poll (Seplemitt, 0oleber, NovemherJmaximum landmaso ecling;i a comparison of0400 LST and all night wind roses bears this Fail wind distributions (fig. 3.10I, althoughtact out. Day wind velocities decrease from showing considirable uniformity, refloat the In-Aprilto May and the nights begin to show tin in- ertea sing number of low and frontal passages ascreased trviquency of calms, north through northeast winds become provaleint.

This preference is not as pronounced at Cap@(,r) Sumnmm. (Japi, July, Auxual) Henry or Oceans which have more uniform dis -

tributions. Winds from a southwest direction,The effect of thlemrsad.Agh en the circu- so frequent in summor, decrease namiceably in

lotion ' n the 'Hampton Roads region in sum- 'the~fall,' The autumn increase in northeast windsmar can be seen in, fig Lure 3412, frequient south-' Ins a result of anticyclonic flow around the. east -west winds tve in evidenc, st-all stations, North- emw side'of UN~A# located to the north of thewost winds, since primarily an, aftermath of cold region; afternoon, Sea broasse still occur infronts, are rare, and when they occur are roon- early fall And UlsoL~o ntribute to the incroasedmiderably weasker than their spring or winter northeast frequency. Northwest and southeastcounterparts. A sat- breezei1s well In existence winds for the, Roads neighboring stations areand is especially evident at Norfolk Municipal least prevalent. Night winds in fall (fig. 3.1fi),Airport. The breaoe., however, does not extend in Addition to showing some diurnal change intoo deeply inland as it is seldom felt in Ports- wind direction,' become calm more frequentlymouth, which is located about 10 musps from the than in any ether season. Langley APB hastmy. Diurnal changes, cma can he seen in figure calms 21.3 percent of the time and Oceans 14.13i.12, are greatest in summer. A nightly gentle percent. The diurnal and se...onal increixac insouth through southw not provailing wimd In plainly calms at Norfoilk Municipal Airport Is not aseivident at all stations, and is due to the cou- pronounced as at the other stations; its maxci-pling of the ciroulatir n around the Apl#~4aA WA mum in nighttime calms occurs in the summer.wid the night land breeze, Other wind direc- The main diurnal wind direction changes are, aslii during the summar are infreequent. B~oth with other seasons, t decrease In northerly,hit cnilms and night cailms are frequent in sum- winds and an Incrieirre in south windaG--thosti,roer; wind %predii average 0 knots during the Oianpres are, howover, not as striking naton sum-dity and 6 to 7 knoto at nigtht. rnrtn.Deviations from normal wind pat-

tern,,3 arc apt to orcur in% tho fall, as tho pro-Figures 3.13 through s.i 5 represent the dny bability of hurricanes tiffecting thei areaii Is it a

arid night wind rosesi for thr' individual surmmcr rnaximl;.n.iuuiihus. These will he discussed together as it

oi evident that little difference exists between ['ho Sepiremhcr wind rosest (fig. 3t.l7) iIni-infltvidiuat months in thomsci yen, and between crkto it predrnmnatnce of nuort thr'ougi, t-w-ohit rIdlivtdual months and the overng.,e'trm' winds [,t alIl stations. The fi~rmu~d, high bf oaIli do%."n

33,

. ..... ... .

HAM 544 Ari

\4Oii!I

"OtD~E4,

AMW PN

(If~sAV

Woo/

417.

£A44Sr A j

r-,rt~vlý/ v r i-,1, i , I-p f'l!', k

Dn c/J

3 4

ft1~I . 1 A.

mw 4A

/IS\

DINI

"Alo 16 4.. 4.

BetAvaiabl Cop

eo

d~. 4 ~ U

'aW-1

OCIP

-Soqvoogta, -

OAT

to,

so#11 "a$00

WAMPTO RGAC

4

2, / ,. ,A#v

h.< WadS,.f,:, j.

L4A

,.±4 1-. 1 4

a, al / 1 1

-- O

a.(K

/ t

WY~I X '51!

A'Jfý

)wq A( 1

01. /I)P f t!p

10,,

__-O ItlitI totW

A IM 0` V ,

Arit

N.V.1

I,. 34 ISIS *444 1,.t Pr t,C

UcN C IPP

Bes Avatic

MAW, it" l.p t

(//At~l AOI'. ,

Airi

W.4-

AINO

SAYP

44NO(r 'A

IOWA/

v. !6 4Sr , Oioro -Vv/tm tr ,-

4* ¶ )

I"' ~ ~ ~ ~ ~ A ! "hp'- 'Q'P "~i' .r.V Y~fn¶t.I ..

nttdi tOw retgioniyt vxt~i fvnvv nn iot'ic~rtite frt - tito Noivttbv~r tliutnal Uli~tingr I:it -i!I Pt-1qucnvv of froritnl putl&O4 TPhe froliI N ill thirý vui-.n 1norir (lif, 11Viliy' y dc'i111 t t tI dV.4 hV tI 11nV Vjru~t -WV/i'M)( tI litI ItIII [(IINItI in lIft triloikt'iI (LIyL'tioiiol uthori v:cycioniv flow bt'hiill ih,.o-t tuid kjoptu ~tImA1oj4 cet'aiid fruur vcy or tnu wuiwin -l,%

prtoductt tiolttl 011,01ugt viini W111111 1,1tht't' t~gki tivilod fort oIther' trontihs, I-, ol-) twillrnl- N- -

tile nortmally thoilght of not-thwroM Winds. Alto, velythor Win mwItprd%; rhow 1110r rkr' 'ii' v ý ;it otown d t~ i he Intioi'r hntIf ot 1it hr onth, 11,111tremIAfitiq 8t' ptvo it''lhvl- 1 1 It Itic u. t'tOlieutr~ thuttt it) t hr fre'quency (if nuorthrngi windf.4,A MuCA br~iezt i'ffel ti vidtintly riCICfW't~t! thn olirycnlenit nntlthrasl wind fin midnertrtmnovtt, 1414 W Ind rttrvt'o toI-ht tiol 0(Iim f I 1), 3 l01, !t;' fi:iwni compnttriin of the~ '1,1001) IL wind rote. mid II1VI'r4 wtitc, ('unim'uirmd1 itt tltt'i'It ott tho v ýTi-111i1, d.1y Windi VOOttN sh1OW0. 11 1m101' fr-0UPlnt Wiwii of wind with he'ight, P'int, lpor1t witt ilt'-northea st Wind tit this houtr. rStinitooilir d Lurnin ect Iion rettinilnet (Immnt tal I y twonw i ilc1ihagesl (fig. 3, 17) C'onsist rilort' Of winid KlpeeI MAP$$ Wert) not, br lUtIfd tin tie' jIiilivn)It to,changes than of wind direction. 'rho move pro. .. 1-"ei~hflouncod subsidence Inversion, found on the vast -ern side of the high pr'essurei cell whic'h follows An importont f~Reot, Inhihiting thu it' pietfrontal passages, caps off the surface from the di ipo rsion (in both time andmti e suoro Pnf at mos -upper flow and produceos more calm winds than phoric pollutant is the promenv'r ohm 1nvvr~tot1,ore found in summer when thin area io under either surface based or basod at gome hight'rthe western side of a high pressure cell. The altitude. Ta'0e0.1 presonts tho porcentagefre-diurnnl wind direction vhanges, which aire In quencirli of low-level invermiionma t Norfolkevidence, arc mainly those previously encoun- Municipal Airport by meutions and by wind apoedstored, increnmo in south winds andi decrease in of (0~ 10 knots and loon, und (b~) gretnter thon l)north winds. Although September s~hows a high knota. Theme Inversions wure dototrminmd Noi'~frequoncy of Qfilms, the average wind speeds 0000 GMT (1000 L.STr) And 1200 GM11 (0700 1.,S')are higher than those of August. soundings Iand its such reprooon't novtttcnuul

radiation inversions more Lao than daytime in-October wined roses (fig. 3. 18) show a sired- versions; inversions durngt the daylight hoitrm

larity to September, except that east winds aire ttre infrequent compared to night houts wid;iase frequent And northwest winds more fre- whenthey occur, tre osunily duft to llnrgort~'rqluent, The area is more mffected by offshore weather systems, On n an inutiil hutii nov turtniktum., producing north through northeast flow, low-level inversionsi art) prrevnt 5I7.0 perverthnn by easterly post, vold frontal anticyclonic of tha time, Surfi~ce based Invet'miurn' uti' byflow present in early September;, the incrolasod tar more frequent thakn Invore'Tion buurwd ho -frequency of cold air outbreaks in responsible twoon the surfAce and 1,3100 foot: olao, itirfacinfor the incrense in northwest winds. Westerly Inversinns with surfaer wind s.pvods of IC0 knatt'and southwosterly Winds Are, in the vicinity or iess occur imuvhnilt unhn~hntU')t(ttif the Rocndo, lenist preva~ilel, TVhe October winds Are glieater thnn 10 knotm, Thri10 knoitnighttime wind% fshown in figitre 3.,111 ropre - point for' thi' Inverfion cinwisfiemint'r by svi'etlsont diurnal vhangap sjimilar to thrtse dimcusAvd Was su~ggstod by tho rmw dntn: thr Invvi,%lonfol. Septombor, Wind Ppeedie In Octaobr tire fr'fquencica for individual wind sriecdY4 brlow 10(fMctnewhat higher than Soptoinber and average knotri werei ditntributilned u ns o makt, any fur-1) to 10 knots at dny and 7 to Ii knnt;% itt night. ther breakdiown mvininlgiu'eim. No invort'ionCntpv Honry oxhibitst no dlurnnl vhAtigt in wind classificiation by met wind ispeeds votild bo notocdsputid in Octobetr. for in voralons nbovo the nurfract atnd tit or hr-

tow 1 ,f00 foot, ttowevtnr, for ptre i -ntation ptt'-'Ihv Novembier wind roises for daytime con- pozcs. the stame wind spord cininI frlrltiori l~ f~ro

dlitluowl(figi. 3.110Li refil-t thl- increnmed ftt'mtmtivy AUAMI'fr ifiVt'V-tctnt' W;04 1,040d,

Niflor,11t ulm'onhrmity In thty mkouh cttwkwist. Wintetr with ith king ni'ihtk,~ im ti oýl eŽur

th',out'h north diirection;, for L.ttinglty andlt the wilh fliy highwgiu Frt'i'tienriy of tioctmiviii hw.-

SIhOw hItN tiltifri'Mlty ilt tjtiP' -AV!1ijircj'0 tIV 11- 4h* 16 , ,,

s'iuithwest iind not'thwt',it throtught north windsri ~~ 0 i GIN r.Mf1 N11 !'!Id

Bost Available. Copy

A~4 0

4A4

U..~~~~ AAY a@f Mato

~

f-w 8Ap W~

Flamm"J

~~N A S & ff, 0 00.

14 4 4L I'A A

ewsd~iAf \

W.O..

I LV

Best p,,vaj1aib16Cop

AA6

I ow m Wa'

,/I

AAOPSN

I~f¾ (WT4 I ),A

N',nnp" r I r, f~rmV Wv l ir iv

Best 'A9 Avllbl AjeTCopyA

Table 3.1.1 Annual and Spaxosil Prequovwy ol Ltiw-Lowr tnvot'usinn

SEASON _________W ERSION HEIGHT MAI,!- Surl'aet - >Sur ace 5 1,SO0 feet

Surace Wind Spe 4~urf act Wind ea

Winter 46.6% 8.9% 55.15% 9.3% 611% 15.4% 70.9%

Spring 30.4% 6.4% 36.8% 10.3% 7.0% 17.3% $4.1%

Summer 29.6% 2.5% 32,1% 10. 7% 5.1% I158% 47.9%

Autumn 45.3% 3.7% 49.0% 4.5% 2.6% 7.11% 56.1%

Annual 38.0% 5 .3% 43.S~% 8.6% 5 .1% i13.7% 57,0

level Inversions, 70.9 percent of the time; and peoially in summer And spring, Invereitonmsummer,the season of minimum frequency, has with winds from a west through northwomst dir-47.9 percent. Autumn and spring both have ap- ection are relatively infrequent; windt4 from.~

proximately the same number of inversions. this direction, quite often a result of a vold(a) safv(.r Based front passage, have a relatively higher vtolocity

and ins accompanying air mass tos usually un-If one first' consider@ surface inversions, stable inthe lower layers (old air ova,' A warm-

then winter still has the maximium (55. 5%) how - er surface), Wind roses for inversions; with sur-over, autumn (with its clear, calm nights) is face wind speed* greater than 10 kn~ots~ inmicate,close behind (49.0%,): spring And summer now even more pronouncedly, the preferred south-are the seasons of minimum inversions. The west And south wind directions during Invor-above sim~ilarity in frequency of inversions for sions; in addition, a secondary maximnum, awinter And autumn (fall) on one hand, and spring north wind, in fall and winter is alsto In evidenceand summer on the other Is more evdent if one for those higher wind speeds.considers only surface inversions, with surfACeOwind speeds of 10 knots or loess in this case (b) Above Surfaeo, bus Ato vio~lauw 1,400 Foo,fail (45.3%) and winter (48.6%6), and springMAIO4% and summer (29.6%) are essentially rho seasonal variation for inversions n-iciqntical. The frequenvy of surface inversions hove the aurfa,ýe and at or below).0 SZOfet lawith surfQac wind speeds greater than 10 knots small, Spring has the highost total frcquonc~yim low, 5.,3 percent nknnuRlly with a range from (17.3%) with summor(13.87n) and winter (115.41'/tI.1l iereent in winter to 2.6 pex-cent in sumnmer, frequencies being Psomewhat lower: wituinm fri'-With those higher win~d speeds the metieon or quencias (7.1%) represent about one -halt of thcn-1-x~i-rnm burface invermton fý--uenclom xhlftm froquenclos. of the other Apcasorp4. The' spoodfromn fall-winter to ,vinter-apr-g. brealdown for' thene inversion,% cdoct not yieuld

nay futithc'r Inforntoion thitn 1,4 nppmront in theFi gurr, 3S.20 proaonitt an annnual Lind the Oiota frovtcticflclv. The relat lye y Jijghv r p(,,-

!,otiso(nklwind dfroction distributiomm asmovial vd contri~es of "here iiuvevsionipi rojund .r, miprign .irfarct bNved Inwersionn, uring the .4ame wid nia~nnmor is duo to surfacc hewot ig whi.,h

''uci )breuak(Itwn ah wak i.,scd for thim jcr-cetogc hi s tnken plaoc by the tinlo or tile (170) I.ST!:ivqiwnr:y ttthulatilon, Clearly evident during (1 !Oo Gm'r mounding. This lotivniinp, o> thitilYwi !,unsu, with low wind .Apoeds (!; 10 knots), Uriting of !A wirfnc~e but-erl invorv41c),rrei vii prt'furre.d sieuuthwot~tAnd itouth whid Mri-

11rlop , 111i ,'ll uiu ;o f c the V01:47, (Indt I'. 'I'l %ind 1'o.*)N s IIIut~ Hgwi A."!:~

Bes-t Avail~abIa. Copmy

-43-

" MIGI WIN ttR 2' 1, 1 WIN¶9rn

304 SIIO 10% SPRING

105% SUMMER 1 *,)j 1011% SUMMER .4

(I.3M40.3% PALL 81 44% FALL 14

ANNUAL / ANA 1 •

Pijww 3.20, Anmi nalrd Swaonul Wind~livndone During urlseo Plgums 3.21, Annual and Seasonal Wind Direct ioho Durinj lnivn.beasedt lruimone at Noriolk (017). Wind Speeda.: alone between the Surface and 1, 5W tc'at at NorifolkgiG1 knots, andj 10 knoate, (ONP), Wind Speods: Z10 knot. and ý-' tO knots,

show considerable difference tram the surface The Hamnpton Roads region, bring infiu-Inversion rose. when compared siansonally, enced by middle latitude cyclonep in tho'colderThe main difference being ain increase in in- seAson and thunderstorms during the warmerversions with northeast and east winds and a montbia,does not have a ebaracte~rlatic: dry :tra-decroaso in inverrions with southwest win Is; son. Figure 3.22 portrays, by mionths, the meanwinter shows the greatest difference In the two number of dAyp with .01 Inches or more of pre-in vittNion clatslfLeticatlfln and summer mhows the cipitation; thei range is narrow and IN from aLepst. Hlowever, the annuail comparison of wind maximnum of 12 drays In March A(nbcit I I rinyvý inroxse for these two classes of Inversions shows April And July) to a minimumi of H day.% oecurr-conmiderable similarity; the basic difforaonee Ing on four neparnie months - June., Sop:te~nb'or,vvident In the %onasonal comparfison, Although October, and I)netnibeor. T[he drtret ,auncctinsvcWill presont, 'Are smnoothed, mronthsa are October, through I)mecemhvr- and !ho

wetterit iiieaivmonths, aro Myarch -Ajdi32.3.3 iriM iW't~ and July -Ai ipoit.

((A) IhRref~Hoh' u ing bock to fiflire 3.2, (MV CI to Cra idomewhat diffe rent pt'~onr'tition atprui

'rCvi[)itiitiott Ni reloired to pImhition in that 4,010on data, hverv normial totlt IVIcithtlI titt&'ii-

rlon ((]' Snow) oiay act 11K a cik ~ t agenit tattool is port'! raed. lIuly 1111-t 'he hirliest tol'liInIho aimnsi'll'ro andi suppr'o%* thw wlide-spread intinhifly roinfall, nenrly itvic that or 7Mv rub,

'ILrIer~i'cr: of CA pootutnnt, prdui'attng heavier '1huvi, lthougzh March hia- niore raiiny datym toir' -tt~ i net h)istr~oion nem~e''r to the ,ourue. Jl~y, the um-oluni of rain, (over ol ¶ :uehva) Er:lilu4

<4 4T"-

... .-..

70 ,~-

is- * LUIS THAN' A DAY

a. 4CAo.. c

Figurte 3.22, Anmfla. Vdalitin @I Not'tol (ORF) of., (a) Numbot ol Oqa Each Nomfif With Precipiloktion, Thurimdi'uton~se, and Hosivi POO;(b) Average Monthly Relative Humidity (%) - Doym Night.

on it given March daylin lessathan on a July day. and calms are the least common during dAy pro-P~recipItation In March is more of the light, cipitation. Annual night rogos (fig. 3.23) do notwarm front type; wherean July has intense indiClAte any significant diutnel chan~eps r'ithers~howery precipitation associated with thunder- in wind speed or direction, during pructpitation.storms. The, fall months, considering bothform% of precipitation presentation (figs, 3.2 The winter day roises (fig. 3.24) depict theanid 3.22) show both fewer rainy days i~nd A Influence of precipitation-produoing told front-rimriler total amount of precipitation, Ainual Al PAceAIges, which 'produce northwest throughPinowrall amootnto are smnll, 4.7 inches on the north winds in this region; Influence!@ of off-l4'r rago; only two days per yeatr have more than shore lows Are also evident but In not AN pro-I inch tonowfallm. nMinced a fashion ar. on an annual basis, Di-

urnal changes (fig. 3.24), in evidence In tht non -Viiurep 3.23 through 3.27 Indicates annual precipitation roses, are essientially abiornt dut

:md ýýeaonal wind direction And speed during to the presence of clouds (which tkuppre~n out-day prv;:ilnaton ftnd night precipitution; theel.) going radiation) and to iitronpar pntskiro~grntli-

1 juosent lnunch m , uniformity between fmnts dtirin~i prc~itpitotitin.itt tmon4 than the nonprecipitation romers prevt -

onsly preeentcri. The ninnunlta dn ox-r (fig. Winda (h iring precipitition io f!ring (rirf.3.2 I) portruy the i nfluun ce orf the most commnon 3 * 2 ) are mainly from the north throuý,.,h tt

rli0n ttrodciurinothe itrea - tin o~fshort-, north - A niignificant doccrenaso is noticoahle fromn wintcr,..tv tLy -mu nov , low premmurto symtem which to tipring in northwost winds, WI ntl friithcprtotut' ft north or northmklelt winds and noummIly mouth r lovkwi cc thrmigth northwtii to- 1rirt

.ti.Thti nruiiining wind directiorot, on an procloininant. Springlinire rain ib4 ti.I~n

~n~ttItitie, ore roxima~tech elual its rain with windst 11owing fin overwor vttyi,

i lrf, Wtve't, 10 lkt tntlorks wewM windn hcino', wilth wvtnnf I 'h Ih havv niv

8 et A

or

§ 7NL I I A? to l IZ

41 =V~

flN -A t

v vm Ný, MOr 7 Ptl n4.o " ý V t J-) 7 7AvlablaCP

II /

I\MAAV A

AAl

061,A - p~y-m4N

'kw Illy.

IV~ ~ -VR-A ,fJ

of Wnd p-d;mdDircri n trFv npw (IKAS~ WNWtv

Bes AvialclC p

- 47 -

ants. 'rhe night winds (fig, 3.25), except for a come morenulmerotim withtho upproach ofvurn-aight dacrtAi, in speed, show little diurnal mar, peak in July-Auvust, drop-off rapidly inchange during precipitation. September thijugn Oo-ouer, and become un-

common in November and December. A piti'Summer with some excepton in windsfrom air-mass thunderstorm ýs less common in this

the west and northwest, shows the most uni- region (over land) than generally th.ught to beform wind distribution of all season@ (fig. 3.20). the case. Some convergence mechanism, inMore uniform wind roses would be expected in addition to solar insolation, is usually necem-summer, sines thunderstorms - the main con- mary for thunderstorm occurrenct. The con-tributor to summer precipitation totals - arc vergence mechanism may appear insignificantapt to be randomly located with respect to a on a weather map, such on a' slight cyclonicstation, thus resulting in random wind direc- curvature of an isobar which 14 part of a hightions during precipitation. The slightly higher pressure cellbut a carefulanalysis of the syn-northeat~t wind frequency is due, in part, to off- optic situation will'reveal that it is the sparkshore lowm which can occur in summer and which is needed to set off the activity, As awhich result in overcast days with light precipi- point ofemphasis, thunderstorm can and do oc-tation. The diurnal changes in summer pre- cur at night in this region,cipitation wind roses, evident in figure 3,20,are mainly an increased frequency of south- Wf) Fogwest windsl,

Fog, likethunderstorms, can be used to ot.-The north through northeast predominant timate atmospheric stability In the lower layers.

wind d'rections for fall day, precipitation wind the prosence of fog, howevor, indicates ratherroses (fig. 3.29) Indicate that offshore cyclonic stable conditions (as opposedto thunderstorms)developments are respon•ible for autumn pre- and thus poor dispersion of n pollutant.oipitation In this region, The remaining winddirections are relatively infrequent and uni- The mean number of days with thick fogform among themselves, Pall, in addition to (visibilitylessthan 1/4 mile) per month is pre-summer, also shows some diurnal change (fig. sented in figure 3,22. The monthly range of3.27), as the frequency of northeast and north- diiys in small with a minimum of 1 UNay in Julywest winds increase, and the frequency of north ar-i a maximum of S days ocuurrino on a sopn-winds decrease slightly. TIle fall night winds -rate months. The fogz inthe foggier successiveshow predominant northwest th, Ai•gh no*rtheast months, October through December, are mainlywinds during procipitationj the remainnin direc-. doeito radiation, a result of long niRhts and cleartions east through w0 st arc uncommon. skies,.

From a pollution standpoint, thunderstorms The presence of clouds during the dayin-are important not only because of the rainfall hibits solar heating at the surface, thus yieldingthey produce. but also because they serve at in- poorer diffusion conditions, On the othor hmnd,dtiators of atmospheric stability: I. e., low- during the night, clouds tend to reduce outgoingIewvl. Months which indicate a high frequency radiation thereby reducing the possibility of anof thunderstorms would also be expectod to -how inve.'sion formation and poor diffusion.strong (superadiabatic) lapse rates, which arerot.o 'onducive to the vertical dispersion of a Monthly mean sky cover, fromn ".tuntrim topollutunt than neutral or inverted lapse rates; runset, is pres•nted in ftigury 3.28a, The mingocominmon during month% of low thunderstorm fre- I from u high of 0,65 hn Jnnuniry to n low of 0,,1)Aquency. For oxample, a Jlly afternoon would in November, Sky cover decresoes from winterdisperao a pollutant more effectively thnn a No- to spring, level' ff in Pummor and fall, an.d be-vember afternoon, on the average,' gns Icnretrir.,, with the approach of wlntt,,,

Anothrr atnt.stic of monthly sky condition itlithe monthly frequency of thunderstorms prosented in figure 3.20h, where tht moan

may he) sven In figure 3.22, where the mean monthly number of days with el'hnr, partl 'ynumiber tfcdays with thutnderstormse is givon for cloudy, and cloudy mkiCe cLan 1w( seon. C lotilvit'h motwh. lhbndnt,,rstorm.5 aare rare in Jnnu- (0.8 to 1.0 tenths sky cover) days arv ot a nnxi -

44 .v, imgin 0.currIni.' in Februntry, giadutally he - intiri in winter and enrly spnginy, and air at a

Best Av'ai

-48

"WOO

N~ (;4;3k

ASA

A14W4 It

WAN PAOY P

0,11,

Ilut... .- /

Mwi'M $

#A VJ

rim WW~~S

r t*M*r NNOF -,S

w a, r~qu tw oIWj d .S ý ..Imi If m to o iv 1 m l n R ad t to .;W se r~ p f fon i ,( ri j

B t va ;

49

N POW 7rV

MAI

) 41.. .41

1) 0 WV

IMD

I' -# 'j4 t,'4

;_. p.d w ' i -snf.Fv,41n fnPP~~.Noi i w. nl!t, w

V. *~t V .J,

coA

Owl .

* /m

WO I,.

*Atop

w#1W!P O-A4 NW

(f ~ d * ftII-4~vi.

I. AM ff 14 tP

MAW" fl~

JAWS_~V.- e- C

-f Wield'~

Bes Avilbl Copy-I

('J) mean ISKY cover

S0.

CLOUDY

(b)s y tt

Pidue, 3.2a, Anfust Vaidedan of No*nthIy Shy Conditions mi Ntirfalk (ORP).

minimum in summer; June has the least num- easterly circulation in this region; the ovairber of cloudy days (9). Partly cloudy days (0.4 water trajectory of this circulation, from reln-to0.7 are more frequent in the warmer months tivoly warmer Gulf Stream waters to the colderas a result of convective activity which tends to waters near the coast, to responsible tor thobe of a partlyocloudy nAture. Tho monthly range, stratuo formation, This type of stratus im itru-of clear (0.0 to 0.3) days is smallor than that ally quite peruistent and will sometimnot .'of the other sky conditions, with October and for days with only slight clearing (luring theNovember showing a distinct max~imum. rhis afternoons of theseo days. The top otthe etratusmaximumn In due more to a reduction In datyx layer attains a height of 2.0 to 5,000 feetwith partly cloudy skies than to a reduction in with bases averaging 50 to 00Q0 feet, Wind speocinovercastt days (convective activity docreasfls of 10 to 15 mileA par hour are mutit favorablec'onpidertably in the fall). for those conditionj6.

One typo of cloud, stratuse, varies with con- Tho other type of common Me~atus ig mouthtvtdorable frequency iand set of mynoptic patterns veonuxi, must prevalunt in xurmmer, it in caurlniin thte nrea to warrant 6pocial discussion. Stra- from an entirely dlfforent syno;_tir. situationtuA (and ~ometimcs tog) may be advocted into the thnn the ndvvcctivt' nothe.:,o mttoiu.- South srra:w. (orrt7Mion froin two different high jtressure regions. fog) is uhtually eaused by a comblorntion of radi-

Ption and advoutlon, atnd although oceto I: tl moreNortheastg .oitats im often found in mpring and often than nortAvoaa s~t rpusa , doces not lwst it* lonp;

ro-tultti from the typiviii gynoptic gituation pre- it usually forms between 0500 FS'l and 01000eomted in figure 3.29. vihe movement of it coil- EST and, due to st roni, munime r livoting, stitrtstineito i polur uir rnas% or of a cold ma ritilow d issipat ing and lifting betweetn 0000 E .ndptoiar Liltr mass to a center over New England, 0900 E~ST. stollhAt, rr~olm(0 fog), hoW'evter, givr."with t wudge of hihi pres~ure extoncling a long evl ing% below 200 feet. andiv ;bIitiŽ ~i,Hic~ Atlatntic cow,!, c auon ena!er'ly or north- 1./2 mile arbout twice the nurirohr of houi-i

Best Avnik-,b Ie C~

TI.4

AA

4iur ?Jo 'Jrff wihasAt 4th ofcru~i

~~4*4e I 4~

4. THE POLLUTION POTINTIAL OF HAMPTON ROADS

In the foregoing moctionl, the major factorg' a result of n sea breeoe which I• produc od r

afiflcting the disper•ton and deposition of con- weak grudiont conditionm in the wurm ')vwn. or

taminstion products, and the cLitratology of the in othvr neivions an a result of offaboto puzi51nq

Hampton Roads area have heon discusied as hwe or the flow around the a.at.rn •o•ti of Of

individual subjects. The fact that a matjor re- high pressure cell. lFigure 4.3 dopicti the goa

lease Itself in meoeo l6p.ehl: tshouil bm "t rongly braleee situation; strong ingoltition ari!d A wind

strecsed, but it is ailso interesting to review speed of4 knotv(2m,/#@c.)tare asurned. Herv,

the probabilities of the various meteorological also due to the large vertical diffusion coof-

occurrences in the event of a pollutant relaxse, ficier~ta involved, significant cdo ago do not

This is a matter of combining the climatology, reach land and occur overthe water. The other

a map of the area, and the various diffusion conditions yielding northeast windci involve

patterns. strong winde and cloudy coiditionm; flure 4.4thus depicts both day and nlight diffusion (a wind

From the foregoing section, it should beo speed of 20 knots Is assumed and neutral sta-evidmnt to the reader that the /tapions Roado arra Aim bility), Although significant dosag•e extend over0 law Polluti p.oofal. land Areas (t0 and D0 unit isopletha), lethal

dosages (greater than 400 units) do not; also, it4,1 Under Seuthwsst Few lshould be noted that the land areas over which

these dosages occur are relatively sparselyThe effect of the Bermuda Alig, with its populated.

southwest flow, it partly responsible for thislow potential. Its effect is felt throughout thewarm season and in many cases even in winter. 4.3 Other Wino Flows end CwdltloesFigure 4,1 might be considered all a probableday diffusion pattern diring the warm season A wind direction from the northwest wouldwhen the Hampton Roads nrea Is under south- tendto disperse (a pollutant ovpr the metropoli-west flow (which is often); a mid-day wind speed tan Norfolk area; however, as hais been seen,of 8 knots ( 4m,/sec,) and moderate insolation northwest winds, contrary to expectations, arehave been usedforillustration. Assuming a re- tifirquome in the region, (Since winter storrmlease occurring in the center of the Roads, it tracks usually are far enough north of this re-can be seen that the significant dosages do not gion so that, following a cold front passage, thisoccur over any population centers and are re- locale is under the anticyclonic flow of a coldatricted to water areas. Figure 4.2 is for a AlgA rather than the tight cyclonic circulationnight release during southwest flow. This situ- of a lows , an is the case in New England.)ation occurs even more often than day southwestNow, as it occurs not only in conjunction with The cities of Hampton And Newport Newsthe Bermuda Al£l but also as a result of a Io- alsohavealow pollution potentialsince R south-cal circulation set up under inversions during east wind. which is needed to carry a pollutantother times of the year; in fact, it is the most released in the Roads in their direction, isfrequent wind direction during inversions (which t,.

occur more than 50% of the time). A speed of4 knots (2 m,/sec.) and a condition of lee than The study ofthecli•ratology hasOlso neowt,3/6 cloudiness has been assumed. Here, some that It is more probable that there will be no rain,significant dosages might temporarily effect the fog, or thunderstorms (that is, the Hamptonsparsely populated lower tip of the Delmarva Roads region is not e.vitm.ol wet or foggy, norp.t-niut.la a!: the plume made its way to the open does It have very sssmemo, thunderstc.'mx), so that('ctnn, However, in most cages motoorologicitl in tin ontimatef of the genea.l pollution potentialconditicns, with the onset of daytime, would of the area, it can be nasumned that thabe meteo-change to some port of laple condition bfole-. 1ologti'a1 Ovntm would not be taking place theaignificant dosages reached the perln.nua. mnajority of the time. it should h(h omphasircd,

however, that the deviations in diffuiton values

4,2 Undor Northeast Flow and marked depoitioln could Pettit , In the eventrain or mhowery pr.cipitation a toc•nted with

Thc, ither wind direr.tion which twour) frre- thunderstorms Were occurring during t pollution,~i'rt !v" isa) corthetnKit wind. Thi g c•' arkt ucr nn episodo,

Best Availabje Copy

CMjit'APý.A0. tA

( HAM' ON (9A~q

N~ N

N.j

CW/ 1r 4 s N

Fiw41 ..bl mstofOAKwlcflý W W4a ýp* Irpo o apo oa

-HES 'FK N

01~( A"MA

F~~~~~~~ ~ ~ ~ ~ i~ur 4. rrbboFlfIo mnlLvlVmt~j(btiAorp a i f. ipo (4

VV r'f ~ tit . AP Ir $'AY

1, 1AMI-t:r N-. W O

~~~ N -. 3

14 '- P,---\1 .*got N11W~

Figwv~~~~~~~ 4.q Prb-l ExtentV olSdLYl otmnn iho lemo uResi h l"lnRms

H, 6NI V'ý N' R r)[)

44~~~~~0 4VtLV ~ ' --

''> ~M) A4m

4-, sC~'r~A ,, nll 'rbl Cop

4.4 Con mtusltn a rrang•qzn nt of thu popu hatioz• curattorr, • ~iv•'• l

populated land cmins, and nrrjpi'3i•P, d %vwr'rThe Hemptott ttadu rogionlhail u rolatively rvgiona, in conjunction with th•' locali win~d r•:-

low air pollution potential. Thim is due to the lime and the nonfraqu-nt oo!'r 'one t o -local topographic featurer and the geographio roloeica, events conducivo to pollution,

Dest AvaiIab U

REF'ERENCES

1, A I I I AIN I" lllI SEIIV KllVI,, "A n Ar'irto rpfev"t I"htK Sft.dy for th o stwe fig tit Undi Nd SItae A,,.'~u,L. T"r 71..~i M O-Novetohsn 1951.

2 t1AS1' WEA11,31 NI' SATION, L ANGLE Fl'lIELD.1, V1IIU1NIA, "3tindi4.toR~ Lftttreoattw ~ 4~,J.~,

3. 1111:111,Y, iaI-6-Ni~ k'i ANI) Il. WEN11-,I. II 'l, llWSON, A tMt'qpAeut' Diff~e (ON ' 8Na a I., Mh whore, ,I ';J~.. -4 Up

fe4 Nel.&R4i" InMI, 2, INt :, ppl 314306, Ju1no 1%;31.

4 (:IIAMOI~ILAIN, A, C., "AmpsrI vf Twrltt ontd I)uPOAoalen of Aotrosl arnd Vaoptata (lumde." 04aio AKO-OvTw*an44i

5,CHAMIEI1, IIAIIIIISON li., "Enxmtain lgiiaitneo of Aommopw~ic fldepopsai cnapeey,o.tam#4A#^m wLwiA.J x~,& at..~4g4.~ ~jtwi?,Vol, 20, %r~, 3, Juine 1959.

6. tDoMAIMfAIS, (4. A., "Wlokbook in A imoppho.r biffusiom Calcutoliona"iv, S. 44oni So#t" &mem44raA.,i V-49006. 61Is. FIsriny 19

7. JISTOQUK,. MAHlIAO 17- "Veniufq of 1101 cases throush ~'40gpprouar. MsersionA." TA !~A"A" rw1*6 N., a, re

i. UlFV0Oill), Ill., r, A., 11 lmaspherr Dsolgin (OCalclation Using the Cenepaliged (,amo Plume Afsihod,' %1afe-A,

&4iq Vol. 1, No. 3, Mc.rh 1960.

9. WITIDINI, M11., F. A,. "AlmoapherpIiap 9d 4#.i4 , Vol, 2. No. 2, l)comlxoe 1%60,

10. GIP110'OiU), JIl, F, A., "Uce, of Roti~ne ,Yeleaorlosiral Obaeorvoidaio for 8101111011 Atmos~pheric MM~fiaprO4," 71M4L44

84igiv. Vol. 2, No. 'I, Jimso 1961.

111. .1111.50,11, WILLIAM F., AND MIANK A. UFIPPXID,.Jt, "CropkA !rip Essiatintau rAmnoePAao Dpr;vX~t oF4e411, V'AO-41. July 1%62,

12. 46Al)I, P. J., *'.eolvmloxi tit Axpeov o0f 1e POOV01e ft it of . o~u e~,"T.L~.e~.* I.n33 p. 1960.

13, PASQULL, P,. "rho 8stimnid1on of the Dde pe@ele i of lFind~imfos Moteriot, %*i~wd.,i4e4 YAOtio Vol, 90, W. 33.9,

14 PA-SQUILL, F., I'Aamoapharf- D11foinio ," Londtm: D,1 Van Nahitrind Coqmpny Lid. 1962.

15. IIANZ, W. E, AND' 1, .It OINSIDNIE, "Some .4spoemof th, Physical Rehoaiar of 4.eORod '.raidele d', 14o AtinoophereTPa.ui" 44no Ina~ 71.u.sm (il, PfTMLU..A 35 P. 1952,

16. 11MIllC"~~O, 1-4. U., "Aerodynamic~ Copturp of Portiddn.," Loodoai: Perarmne" IPrt.X11, 1960.

17. SI.AlA-, DAVID) If., "Climusolep., of Selected Ha borN, " 111. 4'".vlt-1 T.J-*A& SwuA, 11. A. 0-saA' 18,040MApril 1961

18, SIAI)I., l.AVID If., "A (e,,erol Po)rea'ptoni of Atmospheric Rf,.oni t OR hey A'Weir ther Piffuuiinn of Pd~av,~.~.isil. TU4444. Off~I* 4 %44.64201t,? R.A.. .. !L1J40" 1962.

11), STER~IN, AWl1flHlI C_, "4ir Pol',,tiojn, 'New York- Ar'arlemic Prenn l%;2,

2.SU110mN, 0. (1., "Tho Atome fomih Trini on an periwient in Gonveeion,'' INtemig. Vol. 2. pp. 105-110. 1Q447.

21 srrroN, 0 i,"Note (in 'E~ntrain.ment and the AMarimum H~eight of on Atsomic, C.louobY 1.eaer vnioa," ~ 4tA.

~ Vol. 31, pp 217-218. 1950,

AN

REFERENCES (CONTINUED)

22, SUrr1i0i, 0. 0.,. wm~rnJ' New Yntk Metniw Hill1 f3ack Cm"1pony, Ism. 19,'J,

23. U. S. ATOMIC RNHIIUY COMMM5ION. "me tovrtoo fin d A 1"Pi ife,~ y"(~ 10 . 16ii p. July 1955ý

24. U. i, ATOMIC FNIEI4Y M~MMISSION, "TA ireIlvel Poo~bildldiea and Comoequomess of iofeap Avoldinas in borj~to Na.clear Power Plants." lt&A To, 105 p. Mamh 1037,

25, 1U. M. ATOMIC; ENERGHY (MMMUMION, "Neiv~ MvpcAenEhil ReaviaorFinal Satesuarda Repopi jrodponenwl efqolyx~of N8 ',qvsmnnA' Operwitiin at Gadn" %L40616wat~u. Wo m, 4 (A.) 120 p. January 1961,

26. U. S. DEPAnrrm1NTo OF 13hVENSt', "Filogfferix of Nuerlar Dep~"nhno.DC. UnltedtsI.IM Alomke Entr'rgyCrAIm.lon. April 1Q62,

27. U. S. NAVY I'LlPIXT YdHAMMKI FACILITY, NOMIXOU VIRGINIA,'"A Cl imtlug of ~t he Vieirtiai ropom Op.erauila

28. U. &. NAVY MawrP. WIHATIIK IrACILITY, NORFOLK, VIRGINIA, HFrese' andborde for Norfolk. Pilaa theTldewalop Area and the Virolina Capes Operating Area-" 1959.

29. U. S. NAVY WEAThIER RESEARCH FACILITY, "Climatology amd Low.Ln'vo Ali, Pollklion, Potential from SAIPA inSon Diego Haerb.," NWRF 39-0462-056, 94 p. April 1962..

30. U. &. WiFAnIIRI1 IBUREAU. "Pdeieorolosleal Noolmatie for Newport Newo, 80ino01144&~ CPn#e44 ,Is%*A.4.94jjj 1"o"4 , 10 p. Jun" 1958.

31. U, S, W1EA7lIEf DI3UHAU, "Mvie'otolo~ivul Analysie Applicable so Oporattio of a Nuclear Power.cd Viao. 1" Mf4.44%a4&"aa4+(id %*&".~.. Rep duoed Copy. 92 p. floe, Fabruary 1960.

32. U. S. WEA'TI11rr BUREAU, "Local Climnatology' lanmmay with Cornpaeoaive Data." Norfolk, Virsinia. i962,

33. VAN DER HOVIWN. ISSAC, "A Difflamicn.Das Id..:i Model f& PanicuoaJ.e Iffluent fram m Cround.Tweed Nuclear En-

34, WILLIAM, B. B.. "Crii~ngi ftelow 1,01"O fet. and Ptimailiaeie Below mile. al tenmitee Air Force Ra,4h4ef sFavJntu L( .19a.. . AD 131682. ApH~ 1195

APPENDIX • EXAMPLE OP DIFFUSION CALCULATION USING THE GIPFORD MODIFICATi?OF THE PASQUILL FORMULA

i. rho 0ifford Modification of the Pnequitl for- urmning gruund-level roluase ruduceri to:mula is: Q___

w " A'" = \/ (I(

@incr the y and the A in tha oxponcntial terrAwhere Q total unitp of pollutant rileamod equal zart), thereby making the oxponv.ntinl

term equal to one (W' - $))e ground-level total integrated dos-

age In units-eeconds per cubic Thus: • 200,000meter "1 (3)

T a average wind speed in meters persecond From table 1.1, a mummer afternoon with clear

skies results in a condition of strong ineola-A • height of the source above the tion. A combination of strong insolation and a

ground in meters wind speed of 4 meters per second yields imeteorological category of type n (moderntely

Y • lateral (crosswind) distance from unstable condition).the plume axis in meters

Entering figure 1,0 at the intersection of mete-a a horisontal diffusion coefficient in orological category A and an axial di;tone, o(f

meters I kilometer (the distance at which the doanagvalue is desired) we find:

61£ vertical diffusion coefficient inmeters Or a 1.0 x 101 motors.

2. Figures 1, Band 1.7 and table 1.1 reproduced Similarly, entering figure 1.7 we find!here, and located on pages 6 and 7, are usedto calculate of and e, e 1,1 x 101 meters,

3. Example - Let us determine the axial (along Inserting theme values for a, and o, Intoeqtsa-the direction of the wind) total integrated tion (3) we have:dosage a person would bo subjected to at adistance of I kilometer (10' meters) using 200,000the following assumptions: (W) (1, 6x 10' ) (1. I X 101 ) (4)

(a) A summer afternoon with clear skies. .092 units-seconds per cubicmeter.

(b) n wind speed of 4 meters per aecond.Thus, at a distance of 1 kilometer, a person

(W) a release of 200,000 units of pollutant, would recieve a dosage of .002 units-secondsper cubic meter for a ground pollutant relese

(d) a release occurring at ground level, of 200,000 units, on a clear nummer afternoonwith R wind spcod of 4 meterA per recond ( • .9

'['hr difrufion equation for, nxial doango n%- knots).

A-I

• op

I~. ... .. r. . r~ fir

IIfjf~l Ol

Of S LIGHTLY US aD E

x~~E SLITANCY SROMAOBLE

0 2 8 103 2 5 -

X~~dc DIqSTANCE FRMSO~

t'I,

lot____~. 1~.

INIX-if- DISTANC IRM~RE(eeS

Bost~~ Avafik~ Cp

I - ~ ni~ht)(4 ffvrotbO

2 (p4)ii ii

(*1) U A-j

:~~ ~ V12 C ) j

iI,. 'Obrifvtey UnAlubte conditi~mm R.- Slightly ,olbir' rondifinns

GX Sl~igdy ionviubje' ccrnditimci P: Aioderf'ymdvqJiaift cond~i~ot

d -iti 0hI. N4'uu !W lrIdo.O.. t v,0lm (W~iA N), U I. i I ti N 17 1h et.) Vtruwvor~i 13 11, U t, m(7A vprrnmuIPII~II.,W'1"11;t, Ibt¶' Jluy 1260.1

I"ý h.1Y "Vowai, Aduy or nmh'.iI It 1iaIII1,ij to ON%~ than 1,000 10M

N~O-e V' A-11 Wk-. th. '1y.,ru e alovuput -i A mi~d Do via.,

PA ~ u 41:uu4e (j:'

(f :160C trn

35 " - C d~ 160oe~at

150 < .5Sih

iPuytirne. (;l'td Cover Effect on frmduJtioJf

i. if i "i,lif)x ob r irm~x, no cmp

If icinsd.i swrv than I/M'(3

6. j , iri of 1!!:.1 brlnw 16~,000)f, 1 A,~ , .4 ,a It, UIi' w , C toi 1),

f. ding -I(,~ r o'r, ornd ov c'NrI. (if.rj iy), chvnge: .4 lo N BI toJ C. C 140 1).

-A-1

Bes~t Avaitab'i . Copy

fee

OiIcIcP

Best IVwiI

zP1

41 iI0 QjA Zi ii Lo ..

I~ ~ VI

UIJ ~Al

p ~ ~o