Meteorology for Airborne Scientists
-
Upload
jpeterson1 -
Category
Documents
-
view
219 -
download
0
Transcript of Meteorology for Airborne Scientists
-
8/9/2019 Meteorology for Airborne Scientists
1/59
Meteorology for
Airborne Scien1sts
Henry Fuelberg
Department of MeteorologyFlorida State University
-
8/9/2019 Meteorology for Airborne Scientists
2/59
Avia1on Related Parameters
to Forecast
Cloud Cover and Fog Precipita1on WindsSurface and Alo
Temperature
Humidity
-
8/9/2019 Meteorology for Airborne Scientists
3/59
FirstA Few Basics
P = RT
-
8/9/2019 Meteorology for Airborne Scientists
4/59
Atmospheric Pressure
Pressure = Force/Area
Decreases with al1tude
Pascal = Newton m2
millibar (mb) =
hectoPascal (hPa)
Mean sea level pressure =
03.25 mb (or hPa)
-
8/9/2019 Meteorology for Airborne Scientists
5/59
Dry Adiaba1c Process
st Law dh = cv dT + p d OR dh = cp dT dp Consider an unsaturated parcel, let dq = 0 0 = cp dT dp Parcels s1ll can change temperature due to expansion
and contrac1on Exampleparcel expands, expends energy, T gets cooler Make subs1tu1ons and solve for dT/dz dT/dz = g/cp = 9.8 oC/km = d (dry adiaba1c lapse rate) d is posi1ve if T decreases with height, nega1ve forinversions Unsat. parcels always follow d Away from clouds and radia1ve processes, parcels
~ adiaba1c for several days
-
8/9/2019 Meteorology for Airborne Scientists
6/59
Rising air cools, Subsiding air warms
-
8/9/2019 Meteorology for Airborne Scientists
7/59
Poten1al Temperature ()Have a parcel at T and p
is temp. parcel would have if taken dry
adiaba1cally to p = 000 mb
If p = 000 mb, = T
= T (000 mb/ p) R/cp R/cp = 0.286
Parcels conserve during ascent, descent, etc. as
long as condi1ons are adiaba1cT is not conserved, it changes at d
Therefore, can serve as a tracer for parcels
-
8/9/2019 Meteorology for Airborne Scientists
8/59
Water Vapor
Vapor pressure = par1al pressure of vapor (mb) Mixing ra1o = mass vapor/mass dry air (g/kg) Concept of satura1on Dew point temperature = temp to which air must
be cooled to become saturated (oC)
Rela1ve humidity = mixing ra1o / sat. mixing ra1o( how chose to sat. is parcel?)
-
8/9/2019 Meteorology for Airborne Scientists
9/59
Saturated Adiaba1c Process
Parcel is saturated Li parcel, condensa1on occurs, latent heat
released, dq 0
dq = cp dT dp Let dq = latent heat release Perform some magic, get a complicated equa1on s d not a constant, depends on how muchvapor is in the air s 6 oC/km
-
8/9/2019 Meteorology for Airborne Scientists
10/59
-
8/9/2019 Meteorology for Airborne Scientists
11/59
Radiosondes
-
8/9/2019 Meteorology for Airborne Scientists
12/59
-
8/9/2019 Meteorology for Airborne Scientists
13/59
Hydrosta1c Stability
Displace parcel upward (could go downward)
Will displacement be
Suppressed = Stable
Layered clouds, steady precipita1on
Enhanced = Unstable
Towering clouds, showers or Tstorms
Neither = NeutralParcel moves only to where pushed
-
8/9/2019 Meteorology for Airborne Scientists
14/59
-
8/9/2019 Meteorology for Airborne Scientists
15/59
Absolute Instability
Environ. Lapse Rate greater than Dry Adiaba1c Rate (> 0 deg/km)
-
8/9/2019 Meteorology for Airborne Scientists
16/59
Condi1onal Instability
Environmental Lapse Rate between the Dry and Wet
Adiaba1c Rates (between 60 deg/km)
-
8/9/2019 Meteorology for Airborne Scientists
17/59
What Causes Wind to Blow ??
It is acted on by forcesmostof which we cant see
-
8/9/2019 Meteorology for Airborne Scientists
18/59
Straight IsobarsAbove Surface
Isobars
-
8/9/2019 Meteorology for Airborne Scientists
19/59
Flow Around Circular Low
Include Centripetal Accelera1on
-
8/9/2019 Meteorology for Airborne Scientists
20/59
Flow Around Circular High
Include Centripetal Accelera1on
-
8/9/2019 Meteorology for Airborne Scientists
21/59
Upper Level Charts
Pressure is Ver1cal Coordinate (Not Z)
-
8/9/2019 Meteorology for Airborne Scientists
22/59
500 mb Chart 8,000 or 5.5 km
Height Contours Replace Isobars
-
8/9/2019 Meteorology for Airborne Scientists
23/59
Surface MapIsobars = Lines of constant pressure
-
8/9/2019 Meteorology for Airborne Scientists
24/59
Straight IsobarsNear Surface
-
8/9/2019 Meteorology for Airborne Scientists
25/59
Planetary Boundary Layer (PBL) Lowest layer of atmosdirectly influenced by thesurface PBL vs. Free Atmosphere What happens in PBL? Air is heated/cooled from belowradia1on Inversions (stable) at nightsuppress mixing Big lapse rate during dayless stablelots of mixing
Mechanical Turbulenceroughness (day or night) Thermal Turbulencethermals (day) You can bounce around a lot!!
-
8/9/2019 Meteorology for Airborne Scientists
26/59
Wind Speed goes to zero at surface (no slip) Speed increases with height according to Ekman
Theorydirec1on also changes The more mixing the more is constant with height the more mixing ra1o constant with height Height of PBL deep during day, shallow at night Depth determined by
TemperatureWind SpeedOthers
-
8/9/2019 Meteorology for Airborne Scientists
27/59
-
8/9/2019 Meteorology for Airborne Scientists
28/59
-
8/9/2019 Meteorology for Airborne Scientists
29/59
Marine Layer
Strong subsidence due to high pressure
Warm, dry sinking air
Cool moist air
Cold water
T inversion
-
8/9/2019 Meteorology for Airborne Scientists
30/59
Weaker High Pressure
Clouds near top of marine layer
-
8/9/2019 Meteorology for Airborne Scientists
31/59
Low pressure allows marine layer to
deepen as much as 6,000 .
-
8/9/2019 Meteorology for Airborne Scientists
32/59
Smaller Scale Circula1ons
Are Superimposed onLarger Scale Flow
-
8/9/2019 Meteorology for Airborne Scientists
33/59
Sea/Land Breezes
-
8/9/2019 Meteorology for Airborne Scientists
34/59
Mountain/Valley Breezes
-
8/9/2019 Meteorology for Airborne Scientists
35/59
-
8/9/2019 Meteorology for Airborne Scientists
36/59
Clouds
Most clouds are due to rising air
All precipita1on is due to rising air
-
8/9/2019 Meteorology for Airborne Scientists
37/59
0 Basic Cloud Types
-
8/9/2019 Meteorology for Airborne Scientists
38/59
FOG
. Cooling air to satura1on
2. Increasing Water Vapor
content to reach satura1on
-
8/9/2019 Meteorology for Airborne Scientists
39/59
Radia1on Fog
-
8/9/2019 Meteorology for Airborne Scientists
40/59
-
8/9/2019 Meteorology for Airborne Scientists
41/59
History or Future of Air
Trajectories
Backward in 1mewhere did air come from?
What path did it take?
Forward in 1mewhere is air going to?What path will it take?
Kinema1c methodmove parcels using
threedimensional winds
-
8/9/2019 Meteorology for Airborne Scientists
42/59
WRF Nested Grid 45 km, 5 km, 5 km
-
8/9/2019 Meteorology for Airborne Scientists
43/59
Procedure for Forward Trajectories
Start with 4D grid of 3D wind componentshope dataevery few hours
Move parcel one 1me step by these winds
Now at a new 3D loca1on and a new 1me
Take winds at new loca1on and 1me and move parcelanother 1me step Repeat the process un1l you reach desired ending 1me Limit is usually 50 days
Aer that uncertain1es are too great If backward trajectories, process goes in reverse
-
8/9/2019 Meteorology for Airborne Scientists
44/59
-
8/9/2019 Meteorology for Airborne Scientists
45/59
-
8/9/2019 Meteorology for Airborne Scientists
46/59
Par1cle Dispersion Models
Establish loca1ons of emissions and rates of emissionRelease par1cles to simulate emission ratePar1cles have specified mass and are released at
specified rate
Threedimensional winds move the par1clesCan then watch the transport of the emissions
-
8/9/2019 Meteorology for Airborne Scientists
47/59
Fire loca1ons July 2008
-
8/9/2019 Meteorology for Airborne Scientists
48/59
-
8/9/2019 Meteorology for Airborne Scientists
49/59
Sources of Real Time Informa1on
Surface
RadiosondesSatellite
Radar
hp://www.rap.ucar.edu/weather/
-
8/9/2019 Meteorology for Airborne Scientists
50/59
Surface Plot
-
8/9/2019 Meteorology for Airborne Scientists
51/59
-
8/9/2019 Meteorology for Airborne Scientists
52/59
GOESYesterday PM
-
8/9/2019 Meteorology for Airborne Scientists
53/59
Edwards AFB Sounding
-
8/9/2019 Meteorology for Airborne Scientists
54/59
-
8/9/2019 Meteorology for Airborne Scientists
55/59
Forecast Products
All types of input data combined (assimilated) toproduce best 3D ini1al condi1ons for model
Models iterate forward in 1me
Various groups run models NWS, USAF, Navy,Europeans, etc.
Model forecast surface and alo at each itera1on Different models give different solu1ons Meteorologist decides on the most likely forecast
-
8/9/2019 Meteorology for Airborne Scientists
56/59
Your Local NWS Office
hp://www.srh.noaa.gov
-
8/9/2019 Meteorology for Airborne Scientists
57/59
Other Interes1ng Sites
Storm Predic1on Center
hp://www.spc.noaa.gov
Na1onal Hurricane Center
hp://www.nhc.noaa.gov
-
8/9/2019 Meteorology for Airborne Scientists
58/59
NWS Forecast for Palmdale
Friday Night: Clear, with a low around 6.Breezy, with a southwest wind 20 to 25 mph
decreasing to between 0 and 5 mph. Winds
could gust as high as 30 mph.
Saturday: Sunny, with a high near 94.
Southwest wind around 0 mph.
Saturday Night: Clear, with a low around 63.
Southwest wind between 0 and 5 mph, withgusts as high as 25 mph.
Sunday: Sunny and hot, with a high near 98.
Sunday Night: Clear, with a low around 63.
Monday: Sunny, with a high near 95
Monday Night: Clear, with a low around 60.
Tuesday: Sunny, with a high near 94.Tuesday Night: Clear, with a low around 59.
Wednesday: Sunny, with a high near 94.
Wednesday Night: Clear, with a low around 59.
Thursday: Sunny, with a high near 94.
-
8/9/2019 Meteorology for Airborne Scientists
59/59
Santa Barbara Channel