LBA/Physical Climate

Moist Convection in the Amazon

Things models should do that LBA data has pointed out

• easterlies/westerlies and convection

• land features effects on convection– forest vs non-forest– topography– river vs land

Rondônia 1999 850 hPa zonal wind - CPTEC

Santarém 1999 850 hPa zonal wind - CPTEC

Manaus 1999 850 hPa zonal wind - CPTEC

Summers of 1980 to 1999

Carvalho et al , 2002

Summers of 1980 to 1999

Carvalho et al , 2002

Blakeslee, 2000

Petersen, 2000

Blakeslee,2000

Rickenbach et al. 2000

Tokai, 2000

Anagnostou & Morales, 2002

Hourly rainfall rate

from TOGA radar

Hourly average

cloud fraction

GOES

TOGA

6:20 7:20 8:20 9:20 10:20 11:20 12:20

Local Time

Time of first radar echoes

S-Pol Jan/Feb 1999

easterlies

westerlies

0,0

20,0

40,0

60,0

80,0

100,0

Forest Forest

Interface

Pasture

Interface

Pasture

Vegetation at Location of Convection InitiationWet Season - All Cases

TOGA

SPOL

0,0

20,0

40,0

60,0

80,0

100,0

< 95 100 - 295 300 - 495 500 - 695 > 700

Altitude (m)

Altitude at Location of Convection Initiation

Wet Season - All Cases

TOGA

SPOL0,0

20,0

40,060,0

80,0Fr

eque

ncy

(%)

Forest -

Below

Average

Forest -

Above

Average

Pasture -

Below

Average

Pasture -

Above

Average

Vegetation Altitude at Location of Convection Initiation

Wet Season - All Cases

TOGA

SPOL

Pereira et al 2000

TRMM-LBA Region: Forest vs. Non-Forest

SPOL

Profiler

TOGAFOREST

NON-FOREST

Carey et al 2001

TRMM-LBA Region: Topography

“Elevated”>= 223 m

“Non-Elevated”< 223 m

Carey et al 2001

0.001

0.01

0.1

1

10

100

0 10 20 30 40 50 60 70 80 90 100 110 120

Rain Rate Bin (mm h -1)

Fre

qu

en

cy

(%

)

Forested

Non Forested

Category Unconditional Rain Rate mm h-1)

Conditional Rain Rate (mm h-1)

Forested 0.2612 1.834

Non-Forested 0.2436 1.517

Relative Difference

(F-NF)/[(F+NF)/2]

+ 7 % + 19 %

Effects of Deforestation on Rain Rate Statistics

Carey et al 2001

Category Ru (mm h-1) Rc (mm h-1) Fractional Grid Coverage (%)

ALL 0.2535 1.716 100

NE 0.2461 1.507 48.7

E 0.2664 2.004 2 51.3

NF 0.2436 1.517 29.2

F 0.2612 1.834 3

70.8

NF NE 0.2402 1.400 17.6

NF E 0.2504 1.739 4 11.6

F NE 0.2519 1.588 31.1

F E 0.2721 2.097 1

39.7

Ru = Unconditional Mean Rain RateRc = Conditional Mean Rain RateNE = Non Elevated (< 223 m)

E = Elevated ( 223 m)F = ForestedNF = Non Forested

Fractional Rain Duration = % of grid boxes for land type category with rain (R > 0)

Fractional Grid Coverage = % of all grid boxes for land type category

KEY:

TRMM-LBA: Effect of land type on rainfall statistics

Carey et al 2001

Carey et al 2001

Category February 1999 Mean Rain Depth (mm)

Forested 198.5

Non-Forested 183.1

Relative Difference

(F-NF)/[(F+NF)/2]

8 %

TRMM-LBA: SPOL Derived Rain Depth (mm)February 1999

0

1

2

3

4

5

6

7

8

9

10

5 25 45 65 85 105

125

145

165

185

205

225

245

265

285

305

325

345

365

385

mor

e

Rain Depth Bin (mm)

Fra

cti

on

of

Gri

d C

ells

(%

) Forested

Non-Forested

Effects of Deforestation on Cumulative Rain Depth

Carey et al 2001

Category February 1999 Mean Rain Depth (mm)

ALL 194.0

NE 181.0

E 206.4

NF 183.1

F 198.5

NF NE 176.2

NF E 193.6

F NE 183.7

F E 210.7

Land Effects on Rain Depth

Carey et al 2001

TRMM-LBA: S-POL Derived Rain Depth (mm)February 1999

0

1

2

3

4

5

6

7

8

9

10

Rain Depth Bin (mm)

Fra

cti

on

of

Gri

d C

ell

s (

%)

Elevated

Non-Elevated

Effects of Elevation on Rain Depth

Carey et al 2001

0

2

4

6

8

10

12

5 25

45

65

85

10

5

12

5

14

5

16

5

18

5

20

5

22

5

24

5

26

5

28

5

30

5

32

5

34

5

36

5

38

5

mo

re

Rain Depth Bin (mm)F

rac

tio

n o

f G

rid

Ce

lls

(%

)

F E

NF E

0

2

4

6

8

10

12

5

25

45

65

85

10

5

12

5

14

5

16

5

18

5

20

5

22

5

24

5

26

5

28

5

30

5

32

5

34

5

36

5

38

5

mo

re

Rain Depth Bin (mm)

Fra

ctio

n o

f G

rid

Cel

ls (

%)

F NE

NF NE

Elevated Only

Non-Elevated Only

ForestedNon-Forested

ForestedNon-Forested

Carey et al 2001

29,0

29,5

30,0

30,5

31,0

31,5

32,0

08:00 11:00 14:00 17:00

Local time (hours)

Wa

ter

tem

pe

ratu

re (

de

g.C

)

0.1m

0.3 m

0.7 m

1.0 m

c

23 July 2001 Tapajós

(from Pindobal to Boim and back)

26

27

28

29

30

31

32

10:00 10:30 11:00 11:30 12:00

Local time (hours)W

ate

r te

mp

era

ture

(d

eg

.C)

0.1m

0.3 m

0.7 m

1.0 m

28 July 2001 Tapajós & Amazonas

(red line: temperature where the two rivers merge)

-4,0

-2,0

0,0

2,0

4,0

0 6 12 18 24

UTC (for Local time subtract 4 hrs)

U (

m/s

)

24 u

26 u

27 u

28 u

29 u

30 u

31 u

1 u

-4,0

-2,0

0,0

2,0

4,0

0 4 8 12 16 20 24

UTC

v (

m/s

)

24 v

26 v

27 v

28 v

29 v

30 v

31 v

1 v

AWS Jamaraquá

24 July / 1 August 2001

West

East

South

North

Winds at Belterra

radiosonde

Pressure (mb)

Winds and potential temperature

Belterra radiosonde

Wind vector 23 M ABOVE THE SURFACE

wind – streamlines perpendicular to the Tapajós river

Potencial temperature

Model improvements based on LBA data

• USP - RAMS reanalysis - changes in cumulus parameterization

CPTECTHERMODYNAMIM STRUCTURE OF CONVECTIVE ACTIVITY AT WET-AMC/LBA

SITES AND ETA MODEL VALIDATION

Jorge Gomes, Sin Chan Chou and Gilberto Fisch

Deep convection characteristic parameters from soundings over Rondonia AMC-LBA sites were evaluated and compared with Eta model forecasts. Radiosondes were interpolated to 5hPa regular intervals. The model diurnal cycle captured correctly the observed amplitude and timing. Thermodynamic variables such as CAPE, cloud base and top, cloud lapse rate, deficit from saturation pressure, etc. were calculated from observations and model hourly profile outputs. The model adjusts the convective environment toward a drier profile below the freezing level and toward a moister profile in the levels above. The new parameters derived from the observations were input to the model which produced a reasonable forecast over most part of Brazil. Equitable Threat Score showed significant improvement of precipitation forecasts over most of the domains using new set of parameter, however, the model show little change over the Tropical forest region

Model improvements based on LBA data

CPTEC

SIMULATIONS WITH A RADIATION MODEL AND COMPARISONS WITH LBA DATA SETS

Sergio H. Franchito, E. C. Moraes and V. Brahmananda Rao

The LBA data are used to estimate and validate infrared and solar radiation

models calculations of Chou and Suarez. The models are tested for two

contrasting vegetation regions: forest and grassland. Observed data of

several days and different times of a day collected in the two sites are

used to test the models. The results show that the models simulations in

general agree well with the observations for both the forest and grassland

cases. The mean errors are around the same order or lower than the instrument

errors, except in the case of the reflected solar radiation. The radiation

fluxes are strongly correlated with the observed data, significant at 99%

confidence level, except in the case of the downward longwave radiation.

Model improvements based on LBA data

NASA - DAO

THE MOISTURE BUDGET BI-MODAL PATTERN OF THE SUMMER CIRCULATION OVER SOUTH AMERICA

Dirceu Herdies, Arlindo da Silva, Maria A. F. Silva Dias

The LBA observations during january-february 1999 campaing were

divided into South Atlantic Convergence Zone (SACZ) events and

non-SACZ events. These data were used to validate the DAO/NASA

Global Model analyses. The moisture budget over South America

showed that the moisture transport from tropics to extratropics

is more efficient during SACZ than during Low Level Jet events.

Model improvements based on LBA data