The main moisture flux sources in SAMS and evolution

of the system

Iracema F.A.CavalcantiDaniel R. Andres

Adma RaiaSilvio Nilo

Henrique Barbosa

CPTEC/INPE

Models and simulations

• AGCM CPTEC/COLA T62L28 (~200 km)• 10 years simulation (1982-1991)

• 50 years simulation (using 1980-2002)

• Eta Regional Model (40 km)• DJF simulation (1996-2000)

CPTEC/COLA AGCM

MODEL VERTICALLY INTEGRATED MOISTURE FLUX

NCEP REANALYSIS

NCEP VERTICALLY INTEGRATED MOISTURE FLUX

REGIONAL ETA MODEL

1996 to 2000 DJF SIMULATION

Eta Regional Model 40 km

Downscale from CPTEC/COLA AGCM

MOISTURE FLUX

Moisture flux

precipitation

INTERANNUAL CHANGES

EL NINO CPTEC/COLA AGCM

LA NINA CPTEC/COLA AGCM

EL NINO 82/83- LA NINA 88/89 CPTEC/COLA AGCM

Eta Regional Model

DIURNAL CHANGE

PRECIPITATION DIURNAL CYCLE

00 GMT

06 GMT 12 GMT

18 GMT

DJF

WIND FLOW AT 850 hPa

00 GMT

06 GMT 12 GMT

18 GMT

DJF

ETA MODEL

Submonthly monsoon variabilityZCASLLJ

Dependence on the low level flow

IMPROVEMENTS IN THE MODELS

DJF 10 YEARS AVERAGE GRELL ENSEMBLE CONVECTION SCHEME MCGA CPTE/COLA

MONTHLY AND SEASONAL CHANGES

• MONTHLY CHANGES OF MOISTURE FLUX : LARGE DIFFERENCES IN DJF AND JJA.

• MOISTURE FLUX FROM NORTH AND SOUTH ATLANTIC OCEAN TO THE AMAZON REGION AND THEN TO CENTRAL AND SOUTHEAST BRAZIL AND FROM SOUTH ATLANTIC DIRECTLY TO SE, IN DJF.

• IN JJA THE MOISTURE FLUX IS DIRECTED FROM ATLANTIC OCEAN TO NORTHWEST S.A.

CHANGES IN MOISTURE FLUX /WIND FLOW AT LOW LEVELS

• DIURNAL SCALE• SUBMONTHLY SCALE• SEASONAL SCALE• INTERANNUAL SCALE• INTRASEASONAL SCALE ?

ACKNOWLEDGEMENTS

VAMOS/CLIVAR, JOSS/UCAR