Post on 30-Mar-2015
Air-Sea Interactions in the SAMS Region
Paulo NobreCPTEC/INPE
III Reunião de Análise e Previsão Climática do PMTCRH para o Nordeste do Brasil em 2005.
Recife, 17 de março de 2005.
SAMS CLIMATE VARIABILITY & CONVERGENCE ZONES
From: Grodsky and Carton (2002)
ITCZITCZ
SACZSACZ
SITCZSITCZ
Seasonal Precipitation Anomaly CorrelationCPTEC AGCM simulation and CAMS precip.
DJF MAM
From: Marengo et al. (2002)
Nordeste’s Rainfall PredictabilityNordeste’s Rainfall Predictability
personal com.L. MarxCOLA
800W 600W 400W 200W 00 200E
200N
00
200S
200N
00
200S
(B)
(A)
WET
ACOOLER SST
WARMER SST
ITCZ
A
The Atlantic ITCZThe Atlantic ITCZThe Atlantic ITCZThe Atlantic ITCZ
ITCZ
A
A
COOLER SST
WARMER SST
DRY
Adapted from: C. A. Nobre and L. C. B. Molion (1988)
MeridionalGradientSSTA
ATLANTIC ITCZ POSITION AND OLRANOMALY CORRELATION
MAM CPTEC AGCM T062L28ANOMALY CORRELATION
TAUY
RAINFALL
South Atlantic Convergence Zone & SSTA
Prescribed SST anomaly fields
COLD WARM
Nobre et al. (2002)
Nobre et al. (2002)
Nobre et al. (2002)
Chaves and Nobre (2004)
SST DIFFERENCES: OGCM EXPERIMENTS
Warm-Ctrl: Wind + SW
Cold-Ctrl: Wind + SW
CPTEC CGCM SISTEMATIC ERRORS
DFJ Precip Anomaly Correlation
AGCM SIMULATIONS
CGCM PREDICTIONS (October IC)
CPTEC CGCM – AGCM DFJ PRECIP ACOR
Observations: The PIRATA Array
R/V ANTARES
The PIRATA BACKBONE The PIRATA BACKBONE and the SW EXTENSIONand the SW EXTENSION
Background map: Mean No. of SST observations/month COADS 1961-90
(LAMEPE-2002)
(INMET-2004)
To be moored by July 2005.
PIRATA SWE & JASON/T-P ground tracks
ITCZ Sounding Experiment-2006
CTD Stations
SPSP
F. NoronhaFortaleza
Natal
Final Remarks
• Convergence zones represent important mechanisms modulating precipitation variability over South America.
• ITCZ: planetary scale, strongly modulated by SST: – Prediction of SSTA over the tropical (South) Atlantic.
• SACZ: Regional scale, coupled phenomena: – 1-Tear approach is a need.
• Needs: – Coupled model development (eastern basin St. deck),– Coupled data assimilation,– Ensemble prediction techniques, – Sustained ocean observation strategies (e.g. PIRATA)…