PRECIPITATION ANOMALIES OVER SOUTH AMERICA IN THE SUMMER SEASON IN SCENARIOS OF CLIMATE CHANGE Iracema Fonseca de Albuquerque Cavalcanti CENTRO DE PREVISÃO DE TEMPO E ESTUDOS CLIMÁTICOS INSTITUTO NACIONAL DE PESQUISAS ESPACIAIS COLD AIR OUTBREAKS OVER SOUTHEASTERN SOUTH AMERICA IN THE WINTER SEASON IN SCENARIOS OF CLIMATE CHANGE Gabriela Müller Kelen Andrade Iracema FA Cavalcanti

ANOMALOUS PRECIPITATION OVER SOUTH AMERICA NATURAL CLIMATE VARIABILITY ENSO CONDITIONS (EL NINO / LA NINA) TELECONNECTIONS INTRASEASONAL OSCILLATION BEHAVIOUR OF SYNOPTIC SYSTEMS BLOCKING SITUATIONS ETC

DROUGHT IN 2005 DROUGHT IN 2000/2001 DROUGHT IN 1997/1998

THE QUESTION IS: WILL THE ANOMALIES CHANGE IN SCENARIOS OF CLIMATE CHANGE OVER SOUTH AMERICA? HOW THE INTENSITY OF NATURAL VARIABILITY CAN CHANGE IN THE FUTURE? MODELS

CPTEC/COLA AGCM DJF PRECIPITATION CMAP/CAMS

Extreme wet years composite Extreme dry years composite SOUTHEASTERN BRAZIL (50W-40W; 15-25S)

Extreme wet years compositeExtreme dry years composite

IPCC-4 MODEL SIMULATIONS 20 CENTURY SRES A2 PRE-INDUSTRIAL 1% CO2 INCREASE MODELS HADLEY HADCM3 GFDL HADGEN MRI ECHAM CANADIAN

Increase from CO2= ppm at 1% /year rate to doubling, then constant to year 280. Other gases cte from % CO2 EXPERIMENT 20TH CENTURY EXPERIMENT Considers all anthropogenic forcings during the period of 1860 to 2000 (140 years) EXPERIMENTS SRES A2 High degree of global economic development (means high concentration of greenhouse gases) ( ) Forcings agents representative of 1860 conditions constant. Include all greenhouses gases (280 years) PRE-INDUSTRIAL EXPERIMENT

PERIODS OF ANALYSIS LAST 51 YEARS FROM EACH SIMULATION DJF (S.H. SUMMER) 20 CENTURY : SRES A2: OR

20 CENTURY DJF 1979/1980 TO 1999/2000 GFDL MRI HADCM3 OBSERVED PRECIPITATION MODELS SIMULATIONS

HADGENECHAM OBSERVED PRECIPITATION CANADIAN MODELS SIMULATIONS

Difference between two periods in the pre-industrial experiment (year 71 to 280)- (year 11 to 70). The changes are very small, consistent with the absence of anthropogenic forcings. PRE-INDUSTRIAL EXPERIMENT GFDL

The impact on precipitation is seen in the region of South Atlantic Convergence Zone and Southeastern South America considering the two experiments. DIFFERENCES BETWEEN 1%CO2 AND PRE-INDUSTRIAL EXPERIMENT GFDL DIFFERENCES BETWEEN 1%CO2 AND 20th century EXPERIMENTS GFDL ANNUAL GFDL

GFDL (USA) DIFFERENCES (FUTURE -20TH CENTURY) DJF 1%CO2SRES A2

HADCM3 (UK) DIFFERENCES (FUTURE -20TH CENTURY) 1%CO2SRES A2 DJF

GFDL 20 CENTURYLAST PERIOD 1% CO2 INCREASE 250 hPa 850 hPa

Difference between SRES A2 and 20th century wind flow HADLEY.

EXTREME MONTHLY PRECIPITATION ANOMALIES DJF Average of precipitation anomalies over several areas of South America 5 extreme years (+ and -) 20th century and SRES A2 Hadley and GFDL

W Amazonia E Amazonia N La Plata S La Plata AREAS

SE NE

GFDL

AMAZONIA WESTERN SECTOR 20th centuryA2 ANOMALIES RELATED TO THE CLIMATOLOGY OF 20TH CENTURY PRECIPITATION ANOMALIES EASTERN SECTOR GFDL

PRECIPITATION ANOMALIES (AMAZONIA)GFDL

LA PLATA NORTHERN SECTOR LA PLATA SOUTHERN SECTOR GFDL

PRECIPITATION ANOMALIES LA PLATA SOUTHERN SECTOR GFDL

NORTHEAST BRAZILGFDL

PRECIPITATION ANOMALIES NORTHEAST BRAZIL

SOUTHEAST (50W-40W; 15S-25S)

PRECIPITATION ANOMALIES SOUTHEAST BRAZIL

HADLEY

AMAZONIA WESTERN SECTOR EASTERN SECTOR 20th century A2 ANOMALIES

NORTHEAST BRAZIL

LA PLATA NORTHERN SECTOR LA PLATA SOUTHERN SECTOR

SOUTHEAST Brazil

HADLEY

20th century SRES A2 PRECIPITATION ANOMALY CORRELATIONS AREA 15S-25S; 40W-50W (SOUTHEAST) GFDL HADCM3

EXTREME PRECIPITATION ANOMALIES SOUTHEAST (50W-40W ; 15S-25S) 20th century GFDLHADCM3 GFDL HADCM3 NEGATIVE ANOMALIES POSITIVE ANOMALIES

EXTREME PRECIPITATION ANOMALIES SOUTHEAST (50W-40W; 15S-25S) SRES A2 GFDL HADCM3

COLD AIR OUTBREAKS OVER SOUTH AMERICA CNPq colaboration project Argentina, Uruguay, Brazil. Objective: Identify frequency and intensity of extreme cold air outbreaks in the present climate and in the future. Will the global warming affect the frequency and intensity of the cold air outbreaks?

TEMPERATURE CHANGES (annual) GFDL 1% CO2 increase – preindustrial 1% CO2 increase – 20 century

Frequency of cold air over Brazil, Argentina and Uruguay Daily data at (925hPa), 850 hPa SLP, meridional wind and Temperature Average over areas 52W-57W; 23S-28S (Brazil) 52W-57W; 28S-33S (Uruguay) 65-60W; 33-38S (Argentina)

criterium Temperature interval (0-2.5c, < 0c) Reduction of temperature (5-8c; 8-10c; >10c) Increase of SLP and southerly flow at 850hPa

ARGENTINA STATIONS OBS: TEMP. AT 2m Reanalysis: 850hPa

TEMP. 850 hPa c FUTURE 65-60W 33-38S Argentina

TEMP. 850 hPa < 0 c W 33-38S FUTURE Argentina

FUTURE TEMP. 850 hPa c 52W-57W 23S-28S Brazil

FUTURE Temp. 850 hPa <0 0 c 52W-57W 23S-28S Brazil

Next criterium Calculate anomalies and analyze the extremes in each area. Use SLP and meridional wind to get cases associated with frontal systems.

CONCLUSION

COMMON FEATURES IN THE MODELS INCREASE OF PRECIPITATION OVER NORTHWESTERN AND SOUTH/ SOUTHEASTERN SOUTH AMERICA. REDUCTION OF PRECIPITATION OVER SOUTHWESTERN SOUTH AMERICA. THERE IS AGREEMENT IN CHARACTERISTICS ASSOCIATED WITH EL NINO INFLUENCE IN SOME REGIONS

REGIONS WITH DIFERENT RESULTS IN DIFERENT MODELS SUGGEST UNCERTAINTY IN CHARACTERIZING THE FUTURE CLIMATE IN THESE REGIONS. AND THE NEED TO ANALYSE RESULTS OF OTHER MODELS. MULTI-MODEL ENSEMBLE

Extreme monthly anomalous precipitation intensifies in some regions Dipole patterns are reproduced in 20th century and future climate scenario Extremes are connected in some areas

Frequency of cold air cases Number of cold air outbreaks are better simulated by Hadley model (20th century) in two areas of South America. Frequency reduces in SRES A2 scenario (still analysing the intensity)

WORK IN PROGRESS IDENTIFICATION OF MECHANISMS ASSOCIATED WITH THE CHANGES. ANALYSIS OF MODEL PATTERNS ASSOCIATED WITH THE COLD AIR OUTBREAKS ANALYSIS OF DAILY PRECIPITATION AND TEMPERATURE DATA TO IDENTIFY EXTREMES ANALYSIS OF OTHER IPCC MODELS

ACKNOWLEDGEMENTS To CNPq for research support To CNPq/Prosul project To international modeling groups for providing their data for analysis, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) for collecting and archiving the model data, the JSC/CLIVAR Working Group on Coupled Modelling (WGCM) and their Coupled Model Intercomparison Project (CMIP) and Climate Simulation Panel for organizing the model data analysis activity, and the IPCC WG1 TSU for technical support. The IPCC Data Archive at Lawrence Livermore National Laboratory is supported by the Office of Science, U.S. Department of Energy.