Presentation on theme: "PRECIPITATION ANOMALIES OVER SOUTH AMERICA IN THE SUMMER SEASON IN SCENARIOS OF CLIMATE CHANGE Iracema Fonseca de Albuquerque Cavalcanti CENTRO DE PREVISÃO."— Presentation transcript:
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
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= 286.05 ppm at 1% /year rate to doubling, then constant to year 280. Other gases cte from 1860 1% 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) (2000-2100 ) 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 : 1949-1999 SRES A2: 2048- 2098 OR 2049-2099
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
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 0-2.5 0 c 1960-1990 FUTURE 65-60W 33-38S Argentina
TEMP. 850 hPa < 0 c 1960-1990 65-60W 33-38S FUTURE Argentina
FUTURE 1960-1990 TEMP. 850 hPa 0-2.5 0 c 52W-57W 23S-28S Brazil
FUTURE 1960-1990 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.
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.
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