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Variability of the South America Monsoon System: The present Climate and projections for a global change scenario. Rodrigo J. Bombardi and Leila M. V. Carvalho University of Sao Paulo GEM-Group for Studies in Multi-Scales. OBJECTIVES.
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Variability of the South America Monsoon System: The present Climate and projections for a global change scenario Rodrigo J. Bombardi and Leila M. V. Carvalho University of Sao Paulo GEM-Group for Studies in Multi-Scales
OBJECTIVES Investigate the Onset, Duration and total precipitation during the SA Monsoon in coupled IPCC models Examine the performance of IPCC models in simulating SAMS in the 20th century climate and projections for future scenarios. Provide guidance on the use of IPCC models to force regional climate models “Garbage in – Garbage out” (Jeremy Pal)
Observations • Global Precipitation Climatology Project (merge satellite and Stations) Time- resolution: pentads Spatial Resolution: 2.5 x 2.5 (lat,lon)
Onset- Demise Methodology Rn= Pentad Precipitation Liebmann and Marengo 2001 – J. Climate
Mean Annual Cycle of precipitation Western Amazon (70;5.5S) NW S. America(72;2.5S) S Amazon (55.0W;10S) MIROC GFDL
Mean Annual Cycle of precipitation Amazon Delta (50;0.0S) Cerrado (50;17.5S) Central Amazon(60;5.5 S) SACZ(37.5;30.0 S) GFDL No variability
Mean DJF Precipitation (solid lines) and Standard Deviation S (shaded) Light gray → 3 mm ≤ S ≤ 5mm Dark gray → S > 5 mm GPCP - Observed CSIRO-3 -Australia GFDL2.0 - USA GFDL2.1 - USA MIROC-hires - Japan MIROC-medres - Japan
Mean DJF Precipitation (solid lines) and Standard Deviation S (shaded) Light gray → 3 mm ≤ S ≤ 5mm Dark gray → S > 5 mm CNRM - France GPCP - Observed CGCMT63 - Canada ECHAM5 - Germany MRI - Japan FGOALS - China
(Observation) (France) Pentad 60 (Australia) (China) (Japan) (Japan)
(Canada) (Observation) Pentad 60 (USA) (Germany) (Japan) (USA)
(Observation) (France) 3-4 Pentads (Australia) (China) (Japan) (Japan)
(Observation) (France) 36 Pentads (Japan) (China) (Japan) (Canada)
(Observation) (Australia) 36 Pentads (USA) (USA) (Japan) (Germany)
Duration Variability Definedby the Interquartile Range (IQR) 5 best simulations (based on the median)
(France) (Observation) 4 Pentads (Japan) (Australia) (Japan) (Canada)
(China) (Japan) (Japan) (Japan) (France)
(Canada) (Germany) (Australia) (USA) (USA)
Total Precipitation Variability Defined by the Interquartile Range (IQR)
(Observation) (China) (Japan) (Japan) (France) (Japan)
Inter-model Variability described by the Standard Deviation of the Ensemble
Simulation of the 21th Century Climate (scenario A1B)Difference between Median Monsoon Precipitation21th - 20th
(Japan) (Japan) (China) (France)
(USA) (USA) (Australia) Echam-5 not included
CONCLUSIONS Most IPCC models simulate SAMS observed climatological features (ie, median and interquartile range) over central-eastern South America Poor representation of the annual cycle of Precipitation is observed over N and W Amazon (stronger ITCZ) Best Performance of SAMS precipitation Patterns: CNRM (France), FGOALS (China), MIROC3.2-hires e MIROC3.2-mdres (Japan) Worst Performance: ECHAM5 (Germany), GFDL2.0, 2.1 (USA) Low Spreadamong model’s simulations (Onset, End, Duration) is oberved over central Brazil and High spread is observed over Amazon Low spread among model’s simulations of total Precipitation is observed over S and SE Brazil and adjascent Atlantic Ocean MIROC-H and M1, FGOALS, GFDL, indicate statistically significant decrease of total precipitation over eastern Brazil (Cerrado region) for the A1B scenario (~ -100 to -200mm). CNRM, on the other hand, show increase in precipitation (~ 200-300mm) approximately for the same area No statistically significant differences are observed in any model regarding differences in Onset, Demise and duration of SAMS