The Simulation and Analysis of Temperature and Precipitation of CAM on Sahel Drought Yi-Chih Huang
Sahel Drought (I) Nicholson et al Dai et al. 2004
Sahel Drought (II) Todd Mitchell’s web page
GPCP Global Precipitation climatology Project Data – 2.5 x 2.5 degree grid from Jan 1979 to Sep 2009 – 1 x 1 degree grid from Oct 1996 to Jun 2009 Created by merging – rain gauge data – Infrared estimates of precipitation – microwave satellite estimates of precipitation Scattering : Wilheit et al. (1991) histogram approach Emission : Grody (1991) scattering index
CMAP The CPC (Climate Prediction Center) Merged Analysis of Precipitation Data – on 2.5 x 2.5 degree grid from 1979 to 2008 – pentad and monthly analysis Sources – gauge observations – five kinds satellite estimates (IR-based GPI, OLR- based OPI, MSU, microwave scattering and microwave emission) – NCEP/NCAR reanalysis
Hydrological Onset and Withdrawal Index Dalu, et al., 2009
Precipitation in August 2000 (I)
Precipitation in August 2000 (II)
Precipitation in August 2000 (III)
African Surface Temperature CAM v CRU
African Surface Temperature Departures CAM v CRU
Histogram of African Surface Temperature Departures for CAM v CRU
African Surface Temperature Departures with Least/Largest RMSE for CAM v CRU
African Surface Temperature CAM v NCEP
African Surface Temperature Departures CAM v NCEP
Histogram of African Surface Temperature Departures for CAM v NCEP
African Surface Temperature Departures with Least/Largest RMSE for CAM v NCEP
Sahelian Surface Temperature Departures CAM v CRU
Sahelian Surface Temperature Departures with Least/Largest RMSE for CAM v CRU
Sahelian Surface Temperature Departures CAM v NCEP
Sahelian Surface Temperature Departures with Least/Largest RMSE for CAM v NCEP
African Precipitation CAM v CRU
African Precipitation Departures CAM v CRU
RMS Histograms of African Precipitation Departures for CAM v CRU
African Precipitation Departures with Least/Largest RMSE for CAM v CRU
African Precipitation CAM v NCEP
African Precipitation Departures CAM v NCEP
RMS Histograms of African Precipitation Departures for CAM v NCEP
African Precipitation Departures with Least/Largest RMSE for CAM v NCEP
Sahelian Precipitation Departures CAM v CRU
Sahelian Precipitation Departures with Least/Largest RMSE for CAM v CRU
Sahelian Precipitation Departures CAM v NCEP
Sahelian Precipitation Departures with Least/Largest RMSE for CAM v NCEP
CAM Ensemble Tables least RMSE largest RMSE st ΔCAM-ΔCRU st ΔCAM-ΔNCEP pcp ΔCAM-ΔCRU pcp ΔCAM-ΔNCEP Sahel least RMSE largest RMSE st ΔCAM-ΔCRU st ΔCAM-ΔNCEP pcp ΔCAM-ΔCRU pcp ΔCAM-ΔNCEP
Summary Since late 1960’s precipitation in Sahelian region is almost persistently below the longterm mean The patterns of mean CAM ensemble precipitation in August 2000 are very different from CRU, GPCP, CMAP and NCEP CAM is Compared with CRU and NCEP – No ensemble run is in the groups with the least RMSE’s in both temperature and precipitation – Several runs are in groups with the largest RMSE’s in both temperature and precipitation in African and Sahelian domains