HR: 0830h
AN: A41D-01    [Abstracts]
TI: Improved Seasonal Climate Forecasts of the South Asian Summer Monsoon Using a Suite of 13 Coupled Ocean-Atmosphere Models
AU: * Chakraborty, A
EM: arch@io.met.fsu.edu
AF: Department of Meteorology, Florida State University, Tallahassee, FL 32306 United States
AU: Krishnamurti, T N
EM: tnk@io.met.fsu.edu
AF: Department of Meteorology, Florida State University, Tallahassee, FL 32306 United States
AB: Thirteen state-of-the-art coupled atmosphere-ocean models were used to construct a consensus forecast called the synthetic superensemble. The merit of this technique lies in assigning differential weights to the member models based on their past performance. Seasonal forecasts obtained from the synthetic superensemble were compared with the individual models and their ensemble mean over the South Asian monsoon region during 13 years of the Northern summer. The skill of the synthetic superensemble, in terms of RMS errors, were best among all the models and their ensemble mean. The RMS errors of the synthetic superensemble were less than that of the ensemble mean at a significance level of 95% or more (based on a student's t-test). Anomaly correlation from the synthetic superensemble were particularly high when the anomaly was high over the South Asian monsoon domain. This ensures the reliability of the present approach in predicting extreme events. This was illustrated with case studies during the switch on and off of the Indian Ocean Dipole which seems to modulate the Indian monsoon rainfall. The results of this study suggest that superensemble provides some what consistent forecasts on the seasonal time scale. This methodology needs to be tested for real time seasonal climate forecasting over the South Asian region.
DE: 3354 Precipitation (1854)
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly