Relation between subseasonal and interannual variability of Indian monsoon and potential for seasonal predictability in a coupled GCM
Deepthi Achuthavarier, George Mason University, Fairfax, VA; and V. Krishnamurthy
The simulation of subseasonal and interannual variability of the Indian monsoon in the latest coupled general circulation model, the Climate Forecast System (CFS), developed by the National Centers for Environmental Prediction is examined. The daily mean values of precipitation, outgoing longwave radiation (OLR), winds and sea surface temperature (SST) from a long coupled run are analyzed in the present study.
The space-time structures of the dominant modes of subseasonal oscillations and seasonally persisting patterns of rainfall, OLR and winds are isolated using multi-channel singular spectrum analysis (MSSA). The relative contribution of the different MSSA eigenmodes toward the seasonal mean monsoon is examined. The model's results are compared with observed monsoon variability that consists of 45-day and 20-day oscillations and persisting patterns related to El Niņo and Southern Oscillation and the Indian Ocean dipole patterns. From observations, it has been found that the seasonally persisting daily patterns of rainfall and winds are related to SST variations and provide hope for prediction of seasonal mean monsoon. The potential for such seasonal predictability of the CFS due to the slow variability of the boundary conditions is assessed by investigating the relation between the persisting modes and the daily SST generated by the model.
Extended Abstract (1.2M)
Joint Poster Session 4, Joint Poster: Climate & Extremes, Linking Weather and Climate (Joint with Second Symposium on Policy and Socio-economic Research, Symposium on Connections Between Mesoscale Processes and Climate Variability, 19th Conference on Climate Variability and Change, and Climate Change Manifested by Changes in Weather)
Wednesday, 17 January 2007, 2:30 PM-4:00 PM, Exhibit Hall C
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