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The western North Pacific subtropical high(WNPSH)is one of the deterministic predictors of the East Asian sum-mer climate,and a better prediction of the WNPSH favors more reasonable forecast of the East Asian summer cli-mate.This study focuses on seasonal prediction of the WNPSH during neutral summers without strong El Nino-Southern Oscillation(ENSO)forcing,and explores the associated predictable sources,using the one-month lead time retrospective forecasts from the Ensembles-Based Predictions of Climate Changes and Their Impacts(EN-SEMBLES)project during 1960-2005.The results indicate that the ENSEMBLES atmosphere-ocean-land coupled models exhibit considerable prediction skill for the WNPSH during neutral summers,with successful reproduction of the WNPSH in the majority of neutral summers.The anomalous WNPSH in neutral summers,which corresponds to cyclonic/anticyclonic anomalies in the lower troposphere,is highly correlated with an east-west dipole local sea sur-face temperature(SST)distribution over the tropical WNP,suggesting an intimate local air-sea coupling.Further diagnosis of the local SST-rainfall relationship and surface heat flux indicates that the anomalous local SST plays an active role in modulating the variation of the WNPSH during neutral summers,rather than passively responding to the atmospheric change.The local SST anomalies and relevant air-sea coupling over the tropical WNP are reason-ably well reproduced in the model predictions,and could act as primary predictable sources of the WNPSH in neut-ral summers.This could aid in forecasting of the East Asian rainband and associated disaster mitigation planning.