A Study of the Statistical Prediction Method for the East Asian Winter Monsoon Intensity

With the analysis of the precursory signal observed in the key regions of the air－sea system, this study has developed a statistical prediction method for the East Asian winter monsoon (EAWM) intensity, by using the monthly data of the NCEP reanalysis and NOAA extended reconstructed sea surface temperature (SST). The EAWM intensity is closely associated with the prior September－October SST anomalies in the Kuroshio and its extension region and the tropical western Indian Ocean. A strong EAWM activity corresponds well to the positive SST anomaly in the Kuroshio and its extension region and to the negative anomaly in the tropical western Indian Ocean. On the other hand, the EAWM intensity is also significantly correlated with a prior (October) northern hemispheric circulation pattern, whose action centers are located in the central North Pacific, the Northeastern Pacific, North America and the North Atlantic, respectively. The potential of above-mentioned three precursory factors in predicting the EAWM intensity has been discussed and the possible physical linkages between the EAWM intensity and the three precursory factors have also been explored. The fitting analysis and trial predicting examination indicate that the prediction method established here has a high accuracy and is applicable for the qualitative prediction of the East Asian winter monsoon intensity.