Influence of the Tibetan Plateau Snow Depth on the Extended-Range Prediction Skill

The Tibetan Plateau snow cover is an important land surface factor, whose time scale of change is longer than that of the atmosphere and shorter than that of the ocean. This study analyzes the influence of the Tibetan Plateau snow depth anomaly onextended-range prediction technique over extratropical regions. The reforecast data from DERF2.0 (Dynamic Extended Range Forecast 2.0) model provided by the National Climate Center of China and the daily snow depth data inversion calculated by scanning multichannel microwave radiometer (SMMR) and special sensor microwave imager (SSM/I) from 1983 to 2014 are used. The results show that the skill in extended prediction of DERF2.0 is much higher in abnormal years than in normal years, especially over regions significantly affected by snow cover in the Tibetan Plateau like the Tibetan Plateau region, Lake Baikal region and the North Pacific region. With the extension of the forecast lead time, the skill in extended prediction at tenuates the slowest in more-snow years and attenuates the fastest in normal snow years. The above result shows that the predictable time is longer in abnormal years of the Tibetan Plateau snow. The skill in extended prediction is improved, which can be seen from the first pentad in the Tibetan Plateau snow abnormal years, especially in more-snow years. The influence of the snow cover is obviously earlier than that of the ocean. The Tibetan Plateau snow cover has an important contribution to the skill in extended prediction, suggesting that the Tibetan Plateau snow anomaly is a potential source of prediction for extended-range prediction in East Asian.