摘要:高原积雪是重要的陆面因子，其变化的时间尺度长于大气而短于海洋。本文利用国家气候中心第二代月动力延伸期预测模式（DERF2.0）历史回报资料与被动微波资料（SMMR）、被动微波成像专用传感器（SSM/I）数据反演的逐日雪深资料，分析了1983~2014年冬季和春季转换季节高原积雪对热带外地区延伸期尺度预测技巧的影响。结果表明，高原积雪异常年动力模式在高原积雪显著影响的青藏高原地区、贝加尔湖地区和北太平洋地区预报技巧明显高于正常年份。随着预报时效的延长，高原积雪偏多年的技巧衰减最慢、其次为积雪偏少年，积雪正常年最快，表明高原积雪异常年可预报时效更长，且高原积雪异常对预报技巧的改善在第1候的预报中就显现出来，尤其是积雪偏多年，其影响时段明显要早于海洋。结果显示高原积雪对延伸期预报技巧有重要贡献，暗示高原积雪异常为东亚延伸期预报的潜在可预报源。
关键词:青藏高原/
积雪深度/
延伸期预报/
模式评估
Abstract: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.
Key words:The Tibetan Plateau/
Snow depth/
Extended-range prediction/
Model evaluation
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http://www.iapjournals.ac.cn/dqkx/article/exportPdf?id=20190112
