热带气象学报2011，Vol.27Issue(5)：639-648,10.DOI:10.3969/j.issn.1004-4965.2011.05.004
热带MJO对2009年11月我国东部大范围雨雪天气的可能影响
POSSIBLE IMPACTS OF THE MJO ON THE SEVERE ICE-SNOW WEATHER IN NOVEMBER OF 2009 IN CHINA
摘要
Abstract
Possible relationships between the MJO and a severe ice-snow weather process in November of 2009 in Eastern China were analyzed. Results showed that a strong MJO process was one of the strong impact factors. MJO convection was markedly active over the Indian Ocean, especially with the convection center maintaining nine days in phase 3 of MJO (the middle-east Indian Ocean) and just corresponding to two strongest ice-snow processes. Composites of MJO events showed that when the MJO convective center is located over the Indian Ocean, rainfall probability is significantly enhanced and the temperature is lower than normal in eastern China, which is consistent with the situation in November of 2009. Atmosphere circulation anomalies of mid-high latitude can be influenced by the tropical MJO convection forcing and this influence could be realized by tele-connection. When the MJO is over the Indian Ocean, it is favorable for the maintenance of the two ridge-one trough circulation situation at mid-high latitudes; meanwhile, the western Pacific subtropical high is stronger and more westward than normal, and an evident convective belt appears over eastern East Asia. All these circulation anomalies shown in the composite results also appeared in November of 2009, which indicates the general features of relationships between the MJO and the circulation anomalies over the extratropics. Besides the zonal circulation anomalies, the MJO convective can also lead to meridional circulation anomalies. When the MJO is over Indian Ocean, the western Pacific region is dominated by anomalously downward motion, and the eastern East Asia is controlled by convergence and upward motion. Therefore, an anomalous meriadinal circulation is formed between the tropics and middle latitudes, which further enhances the northward transportation of low-level moisture. It is potentially helpful to understand and even forecast, using MJO, such kind of ice-snow weather anomalies as in November 2009.关键词
MJO/雨雪天气/印度洋/热带/中高纬Key words
MJO/ ice-snow weather/ Indian Ocean/ tropics/ middle-high latitudes分类
天文与地球科学引用本文复制引用
贾小龙,梁潇云..热带MJO对2009年11月我国东部大范围雨雪天气的可能影响[J].热带气象学报,2011,27(5):639-648,10.基金项目
国家自然科学基金(40905035、40805027) （40905035、40805027）
973项目(2010CB428606) （2010CB428606）
公益性行业科研专项(GYHY200806004) （GYHY200806004）
科技部科技支撑项目(2007BAC29B04、2009BAC5 1B05)共同资助 （2007BAC29B04、2009BAC5 1B05）
