摘要
夏季印度季风和东亚季风环流的主要差异之一在于：东亚夏季风环流受中高纬度环流影响很大。文中探讨了中高纬度环流对东亚夏季风环流以及长江中下游地区夏季降水的影响。结果表明：东亚夏季降水环流型及长江中下游地区夏季降水的强弱受乌拉尔山和鄂霍次克海形势的影响，特别是东亚夏季梅雨期异常的降水与中高纬度阻塞型的建立密切相关。研究表明：当鄂霍次克海高压建立并稳定时，亚洲中高纬度及东亚东部地区的距平场易分别形成＋－＋的距平波列，东亚地区距平波列的这种分布形势及其相互作用常常造成东亚夏季特别是梅雨期降水偏多；反之，当鄂霍次克海为低值区时，亚洲中高纬度和东亚东部地区的距平场易形成－＋－的距平波列，东亚距平波列的这种分布形势不利于东亚夏季梅雨期的降水。因此，在考虑东亚夏季风环流的形势及其对同期降水的影响时，中高纬度的环流形势及其与低纬环流的相互作用是非常重要的因素。
In the paper, It had been pointed out that the main difference between Indian and East Asian summer monsoon is the circulation of mid high latitude had great influence on East Asian Summer monsoon. The study showed that during the flood years, the center of positive anomaly is around Okhotsk sea, the negative center is around the mid latitude and the another center of positive anomaly is around low latitude over East Asia, the positive and negative anomaly centers at 500 hPa level formed the anomaly wave train from low latitude to high latitude over east Asia, At the same time there is another anomaly wave train from Ural mountains to Okhotsk sea in mid high latitude, the positive anomaly center is around Ural mountains, the negative center is around Lake Baikal, the another positive center is around Okhotsk sea. There is almost opposite wave train arrangement between flood and drought case of Changjiang river basin over Mid high latitude and East Asia. The correlation between Okhotsk sea and North Hemisphere had been made based on 500 hPa height data during 1951～1994 years. The status of Okhotsk sea played an important role in the forming of opposite wave trains for flood and drought case in Changjiang river basin. So, the patterns of anomaly wave trains closely related to the status of Okhotsk sea. A strong persistent anticyclone remained over the Okhotsk sea at 500 hPa level often causes summer flood events in Changjiang river basin.
出处
《气象学报》
CSCD
北大核心
1998年第2期199-211,共13页
Acta Meteorologica Sinica
基金
国家"九五"重中之重项目
关键词
降水
环流影响
亚洲
中高纬度环流
The circulation of mid high latitude, Amonaly wave trains over East Asia, Circulation patterns of summer rainfall.
