摘要
本文利用台站及卫星资料建立了中国西部积雪30年逐月时间序列。该序列是目前资料时间最长、最好的序列,为研究该区积雪月际和年际变化及其影响提供了较可靠的依据。中国西部冬春积雪对我国汛期降水的影响平均为负相关趋势,与6月降水的相关分布较有规律,冬春多(少)雪对应华南、高原及长江上游6月降水偏少(多),其它地区6月降水偏多(少)。我国西部多(少)雪对应6月份500h Pa高度的变化是:高原北边高纬高度降低(升高)及副热带地区升高(降低),有(不)利于高纬冷空气南下及副热带高压脊的西伸北进,因而长江中下游以北的降水增加(减少),华南、高原和长江上游地区的降水减少(增加)。
In this paper the monthly data series of snow cover in western China for 30 years have been built by satellite and ground data. It is the best and longest at present and has supplied better base to study monthly and annual variations. The correlation coefficients between the snow cover in winter and spring in western China and the precipitation during flood period are negative in the mean. Its distribution in June is more regular. When the snow in winter and spring is more (less), the precipitation in June is less (more) in the southern of China, the Qinghai-Xizang Plateau and the upstream of Yangtze River, and more (less) in the other area. When geopotential height at 500 hPa in June in more (less) snow years is dropped(risen) over northern Qinghai-Xizang Plateau, risen(dropped) over subtropic, and this is (not) advantageous to the cold air in high latitude area moving southward and the subtropical ridge moving westward and northward. Then the precipitation increase(decrease) in north of the midstream and downstream of Yangtze River, and decrease (increase) in the southern China, the Qinghai- Xizang Plateau and upperstream of Yangtze River.
出处
《高原气象》
CSCD
北大核心
1993年第4期347-354,共8页
Plateau Meteorology
基金
中国科学院"八五"重大科研项目KY85-10-222资助
关键词
西部
积雪
汛期降水
气候特征
中国
Snow cover in western China
Precipitation during flood period
Climatic characteristics.
