长江下游谷物天气产量变化与大型环流准周期性振动的分析
THE QUASI-PERIODIC FLUCTUATION OF LARGE-SCALE CIRCULATION AND GRAIN YIELD IN THE LOWER YANGTZE
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摘要: 本文分析了近几十年谷物产量和百余年海平面气压场及降水资料。揭示我国东部长江下游粮产区的天气和谷物天气产量存在30-40年的长周期振动和2-3年的短周期振动,并且与特定的相一致的大型环流系统振动相配合。通过分析讨论,提出了一个“环流一天气一天气产量”同步振动模式。简言之,即当冬季贝加尔湖冷高压偏弱和澳洲低压偏强,相应地,春季赤道低压偏强以及夏季南方涛动偏强时,则长江下游处于(长周期振动的)多水期或(短周期振动的)多水年型,谷物天气产量偏低。反之,则处于少水期或少水年型,谷物天气产量偏高。Abstract: Using monthly mean sea-level pressure field over the Eastern Hemisphere during 1871-1976,the data of yearly precipitation and of yearly grain yield in the Lower Yangtze are analyzed, and 36-yr. and 2-3-yr. quasi-periodic fluctuations in the circulation pattern-weather-yield system has been found. A fluctuation model is proposed.
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