论文部分内容阅读
通过相关分析、诊断分析以及数值模拟试验来研究热带海温异常对云南初夏干湿转换季节雨量变化的影响,研究表明前期热带海温异常对云南初夏干湿转换季节雨量有明显的影响,海温与雨量的显著相关区与Walker环流的上升下沉支相对应。提前的时间尺度越长,海温所提供的可预报信息越少;时间尺度越短,提供的可预报信息越大。诊断分析及数值模拟研究还表明在赤道中东太平洋的暖位相期,孟加拉湾地区的季风低压和初夏索马里附近的越赤道气流及印度洋西南季风减弱,反之则加强。海温变化通过海气相互作用影响到季风活动,从而对云南初夏干湿转换季节雨量产生影响。
The correlation analysis, diagnostic analysis and numerical simulation tests were conducted to study the effects of tropical SSTA on the seasonal rainfall in the early summer of Yunnan. The results show that the anomalous tropical SST in the early stage of the year had a significant effect on the seasonal rainfall in the early summer, The significant correlation zone with rainfall corresponds to the ascending subsidence of the Walker circulation. The longer the advance time scale, the less predictable information provided by SST; the shorter the time scale, the greater the predictable information provided. Diagnostic analysis and numerical simulation also show that during the warm phase of the central and eastern equatorial Pacific, the monsoon low pressure in the Bay of Bengal and the cross-equatorial flow near Somalia in early equatorial Pacific and the southwest monsoon weaken in the Indian Ocean, and vice versa. The variation of SST affects the monsoon activity through the interaction of air and sea, which will affect the seasonal precipitation of dry-wet transition in early summer of Yunnan.