江苏秋季霾的年代际变化特征及其影响因素分析

摘要

利用1961-2010年江苏地级市气象站资料分析了近50年江苏秋季霾的年代际变化特征,并从气候背景的影响方面探讨其形成变化的特点:少霾期,大气环流以及水汽输送特征都有利于污染物的输送和稀释；而在调整期,气象条件有所调整,但不显著；在显著上升期,气候背景场对霾的发生起到十分积极的作用.另外,1961-2010年大气净化次数显著减少.海温与霾的年代际变化存在密切关系,当霾日数不断上升时,印度洋到南海海域的海温升高,引起低层风场的辐合,并通过类似于Hadley环流形式使得东亚同经度的中纬度地区低层辐散,利于水汽通道转换,进而有利于霾天气的发生.%By using the NCEP/NCAR reanalysis data and the station-observed haze days and precipitation data in Jiangsu Province during 1961-2010, decadal variability characteristics of haze days in autumn in recent 50 years were discussed and explained from the influencing aspects of climatological background. Results indicate that the atmospheric circulation and vapor transportation during the low incidence period of haze were in favor of the transfer and dilution of pollutants; and in the high incidence period the haze observably increased, the climatological background field played a more active role in the generation of haze weather compared with the low incidence period. Besides, the frequency of air cleaning reduced remarkably in 1961-2010. SST was closely related to the decadal variability of haze. When the haze days increased continuously, the SST became higher from the Indian Ocean to the South China Sea, giving rise to the convergence/divergence in the low-lever wind field over the sea surface/ the middle latitude area with the same longitude (East Asia) by forming a Hadley-like cell, which is conducive to the formation of haze weather in Jiangsu Province.