江西地区低云辐射气温变化特征的初步分析

通过分析近45 a江西地区山丘、平地和环湖站点低云、辐射、气温之间的气候变化关系,发现,1959~1971年,江西地区低云量减少时,气温下降;1971~2003年,低云量增加时,气温上升,同时太阳总辐射减少。江西地区低云、辐射、气温三者的统计关系表明,低云-辐射-气温变化的基本特征为三者的净效应使得该地区在20世纪70年代之后,特别是90年代气温明显上升,其中,低云在增温过程中起到了显著的温室效应增效器的作用,这里的温室效应主要是指温室气体量增加的增胶作用。这种温室效应增效器作用主要体现在低云增加伴随有地面大气能见度降低,将导致太阳总辐射减少,最终引起有效长波逆辐射增加和净增温效应。

A PRIMARY ANALYSIS FOR THE CHANGE OF LOWER CLOUD COVER-IRRADIATION-TEMPERATURE OVER JIANGXI REGION

The relation between lower cloud-cover,irradiation and temperature observation over the massif,plain stations and stations around Poyang Lake in Jiangxi region during recent 45 years is analyzed.The results show that from 1959 to 1971 the temperature is actually decreased when lower cloud-cover is decreased;whereas the temperature increased when lower cloud-cover increased in the period from 1971 to 2003.Furthermore,the statistic analysis for the relation among lower cloud cover,irradiation and temperature over Jiangxi region indicates that,although the relationship of change in lower cloud-cover,irradiation and temperature provides very complicate profiles,its net impact is clear,that such net impact definitely causes the temperature to increase.During the warming period from 1970s,especially after 1990s,the effect of low cloud-cover indeed acts as an amplifying regulator to amplify greenhouse effect remarkably.Such regulator causes the descending of surface visibility and the descending of total irradiation accompanying with the increasing of low cloud-cover;and it finally leads to the increases of effective reverse long-wave radiation and hence the rise of temperature.