山西省气溶胶光学厚度时空变化特征及气候效应分析

Analysis of Spatio-temporal Variation of Aerosol Optical Depth and Climatic Effects in Shanxi Province

利用山西省109个气象台站1981—2016年地面能见度、水汽压和气象资料,反演并分析了山西省气溶胶光学厚度(AOD)的时空分布及长期变化特征,结合气温资料,揭示了AOD在山西省气候变化中的作用。研究显示,山西省气溶胶光学厚度多年平均值为0.23,大体呈由北向南逐渐增加,由中部盆地向两侧山地逐渐减小的特征。山西省AOD上升特征明显,平均每10年上升0.01,然而上升趋势并不完全呈线性,在2008—2013年出现了明显的低谷。冬季、夏季和秋季AOD都呈显著上升趋势,其中以冬季上升幅度最大。山西72%的地区AOD呈上升趋势,多集中在太原盆地、临汾盆地、运城和长治盆地。近年来,山西省气温存在1个显著升温过程(1981—1998)和1个升温停滞过程(1999—2016),气溶胶对山西省1981—1998年间的气候变暖有一定的减缓作用,尤其对冬季增温有显著减缓作用,即山西省AOD越大的地区,冬季气温增速越慢,冬季AOD每增加0.1,平均气温增速减小0.019℃·a^(-1),最高气温增速减少0.020℃·a^(-1)。此外,山西省AOD与气温日较差存在显著负相关关系,随着AOD的增加,山西省气温日较差呈下降趋势;冬、夏季AOD与气温日较差的负相关关系更显著。

Using ground visibility, vapor pressure and synoptic parameters data from 109 meteorological stations across Shanxi Province ranged from 1981 to 2016, long-term variation and spatio-temporal distribution of the aerosol optical depth（AOD） retrieved by visibility and vapor pressure data were analyzed. Combined with the air temperature data, this study aims to explore the climatic effects of AOD. The results showed that the mean annual AOD was 0.23 and generally had geographical feature across Shanxi, which decreased from north to south and from the middle basin to the mountain, with typical central basin feature. AOD showed an increasing trend with the rate of 0.01 every decade across Shanxi from 1981 to 2016. Seasonally, AOD showed a trend of significantly increasing in spring, summer and winter, and AOD in winter had the largest increasing amplitude. AOD were ascended in 79 areas（72%）, mainly distributed in Taiyuan basin, Linfen basin, Yuncheng basin and Changzhi basin. There were a significant warming process（1981—1998） and a temperatures rising stagnation process（1999—2016） between 1981 and 2016 in Shanxi. The climate cooling effects of aerosols had slowed down the climate warming in 1981—1998 across Shanxi. Aerosols in winter can significantly slow climate warming, which meaning the slower of the winter temperature growing with AOD increasing. Daily average temperature growth rate may reduce 0.019 ℃·a-1 in winter, maximum temperature may reduce 0.020 ℃·a-1 with the increasing 0.1 unit of AOD. Besides, AOD in Shanxi had a negative correlation with temperature daily range, which was the more significant in winter and summer.