Trends in sunshine duration and atmospheric visibility in the Yunnan-Guizhou Plateau,1961-2005  

作　　者：XiaoBo Zheng TianLiang Zhao YuXiang Luo ChangChun Duan Juan Chen 

机构地区：[1]Guizhou Institute of Mountainous Climate and Environment, Guizhou Key Laboratory of Mountainous Climate and Resource,Guiyang, Guizhou 550002, China [2]Air Quality Research Division, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario,M3H 5 T4 Canada [3]Yunnan Provincial Meteorological Institute, 77 Xichang Road, Kunming, Yunnan 650034, China

出　　处：《Research in Cold and Arid Regions》2011年第2期179-184,共6页寒旱区科学（英文版）

基　　金：funded by the National Natural Science Foundation of China (NSFC) (Grant No. 40965009);the Guizhou Provincial Meteorological Bureau Key Laboratory Programme (No. KF200906)

摘　　要：Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between -12.2 and -173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols （including air pollutants） resulting from increased energy consumption over the YGP could be a major Factor influencing the reductions of sunshine duration and atmospheric visibility.Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between -12.2 and -173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols （including air pollutants） resulting from increased energy consumption over the YGP could be a major Factor influencing the reductions of sunshine duration and atmospheric visibility.

关 键 词：Yunnan-Guizhou Plateau climatic change sunshine duration VISIBILITY cloudy cover 

分 类 号：P931.5[天文地球—自然地理学] X16[环境科学与工程—环境科学]