黄土高原干旱半干旱地区气溶胶光学厚度遥感分析  

Analyses on Aerosol Optical Depth over Arid and Semi-Arid Region of Loess Plateau Using Remote Sensor Data

作　　者：胡蝶[1] 张镭[1] 王宏斌[1] 

机构地区：[1]半干旱气候变化教育部重点实验室/兰州大学大气科学学院,甘肃兰州730000

出　　处：《高原气象》2013年第3期654-664,共11页Plateau Meteorology

基　　金：国家自然科学基金项目(41075104);国家重大科学研究计划项目(2012CB955302)共同资助

摘　　要：利用兰州大学半干旱气候与环境观测站2006年8月-2008年10月太阳光度计(CE-318)观测资料和同期卫星MODIS(Terra和Aqua)产品资料,分析了该站气溶胶光学厚度(AOD)日变化、月变化和Angstrom波长指数(α指数)月变化特征,发现春季AOD日变幅最大,存在双峰现象,秋、冬季较小;9月AOD最小,4月和12月AOD较大;α指数在4月最小,7月最大。采用太阳光度计反演的550nm AOD与Terra-MODIS和Aqua-MODIS AOD产品相比较,Terra-MODIS与太阳光度计AOD相关系数为0.69,大于Aqua-MODIS的0.62。并从地表反照率假设、气溶胶模型选择和云影响等方面分析了产生对比偏差的原因,进一步分析了黄土高原干旱半干旱地区AOD的分布和季节变化特征。结果表明:气溶胶光学厚度呈西低东高的分布特征;AOD高值中心与大城市有较好对应;黄土高原干旱半干旱地区AOD在春季最大,夏季有所减小,秋季最小,但冬季升高;Aqua-MODIS中深蓝算法对西北荒漠地区亮地表AOD的反演效果较好。The characteristics of diurnal, monthly change of aerosol optical depth （AOD）, and monthly change of Angstrom index （a-index） were analyzed using data of Sun Photometer （CE-318） at the Semi- Arid Climate and Environment Observatory of Lanzhou University （SACOL） from August 2006 to October 2008, it is found that the amplitude of the diurnal AOD change in spring is larger than that in other sea- sons, and it shows the double-peak characteristic. AOD is smaller in September and larger in April and De- cember, a-index reaches its minimum in April, and maximum in July. Correlation coefficients of 550 nm AOD retrieved from sun photometer data and that from Terra and Aqua MODIS data are 0.69/0.62. The errors are analyzed from aspects of surface albedo assumption, aerosol model, and influence of clouds. Ad- ditionally, Terra and Aqua MODIS data are used for analyzing spatial and seasonal characteristics of AOD above the arid and semi-arid regions of Loess Pl.ateau. Results show that east region has larger AOD, and local maximums are corresponding to capital cities of those provinces. AOD above the arid and semi-arid regions reaches maximum in spring and minimum in autumn. The Deep Blue algorithm for Aqua-MODIS is a good supplement for the retrieval of AOD above bright surface of deserts in Northwest China.

关 键 词：气溶胶光学厚度 太阳光度计 MODIS 黄土高原 干旱半干旱区 

分 类 号：P407[天文地球—大气科学及气象学]