塔克拉玛干沙漠腹地太阳紫外UV-B辐射的观测与分析

利用塔中站(39°01′N,83°40′E)直接探测的紫外辐射资料,对塔克拉玛干沙漠近地层紫外辐射特征进行了系统的分析。结果表明,紫外UV-B辐射年总量为8.59 MJ.m-2.a-1。夏季紫外线辐射强度较大,7月达到最大为1.24 MJ.m-2,占紫外UV-B辐射年总量的14.44%;冬季紫外线辐射强度较小,约为7月的1/5,1月出现最低值为0.257 MJ.m-2;紫外UV-B瞬时辐射强度全年峰值为2.51 W.m-2,出现在6月。1、4、7、10月紫外UV-B辐射的日总量变化对天气现象有不同程度的反映,天气现象较少的1月逐日紫外辐射上下变动的离散度较小,7月最大。紫外UV-B辐射随云量增多而降低;沙尘使紫外UV-B辐射的降低较为显著,沙尘暴时,其值为各类风沙天气中最低。

Observation and Analysis of Solar UV-B Radiation over the Taklimakan Desert Hinterland

A set of ultraviolet radiation data from the Tazhong station (83°40′ E, 39°01′ N) were analyzed. The results show that the annual total UV-B radiation is 8.59 MJ·m-2·a-1. In detail, the monthly irradiance intensity is strong in summer, occupying 14.44% of the annual total and reaching the highest of 1.24 MJ·m-2 in July; it is weak in winter, declining to the lowest of 0.257 MJ m-2 in January. The peak value of instantaneous irradiation intensity is 2.51 W·m-2 in June. The variety of daily accumulative UV-B radiation in January, April, July and October is restricted to the weather phenomena in different degree. The dispersed degree of the daily accumulative UV-B radiation in January is less because of its lesser weather phenomena, and it is most in July because of its more weather phenomena. The UV-B radiation should increase when the cloud amount reduces. Sand dust can cause the UV-B radiation reduced remarkably, and it is the smallest in sand storm.