塔克拉玛干沙漠腹地总辐射变化特征及影响因子分析

 利用塔克拉玛干沙漠大气环境观测站(塔中站)直接探测的总辐射资料,对流动沙漠区近地层总辐射的变化特征及影响因子进行了分析。结果表明:总辐射的连续日变化对天气现象有不同程度的反映,天气现象较少的1月逐日总辐射上下变动的离散度较小,4月最大;1月、4月、8月、10月总辐射的平均日变化曲线皆呈正态分布,与同纬度地区比较,其年变幅较小;总辐射瞬时最大值为1 182.6 W·m-2,未超过太阳常数。总辐射随总云量增多而降低,且其在碧空最大,高、中、低云时逐渐降低,阴天Ci、Ac、Sc和Cb的平均总辐射约比晴天时分别减少5%、27%、51%和59%;沙尘使总辐射降低较为显著,风沙季节总辐射日变化与地面风速日变化对应,且主要受控于湍流作用,最大值出现与热力湍流和地面风力有关。

Global Radiation Characteristics and Influencing Factors of Taklimakan Desert Hinterland

The related global radiation data from the atmosphere environment observation station (TaZhong station) were used to analyze the characteristics and influencing factors of surface global radiation in sand-moving desert in this paper. The results show that the daily variations of global radiation respond to weather phenomena in some sense. The dispersed degree of daily global radiation is less in January with lesser weather phenomena, but most in April. The diurnal changing curves of global radiation in January, April, August and October is all fit for normal function; compared with that of the same latitude areas its inter-year changing amplitude is smaller. The largest instantaneous global radiation is 1 182.6 W\5m-2 in Takilimakan Desert hinterland, which does not exceed the solar constant. The global radiation gradually decreases along with the total cloud cover increasing; The mean daily global radiation under cloudy sky with Ci, Ac, Sc and Cb cloudy cover reduced respectively by 5%,27%,51% and 59% compared with that under clear sky. The global radiation reduced remarkably in sand blown weather. In sand blown season, the diurnal variation of global radiation responded to the diurnal variation of surface wind speed, furthermore, the global radiation variation is principally controlled by turbulent airstreams, whether its maximum comes up relates with the heat turbulent airstreams and ground wind power.