沙漠地区春季的大气浑浊度及沙尘大气对地面辐射平衡的影响

THE ATMOSPHERIC TURBIDITY AND THE INFLUENCE OF THE DUST ATMOSPHERE ON THE SURFACE RADIATION BALANCE IN DESERT IN REGION SPRING

黑河实验区即是亚洲大气沙尘由我国西部向东输送的必经之地，也是其重要的源地之一。本文利用ＨＥＩＦＥ沙漠站１９９１年的观测资料，着重分析了本区春季的大气浑浊度特征及沙尘大气对地面辐射能收支的影响。春季（３—５月）受沙尘暴天气的影响，本区大气的平均状况明显浑浊。每次沙尘暴天气产生的大量沙尘滞留在大气中，约一星期时间大气浑浊度才会恢复到沙尘暴前的天气状况。大气沙尘的尺度分布服从Ｊｕｎｇｅ分布，其消光系数很大。明显浑浊的沙尘大气，减少到达地面的总辐射，增大向下的长波辐射，对地面向上的波长辐射，白天减少，夜间增大。其综合结果是：白天减小地面净辐射能收入。

By using of the observed data at desert station of HFIFE in 1991,the characteristics of the atmospheric turbidity and the effect of the dust atmosphere on the surface radiative energy budget over desert region of Heihe River basin in spring were analysed In spring (March May),the mean atmospheric turbidity is high affected by the dust storm Most of the dust caused by the dust storm are held in the atmosphere for a long time About one week after dust storm the atmospheric turbidity return to normal The size distribution of the atmospheric dust is identical with Junge distribution The optical depth of the atmospheric dust is high and has good relationship with the atmospheric turbidity coefficient In case of very turbid condition the global radiation decreases,the incoming IR radiation decerases, the outgoing IR radiation decerases in the daytime and increases in the night,for the surface radiative energy budget, the net gain of the radiative energy on the ground surface decreases in the daytime, and the net lose of it decreases in the night