沙尘气溶胶对直接太阳辐射的衰减研究

基于在腾格里沙漠东南端进行的太阳辐射与气象要素观测,探讨晴空无云时沙尘气溶胶对直接太阳辐射的衰减;并利用太阳辐射观测资料,给出沙漠边缘垂直上空的大气混浊度的变化。根据4月份至9月份的观测资料,只选取天空无云(可测的太阳辐射)的气象条件,研究沙尘气溶胶造成的直接太阳辐射的衰减。结果表明,在晴好天气约为47.0%~2.6%,平均衰减约为16.9%;在沙尘天气约为90%~10%,平均衰减约为38%;沙尘天气气溶胶对太阳辐射衰减变化较大。大气混浊度(atmospheric turbidity:τ_a)在晴好天气下约为0.048~0.631,平均约为0.260;沙尘天气约为0.177~2.475,平均约为0.741。

Study on Attenuation of Direct Solar Flux by Sand-Dust Aerosol in Tengger Desert

An operation to measure the surface solar radiant flux and meteorological elements was done from April to September 2001 at the southeast of Tengger Desert.The main purpose was to study the effect of aerosols on attenuation of solar flux and to retrieve the atmospheric turbidity based on the surface solar flux dataset.It was noted that under clear weather,aerosols tend to attenuate the direct solar flux by 47.0%~2.6%,the average was about 16.9%;under dusty weather,aerosols tend to attenuate the direct solar flux by 90%~10%,the average was about 38%.As to the retrieved mean turbidity for broadband(300~4 000 nm) flux,i.e.the optical depth of dust aerosols,it was 0.048~0.631 in clear weather,the average was about 0.260;it was 0.177~2.475 in dusty weather,the average was about 0.741.