摘要
利用CCM3的辐射模式CRM研究大气沙尘的辐射强迫特性。大气沙尘减小地面净辐射冷却地面同时增暖沙尘层大气 ,最大加热率出现在沙尘层的上部和贴近地面处。地表反照率对地面冷却和大气加热的大小有影响 ,地面净辐射的减幅和大气加热率在高地表反照率的沙漠大于低地表反照率的绿洲。大气沙尘对地 -气系统的辐射强迫同样受地表反照率的影响 ,存在着一个“临界地表反照率” ,其值在 0 .2 5～ 0 .3之间。当地表反照率高于“临界地表反照率”(如沙漠 ) ,大气沙尘减小行星反照率增暖地 -气系统 ,反之 (如在绿洲 ) ,大气沙尘增大行星反照率冷却地 -气系统。
The atmospheric dust is the main composition of atmospheric aerosols in the troposphere. Its radiative forcing was studied by using the radiationmodel(CRM/CCM3).The radiative effects ofthe atmosphericdust is cooling the surface and warming the air in the dust layer, two maximum heating rates were found at the upper part of the dust layer and near the surface respectively. The surface albedoplays animportant role on the radiative forcing of the dust aerosol. The cooling rate of the surface andthe warming rate of the air are higher in the higher surface albedoarea than that in lower surface albedoarea. Forthe earth-atmosphere system, there is a'critical value' of the surface albedo which is about 0.25～0.3. The atmospheric dust decreases the planetary albedo and therefore warms the whole earth-atmosphere system when the surface albedo is higher than that (for example, in Desert ), otherwise (for example, in oasis), the atmospheric dust increases the planetary albedo and therefore cools the whole earth-atmosphere system.
出处
《高原气象》
CSCD
北大核心
2002年第5期473-478,共6页
Plateau Meteorology
基金
973项目"中国北方沙漠化过程及其防治研究"(G2 0 0 0 0 4870 3 )
中国科学院创新重大方向项目"亚洲沙尘形成
输送机制及其辐射强迫研究" (KZCX2 -3 0 5 )
中国科学院和甘肃省合作项目"兰州市大气污染及对策研究"共同资助
关键词
中国西北
大气沙尘
辐射强迫
地表反照率
Northwest China
Atmospheric dust
Radiative forcing
Surface albedo
