SBDART对云地面长波辐射强迫的模拟研究

为了研究云的地面长波辐射强迫与云的关系,利用SBDART辐射传输模式模拟了云量、云底高和云光学厚度对云的地面长波辐射强迫的影响,并对国内外学者研究的云的地面长波辐射强迫随云量变化的非线性原因进行了理论分析.结果表明:对相同的云,在不同的大气条件下,地面长波辐射强迫是不同的；云的地面长波辐射强迫随云量的增大而增大,随云底高的增大而减小,随云光学厚度的增大而增大,当光学厚度大于10以后,几乎不再增大.随云量的增加,低云和光学厚度大的云出现概率增大,是云的地面长波辐射强迫随云量变化呈非线性的两个原因.

Research on Cloud Surface Long-Wave Radiative Forcing by Using SBDART

In order to obtain the relationships between cloud surface long-wave radiative forcing and cloud,the effects of cloud amount,cloud base height and cloud optical depth on cloud surface long-wave radiative forcing are investigated by using SBDART.And the causes of the nonlinearity of the relationships between cloud surface long-wave radiative forcing and cloud amount derived from other experts are analyzed.The results show that,the cloud surface long-wave radiative forcing of the same cloud shows different characteristics in different atmospheric conditions.The cloud surface long-wave radiative forcing increases with cloud cover, and decreases with cloud base height.The cloud surface long-wave radiative forcing also increases with cloud optical depth,but the increasing stops when the optical depth is greater than 10.The nonlinearity of the relationship is caused by the more frequent occurrence of low altitude cloud and cloud of great optical depth as the cloud cover increases.