CRTM云模式的建立与敏感性试验

云污染会严重影响云区辐射的模拟，导致大量云区卫星资料被废弃。结 合快速辐射传输模式(Community Radiative Transfer Model, CRTM)的应用现状以及 红外遥感原理，对CRTM模式中的辐射传输模块进行了修改，并提出了能够模拟云 区红外辐射的CRTM云模式。利用CRTM云模式模拟了高光谱大气红外探测 器(Atmospheric Infrared Sounder, AIRS)的通道亮温，并针对云模式中新增的参数进行了 敏感性分析。结果表明，随着通道高度的下移，对卫星接收辐射贡献较大的大气层也在下移，偏 差大值区所处的高度也越来越低；在偏差大值区中，偏差值会随着云量的增加而增大，直到全云覆盖时，偏 差值最大；云量较大时，输入的温度廓线的垂直变化会引起云顶发射辐射产生相同的垂 直分布，这与用CRTM云模式模拟出的亮温随云顶高度抬升而出现的垂直变化一致；用CRTM云模 式模拟的亮温值对新增的云量和云顶高度参数的敏感性较强，符合大气红外辐射传输的规律。

Establishment of CRTM Cloud Mode and Test of Sensitivity

Cloud contamination may affect the simulation of the radiation of a cloud area and hence results in the discard of a large number of satellite data. According to the current application of the Community Radiative Transfer Model (CRTM) and the principle of infrared remote sensing, the radiation transfer module in the CRTM is modified and a CRTM cloud mode which can simulate the infrared radiation of cloud areas is proposed. The CRTM cloud mode is used to simulate the channel brightness temperature of the Atmospheric Infrared Sounder (AIRS). The sensitivity of the new parameters added to the cloud mode is analyzed. The results show that with the decline of channel altitude, the atmosphere which contributes greatly to the radiation received by the satellite decline too. The altitude where the large deviation area locates is becoming lower and lower. In the large deviation area, the deviation increases with the increasing of cloud amount. When the sky is fully covered by cloud, the deviation reaches its maximum. When cloud amount becomes larger, the vertical variation of the temperature profile inputted may cause the radiation emitted by cloud top to form the same vertical distribution. This is in accordance with the vertical variation occurred when the brightness temperature simulated by the CRTM cloud mode increases with the rising of cloud top. The brightness temperature value simulated by the CRTM cloud mode is more sensitive to the newly added parameters of cloud amount and cloud top altitude. This accords with the law of atmospheric infrared radiation transfer.