辐射传输模式中地表参数对大气长波辐射的影响

Effect of Surface Thermal Parameters on Atmospheric longwave Radiative Fluxes in a Radiative Transfer Model

本文利用Ｌｉｏｕ－Ｏｕ一维宽带辐射传输模式，对地表热力参数取值部分作了改进，使用模式大气和青藏高原实测资料对下垫面温度与地表空气温度两者不能合二为一的问题进行了分析，同时还讨论了下垫面温度的日变化对大气长波辐射通量日变化的影响及地表比辐射率的变化对大气长波辐射通量计算结果的修正作用。

Solving the atmospheric longwave radiative transfer equation would involve two discrete temp'!rature values across the surface--atmosphere interface, i.e., the underlying surface ie￣rature (Ti ) Indthe surface air temperature (TO ). If the atmospheric longwave radiative transfer equation is solve(1 byanalytical method, it may be assumed that TO is close to Ti in an unlimited thin layer across the urface--atthosphere interface. But when the atmospheric longWave radiative transfer equation is solve<' bydifference method for limited layers of the atmosphere, both To and Ti cannot be considered t(' beidentical, otherwise the computed atmospheric longwave radiative fluxes and heating rates in the ic'vertroposphere would be severely affected. In this paper, the improvement to the surface then,lalparameters in the Lion--On one--dimensional atmosphere radiative transfer model is describe, the mpact of the surface thermal parameters on the computed atmospheric longwave radiative fluxes i ndheating rates in the model is analyzed based on the data of the model atmosphere and that measu'-edover Qinghai--Xizang Plateau. In addition, both the effect of Ti on the diurnal cycle of atmosph(riclongwave radiative fluxes and the effect of modulating of surface emissivity on the atmosph(riclongWave radiative fluxes are discussed.