中文摘要：

利用中国科学院长白山森林生态系统定位站的近地面气象观测数据,分析评价了目前被广泛使用的8个晴天与8个云天大气长波辐射参数化模型的模拟性能.结果表明：晴天时Satterlund模型最适用,其偏差（BIAS）与均方根误差（RMSE）分别是-23.34和28.55W·m-2;系数校正后,虽然其参数值变化不大,但其模拟效果有很大提高,BIAS与RMSE分别降低为-6.33和18.08 W·m-2;云天时Jacobs模型最准确,BIAS和RMSE只有0.38和29.29W·m-2.对模型中大气发射率的敏感性分析表明,大气发射率对水汽压的变化最敏感,对温度的变化不敏感.应用优选模型（晴天和云天）得到的模拟值与观测值的日变化趋势基本一致,但在云量发生突变的节点上模拟效果不太理想.

英文摘要：

A total of eight clear-sky and eight cloudy-sky parameterized models for estimating day- time downward longwave radiation were evaluated by using the meteorological data measured in the Changbai Mountains region, Northeast China. The results indicated that the.Satterlund model per- formed better in estimating clear-sky downward longwave radiation, and the bias （BIAS） and root mean square error （RMSE） were -23.34 and 28.55 W · m-2, respectively. Although the coeffi- cients were not significantly changed, the performance of Satterlund model was significantly im- proved after the locally calibrated, and the BIAS and RMSE decreased to -6.33 and 18.08 W · m-2, respectively. Jacobs model was found to be best for modeling cloudy-sky downward long- wave radiation and the BIAS and RMSE were 0.38 and 29.29 W · m-2, respectively. Sensitivity analysis showed that the vapor pressure was the most sensitive variable to the atmospheric emissivity and the temperature was not sensitive to it. The predicted results of the optimal model （clear- and cloudy-sky） were consistent with the measured data, while the performance of these models was affected by a sudden change of cloudy cover.