新疆博湖地区大气向下红外辐射特性及其对云识别应用的研究

为加强新疆戈壁地区云的自动观测，利用辐射传输模式SBDART和新疆博湖地区历史气候资料，分析了当地大气向下红外辐射对大气影响因子的敏感性和利用全天空红外辐射进行云识别分类的可行性，并提出了一种基于典型云族红外阈值的云分类方法。结果表明：（1）水汽、云、天顶角、能见度等对中红外波段向下红外辐射值都有较大影响；（2）当能见度较差时，气溶胶对向下红外辐射的贡献不可忽略，并由于局地气溶胶辐射特性难以确定，因此是利用天空向下红外辐射进行云识别时的一个不确定因素；（3）根据8～14μm波段不同云族的辐射特性差异分析，阈值法是进行云识别和云族区分的有效方法。但该方法应用效果的好坏依赖于实测探空数据和历史气候数据的有效性及准确性。

Analysis of Atmospheric Downward Infrared Radiation Characteristics in the Bosten Lake Area and Application in All-sky Cloud Identification

To strengthen ground-based automatic cloud observations in the Gobi region in Xinjiang, based on radiative transfer model SBDART and historical climate data in the Bosten lake area, the sensitivity of all-sky downward infrared radiation to different atmospheric impact factors are analyzed, a cloud classification method based on infrared threshold and the look-up table method is proposed. The results show that： （ 1 ）water vapor, clouds, zenith angle and visibility have a great impact on downward infrared radiance; （2）when the visibility is poor, the contribution of the aerosols to infrared radiation cannot be ignored; （3）According to the radiation characteristics of different clouds in 8~14 band, the threshold method is an effective method for cloud identification and classification.