基于UWYO大气探空廓线的中国区域大气模式构建

Construction of local atmospheric models in China based on UWYO atmospheric profiles

关键词:  UWYO廓线  MODTRAN5.2  中国五大气候区  局地大气模式

Key words:  UWYO atmospheric profiles  MODTRAN5.2  five climatic zones in China  local atmospheric models

摘要:

【目的】 常规大气辐射传输模型的标准大气模式仅适合表征大尺度区域的大气特征，难以精确刻画局地大气特性的动态变化，这会对局地地表温度、土壤湿度等参数的反演和验证精度造成影响，从而限制了这些参数在农业生产、农业气象灾害监测等方面的应用。【方法】 文章利用1973—2019年的UWYO大气探空廓线构建了中国五大气候区的局地大气模式，对大气压强、温度和湿度廓线进行了特征分析，并对比了利用局地大气模式与MODTRAN5.2内置大气模式计算的大气水汽总量和平均大气透过率。【结果】 大气温度和水汽质量混合比廓线具有明显的区域和季节特征，在1 km高程处，相同季节不同气候区的大气温度及水汽质量混合比最大差异分别约为26 K和9.7 g/kg，相同气候区不同季节的大气温度及水汽质量混合比最大差异分别约为21 K和11.3 g/kg。局地大气模式计算的大气水汽总量和平均大气透过率也呈现区域和季节特征，且波段越大特征越明显。其中，大气水汽总量的最高值和最低值分别约为6 g/cm²和0.6 g/cm²，平均大气透过率的最高值和最低值分别约为0.82和0.32。与MODTRAN5.2内置大气模式相比，局地大气模式计算的大气水汽总量及平均大气透过率更贴合中国五大气候区的实际情况。【结论】 局地大气模式可以有效地提高中国区域的大气辐射传输模拟精度、可以真实地反映具体地区的大气特征动态变化，从而可以在局地地区反演得到更加精确的地表温度、土壤湿度等环境参数，这对区域尺度的农业生产、农业气象灾害监测等方面的农业研究具有重要意义。

Abstract:

[Purpose] Standard atmosphere models of conventional atmospheric radiative transfer models are only suitable for characterizing the atmospheric characteristics about large scale regions，and it is difficult to accurately describe the dynamic changes of local atmospheric characteristics，which will affect the retrieval and verification accuracy of parameters such as surface temperature and soil moisture in local areas. Therefore，the applications of these parameters in agricultural production research and agrometeorological disaster monitoring are limited.[Method] In paper study，we constructed local atmospheric models for five climate zones in China using UWYO atmospheric profiles from 1973 to 2019. Furthermore，we analyzed the characteristics of atmospheric pressure，temperature and humidity profiles，and compared total water vapor content and average atmospheric transmittance calculated using the local atmospheric models and the built-in atmospheric models of MODTRAN5.2.[Result] The atmospheric temperature profile and water vapor mass mixed ratio profile have obvious regional and seasonal characteristics. At the altitude of 1 km，the maximum differences in atmospheric temperature and water vapor mass mixing ratio in different climate regions in the same season are about 26 K and 9.7 g/kg，respectively. The maximum differences in atmospheric temperature and water vapor mass mixing ratio in different seasons in the climate region are about 21 K and 11.3 g/kg，respectively. Moreover，the total water vapor content and mean atmospheric transmittance calculated by local atmospheric model also show regional and seasonal characteristics，and the larger the band is，the more obvious the characteristics are. The maximum and minimum values of the total water vapor content calculated by local atmospheric model are about 6 g/cm² and 0.6 g/cm²，respectively. And the maximum and minimum values of mean atmospheric transmittance calculated by local atmospheric model are about 0.82 and 0.32，respectively. Compared with built-in atmospheric model of MODTRAN5.2，the total water vapor content and the mean atmospheric transmittance calculated by the local atmospheric model are more consistent with the actual conditions of the five climatic regions in China.[Conclusion] The local atmospheric models can not only effectively improve the accuracy of atmospheric radiative transfer simulation，but also better reflect the dynamic changes of atmospheric characteristics in China，so that more accurate environmental parameters such as surface temperature and soil moisture can be retrieved. Therefore，it is of great significance for regional scale agricultural production research and agrometeorological disaster monitoring.