对流层顶的变化趋势对加权平均温度的影响

Effect of the Changes of Tropopause on Weighted Mean Temperature

对流层顶与加权平均温度和可降水量(precipitable water vapor, PWV)之间存在很强的相关性,然而目前几乎没有学者讨论它对加权平均温度和PWV的影响。针对对流层顶对GNSS(global navigation satellite system)气象模型影响研究所存在的空白,基于已有学者提出的联系对流层顶和加权平均温度的公式,首次讨论中国区域对流层顶变化对加权平均温度的影响。在不损失公式精度的前提下,将该公式整理后得到对流层顶与加权平均温度的二次函数关系,分析了中国不同纬度区域的对流层顶对加权平均温度的影响,利用探空站观测数据得到了影响分布图。该图可以预测对流层顶对加权平均温度和PWV的影响。

The variation of tropopause serves as an indicator of global scale meteorological change.Although a lot of research on tropopause has been done,it has rarely been discussed in GPS meteorology.In fact,the tropopause shows strong correlation with weighted mean temperature and precipitable water vapor(PWV).The correlations suggest that the tropopause has been the main influencing factor,except surface temperature.Yao has proposed a formula that links the weighted mean temperature and tropopause.The formula is rearranged and the approximated quadratic functional relationship between tropopause and weighted mean temperature is derived.The following works focus on discussing the abscissa of extremum and the coefficient sign of quadratic function,using radiosonde data.The sign from one of the coefficients of quadratic function is plotted in China region.Combing the map of positive-negative signs and vertex height of abscissa of extremum with the seasonal changes of tropopause,it’s easy to predict the influence of tropopause on weighted mean temperature.After discussing the relationship between tropopause and weighted mean temperature,its influence on PWV is easy to describe.The curve of PWV change will be sharp or mild when tropopause enhances or reduces the influence of surface temperature on weighted mean temperature.