A weighted mean temperature (Tm) augmentation method based on global latitude zone
A weighted mean temperature (Tm) augmentation method based on global latitude zone
复制标题
DOI：
10.1007/s10291-022-01335-y
复制
发表时间：
2022-09
期刊：
影响因子：
4.9
通讯作者：
Fei Yang;Lei Wang;Zhicai Li;Weijing Tang;Xiao-lin Meng
中科院分区：
文献类型：
--
作者：
Fei Yang;Lei Wang;Zhicai Li;Weijing Tang;Xiao-lin Meng
加权平均温度（Tm）是大气温度和垂直湿度廓线的函数。它在利用GNSS信号对流层延迟反演水汽信息的过程中起着至关重要的作用。在GNSS气象学中，天顶湿延迟（ZWD）与可降水量（PWV）的转换通常采用经验模型估算的Tm。然而，这些Tmin模型使用三角函数，难以描述Tmin的细节，并且随着纬度的变化，精度有明显的差异。因此，对模式采用全球纬度带增广模式，通过引入实测地表温度，采用最小二乘法得到各纬度带的增广系数。利用2011-2015年的探空资料，对GPT 3、UNB 3 m和GWTMD模型进行了扩充和分析。结果表明，与原模型相比，所有增强模型均能提高Tm的估计精度，且提高程度不同.这三个增强模型的平均RMSE分别为2.79 K、3.47 K和3.22 K，分别比GPT 3模型、UNB 3 m模型和GWTMD模型提高了22%、49%和8%。此外，还与Tmlinear公式进行了比较，表明了增广模型的优越性。
The weighted mean temperature (Tm) is a function of atmospheric temperature and vertical humidity profiles. It plays a crucial role in the progress of retrieving water vapor information from the tropospheric delay of GNSS signals. TheTmestimated by the empirical models is always used to convert the zenith wet delay (ZWD) to precipitable water vapor (PWV) in GNSS meteorology. However, these empiricalTmmodels used trigonometric functions, making it difficult to describeTmin detail and leading to an obvious accuracy difference with latitude changes. Thus, a global latitude zone augmentation mode was adopted for the empiricalTmmodels; the augmentation coefficients for each latitude zone were obtained by introducing the measured surface temperature and using the least-squares method. Using theTmdata of 2011–2015 derived from radiosonde, the GPT3 model, UNB3m model, and GWTMD model were augmented and analyzed. The results show that all augmentation models can improve the accuracy of the estimatedTmcompared with their corresponding original models, and their levels of improvement are different. The three augmentation models achieved an average RMSE of 2.79 K, 3.47 K, and 3.22 K, which correspond to 22%, 49%, and 8% improvement against the GPT3 model, UNB3m model, and GWTMD model. In addition, the comparisons with theTmlinear formula were carried out and showed the superiority of the augmentation models.