气球漂移对应用探空资料评估地基微波辐射计温度测量精度的影响

Impact of Balloon Drift on Evaluation of Temperature Measurement Accuracy of Ground-Based Microwave Radiometer Using Radiosonde Data

摘要:

高空气象观测过程存在探空仪随气球漂移现象，漂移数据特征对评估地基微波辐射计反演产品精度具有重要意义。通过研究2017年10月31日至2023年12月31日西安泾河国家基本站0～10 km高度区间探空数据的漂移特点，在划分测站区域和漂移区域的基础上，对比分析不同天气下漂移对地基微波辐射计温度评估的影响。结果显示：漂移区域的均方根误差均大于测站区域、相关系数小于测站区域，且有明显的区间特征。在对流中低层晴空天气的均方根误差减小、相关系数增大，区域差值在4.25 km最大，有云天气的均方根误差和相关系数均增大，相关系数的区域差值在5.25 km最大；高度升高后晴空天气的均方根误差和相关系数与测站趋于接近，而有云天气只有相关系数趋于接近，并在8 km上下重合。受探空漂移和天气条件的双重影响，同区域不同天气的评估指标也存在差异，在测站区域，晴空天气大部分高度层的均方根误差较有云天气更大，且相关系数较小；而在漂移区域，晴空有云天气的均方根误差接近，但晴空的相关系数依然较小。探空远距离漂移环境下，风的作用导致动能和热能变化，特别是在对流层7 km高度区间，不同天气条件下的风速差异显著，这些因素是造成地基微波辐射计温度评估指标出现较大偏差的主要原因，本研究可为探空资料评估新型大气探测设备数据精度和产品应用提供参考。

Abstract:

The drift phenomenon exists in the process of radisonde meteorological observation, and the characteristics of drifting data are of great significance for evaluating the accuracy of ground-based microwave radiometer retrieval products. By researching the drift characteristics of radisonde data at the 0 to 10 km height range of Jinghe National Basic Station in Xi’an from 31 October 2017, to 31 December 2023, on the basis of dividing the station area and the drifting area, this study discusses the influence of drift on temperature evaluation of ground-based microwave radiometers under different weather conditions. The results show that both the Root Mean Squared Error (RMSE) and Correlation Coefficient (Corr) of the drift area are larger than those of the station area, and the Corr is smaller than that of the station area, exhibiting distinct interval characteristics. For clear-sky conditions, the RMSE decreases while the Corr increases in the middle and lower troposphere, and the maximum regional difference occurs at 4.25 km. For cloudy conditions, both the RMSE and Corr increase, and the maximum regional difference in the correlation coefficient occurs at 5.25 km. As altitude increases, for clear-sky conditions, the RMSE and Corr tend to approach those of the station area, while for cloudy conditions, only the Corr approaches and overlaps around 8 km. Due to the combined influence of sounding drift and weather conditions, there are differences in the evaluation indexes of different weather in the same region. The RMSE of clear-sky weather is larger than that of cloudy weather, and the Corr is smaller. The RMSE of the drifting region is close, and the Corr of clear sky is small. Under long-distance sounding drift conditions, wind effects lead to changes in kinetic and thermal energy, particularly within the 7 km altitude range in the troposphere, where wind speed differences under different weather conditions are significant. These factors are the main reasons for the large deviations in temperature evaluation metrics of ground-based microwave radiometers. The study provides a reference for using sounding data to evaluate the data accuracy and product application of new atmospheric detection equipment.