TP-PROFILE: Monitoring the Thermodynamic Structure of the Troposphere over the Third Pole

Ground-based microwave radiometers (MWRs) operating in the K- and V-bands (20–60 GHz) can help us obtain temperature and humidity profiles in the troposphere. Aside from some soundings from local meteorological observatories, the tropospheric atmosphere over the Tibetan Plateau (TP) has never been continuously observed. As part of the Chinese Second Tibetan Plateau Scientific Expedition and Research Program (STEP), the Tibetan Plateau Atmospheric Profile (TP-PROFILE) project aims to construct a comprehensive MWR troposphere observation network to study the synoptic processes and environmental changes on the TP. This initiative has collected three years of data from the MWR network. This paper introduces the data information, the data quality, and data downloading. Some applications of the data obtained from these MWRs were also demonstrated. Our comparisons of MWR against the nearest radiosonde observation demonstrate that the TP-PROFILE MWR system is adequate for monitoring the thermal and moisture variability of the troposphere over the TP. The continuous temperature and moisture profiles derived from the MWR data provide a unique perspective on the evolution of the thermodynamic structure associated with the heating of the TP. The TP-PROFILE project reveals that the low-temporal resolution instruments are prone to large uncertainties in their vapor estimation in the mountain valleys on the TP. 整个青藏高原上空的对流层大气廓线从未被连续观测过, 第二次青藏高原科学考察与研究计划利用中国自主生产的多通道微波辐射计构建了覆盖西风、 季风断面的全天候大气廓线实时观测系统---TP-PROFILE. TP-PROFILE旨在建立一个能够覆盖整个高原对流层大气的多通道微波辐射计观测网络, 以研究青藏高原上空的天气过程和环境变化. 本文利用TP-PROFILE收集的近三年数据, 结合8个探空站的观测数据, 对TP-PROFILE反演的高原对流层大气温度和湿度的精度做了全面评估. 系统介绍了TP-PROFILE观测站点的布设、 观测的变量、 数据质量和精度, 并展示了研究人员利用TP-PROFILE获得的一些观测结果. 主要结论如下: 与空间距离最近的无线电探空仪观测相比较, TP-PROFILE系统能够监测青藏高原上空对流层大气的水热结构变化, 从TP-PROFILE数据中获得的连续温度和湿度分布为分析高原加热引起的“热岛”效应提供了独特的观测视角. TP-PROFILE利用22.2、 30.0和51.2GHz通道亮温数据在降水前快速增加的信息能够对高原降水的发生进行提前预报. TP-PROFILE的温度偏差比湿度偏差要小. TP-PROFILE在昌都、 那曲观测到的高原“热岛”效应最显著. 利用TP-PROFILE每2分钟的资料表明, 低时间分辨率的观测仪器在青藏高原山地的水汽估计中会有相对高的偏差.