Guo Ao, Xu Yan, Jiang Nan, Wu Yuhao, Gao Zhaorui, Li Song, Xu Tianhe, Bastos Luísa
Institute of Space Sciences, Shandong University, Weihai 264209, China.
Institute of Space Sciences, Shandong University, Weihai 264209, China.
Sci Total Environ. 2023 May 10;872:162225. doi: 10.1016/j.scitotenv.2023.162225. Epub 2023 Feb 14.
Earthquake is a common and destructive natural disaster. The enormous amount of energy released from seismic events can result in anomalous land surface temperature (LST) and catalyze the accumulation of water vapor in the atmosphere. The majority of previous works are not consensual concerning precipitable water vapor (PWV) and LST after the earthquake. Here, we utilized multi-source data to analyze the changes of PWV and LST anomaly after three Ms 4.0-5.3 crustal earthquakes at low depth (8-9 km) that occurred in Qinghai-Tibet Plateau. Firstly, PWV retrieval using Global Navigation Satellite System (GNSS) technology is performed, showing that its root mean square error (RMSE) is less than 1.8 mm against radiosonde (RS) data or European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5) PWV data. The PWV change derived from the nearest GNSS stations around the hypocenter during the earthquakes shows anomalies, and the results reveal that PWV anomalies occurred after the earthquakes, mainly obeying a trend of increasing first and then decreasing. In addition, LST increases three days before PWV peak with a thermal anomaly of 12 °C higher than that of previous days. Robust Satellite Technique (RST) algorithm and ALICE index on Moderate Resolution Imaging Spectroradiometer (MODIS) LST products are introduced to analyze the correlation between the abnormality of LST and PWV. Based on ten-year background field data (2012-2021), the results show that LST during the earthquake has more thermal anomaly occurrences than in previous years. The more severe the LST thermal anomaly is, the higher the probability of a PWV peak occurring.
地震是一种常见且具有破坏性的自然灾害。地震事件释放的大量能量会导致地表温度异常，并促使大气中水汽的积聚。以往的大多数研究对于地震后的可降水量水汽（PWV）和地表温度（LST）并未达成共识。在此，我们利用多源数据来分析青藏高原发生的三次震级为Ms 4.0 - 5.3、震源深度较浅（8 - 9千米）的地壳地震后PWV和LST异常的变化情况。首先，利用全球导航卫星系统（GNSS）技术进行PWV反演，结果表明，相对于探空仪（RS）数据或欧洲中期天气预报中心（ECMWF）再分析5（ERA5）的PWV数据，其均方根误差（RMSE）小于1.8毫米。地震期间震源附近最近的GNSS台站得出的PWV变化显示出异常，结果表明地震后出现了PWV异常，主要呈现先增加后减少的趋势。此外，LST在PWV峰值出现前三天升高，热异常比前几日高12℃。引入稳健卫星技术（RST）算法和中分辨率成像光谱仪（MODIS）LST产品上的ALICE指数来分析LST异常与PWV之间的相关性。基于十年的背景场数据（2012 - 2021年），结果表明地震期间的LST比往年出现了更多的热异常情况。LST热异常越严重，PWV峰值出现的概率就越高。
