Long-term correlation analysis between monthly precipitable water vapor and precipitation using GPS data over China

• Published in: Advances in space research 2022-07, Vol.70 (1), p.56-69
• Main Authors: Zhou, Linghao, Fan, Lei, Zhang, Weixing, Shi, Chuang
• Format: Article
• Language: English
• Subjects: Cross-correlation analysis; Cross-wavelet analysis; Global Positioning System (GPS); Precipitable water vapor (PWV); Precipitation
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/j.asr.2022.04.026

Precipitable Water Vapor (PWV) is an important driving factor for the occurrence of precipitation. A deep understanding of the correlation between the PWV and the precipitation helps to understand the regional water cycle based on the theory of atmospheric water balance. This study aims to analyze the correlation between the precipitation and the PWV derived from Global Positioning System (GPS) observations collected from a total of 233 Global Navigation Satellite System (GNSS) stations in China mainland over 10 years. The PWV was calculated through Zenith Total Delay (ZTD) from the Precise Point Positioning (PPP) technique and metrological data from the European Centre for Medium-Range Weather Forecasts (ECMWF). The relationship between PWV derived from GPS and the precipitation from the Tropical Rainfall Measuring Mission (TRMM) at monthly temporal resolution was analyzed through the cross-correlation analysis and the cross-wavelet analysis. Results showes that a 1-month lag was observed between monthly PWV and precipitation at some inland stations in the south-eastern region of China, which is due to the earlier peaks of precipitation caused by the quasi-stationary front in this region. After the time-lag shift, most of the stations showed a cross-correlation coefficient higher than 0.7, indicating that monthly PWV and precipitation are generally correlated over China mainland. Specifically, the cross-correlation coefficients from stations located in western China have a wide range of 0.16–0.95 and a large dispersion degree with the standard deviation (STD) of 0.2, which is due to the variable climatic conditions caused by the topographical distribution. The cross-correlation coefficients from stations located in the middle and north-eastern region of China are generally greater than 0.75 and have an STD of 0.08, while those located in the south-eastern region of China are generally less than 0.65 and have an STD of 0.09. This is because the south-eastern region of China has a relatively longer rainy season caused by the influences from Asian monsoon systems. These results could contribute to the further understanding of the regional water cycle based on the theory of atmospheric water balance within China.