Abstract
The rapid variation of atmospheric water vapor is important for a regional hydrologic cycle and climate change. However, it is rarely investigated in China, due to the lack of a precipitable water vapor (PWV) dataset with high temporal resolution. Therefore, this study focuses on the generation of an hourly PWV dataset using Global Navigation Satellite System (GNSS) observations derived from the Crustal Movement Observation Network of China. The zenith total delay parameters estimated by GAMIT/GLOBK software are used and validated with an average root mean square (RMS) error of 4–5 mm. The pressure (P) and temperature (T) parameters used to calculate the zenith hydrostatic delay (ZHD) and weighted average temperature of atmospheric water vapor (Tm) are derived from the fifth-generation reanalysis dataset of the European Centre for Medium-Range Weather Forecasting (ECMWF ERA5) products. The values of P and T at the GNSS stations are obtained by interpolation in the horizontal and vertical directions using empirical formulas. Tm is calculated at the GNSS stations using the improved global pressure and temperature 2 wet (IGPT2w) model in China with an RMS of 3.32 K. The interpolated P and T are validated by interpolating the grid-based ERA5 data into radiosonde stations. The average RMS and bias of P and T in China are 2.71/−1.11 hPa and 1.88/−0.51 K, respectively. Therefore, the error in PWV with a theoretical RMS of 1.85 mm over the period of 2011–2017 in China can be obtained. Finally, the hourly PWV dataset in China is generated and the practical accuracy of the generated PWV dataset is validated using the corresponding AERONET and radiosonde data at specific stations. Numerical results reveal that the average RMS values of the PWV dataset in the four geographical regions of China are less than 3 mm. A case analysis of the PWV diurnal variations as a response to the EI Niño event of 2015–2016 is performed. Results indicate the capability of the hourly PWV dataset of monitoring the rapid water vapor changes in China.
Highlights
Atmospheric water vapor is a key component of the troposphere, and it affects the global/regional water cycles and climate change [1]
Precipitable water vapor (PWV), which is used to reflect the content of atmospheric water vapor, is the value corresponding to the conversion of all atmospheric water vapor into liquid water in the air column of a unit area from the surface to the troposphere high
The grid-based P and T data derived from ERA5 must be interpolated into the RS stations prior to comparison; the interpolation can be completed on the basis of the following formula [26]: Radiosonde data are selected in the current work to validate the accuracy of P and T derived from ERA5 and PWV using Global Navigation Satellite System (GNSS) and ERA5 data
Summary
Atmospheric water vapor is a key component of the troposphere, and it affects the global/regional water cycles and climate change [1]. Water vapor is an important greenhouse gas, which is highly related to the heat feedback function. Knowledge of rapid water vapor variations is important for analyzing global/regional water vapor distributions [2]. The distribution of atmospheric water vapor with high temporal–spatial resolutions is still difficult to monitor, due to the shortcomings of traditional techniques for water vapor monitoring. Precipitable water vapor (PWV), which is used to reflect the content of atmospheric water vapor, is the value corresponding to the conversion of all atmospheric water vapor into liquid water in the air column of a unit area from the surface to the troposphere high.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
