“…Various studies have quantified the spatial and temporal variation and trend in atmospheric water vapor using two types of water vapor data: (i) measurements or retrievals from sensor observations and (ii) reanalysis data produced by assimilating various observations. The first data type includes both ground-based in situ and spaceborne observations: longterm radiosonde measurements (Zhai and Eskridge, 1997;Ross and Elliott, 2001;Ho et al, 2010;Zhao et al, 2012;Zhang et al, 2018), weather station data (Dai, 2006), water vapor retrieved from ground-based Global Positioning System (GPS) station data (Kursinski et al, 1997;Bock et al, 2007;Nilsson and Elgered, 2008;Vey et al, 2010;Huang et al, 2013;Chen and Liu, 2016;Yuan et al, 2023), water vapor retrievals from spaceborne radio occultation observations (Ho et al, 2009;Huang et al, 2013Huang et al, , 2018Zhang et al, 2018;Andrisaniand and Vespe, 2020;Gleisner et al, 2022), visible-spectral-range sensor observations Grossi et al, 2015;Borger et al, 2023), microwave observations (Rosenkranz, 2001;Chen and Liu, 2016;Ho et al, 2018;Yadav et al, 2021), and infrared sounder observations (Susskind et al, 2003).…”