Elastic Displacement of the Solid Earth and GRACE/GRACE‐FO Response to Variations in Global Lake and Reservoir Storage

Abstract We estimate the solid Earth's elastic response and change in equivalent water thickness produced by 983 global natural lakes and artificial reservoirs. Using the altimetry and LandSat based lake water storage compilation of Yao et al. (2023b, https://zenodo.org/records/7946043 ), we assemble the following data products: (a) change in water volume for 287 natural lakes and 696 artificial reservoirs interpolated to be continuous from October 1992 to October 2020, (b) maps of change in lake water storage each month, (c) lake‐generated change in equivalent water thickness as seen by Gravity Recovery and Climate Experiment (GRACE) in spherical harmonic coefficients and 3‐degree mass concentration elements (mascons), (d) lake‐generated east, north, and up components of elastic displacement at 19,827 Global Navigation Satellite System (GNSS) sites that the Nevada Geodetic Laboratory analyzes. Removing estimates of lake water storage reduces the variance of 79% of the 333 affected 3‐degree mascons in JPL's mascon solution, with a mean reduction of 2 cm (7%). In northern North America and Asia, lake water storage is predicted to reach its seasonal maximum 4–6 months after observed terrestrial water storage from GRACE, which can increase GRACE's variance when lake water is removed. Removing lake‐generated elastic displacements from GNSS station displacements reduces the weighted root mean square of residuals relative to a trended sinusoid with a seasonal period by an average of 4 mm (12%). Applications of GNSS displacements observations, such as glacial isostatic adjustment modeling and tectonic reconstructions can be biased due to lake water loading in the case of stations with short records and large lake water changes.