Mass Flux From Atmospheric and Land Surface Perspectives Using Combined GRACE/GRACE-FO and Model Data

Abstract:

Characterization of the water cycle is vital to modeling and monitoring the global climate system. This work seeks to expand on accounting of major mass flux processes related to the water cycle at temporal and spatial scales resolvable by the GRACE and GRACE-FO missions. Using GRACE/GRACE-FO data as a total constraint on changes in terrestrial water storage, the major fluxes of atmospheric convergence, surface and subsurface runoff, precipitation, and evapotranspiration are combined into a mass balance of the water cycle. The balance is undertaken in two separate approaches: one isolating the terrestrial water storage variations using land surface models and the other utilizing combined land surface and atmospheric models to characterize the variation in the total water column. Analysis of a variety of regions lends clarity to the resolvable limits on this sort of accounting, contingent on the models and flux approach utilized, as well as the particular climate and geography. Additionally, a mass balance is undertaken for global flux, leading to an estimate of land-ocean exchange at the continental scale.