Advancements in the GRACE and GRACE-FO Gradiometer Mode

Gravity gradients have not been globally measured since 2013. Accordingly, we advance GRACE gradiometer mode (GM) to enable GRACE, GRACE-FO, and future gravity missions to be used in a gravity gradient mode. The benefit for the geosciences is that gravity and gravity gradients contain complementary information about Earth’s structure. Based on the seminal contribution from Peidou (2020), we develop a novel configuration for GM that views any single gravimeter satellite as a ‘gradiometer’. The new GRACE-C ‘gradiometer’ gradients more clearly delineate global tectonic plate boundaries in the Himalayas and North Africa regions, the Aleutian trench, the Java trench, and the Peru-Chile trench. Over Canada, the effect of glacial isostatic adjustment is apparent. We also observe signals resembling terrestrial water storage changes in Africa, among others. Overall, we highlight the usefulness of GM gradients for a wide variety of geoscience applications. We then develop a software package to produce GM gradients.