SLR, GRACE and Swarm Gravity Field Determination and Combination

Meyer, Ulrich; Sosnica, K.; Arnold, Daniel; Dahle, C.; Thaller, D.; Dach, Rolf; Jäggi, Adrian (2019). SLR, GRACE and Swarm Gravity Field Determination and Combination. Remote sensing, 11(8), p. 956. MDPI 10.3390/rs11080956

Preview

Text remotesensing-11-00956-v2.pdf - Published Version Available under License Creative Commons: Attribution (CC-BY). Download (14MB) | Preview

Satellite gravimetry allows for determining large scale mass transport in the system Earth and to quantify ice mass change in polar regions. We provide, evaluate and compare a long time-series of monthly gravity field solutions derived either by satellite laser ranging (SLR) to geodetic satellites, by GPS and K-band observations of the GRACE mission, or by GPS observations of the three Swarm satellites. While GRACE provides gravity signal at the highest spatial resolution, SLR sheds light on mass transport in polar regions at larger scales also in the pre- and post-GRACE era. To bridge the gap between GRACE and GRACE Follow-On, we also derive monthly gravity fields using Swarm data and perform a combination with SLR. To correctly take all correlations into account, this combination is performed on the normal equation level. Validating the Swarm/SLR combination against GRACE during the overlapping period January 2015 to June 2016, the best fit is achieved when down-weighting Swarm compared to the weights determined by variance component estimation. While between 2014 and 2017 SLR alone slightly overestimates mass loss in Greenland compared to GRACE, the combined gravity fields match significantly better in the overlapping time period and the RMS of the differences is reduced by almost 100 Gt. After 2017 both, SLR and Swarm indicate moderate mass gain in Greenland.

Interest & Impact

Downloads

172 since deposited on 31 Jul 2019
15 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item