ITRF2014 GNSS vertical velocities, geocenter motions and ellipticity time variations.
Abstract
We investigate the GNSS station vertical velocities provided by the new solution of the International Terrestrial Reference Frame, entitled ITRF2014. Constructed from a global network of approximately 1500 stations of the different space geodetic techniques, this new solution provides two times more GNSS station velocities than the ITRF2008. We show here that ITRF2014 solution presents a peculiarity compared to all precedent solutions: very large vertical velocities can be seen across Greenland, South East Alaska and the Antarctic Peninsula, which are a priori caused by recent ice sheet melting. This signal, which is larger than the Glacial Isostatic Adjustment signal, tends in addition to accelerate. As a consequence, we had to introduce multiple velocity discontinuities in ITRF2014 GNSS time series to account for the specific behavior of stations close to ice sheets. Then, we investigate the global Earth figure variations as seen by the ITRF2014 GNSS vertical velocities. We particularly focus on the geocenter motion, the ellipticity of the solid Earth, and the J2-dot time rate.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.G41A1001M
- Keywords:
-
- 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions;
- GEODESY AND GRAVITYDE: 1229 Reference systems;
- GEODESY AND GRAVITYDE: 1240 Satellite geodesy: results;
- GEODESY AND GRAVITYDE: 1295 Integrations of techniques;
- GEODESY AND GRAVITY