TY - JOUR
T1 - A global semi-empirical glacial isostatic adjustment (GIA) model based on Gravity Recovery and Climate Experiment (GRACE) data
AU - Sun, Yu
AU - Riva, Riccardo E.M.
PY - 2020
Y1 - 2020
N2 - The effect of glacial isostatic adjustment (GIA) on the shape and gravity of the Earth is usually described by numerical models that solve for both glacial evolution and Earth's rheology, being mainly constrained by the geological evidence of local ice extent and globally distributed sea level data, as well as by geodetic observations of Earth's rotation. In recent years, GPS and GRACE observations have often been used to improve those models, especially in the context of regional studies. However, consistency issues between different regional models limit their ability to answer questions from global-scale geodesy. Examples are the closure of the sea level budget, the explanation of observed changes in Earth's rotation, and the determination of the origin of the Earth's reference frame. Here, we present a global empirical model of present-day GIA, solely based on GRACE data and on geoid fingerprints of mass redistribution.We will show how the use of observations from a single space-borne platform, together with GIA fingerprints based on different viscosity profiles, allows us to tackle the questions from globalscale geodesy mentioned above. We find that, in the GRACE era (2003-2016), freshwater exchange between land and oceans has caused global mean sea level to rise by 1:2±0:2mmyr-11, the geocentre to move by 0:4± 0:1mmyr-11, and the Earth's dynamic oblateness (J2) to increase by 6:0±0:4×10-11 yr-11,.
AB - The effect of glacial isostatic adjustment (GIA) on the shape and gravity of the Earth is usually described by numerical models that solve for both glacial evolution and Earth's rheology, being mainly constrained by the geological evidence of local ice extent and globally distributed sea level data, as well as by geodetic observations of Earth's rotation. In recent years, GPS and GRACE observations have often been used to improve those models, especially in the context of regional studies. However, consistency issues between different regional models limit their ability to answer questions from global-scale geodesy. Examples are the closure of the sea level budget, the explanation of observed changes in Earth's rotation, and the determination of the origin of the Earth's reference frame. Here, we present a global empirical model of present-day GIA, solely based on GRACE data and on geoid fingerprints of mass redistribution.We will show how the use of observations from a single space-borne platform, together with GIA fingerprints based on different viscosity profiles, allows us to tackle the questions from globalscale geodesy mentioned above. We find that, in the GRACE era (2003-2016), freshwater exchange between land and oceans has caused global mean sea level to rise by 1:2±0:2mmyr-11, the geocentre to move by 0:4± 0:1mmyr-11, and the Earth's dynamic oblateness (J2) to increase by 6:0±0:4×10-11 yr-11,.
UR - http://www.scopus.com/inward/record.url?scp=85079572218&partnerID=8YFLogxK
U2 - 10.5194/esd-11-129-2020
DO - 10.5194/esd-11-129-2020
M3 - Article
AN - SCOPUS:85079572218
SN - 2190-4979
VL - 11
SP - 129
EP - 137
JO - Earth System Dynamics
JF - Earth System Dynamics
IS - 1
ER -