TY - JOUR
T1 - Assessing Global Present‐day Surface Mass Transport and Glacial Isostatic Adjustment from Inversion of Geodetic Observations
AU - Jiang, Yan
AU - Wu, Xiaoping
AU - van den Broeke, Michiel R.
AU - Munneke, Peter Kuipers
AU - Simonsen, Sebastian B.
AU - van der Wal, Wouter
AU - Vermeersen, Bert L.
PY - 2021
Y1 - 2021
N2 - Long‐term monitoring of global mass transport within the Earth system
improves our ability to mitigate natural hazards and better understand
their relations to climate change. Satellite gravity is widely used to
monitor surface mass variations for its unprecedented spatial and
temporal coverage. However, the gravity data contain signals from
visco‐elastic deformation in response to past ice sheet melting,
preventing us from extracting signals of present‐day surface mass trend
(PDMT) directly. Here we present a global inversion scheme that
separates PDMT and visco‐elastic glacial isostatic adjustment (GIA)
signatures by combining satellite gravimetry with satellite altimetry
and ground observations. Our inversion provides global dual data
coverage that enables a robust separation of PDMT and GIA spherical
harmonic coefficients. It has the advantage to provide estimates of the
Earth's long wavelength deformation signatures and their uncertainties.
Our GIA result, along with its uncertainty estimates, can be used in
future GRACE processing to better assess the impact of GIA to surface
mass change. Our GIA estimates includes rapid GIA uplift in the
Southeast Alaska and the Amundsen Sea Embayment, due to the
visco‐elastic response to recent glacial unloading. We estimate the
average surface mass change rate from 2002‐2010 to be ‐203±3 GT·a‐1 in
Greenland, ‐126±18 GT·a‐1 in Antarctica and ‐62±5 GT·a‐1 in Alaska. The
GIA low degree spherical harmonic coefficients are sensitive to
rheological properties in Earth's deep interior. Our low‐degree GIA
estimates include geocenter motion and J̇2 which provide unique
constraints to understand Earth's lower mantle and ice history.
AB - Long‐term monitoring of global mass transport within the Earth system
improves our ability to mitigate natural hazards and better understand
their relations to climate change. Satellite gravity is widely used to
monitor surface mass variations for its unprecedented spatial and
temporal coverage. However, the gravity data contain signals from
visco‐elastic deformation in response to past ice sheet melting,
preventing us from extracting signals of present‐day surface mass trend
(PDMT) directly. Here we present a global inversion scheme that
separates PDMT and visco‐elastic glacial isostatic adjustment (GIA)
signatures by combining satellite gravimetry with satellite altimetry
and ground observations. Our inversion provides global dual data
coverage that enables a robust separation of PDMT and GIA spherical
harmonic coefficients. It has the advantage to provide estimates of the
Earth's long wavelength deformation signatures and their uncertainties.
Our GIA result, along with its uncertainty estimates, can be used in
future GRACE processing to better assess the impact of GIA to surface
mass change. Our GIA estimates includes rapid GIA uplift in the
Southeast Alaska and the Amundsen Sea Embayment, due to the
visco‐elastic response to recent glacial unloading. We estimate the
average surface mass change rate from 2002‐2010 to be ‐203±3 GT·a‐1 in
Greenland, ‐126±18 GT·a‐1 in Antarctica and ‐62±5 GT·a‐1 in Alaska. The
GIA low degree spherical harmonic coefficients are sensitive to
rheological properties in Earth's deep interior. Our low‐degree GIA
estimates include geocenter motion and J̇2 which provide unique
constraints to understand Earth's lower mantle and ice history.
U2 - 10.1029/2020JB020713
DO - 10.1029/2020JB020713
M3 - Journal article
VL - 126
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
SN - 0148-0227
M1 - e2020JB020713
ER -
