Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry

Interannual variations of the Antarctic ice sheet due to surface mass balance (SMB) fluctuations are important for mass balance estimates and interpretations. To date, these variations are primarily assessed by global or regional atmospheric modelling. Satellite altimetry and satellite gravimetry ov...

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Published in:Geophysical Journal International
Main Authors: Horwath, Martin, Legrésy, Benoît, Rémy, Frédérique, Blarel, Fabien, Lemoine, Jean-Michel
Format: Text
Language:English
Published: Oxford University Press 2012
Subjects:
Online Access:http://gji.oxfordjournals.org/cgi/content/short/189/2/863
https://doi.org/10.1111/j.1365-246X.2012.05401.x
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spelling fthighwire:oai:open-archive.highwire.org:gji:189/2/863 2023-05-15T13:24:18+02:00 Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry Horwath, Martin Legrésy, Benoît Rémy, Frédérique Blarel, Fabien Lemoine, Jean-Michel 2012-05-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/189/2/863 https://doi.org/10.1111/j.1365-246X.2012.05401.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/189/2/863 http://dx.doi.org/10.1111/j.1365-246X.2012.05401.x Copyright (C) 2012, Oxford University Press Gravity geodesy and tides TEXT 2012 fthighwire https://doi.org/10.1111/j.1365-246X.2012.05401.x 2015-02-28T17:33:51Z Interannual variations of the Antarctic ice sheet due to surface mass balance (SMB) fluctuations are important for mass balance estimates and interpretations. To date, these variations are primarily assessed by global or regional atmospheric modelling. Satellite altimetry and satellite gravimetry over the ice sheet provide complementary observations of the related volume and mass effects, respectively. Yet, so far the interannual signal contents of these observations have not been extensively studied. We compare and jointly interpret ENVISAT radar altimetry (RA) and GRACE satellite gravimetry results, relying on RA products from the along-track repeat satellite RA approach and on the GRACE 10-d solutions by CNES/GRGS. RA results and GRACE results are expressed in terms of variations of ice sheet thickness, Δ z ( t ), and ice-equivalent thickness, Δ z ice ( t ), respectively. In view of the different errors and limitations of both techniques and of differences between Δ z ( t ) and Δ z ice ( t ) expected due to firn-related processes, our principal approach is a comparison of qualitative patterns in space and time. To adjust the spatial resolution of both data sets, we describe the spatial filtering inherent to the regularization of the CNES/GRGS GRACE solutions and apply this filtering to the ENVISAT RA height changes in a consistent fashion. After correction for glacial isostatic adjustment, the spatial patterns of linear trends seen by ENVISAT RA and GRACE over the period 2002 October to 2009 August agree well, not only for the extreme ice losses in the West Antarctic Amundsen Sea Sector but also for an alternating sequence of gains and losses along the East Antarctic coast. Our main focus is on interannual signals, which we represent by the low-pass filtered non-linear, non-seasonal components of the Δ z ( t ) and Δ z ice ( t ) time-series. These components should reflect interannual SMB variations, apart from effects of changes in ice flow. We find an agreement between the interannual variation patterns from ... Text Amundsen Sea Antarc* Antarctic Ice Sheet HighWire Press (Stanford University) Amundsen Sea Antarctic The Antarctic Geophysical Journal International 189 2 863 876
institution Open Polar
collection HighWire Press (Stanford University)
op_collection_id fthighwire
language English
topic Gravity
geodesy and tides
spellingShingle Gravity
geodesy and tides
Horwath, Martin
Legrésy, Benoît
Rémy, Frédérique
Blarel, Fabien
Lemoine, Jean-Michel
Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
topic_facet Gravity
geodesy and tides
description Interannual variations of the Antarctic ice sheet due to surface mass balance (SMB) fluctuations are important for mass balance estimates and interpretations. To date, these variations are primarily assessed by global or regional atmospheric modelling. Satellite altimetry and satellite gravimetry over the ice sheet provide complementary observations of the related volume and mass effects, respectively. Yet, so far the interannual signal contents of these observations have not been extensively studied. We compare and jointly interpret ENVISAT radar altimetry (RA) and GRACE satellite gravimetry results, relying on RA products from the along-track repeat satellite RA approach and on the GRACE 10-d solutions by CNES/GRGS. RA results and GRACE results are expressed in terms of variations of ice sheet thickness, Δ z ( t ), and ice-equivalent thickness, Δ z ice ( t ), respectively. In view of the different errors and limitations of both techniques and of differences between Δ z ( t ) and Δ z ice ( t ) expected due to firn-related processes, our principal approach is a comparison of qualitative patterns in space and time. To adjust the spatial resolution of both data sets, we describe the spatial filtering inherent to the regularization of the CNES/GRGS GRACE solutions and apply this filtering to the ENVISAT RA height changes in a consistent fashion. After correction for glacial isostatic adjustment, the spatial patterns of linear trends seen by ENVISAT RA and GRACE over the period 2002 October to 2009 August agree well, not only for the extreme ice losses in the West Antarctic Amundsen Sea Sector but also for an alternating sequence of gains and losses along the East Antarctic coast. Our main focus is on interannual signals, which we represent by the low-pass filtered non-linear, non-seasonal components of the Δ z ( t ) and Δ z ice ( t ) time-series. These components should reflect interannual SMB variations, apart from effects of changes in ice flow. We find an agreement between the interannual variation patterns from ...
format Text
author Horwath, Martin
Legrésy, Benoît
Rémy, Frédérique
Blarel, Fabien
Lemoine, Jean-Michel
author_facet Horwath, Martin
Legrésy, Benoît
Rémy, Frédérique
Blarel, Fabien
Lemoine, Jean-Michel
author_sort Horwath, Martin
title Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
title_short Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
title_full Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
title_fullStr Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
title_full_unstemmed Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry
title_sort consistent patterns of antarctic ice sheet interannual variations from envisat radar altimetry and grace satellite gravimetry
publisher Oxford University Press
publishDate 2012
url http://gji.oxfordjournals.org/cgi/content/short/189/2/863
https://doi.org/10.1111/j.1365-246X.2012.05401.x
geographic Amundsen Sea
Antarctic
The Antarctic
geographic_facet Amundsen Sea
Antarctic
The Antarctic
genre Amundsen Sea
Antarc*
Antarctic
Ice Sheet
genre_facet Amundsen Sea
Antarc*
Antarctic
Ice Sheet
op_relation http://gji.oxfordjournals.org/cgi/content/short/189/2/863
http://dx.doi.org/10.1111/j.1365-246X.2012.05401.x
op_rights Copyright (C) 2012, Oxford University Press
op_doi https://doi.org/10.1111/j.1365-246X.2012.05401.x
container_title Geophysical Journal International
container_volume 189
container_issue 2
container_start_page 863
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