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| Titel |
Antarctic interannual accumulation signals consistently monitored by GRACE satellite gravimetry and ENVISAT radar altimetry |
| VerfasserIn |
Martin Horwath, Benoît Legrésy, Frederique Remy, Fabien Blarel, Jean-Michel Lemoine |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052626
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| Zusammenfassung |
| Interannual variations of the Antarctic ice sheet, notably due to surface mass balance (SMB)
fluctuations, are relatively poorly constrained by modeling. Satellite altimetry and satellite
gravimetry over the ice sheet provide complementary observations of the related volume and
mass effects, respectively. Yet, the (nonlinear) interannual signal contents of these
observations have not been extensively studied so far. 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-day solutions by CNES/GRGS. We adjust the spatial resolution of
both datasets based on a rigorous description of the spatial filtering inherent to the
GRACE solutions. After correction for glacial isostatic adjustment, the spatial patterns
of trends seen by ENVISAT RA and GRACE over the period 10/2002-08/2009
agree well. Even more, the nonlinear interannual variations agree very well with
correlation coefficients typically in the order of 0.8. This agreement gives confidence that
ENVISAT RA and GRACE consistently reflect geophysical interannual variations.
Combining both geodetic datasets aids their interpretation and promises to be valuable for
SMB studies on the way to reduce present SMB uncertainties. In a case study we
describe the most prominent nonlinear interannual feature as an event of excess snow
accumulation in West Antarctica in September/October 2005 with a mass effect of 82 ± 31
Gt. |
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