|
Titel |
Reconstruction of the 1979–2006 Greenland ice sheet surface mass balance using the regional climate model MAR |
VerfasserIn |
X. Fettweis |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1994-0416
|
Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 1, no. 1 ; Nr. 1, no. 1 (2007-10-31), S.21-40 |
Datensatznummer |
250000107
|
Publikation (Nr.) |
copernicus.org/tc-1-21-2007.pdf |
|
|
|
Zusammenfassung |
Results from a 28-year simulation (1979–2006) over the Greenland ice sheet
(GrIS) reveal an increase of solid precipitation (+0.4±2.5 km3 yr−2)
and run-off (+7.9±3.3 km3 yr−2) of surface
meltwater. The net effect of these competing factors is a significant
Surface Mass Balance (SMB) loss of −7.2±5.1 km3 yr−2.
The contribution of changes in the net water vapour flux (+0.02±0.09 km3 yr−2)
and rainfall (+0.2±0.2 km3 yr−2) to
the SMB variability is negligible. The meltwater supply has increased
because the GrIS surface has been warming up +2.4°C since 1979. Sensible
heat flux, latent heat flux and net solar radiation have not varied
significantly over the last three decades. However, the simulated downward
infrared flux has increased by 9.3 W m−2 since 1979. The natural
climate variability (e.g. the North Atlantic Oscillation) does not explain
these changes. The recent global warming, due to the greenhouse
gas concentration increase induced by human activities, could be a cause
of these changes. The doubling of surface meltwater flux into the ocean
over the period 1979–2006 suggests that the overall ice sheet mass balance
has been increasingly negative, given the likely meltwater-induced acceleration of outlet
glaciers. This study suggests that increased melting overshadows
over an increased accumulation in a warming scenario and that the GrIS is likely
to keep losing mass in the future. An enduring GrIS melting will probably affect
in the future an certain effect on the stability of the thermohaline circulation
and the global sea level rise. |
|
|
Teil von |
|
|
|
|
|
|