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| Titel |
Surface energy budget on Larsen and Wilkins ice shelves in the Antarctic Peninsula: results based on reanalyses in 1989–2010 |
| VerfasserIn |
I. Välisuo, T. Vihma, J. C. King |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 4 ; Nr. 8, no. 4 (2014-08-20), S.1519-1538 |
| Datensatznummer |
250116265
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| Publikation (Nr.) |
 copernicus.org/tc-8-1519-2014.pdf |
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| Zusammenfassung |
| Ice shelves in the Antarctic Peninsula have significantly disintegrated
during recent decades. To better understand the atmospheric contribution
in the process, we have analysed the inter-annual variations in radiative
and turbulent surface fluxes and weather conditions over Larsen C Ice Shelf
(LCIS) and Wilkins Ice Shelf (WIS) in the Antarctic Peninsula in 1989–2010.
Three atmospheric reanalyses were applied: ERA-Interim by ECMWF, Climate
Forecast System Reanalysis (CFSR) by NCEP, and JRA-25/JCDAS by the Japan
Meteorological Agency. In addition, in situ observations from an automatic
weather station (AWS) on LCIS were applied, mainly for validation of the
reanalyses. The AWS observations on LCIS did not show any significant
temperature trend, and the reanalyses showed warming trends only over WIS:
ERA-Interim in winter (0.23 °C yr−1) and JRA-25/JCDAS in
autumn (0.13 °C yr−1). In LCIS from December through
August and in WIS from March through August, the variations of surface net
flux were partly explained by the combined effects of atmospheric pressure,
wind and cloud fraction. The explained variance was much higher in LCIS (up
to 80%) than in WIS (26–27%). Summer melting on LCIS varied between
11 and 58 cm water equivalent (w.e.), which is comparable to previous
results. The mean amount of melt days per summer on LCIS was 69. The high
values of melting in summer 2001–2002 presented in previous studies on the
basis of simple calculations were not supported by our study. Instead, our
calculations based on ERA-Interim yielded strongest melting in summer
1992–1993 on both ice shelves. On WIS the summer melting ranged between 10
and 23 cm w.e., and the peak values coincided with the largest
disintegrations of the ice shelf. The amount of melt on WIS may, however, be
underestimated by ERA-Interim, as previously published satellite
observations suggest that it suffers from a significant bias over WIS. |
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