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Titel |
ENSO influence on surface energy and mass balance at Shallap Glacier, Cordillera Blanca, Peru |
VerfasserIn |
F. Maussion, W. Gurgiser, M. Großhauser, G. Kaser , B. Marzeion |
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 ; 9, no. 4 ; Nr. 9, no. 4 (2015-08-21), S.1663-1683 |
Datensatznummer |
250116840
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Publikation (Nr.) |
copernicus.org/tc-9-1663-2015.pdf |
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Zusammenfassung |
The El Niño/Southern Oscillation (ENSO) is a major driver of climate
variability in the tropical Andes, where recent Niño and Niña events
left an observable footprint on glacier mass balance. The nature and strength
of the relationship between ENSO and glacier mass balance, however, varies
between regions and time periods, leaving several unanswered questions about
its exact mechanisms. The starting point of this study is a 4-year long
time series of distributed surface energy and mass balance (SEB/SMB)
calculated using a process-based model driven by observations at Shallap
Glacier (Cordillera Blanca, Peru). These data are used to calibrate a
regression-based downscaling model that links the local SEB/SMB fluxes to
atmospheric reanalysis variables on a monthly basis, allowing an
unprecedented quantification of the ENSO influence on the SEB/SMB at
climatological time scales (1980–2013, ERA-Interim period). We find a
stronger and steadier anti-correlation between Pacific sea-surface
temperature (SST) and glacier mass balance than previously reported. This
relationship is most pronounced during the wet season (December–May) and at
low altitudes where Niño (Niña) events are accompanied with a
snowfall deficit (excess) and a higher (lower) radiation energy input. We
detect a weaker but significant ENSO anti-correlation with total
precipitation (Niño dry signal) and positive correlation with the
sensible heat flux, but find no ENSO influence on sublimation. Sensitivity
analyses comparing several downscaling methods and reanalysis data sets
resulted in stable mass balance correlations with Pacific SST but also
revealed large uncertainties in computing the mass balance trend of the last
decades. The newly introduced open-source downscaling tool can be applied
easily to other glaciers in the tropics, opening new research possibilities
on even longer time scales. |
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