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| Titel |
Weak precipitation, warm winters and springs impact glaciers of south slopes of Mt. Everest (central Himalaya) in the last 2 decades (1994–2013) |
| VerfasserIn |
F. Salerno, N. Guyennon, S. Thakuri, G. Viviano, E. Romano, E. Vuillermoz, P. Cristofanelli, P. Stocchi, G. Agrillo, Y. Ma, G. Tartari |
| 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. 3 ; Nr. 9, no. 3 (2015-06-17), S.1229-1247 |
| Datensatznummer |
250116813
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| Publikation (Nr.) |
 copernicus.org/tc-9-1229-2015.pdf |
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| Zusammenfassung |
| Studies on recent climate trends from the Himalayan range are limited, and
even completely absent at high elevation (> 5000 m a.s.l.). This
study specifically explores the southern slopes of Mt. Everest, analyzing
the time series of temperature and precipitation reconstructed from seven
stations located between 2660 and 5600 m a.s.l. during 1994–2013,
complemented with the data from all existing ground weather stations located
on both sides of the mountain range (Koshi Basin) over the same period.
Overall we find that the main and most significant increase in temperature
is concentrated outside of the monsoon period. Above 5000 m a.s.l. the
increasing trend in the time series of minimum temperature
(+0.072 °C yr−1) is much stronger than of maximum temperature
(+0.009 °C yr−1), while the mean temperature increased by
+0.044 °C yr−1. Moreover, we note a substantial liquid
precipitation weakening (−9.3 mm yr−1) during the monsoon season. The
annual rate of decrease in precipitation at higher elevations is similar to
the one at lower elevations on the southern side of the Koshi Basin, but the
drier conditions of this remote environment make the fractional loss much
more consistent (−47% during the monsoon period). Our results challenge
the assumptions on whether temperature or precipitation is the main driver
of recent glacier mass changes in the region. The main implications are the
following: (1) the negative mass balances of glaciers observed in this
region can be more ascribed to a decrease in accumulation (snowfall) than to
an increase in surface melting; (2) the melting has only been favoured during
winter and spring months and close to the glaciers terminus; (3) a decrease
in the probability of snowfall (−10%) has made a significant impact only
at glacier ablation zone, but the magnitude of this decrease is distinctly
lower than the observed decrease in precipitation; (4) the decrease in
accumulation could have caused the observed decrease in glacier flow
velocity and the current stagnation of glacier termini, which in turn could
have produced more melting under the debris glacier cover, leading to the
formation of numerous supraglacial and proglacial lakes that have
characterized the region in the last decades. |
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