 |
| Titel |
Seasonal changes in surface albedo of Himalayan glaciers from MODIS data and links with the annual mass balance |
| VerfasserIn |
F. Brun, M. Dumont, P. Wagnon, E. Berthier, M. F. Azam, J. M. Shea, P. Sirguey, A. Rabatel, Al. Ramanathan |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 1 ; Nr. 9, no. 1 (2015-02-13), S.341-355 |
| Datensatznummer |
250116754
|
| Publikation (Nr.) |
 copernicus.org/tc-9-341-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Few glaciological field data are available on glaciers in the Hindu Kush–Karakoram–Himalayan (HKH) region, and remote sensing data are thus
critical for glacier studies in this region. The main objectives of
this study are to document, using satellite images, the seasonal
changes of surface albedo for two Himalayan glaciers, Chhota Shigri
Glacier (Himachal Pradesh, India) and Mera Glacier (Everest region,
Nepal), and to reconstruct the annual mass balance of these glaciers
based on the albedo data. Albedo is retrieved from Moderate Resolution Imaging
Spectroradiometer (MODIS) images, and evaluated using ground based
measurements. At both sites, we find high coefficients of
determination between annual minimum albedo averaged over the
glacier (AMAAG) and glacier-wide annual mass balance
(Ba) measured with the glaciological method
(R2 = 0.75). At Chhota Shigri Glacier, the relation between AMAAG
found at the end of the ablation season and Ba suggests
that AMAAG can be used as a proxy for the maximum snow line altitude
or equilibrium line altitude (ELA) on winter-accumulation-type
glaciers in the Himalayas. However, for the summer-accumulation-type Mera Glacier,
our approach relied on the hypothesis that ELA information is preserved during the
monsoon. At Mera Glacier, cloud obscuration and snow accumulation limits the
detection of albedo during the monsoon, but snow redistribution and sublimation
in the post-monsoon period allows for the calculation of AMAAG. Reconstructed
Ba at Chhota Shigri Glacier agrees with mass balances
previously reconstructed using a positive degree-day method.
Reconstructed Ba at Mera Glacier is affected by heavy
cloud cover during the monsoon, which systematically limited our
ability to observe AMAAG at the end of the melting period. In
addition, the relation between AMAAG and Ba is
constrained over a shorter time period for Mera Glacier
(6 years) than for Chhota Shigri Glacier
(11 years). Thus the mass balance reconstruction is less
robust for Mera Glacier than for Chhota Shigri Glacier. However our
method shows promising results and may be used to reconstruct the
annual mass balance of glaciers with contrasted seasonal cycles in
the western part of the HKH mountain range since the early 2000s
when MODIS images became available. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|