Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014
| Autor: | Østby, T.I., Schuler, T.V., Hagen, J.O., Hock, Regine, Kohler, J., Reijmer, C.H., Sub Dynamics Meteorology, Marine and Atmospheric Research |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
lcsh:GE1-350
Glacier ice accumulation geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Geofysik lcsh:QE1-996.5 Firn Accumulation zone Glacier Albedo 010502 geochemistry & geophysics Snow 01 natural sciences lcsh:Geology Geophysics Ice core Climatology Environmental science lcsh:Environmental sciences 0105 earth and related environmental sciences Earth-Surface Processes Water Science and Technology Ablation zone |
| Zdroj: | The Cryosphere, 11, 191. Copernicus Publications The Cryosphere, Vol 11, Iss 1, Pp 191-215 (2017) |
| ISSN: | 1994-0424 1994-0416 |
| Popis: | Estimating the long-term mass balance of the high-Arctic Svalbard archipelago is difficult due to the incomplete geodetic and direct glaciological measurements, both in space and time. To close these gaps, we use a coupled surface energy balance and snow pack model to analyse the mass changes of all Svalbard glaciers for the period 1957–2014. The model is forced by ERA-40 and ERA-Interim reanalysis data, downscaled to 1 km resolution. The model is validated using snow/firn temperature and density measurements, mass balance from stakes and ice cores, meteorological measurements, snow depths from radar profiles and remotely sensed surface albedo and skin temperatures. Overall model performance is good, but it varies regionally. Over the entire period the model yields a climatic mass balance of 8.2 cm w. e. yr−1, which corresponds to a mass input of 175 Gt. Climatic mass balance has a linear trend of −1.4 ± 0.4 cm w. e. yr−2 with a shift from a positive to a negative regime around 1980. Modelled mass balance exhibits large interannual variability, which is controlled by summer temperatures and further amplified by the albedo feedback. For the recent period 2004–2013 climatic mass balance was −21 cm w. e. yr−1, and accounting for frontal ablation estimated by Błaszczyk et al.(2009) yields a total Svalbard mass balance of −39 cm w. e. yr−1 for this 10-year period. In terms of eustatic sea level, this corresponds to a rise of 0.037 mm yr−1. Refreezing of water in snow and firn is substantial at 22 cm w. e. yr−1 or 26 % of total annual accumulation. However, as warming leads to reduced firn area over the period, refreezing decreases both absolutely and relative to the total accumulation. Negative mass balance and elevated equilibrium line altitudes (ELAs) resulted in massive reduction of the thick (> 2 m) firn extent and an increase in the superimposed ice, thin ( |
| Databáze: | OpenAIRE |
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