DOI: 10.5194/tc-11-191-2017
Scopus记录号: 2-s2.0-85010749666
论文题名: Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957-2014
作者: Østby T ; I ; , Vikhamar Schuler T ; , Ove Hagen J ; , Hock R ; , Kohler J ; , Reijmer C ; H
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 1 起始页码: 191
结束页码: 215
语种: 英语
英文关键词: albedo
; archipelago
; energy balance
; equilibrium line
; eustacy
; glacier
; glacier mass balance
; hydrology
; ice core
; meltwater
; model validation
; radar
; remote sensing
; snowpack
; spatiotemporal analysis
; surface energy
; thermal regime
; Arctic
; Svalbard
; Svalbard and Jan Mayen
英文摘要: 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 1km 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 8.2cm w. e. yr-1, which corresponds to a mass input of 175Gt. Climatic mass balance has a linear trend of -1.4 ± 0.4cm 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 -21cm w. e. yr-1, and accounting for frontal ablation estimated by BÅ aszczyk et al.(2009) yields a total Svalbard mass balance of -39cm w. e. yr-1 for this 10-year period. In terms of eustatic sea level, this corresponds to a rise of 0.037mm yr-1. Refreezing of water in snow and firn is substantial at 22cm 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 (> 2m) firn extent and an increase in the superimposed ice, thin (< 2m) firn and bare ice extents. Atmospheric warming also leads to a marked change in the thermal regime, with cooling of the glacier mid-elevation and warming in the ablation zone and upper firn areas. On the long-term, by removing the thermal barrier, this warming has implications for the vertical transfer of surface meltwater through the glacier and down to the base, influencing basal hydrology, sliding and thereby overall glacier motion. © Author(s) 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75614
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Institute of Geoscience, University of Oslo, PO Box 1047, Blindern, Oslo, Norway; Geophysical Institute, University of Alaska, Fairbanks, AK, United States; Department of Earth Sciences, Uppsala University, Villavägen 16, Uppsala, Sweden; Norwegian Polar Institute, Fram Centre, PO Box 6606, Langnes, Tromsø, Norway; Institute for Marine and Atmospheric Research, Utrecht University, Princetonplein 5, Utrecht, Netherlands
Recommended Citation:
Østby T,I,, Vikhamar Schuler T,et al. Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957-2014[J]. Cryosphere,2017-01-01,11(1)