An 11-year record of mass balance of Brewster Glacier, New Zealand, determined using a geostatistical approach
| Autor: | NICOLAS J. CULLEN, BRIAN ANDERSON, PASCAL SIRGUEY, DOROTHEA STUMM, ANDREW MACKINTOSH, JONATHAN P. CONWAY, HUW J. HORGAN, RUZICA DADIC, SEAN J. FITZSIMONS, ANDREW LORREY |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Journal of Glaciology, Vol 63, Pp 199-217 (2017) |
| Druh dokumentu: | article |
| ISSN: | 0022-1430 1727-5652 |
| DOI: | 10.1017/jog.2016.128 |
| Popis: | Recognising the scarcity of glacier mass-balance data in the Southern Hemisphere, a mass-balance measurement programme was started at Brewster Glacier in the Southern Alps of New Zealand in 2004. Evolution of the measurement regime over the 11 years of data recorded means there are differences in the spatial density of data obtained. To ensure the temporal integrity of the dataset a new geostatistical approach is developed to calculate mass balance. Spatial co-variance between elevation and snow depth allows a digital elevation model to be used in a co-kriging approach to develop a snow depth index (SDI). By capturing the observed spatial variability in snow depth, the SDI is a more reliable predictor than elevation and is used to adjust each year of measurements consistently despite variability in sampling spatial density. The SDI also resolves the spatial structure of summer balance better than elevation. Co-kriging is used again to spatially interpolate a derived mean summer balance index using SDI as a co-variate, which yields a spatial predictor for summer balance. The average glacier-wide surface winter, summer and annual balances over the period 2005–15 are 2484, −2586 and −102 mm w.e., respectively, with changes in summer balance explaining most of the variability in annual balance. |
| Databáze: | Directory of Open Access Journals |
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