Temporal downscaling of glaciological mass balance using seasonal observations

• Published in: Journal of Glaciology
• Main Authors: Michael Zemp, Ethan Welty
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press
• Subjects: Glacier mass balance; glacier modelling; glacier monitoring; temporal downscaling; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2023.66; https://doaj.org/article/9820a070230d4c9799c49b4c4e3083ac

Glaciological mass-balance measurements have been the backbone of internationally coordinated glacier monitoring. The resulting annual observations have been used to understand glacier reactions to climate change, and to assess both regional and global glacier mass changes and related contributions to runoff and sea-level rise. However, the comparability of annual observations is hampered by differences in survey periods and mass-balance amplitudes between glaciers, regions and hemispheres. This study presents a simple approach to temporally downscale glaciological mass balance using seasonal observations and sine functions. The proposed analytical model allows reconstruction of the seasonal course of glacier mass balance at weekly to monthly resolution from only annual or seasonal observations. Strengths and limitations of this analytical approach are discussed and compared with results from numerical mass-balance modelling. Potential applications include seasonal corrections of glaciological and geodetic observations and comparisons to monthly results from spaceborne gravimetry and altimetry.