How to handle glacier area change in geodetic mass balance

• Published in: Journal of Glaciology
• Main Authors: Caitlyn Florentine, Louis Sass, Christopher McNeil, Emily Baker, Shad O'Neel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press
• Subjects: glacier mapping; glacier mass balance; mountain glaciers; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; alaska range; glacier; glaciers; Journal of Glaciology; Alaska
• Online Access: https://doi.org/10.1017/jog.2023.86; https://doaj.org/article/0d079ba073ca42ac8af2133ea1b3592c

Innovations in geodesy enable widespread analysis of glacier surface elevation change and geodetic mass balance. However, coincident glacier area data are less widely available, causing inconsistent handling of glacier area change. Here we quantify the bias introduced into meters water equivalent (m w.e.) specific geodetic mass balance results when using a fixed, maximum glacier area, and illustrate the bias for five North American glaciers. Sites span latitudes from the northern U.S. Rocky Mountains (48°N) to the Central Alaska Range (63°N) between 1948 and 2021. Results show that fixed (maximum) area treatment subdues the m w.e. mass change signal, underestimating mass balance by up to 19% in our test cases. This bias scales with relative glacier area change and the mass balance magnitude. Thus, the bias for specific geodetic mass balances will be most pronounced across rapidly deglaciating regions. Our analysis underscores the need for temporally resolved glacier area in geodetic mass balance studies.