Modelling spatial patterns of near-surface air temperature over a decade of melt seasons on McCall Glacier, Alaska ...

• Main Authors: Troxler, Patrick, Ayala, Alvaro, Shaw, Thomas E., Nolan, Matt, Brock, Ben W., Pellicciotti, Francesca
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2020
• Subjects: Glacier meteorology; Melt-surface; Arctic glaciology; Arctic; glacier; Alaska
• Online Access: https://dx.doi.org/10.3929/ethz-b-000416458; http://hdl.handle.net/20.500.11850/416458

We examine the spatial patterns of near-surface air temperature (Ta) over a melting glacier using a multi-annual dataset from McCall Glacier, Alaska. The dataset consists of a 10-year (2005–2014) meteorological record along the glacier centreline up to an upper glacier cirque, spanning an elevation difference of 900 m. We test the validity of on-glacier linear lapse rates, and a model that calculates Ta based on the influence of katabatic winds and other heat sources along the glacier flow line. During the coldest hours of each summer (10% of time), average lapse rates across the entire glacier range from −4.7 to −6.7°C km−1, with a strong relationship between Ta and elevation (R2 > 0.7). During warm conditions, Ta shows more complex, non-linear patterns that are better explained by the flow line-dependent model, reducing errors by up to 0.5°C compared with linear lapse rates, although more uncertainty might be associated with these observations due to occasionally poor sensor ventilation. We conclude ... : Journal of Glaciology, 66 (257) ...