CryoSwath: a CryoSat-2 swath processor and monthly surface elevation dataset for Arctic mountain glaciers

Abstract. Mountain glaciers are projected to lose between 26 and 41 % of their mass from 2015 until 2100 depending on the assumed global temperature change scenario. Melting glacier ice contributes to sea-level rise and reduces terrestrial freshwater storage. Monitoring glacier change contributes to the evidence base that can help affected communities assess whether adaptation is necessary and identify appropriate measures. We introduce the open-source Python package CryoSwath, which estimates glacier surface elevations from freely available CryoSat-2 altimetry data. Alongside, we establish a process-informed interpolation method and estimate uncertainty correlations from systematic comparison to a photogrammetry-based reference (ArcticDEM strips). Further, we present a CryoSwath-produced dataset of monthly sampled, three-month rolling-window glacier surface elevation estimates at a 500 m resolution covering nearly all glaciated areas in the Arctic during the period 2010 to 2024. We find that glaciers in Alaska are thinning most rapidly while those in Arctic Canada North and Greenland Periphery show the slowest region-wide change rates. However, negative trends are ubiquitous with an Arctic-wide mass loss of 197 +/- 10 Gt yr^-1.

The dataset opens research opportunities to study these changes in detail and to contextualize the glacier response to variability in atmospheric or oceanic forcing. The open software enables non-expert researchers from different fields to efficiently process CryoSat-2 data at scale over glaciated regions and inspect the data at intermediate processing stages. The user has full control over the processing and, with that, the means to derive and output non-default quantities.