Long-term analysis of surface temperature trends and dynamics deglaciation of the Eidembreen glacier (Svalbard) based on Landsat data for 1984–2025

Abstract. Climate warming in the Arctic leads to accelerated glacier retreat and the formation of extensive deglaciated surfaces, substantially altering glacier–periglacial interactions. On the western coast of Svalbard, retreat of the polythermal Eidembreen Glacier is accompanied by the development of a mosaic deglaciated surface including a glacial–accumulative plain, a lagoonal basin, and a barrier spit. The aim of this study is to assess the role of the thermal regime of the deglaciated surface in glacier dynamics over a multi-decadal timescale. The analysis is based on Landsat Level-2 satellite data (Landsat 5 TM, 7 ETM+, 8 OLI/TIRS, and 9 OLI-2/TIRS-2) acquired during the period of maximum ablation (July–September) for 1984–2025. Land surface temperature (LST) and the Normalized Difference Snow Index (NDSI) were used to characterize thermal and cryospheric conditions. The satellite analysis was complemented by glacier front mapping, estimation of deglaciated area extent, and assessment of lagoon dynamics using historical aerial photographs and modern orthophotos. The results indicate an almost monotonic increase in deglaciated area from ~13.5 km² in the late 1970s to ~29.5 km² by 2025, despite pronounced interannual LST variability. Glacier retreat rates range from 19 to 42 m yr⁻¹, with maximum values in the early 21st century and renewed intensification after 2015. A strong negative correlation (r = −0.97) was identified between NDSI and deglaciated area, whereas LST primarily controls short-term melt intensity. These findings highlight the cumulative and inertial nature of deglaciation and emphasize the role of periglacial surface thermal properties in polythermal glacier dynamics.