Accelerated mass loss of Austre Lovénbreen glacier, Svalbard: Drivers and thresholds

Austre Lovénbreen glacier (78.91°N, 11.90°E), a polythermal valley glacier in northwest Svalbard spanning 50–550 m a.s.l., within the rapidly warming Ny-Ålesund region. We present a 14-year (2005/06–2018/19) glaciological mass balance record derived from 19 stake measurements, snow pit density surveys, and an updated glacier boundary. Results indicate a mean annual mass loss of − 0.47 ± 0.22 m w.e. yr⁻¹, equivalent to a cumulative deficit of − 6.53 ± 0.84 m w.e. Over two-thirds (65 %) of this loss originated below 200 m a.s.l., while accumulation above 400 m a.s.l. was insufficient to counteract continued frontal retreat, emphasizing the combined role of Arctic amplification and glacier geometry in accelerating ablation. Regional comparison shows that Austre Lovénbreen’s mass loss aligns with the Svalbard mean (− 0.47 m w.e. yr⁻¹). This balance highlights the glacier’s sensitivity to marine climate forcing and its role as a representative indicator of hydrological change in northwest Svalbard. The findings underscore the dominance of low-elevation meltwater production, with implications for proglacial runoff, sediment fluxes, and downstream ecosystems under continued warming. • First 14-yr mass-balance record for Austre Lovenbreen reveals accelerated Arctic glacier retreat: -0.47±0.22 m w.e./yr. • Low-elevation zones (<200 m) drive 65 % of mass loss, as high-altitude accumulation cannot offset terminus retreat. • Cumulative deficit: − 6.53 ± 0.84 m w.e. signals accelerating ablation. • ELA rise to > 500 m reduces AAR below 0.5, indicating ablation dominance.