Mineral Dust in Seasonal Snow and Firn on Svalbard Glaciers: Deposition Rates, Composition, and Albedo Impacts

Warming on Svalbard is occurring up to seven times faster than the global average and is driving widespread glacier retreat. In addition to rising air temperatures, light absorbing particles (LAP; including black carbon and mineral dust) can enhance snow and ice melt by reducing surface albedo. While black carbon has been studied extensively on Svalbard, mineral dust remains relatively understudied despite growing evidence that high latitude dust emissions may increase due to decreases in snow cover and glaciers retreat.

To address this knowledge gap, we analyzed mineral dust and black carbon in seasonal snow and firn cores collected from twelve spatially distributed Svalbard glaciers between 2022 and 2026. Dust concentrations and deposition rates were quantified using gravimetric filtration and ICP-MS, while dust mineral composition was characterized using X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. Black carbon was measured on select firn samples using a Single Particle Soot Photometer.

Results show pronounced seasonal variability, with low winter dust concentrations and enhanced summer–fall deposition, as well as substantial spatial variability in dust concentration, mineralogy, and spectral reflectance. Winter dust concentrations ranged from 0.3 to 17.6 µg g⁻¹ (median 0.9 µg g⁻¹), with deposition rates between 0.1 and 1.5 g m⁻² (median 0.4 g m⁻²). Mineralogical analyses reveal abundant sheet silicates and common rock-forming minerals across all sites, with carbonates largely restricted to central Svalbard glaciers, indicating variability in dust sources and depositional processes. Radiative transfer modeling demonstrates that mineral dust dominates LAP driven albedo reductions, exceeding contributions from black carbon. These findings highlight the growing importance of mineral dust for Svalbard snow and ice melt in the warming Arctic.