Investigating Spatial and Temporal Variability in Dust Deposition onto Svalbard Glaciers

The objective of this project is to provide important information of mineral dust deposition onto Svalbard glaciers, how consistent dust deposition is across Svalbard, and the role of dust and other light absorbing particles on snow and glacier melt. During winter-spring 2025 we will collect shallow (~10 m) firn cores from six Svalbard glaciers in the vicinity of Ny-Ålesund and Longyearbyen. These cores will be used to provide multi-year (5-10 years) records of dust and other light absorbing particle deposition on Svalbard glaciers. Svalbard is warming 5-7 times the global average, resulting in widespread glacier melt. In addition to warming, the deposition of light absorbing particles including black carbon from the incomplete combustion of fossil and bio-fuels, mineral dust and light absorbing organics can also contribute to snow and glacier melt by darkening the snow/ice surface and increasing absorption of energy from the sun. While black carbon has been studied extensively on Svalbard, there is a knowledge gap of mineral dust deposited onto Svalbard snow and glaciers. Numerous recent studies identify the need to study the impacts of high-latitude mineral dust on snow and glaciers, and specifically on Svalbard to assess dust sources, dust deposition, and the contribution of dust to snow darkening and melt. These studies suggest that the extent and emission strength of dust sources are likely increasing due to reduced snow cover and glacier retreat, and there is interest in how dust emissions have changed and will continue to change in the future. Changes on Svalbard are an indicator of changes that can be anticipated elsewhere in the Arctic, including changes in dust emissions and how this impacts snow and glaciers. Characterizing the contribution of dust and other light absorbing particles to snow and ice melt advances understanding of the factors contributing to sea level rise that has global consequences.

Svalbard is warming 5-7 times the global average, resulting in widespread glacier melt. In addition to warming, the deposition of light absorbing particles (LAP) including black carbon (BC) from the incomplete combustion of fossil and bio-fuels, mineral dust and light absorbing organics can also contribute to snow and glacier melt by darkening the snow/ice surface (i.e. lower the albedo) and increasing solar energy absorption (Skiles et al, 2018). While BC has been studied extensively on Svalbard, there is a knowledge gap of mineral dust deposited onto Svalbard snow and glaciers. Numerous recent studies identify the need for assessment of the impacts of high-latitude dust on the cryosphere (e.g. Boy et al., 2019), and specifically on Svalbard to assess dust sources, dust deposition, and the contribution of dust to snow albedo reductions and melt (DiMauro et al., 2023; Zdanowicz et al., 2023). These studies further hypothesize that the extent and emission strength of dust sources are likely increasing due to reduced snow cover and glacier retreat, and there is interest in how dust emissions have changed and will continue to change in the future. There is also interest in the role of dust in microbial processes in snow or firn, which affects delivery of productivity-limiting nitrate to downstream fjord ecosystems (e.g. Ansari et al, 2013). The role of dust as a vector for both nitrifying bacteria and clay-bound ammonium within firn will therefore also be investigated. During winter-spring 2025 we will collect shallow (~10 m) firn cores from six Svalbard glaciers in the vicinity of Ny-Ålesund and Longyearbyen that still have an accumulation zone, providing a multi-year (5-10 years depending on the net accumulation at each site) record of LAP and dust deposition on Svalbard glaciers. Combined these records will provide important information of dust deposition onto Svalbard glaciers, how coherent dust deposition is across Svalbard, and the role of LAP in glacier melt.