TCD The Cryosphere Discussions TCD The Cryosphere Discuss. 1994-0440 Göttingen, Germany 10.5194/tc-2022-195 Light absorbing particles and snow aging feedback enhances albedo reduction on the Southwest Greenland ice sheet Cintron-Rodriguez Isatis M. 1 Rennermalm Åsa K. 2 Kaspari Susan 3 Leidman Sasha 2 Department of Environmental Sciences, Rutgers, The State University of New Jersey, New Brunswick 08901, New Jersey, USA Department of Geography, Rutgers, The State University of New Jersey, New Brunswick 08901, New Jersey, USA Department of Geological Sciences, Central Washington University, Ellensburg, WA 98926, USA 02 12 2022 2022 1 31 Copyright: © 2022 Isatis M. Cintron-Rodriguez et al. 2022 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://tc.copernicus.org/preprints/tc-2022-195/ The full text article is available as a PDF file from https://tc.copernicus.org/preprints/tc-2022-195/tc-2022-195.pdf

<p>Greenland&rsquo;s ice sheet mass loss rate has tripled since the mid-1950s in concert with sharply lowered albedo leading to increased absorption of solar radiation and enhanced surface melt. Snow and ice melt driven by solar absorption is enhanced by the presence of light absorbing particles (LAPs), such as black carbon (BC) and dust. Yet, the LAP impact on melt is poorly constrained, partly due to scarce availability of in-situ measurements. Here, we present a survey of snow properties and LAPs deposited in winter snow layers at five sites in southwest Greenland collected in May 2017. At these sites, BC and dust concentrations were 0.62 &plusmn; 0.35 ng g<sup>-1</sup> and 2.09 &plusmn; 1.60 &micro;g g<sup>-1</sup>, respectively. By applying the SNICAR model, we show the LAP influence on albedo through the combined effect of surface darkening and snow metamorphism. While the LAP concentrations are low, they result in a 1.7 % and 3.0 % reduction in albedo within the visible spectrum for spring and summer, respectively. Past studies have shown that even minor LAP induced albedo reductions, if widespread, can have a large impact on the overall surface mass balance. SNICAR simulations constrained by our measurements show that LAP-snow aging feedback reduce albedo reduction 4 to 10 times more than previously thought, therefore LAPs are likely a significant contributor to Greenland's accelerated mass loss. As far as we know, this is the first field study to consider the LAP impact on snow aging on the Greenland ice sheet.</p>