Variability in black carbon mass concentration in surface snow at Svalbard

Abstract

Abstract. Black carbon (BC) is a significant forcing agent in the Arctic, but substantial uncertainty remains to quantify its climate effects due to the complexity of the different mechanisms involved, in particular related to processes in the snowpack after deposition. In this study, we provide detailed and unique information on the evolution and variability in BC content in the upper surface snow layer during the spring period in Svalbard (Ny-Ålesund). A total of two different snow-sampling strategies were adopted during spring 2014 (from 1 April to 24 June) and during a specific period in 2015 (28 April to 1 May), providing the refractory BC (rBC) mass concentration variability on a seasonal variability with a daily resolution (hereafter seasonal/daily) and daily variability with an hourly sampling resolution (hereafter daily/hourly) timescales. The present work aims to identify which atmospheric variables could interact with and modify the mass concentration of BC in the upper snowpack, which is the snow layer where BC particles affects the snow albedo. Atmospheric, meteorological and snow-related physico-chemical parameters were considered in a multiple linear regression model to identify the factors that could explain the variations in BC mass concentrations during the observation period. Precipitation events were the main drivers of the BC variability during the seasonal experiment; however, in the high-resolution sampling, a negative association has been found. Snow metamorphism and the activation of local sources (Ny-Ålesund was a coal mine settlement) during the snowmelt periods appeared to play a non-negligible role. The statistical analysis suggests that the BC content in the snow is not directly associated to the atmospheric BC load.

Long‐Term Observations of Levoglucosan in Arctic Aerosols Reveal Its Biomass Burning Source and Implication on Radiative Forcing

“…Berto et al. (2021) showed that the impacts of BC, which come from long‐distance BB episodes, might be overestimated. The climate in the high Arctic is changing at twice the rate of the rest of the world (Walsh, 2014; Yu et al., 2021).…”

“…Recent studies have shown that mid/high latitude boreal forest fires in summer contribute significantly to the aerosol burden over the Arctic (Jacob et al, 2010;Raut et al, 2017). Several studies have also addressed the BC concentration over the Arctic (Berto et al, 2021;Zdanowicz et al, 2021). Berto et al (2021 showed that the impacts of BC, which come from long-distance BB episodes, might be overestimated.…”