Horizontal Meter Scale Variability of Elemental Carbon in Surface Snow

Abstract: Soot deposited in snow and ice lowers the albedo of the surface and affects the radiative balance. Soot’s climatic forcing has received increased attention during the last decade, however, measurements of soot concentrations in Arctic snow are rare. This thesis investigates the horizontal variability of elemental carbon (EC), a proxy of soot, on a meter scale in surface snow from a site with limited regional pollution in Arctic Finland and a site with significant regional pollution near Stockholm, Sweden. A variability of EC in the sampled grid-nets was observed at both of the sites; however, the site with less pollution affecting it presented greater variation in comparison to the polluted site. In side-by-side ratios between neighboring samples, a ratio of as much as ~16 is observed, presenting the potential variation at the less polluted site. An important process that is partly responsible for the variation at this site is wind. The EC concentrations increased over time at both of the sites, which supports the hypothesis that EC remains at the snow surface even as snow melt occurs in the spring.