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.
Spatial Characterization of Black Carbon Mass Concentration in the Atmosphere of a Southeast Asian Megacity: An Air Quality Case Study for Metro Manila, Philippines