[ACC39-06] Annual and seasonal variation trend of light-absorbing snow impurities components at Sapporo, Japan
Keywords:Surface Snow, Light absorbing snow impurities, Sapporo
The EC, OC, and dust concentrations of the surface layer for 11 years fluctuated greatly in the ranges of 0.002-1.92, 0.013-12.7, and 0.137-260 ppmw, respectively. Also, the median values were 0.143, 0.301, and 3.57 ppmw, respectively. Here, we divided the snow-covered season (December to April) into the following two periods by referring to the variations of snow depth and snow surface temperature; that is, accumulation season and melting season. Seasonal fluctuation patterns of EC, OC, and dust in both the surface layer and the sub-surface layer were very similar, and all components showed high values in the snow melting season (Fig. 1). We also found the relationship between EC and OC concentrations were clearly different in each period (Fig. 2), and the relationship in the melting period (Fig. 2b) was similar to the previously reported result in aerosol of China3). From the result, we suggest that the EC-OC relationship in the snow at Sapporo can be affected by the aerosol from China especially during the melting season when airmass transportation from China to Japan occurs frequently.
1)Warren and Wiscombe, 1980, J. Atmos. Sci., 37, 2734-2745.
2)Niwano et al., 2012, J. Geophys. Res., 117, F03008.
3)Cao et al., 2005, Atmos. Chem. Phys., 5, 3127–3137.