9:45 AM - 10:00 AM
[ACC26-04] Temporal variations of concentrations, size distributions, and seasonal variations of anthropogenic and natural black carbon in Greenland
Keywords:Black carbon, Greenland, Ice core
Here we report the variability of monthly resolved BC concentrations and size distributions over the past 350 years. BC number and mass concentrations started to increase in the 1870s, reached its maximum in the 1920s - 1930s, and decreased again since then. The increases are likely due to anthropogenic input. The increases are most significant in fall and winter months. We find anthropogenic changes in seasonality of BC concentration: annual concentration peak shifted from summer to winter. We also find anthropogenic changes in size distribution of BC: the mode diameter of mass concentration and average mass of BC particles became larger. This suggests that anthropogenic BC particles are larger than natural ones in the snow deposited in Greenland. Apart from anthropogenic BC, BC concentration occasionally showed large spikes in summer. They are likely originated from biomass burnings. We will compare the results from the SIGMA-D core with those from other ice cores drilled in Greenland and discuss spatial variations of BC.