Non-ignorable contribution of anthropogenic source to aerosols in Arctic Ocean

Abstract

Arctic Ocean (AO) atmospheric aerosols, which are a factor influencing regional and global climate, have been greatly influenced by an increase in anthropogenic sources. To identify the impact of anthropogenic sources on regional aerosols in the AO and middle and low latitudes (MLO), a single-particle aerosol mass spectrometer was used to count and size aerosols with diameters less than 2.5μm (PM2.5) and determine their chemical composition. The mean hourly count of PM2.5 aerosols was 1639/h in the AO, which was 57.1% lower than that in the MLO. Na_MSA, sulfate, and Na_rich were three major components, which accounted for 74.3% of PM2.5 aerosols in the AO. The size distribution of PM2.5 aerosols was unimodal, peaking between 0.42μm and 1.64μm. A source apportionment method for single aerosol particles in the Arctic was established using positive matrix factorization (PMF) combined with backward air mass trajectory and principal component analysis (PCA). Three potential sources of aerosols were identified: marine sources; anthropogenic sources; and secondary formation. The largest contribution to aerosols in the AO was from marine sources, accounting for 50.6%. This source was 20.4% higher in the AO than that in the MLO. Secondary formation contributed 19.8% and 36.5% to aerosols in the AO and MLO, respectively. However, the contribution of anthropogenic sources to aerosols was 29.6% in the AO, and this was 3.7% lower than that in the MLO. Our study provides a useful method for identifying sources of aerosols in the Arctic, and the results showed that although marine sources were the largest contributors to aerosols in the AO, the contribution of anthropogenic sources could not be ignored.