Low contributions of dimethyl sulfide (DMS) chemistry to atmospheric aerosols over the high Arctic Ocean

Abstract

The Arctic Ocean is continuously warming, resulting in sea ice retreat, which significantly impacts the marine biogenic sulfur cycle. The formation of aerosols from DMS oxidation and their climatic effects in polar regions are of great concern. However, the impact of DMS chemistry on atmospheric aerosols in the high Arctic Ocean (AO) is still unclear due to the limitation of field observations and datasets. Gaseous methanesulfonic acid (MSA) and aerosol chemical species (MSA, SO42− and DMA, etc.) were determined simultaneously with a high time resolution (1 h) in the AO and Pacific Ocean (PO) to reveal the DMS chemistry in these regions. The particulate MSA concentration indicated significant spatial variation with a decreasing tendency from the low latitude oceans to high AO. Extremely low particulate MSA concentrations were observed in the high AO, with an average of only 7.42 ± 6.6 ng·m−3. In contrast, highest particulate MSA concentrations, with an average of 168.6 ± 167.6 ng·m−3 were observed in the mid-latitude regions (45°–60°N) in July. Sea salt aerosols were the most dominant source in the high Arctic Ocean, accounting for 88.78% of the total suspended particle mass, which was much larger than the values in the other regions. Low DMS chemistry was determined based on the low DMS emissions in the high latitude (HL, 75°–85°N) region. These results highlight the contribution of DMS chemistry to atmospheric aerosols and extend the knowledge of how biogenic aerosols impact the regional atmosphere in the high AO.