Influence of oceanic emission and gas transfer velocity on atmospheric dimethyl sulfide distribution over the Southern Ocean

Abstract

Oceanic dimethyl sulfide (DMS) is a major source of atmospheric sulfur, particularly significant in the Antarctic region. This study conducted nine sensitivity simulations using the Community Earth System Model version 2, combining three seawater DMS climatological inventories and three gas transfer velocities. The most sensitive changes in atmospheric DMS were simulated over the subpolar region according to the DMS inventories and gas transfer velocities. Seasonal variations in atmospheric DMS peaked during the austral summer, except for the continental region, where the peaks occurred in the austral winter. These simulation results were also compared with ship-borne measurements obtained in March 2018, and generally showed significant consistency under specific temporal and regional conditions. The model indicated that DMS concentrations are strongly influenced by the seawater DMS inventory and gas transfer velocity, with this sensitivity varying considerably across different regions and periods, particularly under intense wind conditions.