The Seasonal Burden of Dimethyl Sulphide-Derived Aerosols in the Arctic and the Impact on Global Warming

Abstract

Global climate changes have led to remarkable environmental changes in the Arctic. On the other hand, Dimethyl sulphide (DMS) emission in Arctic Ocean plays an important role for the global warming. The ice cover as the special feature of Arctic Ocean has significant effect on regulation of the large distribution of phytoplankton production. Chlorophyll-a (CHL), as the primary production of phytoplankton, has its strong relationship with DMS derived aerosol in the ocean surface. This paper will describe the physical and phytoplankton data (based on the past 5 years SeaWiFS satellite data recorded 1998-2002) in the Barents Sea region (30-35Šand 70-80Ω. The relationship between temperatures, photosynthetic available irradiance (PAR), cloud cover, ice cover and CHL were also analysed. The field data was based on the three Cruises gathered biological and physical measurement on vertical potential density, temperature, salinity, CHL as well as sulful compounds. The field data is compared with the satellite data within the study region and the good agreement was achieved before calibrating parameters of the developed DMS model using Genetic Algorithm. The significant inter-annual variation of CHL leads significant inter-annual production of DMS in this study region. The DMSPd field data is used for further DMS calibration. We finally applied the CSIRO GCM forcings to the calibrated DMS model to predict sea-to-air flux of DMS for enhanced greenhouse conditions (from 1xCO2 to 3xCO2) in the zonal 70ୠ80Πglobal belt.