Modelling the production and cycling of dimethylsulphide during the vernalbloom in the Barents Sea

Recent field work suggests an important role for the Arctic Ocean in the gl obal budget of dimethylsulphide (DMS), a climatically active volatile sulph ur compound. Here, we have used an existing DMS production model and local field data to examine the temporal dynamics of the DMS cycle during the spr ing bloom in the Arctic shelf of the Barents Sea. The timing and duration o f the spring phytoplankton bloom has been shown to be a key determinant of the flux of DMS to the atmosphere. Particular oceanic conditions due to the retreating ice-edge (e.g., a shallow mixed layer) can have an important ef fect on the timing of the phytoplankton bloom and thus the efflux of DMS in this region. Model simulations support the view that algal taxonomy is not the most important factor determining DMS production in these waters. The mean vernal DMS flux is predicted to be 0.063 mg S m(-2) d(-1) which is in general agreement with previous summer season averages in the Arctic.