A newly developed eddy covariance flux system will be used to quantify fluxes of dimethyl sulfide (DMS) and elucidate the factors controlling these fluxes. An atmospheric pressure ionization mass spectrometer with an isotopically labeled standard (APIMS-ILS) will be used on ships to make fast measurements of atmospheric DMS for use in the eddy covariance studies of the flux of DMS. Laboratory work will be performed to improve characterization of the errors and improving the sensitivity of the instrument, and the software will be upgraded to allow real time feedback from the instrument in the field. Several ship cruises have been identified for measurements of DMS flux under different conditions and with differing overall objectives. Through collaborations with other cruise participants, ancillary measurements will be available. The objectives include investigating the factors controlling DMS exchange velocity, such as surface wind speed, temperature, and biological variations; and studying the relationship between DMS production, air-sea exchange, oxidation to sulfate, and particle formation to climate forcing.
This project will lead to an improvement in our understanding of marine aerosol formation and air-sea gas exchange, which in turn will improve our understanding of the linkages between the sulfur cycle and climate. The project will contribute to the training of a graduate student.
