Measuring the Ocean's Breath: Automated Measurements of Atmospheric Dimethylsulfide (DMS) at Tudor Hill, Bermuda
John Dacey, Biology
OCCI Funded Project: 2010
Given the long-standing implication of DMS in the dynamics of aerosols over the world’s oceans, there is a distinct need for high-frequency, long-term measurements of this gas in the marine atmosphere. The seminal data describing seasonal aqueous DMS dynamics is centered at Bermuda, making it the perfect place to establish a complementary atmospheric time-series. There is also an established and on-going array of atmospheric measurements including aerosol collection at Tudor Hill on Bermuda, managed by BIOS and supported by NSF. The missing link in aerosol formation between oceanic DMS and its atmospheric oxidation products is the measurement of DMS itself. A system measuring atmospheric DMS at Bermuda would provide a breadth of complementary data unmatched anywhere in the world.
I propose to deploy a fully-automated and calibrated DMS measurement system at Tudor Head. The system will be modeled after a prototype system I have deployed at the NOAA Observatory in Barrow AK. The system will be monitored using a web server on the system’s PC, and modifications to protocols and diagnostics will be run by sending commands to the PC by SFTP. Raw data and processed data will be retrieved SFTP. The system will make measurements several times an hour and will include calibrations using standards prepared automatically on-site to span the range of concentrations observed. The system will generate calibrated data at a higher frequency and for a longer time than any previous DMS measurements, allowing unmatched analysis of its dynamics with respect to short and long term changes in ocean biogeochemistry and its effects on aerosols.