Michael Bender and Mary-Lynn Dickson; Princeton University and University of Rhode Island

"Oxygen Dynamics During the JGOFS Southern Ocean Process Study"

Our interest in the Southern Ocean Process Study is directed towards using oxygen to constrain carbon fluxes on three scales; the large scale, the mesoscale, and the local scale. In order to assess large scale rates of net oceanic production for the entire Southern Ocean, we will collect air samples while in transit and on station and measure the O²/N² ratio of the air. Similarly, we will estimate net production from the mesoscale oxygen field by continuously measuring subsurface oxygen concentrations along the cruise track and while on station. On the local scale we will constrain carbon flow by undertaking measurements of gross and net oxygen production rates and respiration rates. Seawater samples will also be incubated to measure net changes in nitrate concentrations and compared with our net oxygen production rates. As well, we will undertake photosynthesis irradiance (PI) experiments to measure gross and net oxygen production.

Our interactions with other groups will involve comparison of daily oxygen production rates with primary production rates measured with ¹⁴C and ¹⁵N. We will also compare the photosynthetic parameters derived from our PI experiments with those made using ¹⁴C. We hope to collaborate in experiments with the microbiologists and organic chemists to simultaneously measure bacterial respiration rates and DOC consumption rates. Finally, we will compare our net production values with new production estimates made using ¹⁵N and export production measurements made with ²³⁴Th and sediment traps.

We would like to participate on process studies I, II and III in the Ross Sea during 1996 and 1997 and on process studies I and II in the APFZ in 1997 and 1998.