An invitation to participate in a cruise to the Arabian Sea during and after the SW monsoon provides a scientist from the University of Southern California with a unique opportunity to determine which of the two conclusions put forth to date, Fe limitation or grazing, is responsible for regulating primary production in this region. Specifically, the researcher plans to test the following three hypotheses: (1) growout experiments would be used to show that carbon fixation in the western Arabian Sea is Fe-limited; (2) carbon fixation is limited by Fe and Cu, which in turn limit Fe utilization by diatoms; and (3) primary production and carbon export fluxes would be highest in the low Fe northern jets reflecting differences in shelf width and thereby the Fe content of upwelled water. Also, this project would identify how projected changes in monsoon intensity and trajectories in response to climate change would influence carbon and nitrogen cycling in this area.
As regards broader impacts, this project would further a collaboration between scientists from the U.S., India (National Institute of Oceanography, Physical Research Laboratory), and Oman (Sultan Qaboos University).
