Collaborative Research: The O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) Study

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The Southern Ocean plays a dominant role in the oceanic uptake of excess (anthropogenic) carbon, yet the extent of this air-sea exchange process is poorly represented by earth system models, and its future projection remains highly uncertain. The O2/N2 Ratio and CO2 Airborne Southern Ocean Study (ORCAS) seeks to advance understanding of the physical and biological controls on air-sea exchange and uptake of O2 and CO2 in the vast Southern Ocean. This will be investigated through intensive airborne surveys of atmospheric O2, CO2, related gases, their state of equilibrium, along with other ocean surface properties over diverse biogeochemical regions adjacent to the southern tip of South America and the Western Antarctic Peninsula. ORCAS will utilize the NSF Gulfstream V (GV) aircraft equipped with a suite of high-precision in situ and remote sensing instruments, on 14 flights over a period of 6 weeks in austral mid-summer, from Punta Arenas, Chile, out over the Drake Passage, and with concurrent overflights of the ARSV LM Gould sampling the Palmer LTER site. ORCAS observations will be guided by, and used to test a suite of ocean biogeochemistry models to improve our understanding of key processes and feedbacks in this under sampled yet climatically important region of the world.