Distribution, Sources, and Air-Sea Fluxes of Short-Lived Organic Compounds During the O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) Study

University Of Miami, Coral Gables FL

Investigators

Abstract

A large field campaign is being planned for the Southern Hemisphere summer of 2016 to improve understanding of air-sea exchange processes and the uptake of oxygen and carbon dioxide in the vast Southern Ocean. This project includes the measurement of many trace gases to characterize and examine the relationships between biological activity in the ocean, trace gas fluxes, and carbon and oxygen exchanges. The results will be used to test a suite of ocean biogeochemistry models to improve the understanding of key processes and feedbacks in this under sampled yet climatically important region of the world. The O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) field campaign will include the measurement of a range of short-lived (i.e. reactive) halocarbons and other gases that can have both a regional and even global impact on atmospheric chemistry. For example, emissions of short-lived bromine compounds such as bromoform contribute to the global burden of reactive bromine, which is important in the chemistry of ozone loss in the stratosphere. Other reactive gases, including dimethyl sulfide and various organic iodine gases, are related to aerosol formation processes and heterogeneous chemical processing. Organic nitrate emissions from the surface ocean represent a major fraction of reactive oxidized nitrogen in the Southern Ocean atmosphere. Present knowledge of the atmospheric distributions and fluxes of these reactive species in the region of the Southern Ocean is limited. This research will help to link reactive trace gas exchanges to the basic biogeochemical cycles of carbon and oxygen as well as to detailed remotely sensed ocean properties. The results will help advance the ability to predict reactive trace gas fluxes and improve the understanding of their role in biogeochemical cycles and climate change.