Southern Ocean Biogeochemistry Control on Short-Lived Ozone-Depleting Substances and Impacts on the Climate System

A class of small molecules, very short-lived substances (VSLS; e.g. CHBr3,CH2Br2, and CH3I) are important components in the climate system where they act as tropospheric ozone destroyers as described in the multilateral environmental Montreal Protocol on Substances that Deplete the Ozone Layer. The Southern Ocean represents a key component in the climate system and has a critical role in other global biogeochemical cycles.

This project will use the NSF/NCAR Community Earth System Model (CESM) with a newly developed online air-sea exchange framework, to evaluate biogeochemical controls on the marine sources of VSLS in the Southern Ocean as well as the Southern Hemisphere. A machine-learning approach will be used to couple ocean biogeochemistry with air-sea exchange for these compounds.

A variety of oceanic and atmospheric observations of VSLS will be used to evaluate a unique oceanic VSLS inventory. In particular, the recent ORCAS field campaign provides a unique opportunity to examine Southern Ocean VSLS emissions, and their impacts from ocean biogeochemistry, meteorology and sea ice cycles. The project will also support a postdoctoral early-career researcher, and a specific effort of this project is STEM education and public outreach activities.

The research team will extend opportunities to high school and undergraduate students so they may gain experience in the coupled ocean and atmospheric sciences, including exposure to and experience in programming and modeling.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.