1316 Investigating Antarctic Intermediate Water Changes in the Southern Ocean Under RCP 8.5 Using CESM-BGC

Wednesday, 25 January 2017
Stephanie C Pennington, University of Maryland, College Park, MD; and C. Hartin

Antarctic Intermediate Water (AAIW), formed primarily in the Southern Ocean, is an important water mass responsible for nutrient transport, heat storage, and uptake of anthropogenic CO2 throughout the global oceans.  AAIW is thought to be the most important global source of O2 and nutrient transfer to the equatorial regions.  In this study we investigate changes in the surface properties of AAIW in the South Pacific, under historical (1970-1990) and RCP8.5 (2080-2100) scenarios, using CESM-BGC. These surface properties will then be subducted within intermediate water and distributed throughout the subtropical gyre. AAIW within the South Pacific is identified based on a low salinity of 34.2 psu.  We investigate changes in AAIW surface properties (e.g., salinity, O2, NO3) under the RCP 8.5 (+8.5 W/m2 from pre-industrial values) scenario. Initial results indicate a decrease in surface oxygen levels of < 0.02 mol/m3 between 1970 to 2100.  Identifying changes in AAIW can be valuable in diagnosing a changing climate.
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner