College Park, MD 20740
ABSTRACT: The formation of Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW) significantly contributes to the total uptake and storage of anthropogenic gases, i.e. CO2 and CFCs within the Southern Hemisphere. These water masses play an important role in the earth’s heat, freshwater, carbon budgets and resupply of oxygen and nutrients to the subtropical oceans sustaining the marine ecosystem. The South Pacific is a principle formation site of SAMW and AAIW in the Southern Hemisphere. Formation rates of SAMW and AAIW within the South Pacific are calculated based on CFC-12 inventories from World Ocean Circulation Experiment (WOCE), Climate Variability and Prediction (CLIVAR), and hydrographic data collected in the southeast Pacific in the winter of 2005. These programs allow for the direct comparison of model CFC fields with hydrographic observations. CFC uptake within the National Center for Atmospheric Research (NCAR) Community Climate System Model version 4 (CCSM4) in the South Pacific is underestimated compared to observations particularly in the density surfaces that define SAMW and AAIW. To quantify this bias, we compare observed and model formation rates of SAMW and AAIW based on CFC-12 inventories across the South Pacific. Model formation rates in the South Pacific for SAMW are about one-third of the observational rate. Shallow mixed layer depths and insufficient meridional transport of high CFC waters in CCM4 are likely reasons for lower SAMW formation rates. However, for AAIW in CCSM4, formation rates are slightly higher than the observational rates. Higher CFC-12 inventories in CCSM4, particularly in the southwest and central Pacific, and higher surface inventories are likely the main reasons for greater formation rates of AAIW. This research demonstrates the importance of model-observational comparisons to better to identify the important biases in the model simulation, as well as increasing our understanding of SAMW and AAIW in the South Pacific.
BIOGRAPHY: I graduated from Queens College in New York in 2006 with a B.S. in Geology and from there went on to my Ph.D. at the Rosenstiel School of Marine and Atmospheric Science at the University of Miami, working under Dr. Rana Fine. I am currently finishing up my Ph.D. research on Subantarctic Mode Water and Antarctic Intermediate Water in the South Pacific. This research has involved extensive use of hydrographic and tracer data, as well as working with numerical model output of present and paleo oceans. I recently was awarded the best student presentation at the World Climate Research Programme conference in Denver and the Koczy Prize by RSMAS for best graduate research for a student in their last year.