Interdisciplinary Seminar: Jana Haddad

An Interdisciplinary seminar from UNC Marine Sciences graduate student, Jana Haddad. Presented by the UNC-CH Department of Marine Sciences and UNC’s Institute of Marine Sciences (IMS). The main location of this event will be in room 222 at IMS in Morehead City, NC. The seminar will be streamed live to seminar room G201 on the ground floor of Murray Hall on UNC-CH campus in Chapel Hill, NC. This event will be held on Monday, April 2nd at 12:20pm.

Seminar Title: Chlorofluorocarbons as tracers of ocean dynamics in the North Atlantic

Abstract: When water masses are subducted, they carry with them atmospheric constituents.  Chlorofluorocarbons (CFCs), which are synthetic halogenated methanes, are one such gas that can serve as a transient tracer in the ocean.  While CFCs present an environmental concern in their role as greenhouse gases and in depleting stratospheric ozone, oceanographers have found multiple effective applications for the approximately 1% of CFCs released which have been dissolved in the oceans in the last century. Since the atmospheric history of CFCs is well known, use of CFCs as a tracer has the added advantage of a built in “clock”. Analysis of the pathways and concentrations of CFCs in the surface and deep ocean provides information on ocean circulation and its decadal variability. While certain sources of uncertainty must be accounted for, CFCs are successfully used to identify decadal variabilities in thermocline ventilation in the North Atlantic.  Shipboard CFC measurements also provide information about the deep meriodional overturning circulation (MOC), and are used to determine rates of subduction, mixing, and water mass formation rates.  More recently, CFC-derived ages have been applied to validation of ocean circulation models, and CFC concentrations have been used to estimate ocean inventories of anthropogenic CO₂.