1. Chlorofluorocarbons in the Ocean Cesar Colon August 1, 2005

2. Ocean Tracer Group Cesar Colon Dr. Tim Hall Dr. Christian Rodehacke Rayhan Ahmed Scott Alfano

3. Introduction Chlorofluorocarbons (CFCs) are trace gases of industrial origin and are infamous for their role in stratospheric ozone depletion. Less well known the fact that a small fraction of atmospheric CFCs have entered the ocean via gas exchange Chlorofluorocarbons (CFCs) are trace gases of industrial origin and are infamous for their role in stratospheric ozone depletion. Less well known the fact that a small fraction of atmospheric CFCs have entered the ocean via gas exchange CFCs are chemically inert in seawater, and are carried by currents and turbulent mixing CFCs are chemically inert in seawater, and are carried by currents and turbulent mixing

4. Introduction (cont.) Propagation of CFCs from surface entry points to ocean interior provides crucial information on rates of ocean transport Propagation of CFCs from surface entry points to ocean interior provides crucial information on rates of ocean transport This information can be applied to quantities such as CO 2 and heat This information can be applied to quantities such as CO 2 and heat

5. Project Tasks Work with ocean CFC data to document the evolution of CFCs in ocean surface waters; Quantifying this evolution is the first step in extracting information from CFC surface-to- interior transport rates Work with ocean CFC data to document the evolution of CFCs in ocean surface waters; Quantifying this evolution is the first step in extracting information from CFC surface-to- interior transport rates Work with measurements taken during several sea-going research routes, coupled with the observed atmospheric CFC history Work with measurements taken during several sea-going research routes, coupled with the observed atmospheric CFC history

6. Project Tasks (cont.) Compare actual surface water CFC concentrations to those that would be expected if surface water CFCs were in equilibrium with atmosphere, using well known equilibrium relationships Compare actual surface water CFC concentrations to those that would be expected if surface water CFCs were in equilibrium with atmosphere, using well known equilibrium relationships

7. Project Goals Quantify the ocean’s role in sequestering quantities of CFCs and other gases in order to better understand the Earth’s climate Quantify the ocean’s role in sequestering quantities of CFCs and other gases in order to better understand the Earth’s climate Learning how the difference from air-sea equilibrium of CFCs has changed over time Learning how the difference from air-sea equilibrium of CFCs has changed over time

8. Atmospheric History

9. The Indian Ocean Well represented during WOCE, therefore plenty of data Well represented during WOCE, therefore plenty of data Some data goes back to late 1980s. It is important to have well documented history because it provides more detail for analysis Some data goes back to late 1980s. It is important to have well documented history because it provides more detail for analysis

10. Indian Ocean Data

11. Indian Ocean Data (cont.)

13. Region Analyzed We looked for a region with large time overlap in terms of data gathered, as well as a small enough region so that T and S don’t vary much We looked for a region with large time overlap in terms of data gathered, as well as a small enough region so that T and S don’t vary much

14. Indian Ocean CFC-11

15. Indian Ocean CFC-12

16. Future Work Calculate CFC-12 Actual and Theoretical Concentrations over time for same region and compare Calculate CFC-12 Actual and Theoretical Concentrations over time for same region and compare Seasonal averages from Indian Ocean; would produce more accurate results as well as possible information about CFC saturation differences between different times of year Seasonal averages from Indian Ocean; would produce more accurate results as well as possible information about CFC saturation differences between different times of year

17. Future Work (cont.) Repeat process on different areas around Indian Ocean with time overlap to achieve a more complete view Repeat process on different areas around Indian Ocean with time overlap to achieve a more complete view Repeat for other bodies of water, such as the North Atlantic or South Pacific Oceans Repeat for other bodies of water, such as the North Atlantic or South Pacific Oceans