1. Surface Dispersion by Mesoscale Eddies Using Altimeter Data Long Zhou 3nd Student Seminar, 11/06/2006

2. Outline Objectives and Applications Dataset Method One example of model output Results Summary and future work

3. Objectives Examine absolute dispersion at ocean surface Find out the relative diffusivities at different separation distances Applications Improve parameterization of eddy diffusivity in climate numerical modeling Pollutant fate (e.g. oil spills) Larval transport

4. Dataset: Satellite altimetry JETEG along-track sea level anomalies (SLA) for three years 02/25/2003 to 02/25/2006 Jason1EnvisatTopex2ERSGFO Note: GFO=Geosat Follow-on

5. Method a.Objective mapping of JETEG with a space-time correlation model => daily SLA maps (02/25/2003 to 02/25/2006). b.Derive stirring velocities V s from SLA assuming geostrophic balance holds. c.Random walk numerical model with a daily time step and 1/6 degree of spatial resolution., where

6. One example of model output: where to deploy KE: kinetic energy

7. One example of model output 03/02/2003-07/30/2003

8. 0.5-0.9 3 0.1 Results Find RDV to be 0.75 to reasonably represent submesoscale process. 3 0.5-0.9 0.1

9. Absolute dispersion: zonal > meridional a b c d

10. At scale of less than 200 km, relative diffusivity grow quadratically. Later can be scaled as distance to the 2/3 power.

11. Summary RDV=0.75 to reasonably represent submesoscale process. Absolute dispersion: zonal > meridional. Relative diffusivities can be scaled with separation distance. Future Work Statistical analysis of ensembles Add larva growth rate

12. Acknowledgement GSO: Dave Hebert Tom Rossby WHOI: Valery Kosnyrev Dennis McGillicuddy Real-time Altimeter Data Research Group at Colorado Center for Astrodynamics CLS Space Oceanography Division

15. RDV=0.1

16. RDV=3