1 / 21

On the role of eddies for coastal productivity and carbon cycling

On the role of eddies for coastal productivity and carbon cycling. Hartmut Frenzel 1 , Nicolas Gruber 2,1 , Gian-Kasper Plattner 2 , Takeyoshi Nagai 3,1 , James C. McWilliams 1 , Zouhair Lachkar 2 1 IGPP & DAOS, UCLA

dunne
Download Presentation

On the role of eddies for coastal productivity and carbon cycling

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. On the role of eddies for coastal productivity and carbon cycling Hartmut Frenzel1, Nicolas Gruber2,1, Gian-Kasper Plattner2, Takeyoshi Nagai3,1, James C. McWilliams1, Zouhair Lachkar2 1 IGPP & DAOS, UCLA 2 Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Switzerland 3 Tokyo Institute of Fisheries, Japan

  2. (gC m-2 yr-1)

  3. US WEST COAST CONFIGURATION OF ROMS • NPZD model • Nitrogen based (no iron limitation) • Upwelling system focused • Fixed stoichiometric ratios of C:N • Horizontal resolution: 5 km • Vertical resolution: 20 levels • climatological forcing • WOA01 for T,S; • COADS for winds [Gruber et al., DSR I, 2006]

  4. USWC-5km ROMS

  5. IMPACT OF MESO-SCALE PROCESSES Standard (eddy) run: #define UV_ADV Linear run: #undef UV_ADV (VISC2 = 100 m2/s) Both for USWC 5 km configuration

  6. (all fluxes: mol C m-2 yr-1)

  7. Eddy induced anomalous circulation

  8. California upwelling: highest TKE and lowest PP

  9. NPP: California vs. Canary Current System [Gruber et al., in prep. 2007 ]

  10. UWI: California vs. Canary Current System [Gruber et al., in prep. 2007]

  11. EKE: California vs. Canary Current System [Gruber et al., in prep. 2007]

  12. [Gruber et al., in prep. 2007]

  13. NPP/UWI and NPP/EKE: California and Canary CS [Gruber et al., in prep. 2007]

  14. SUMMARY • Meso- and submesoscale processes tend to suppress primary production and air-sea fluxes of CO2 in coastal upwelling systems. • This is due to an eddy-induced "overturning" circulation that counteracts the upwelling and leads to a “leakage” of nutrients out of the upwelling region. • First results indicate that the differing levels of eddy kinetic energy in the various upwelling systems are a primary reason for their large differences in primary production.

  15. >60% of offshore transport by eddies Fraction by Eddies EDDY CONTRIBUTION TO OFFSHORE TRANSPORT Offshore distance Eddy-tracking Total offshore transport of NO3 & NH4 Eddy-part Non-eddy part Nagai et al. (in prep. 2007)

  16. MECHANISMS OF OFFSHORE TRANSPORT Upwelling Nearshore ~200km Filament transport Subduction Beyond 200 km Westward propagating eddies

  17. Acknowledgments Funding: NASA and NSF Computer time: NCSA

More Related