1. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 1 Continental Shelf Pump Revisited K.-K. Liu Inst. of Hydrological & Oceanic Sciences National Central University, Taiwan

2. 16-20 June 2008 Busan 2008 AOGS Annual Meeting 2 -35 gC/m 2 /y Continental Shelf Pump POC+DOC=12.7 TgC/y

3. Carbon export by isopycnal mixing: Diffusion pump 5-9 Oct 2009 Bergen Final CarboOcean Meeting 3 Kuroshio

4. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 4 Cross-shelf exchange Currents varying on time-scales of days or longer tend to be constrained by geosptrophy to flow along depth contours;..... Thus geostrophy inhibits ocean-shelf exchange,..... On smaller time and space scales, geostrophy is broken, allowing excursions [of the ocean current] onto the shelf. Huthnance (1995) Circulation, exchange and water masses at the ocean margin...., [Progr. in Oceanogr.]

5. Physical processes Diffusion pump Injection pump Bypass pump Cascading pump 5-9 Oct 2009 Bergen Final CarboOcean Meeting 5

6. Injection pump: Wash- out of POC by “new water” (Thomas et al., 2005) 5-9 Oct 2009 Bergen Final CarboOcean Meeting 6

7. Bypass pump: Sweeping-out of shelf water by oceanic currents (Thomas et al., 2005) 5-9 Oct 2009 Bergen Final CarboOcean Meeting 7

8. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 8 Cascading pump: Flushing of shelf water and its content into the deep ocean by brine or dense water formation (R. Macdonald)

9. Biogeochemical processes Nutrient-enhanced bio-pump –Nutrient-shuttle pump Iron pump Ballast pump Alkalinity pump 5-9 Oct 2009 Bergen Final CarboOcean Meeting 9

10. Nutrient-enhanced bio-pump 5-9 Oct 2009 Bergen Final CarboOcean Meeting 10 Chl-a DIN

11. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 11 Iron pump: benthic Fe-flux enhanced bio-pump Fe (II) Pennington et al. (2009) California Current System: Sea-air CO 2 flux Coastal upwelling-EBC system

12. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 12 Ballast pump: Enhanced delivery and preservation of organics by ballasting materials (e.g. minerals, shells) OMEX Burial Delivery Efficient delivery & burial of POC due to ballast effect of sediments Taiwan Delivery & burial efficiency of POC wrt PP in margins: SW Taiwan vs Bay of Biscay (OMEX-I) (Kao et al., 2006, CSR)

13. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 13 Alkalinity pump Suboxic and anoxic respiration results in production of alkalinity. Alkalinity helps increase pH and decrease pCO 2. The effective alkalinity flux resulting from denitrification (in Mid Atlantic Bight) is large compared to estimates of anthropogenically driven coastal acidification. (Fennel et al., 2008, GRL)

14. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 14 Synergistic processes in the North Sea (Thomas et al., 2005) -17 gC m -2 yr -1 Nutrients-enhanced bio-pump Nutrient-shuttle: Over- consumption of C due to preferential recycling of nutrients Bypass pump Prefer. N,P recycle

15. 5-9 Oct 2009 Bergen 2008 AOGS Annual Meeting 15 Synergistic processes in the East China Sea SeaWiFS Chl-a (mg/m 3 ) Flow field (Lee et al., 2004) Nutrients- enhanced bio- pump Ballast pump Bypass pump

16. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 16 Impact of continental shelf pump on ocean interior: fate of CO 2 injected by shelf pump Increase of DIC (uM) from margin injection (Yool & Fasham, GBC, 2001)

17. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 17 We may find that the vital organs in the body of Gaia are not on land surfaces but in estuaries, wetlands, and muds on the continental shelves. There, the rate of carbon adjusts automatically to regulate the concentration of oxygen and essential elements are returned to the atmosphere. Egon T. Degens 1928-1989 A pioneer biogeochemist

18. To be posted @ http://cmtt.pangaea.de 16-20 June 2008 Busan 2008 AOGS Annual Meeting 18

19. 16-20 June 2008 Busan 2008 AOGS Annual Meeting 19

20. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 20 SeaWiFS Chl-a in the East China Sea (Summer) Why not just continental shelves?

21. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 21 East China Sea: TOC in sediments (Kao et al. 2003)

22. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 22 Estimated Global Riverine loads of nutrients (Gmol/yr) *No distinction between organic or inorganic forms was specified. **No distinction between organic or inorganic forms or between natural or anthropogenic origins was specified.

23. 5-9 Oct 2009 Bergen 2008 AOGS Annual Meeting 23 P-cycling in continental shelf

24. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 24 Demand & riverine supply of nutrients in margins Riverine fluxes from Global NEWS model (Seitzinger et al., 2005)

25. 16-20 June 2008 Busan 2008 AOGS Annual Meeting 25

26. 5-9 Oct 2009 Bergen 2008 AOGS Annual Meeting 26 Contents of terrigenous & marine organic carbon off SW Taiwan Kao et al., 2006, CSR TOCmar burial = 2.3% PP

27. 16-20 June 2008 Busan 2008 AOGS Annual Meeting 27 -10 -8 -7 -6 -5 4 -3 -2 -1 0 1 2 3 4 5 6 10 Net flux (10 12 grams C/ yr in each 4 x 5 o area) JGOFS/WOCE: Global air-sea CO 2 flux

28. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 28 Pre-anthropocene: C cycle at steady state with land-sea C sub-cycle Fred Mackenzie 0.8

29. Most shelf production + OrgC from land respired: R > P Currents varying on time- scales of days or longer tend to be constrained by geosptrophy to flow along depth contours;..... Thus geostrophy inhibits ocean-shelf exchange,..... Huthnance (1995) 5-9 Oct 2009 Bergen Final CarboOcean Meeting 29 X

30. 5-9 Oct 2009 Bergen Final CarboOcean Meeting 30 Continental shelf pump Simplified view: Cross shelf exchange is rapid enough to allow export of organic carbon from shelf to deep ocean. The reality is more complicated.

31. Carbon export by isopycnal mixing: Diffusion pump 16-20 June 2008 Busan 2008 AOGS Annual Meeting 31 Kuroshio