1. The carbon budget for coastal waters of the eastern United States R. Najjar, M. Friedrichs, W.-J. Cai, D. Butman,K. Kroeger, W. M. Kemp, M. Herrmann, L. McCallister, Z. Wang, S. Signorini, C. Pilskaln, D. Burdige, P. Vlahos, R. Vaillancourt 1 Outline 1.Importance of coastal ocean 2.NACP Coastal Synthesis 3.East coast carbon budget

2. Importance of the coastal ocean (depth < 200 m, 4.7% of ocean area) Pg C yr -1 % ocean total Primary Production 6.512 Export Production 2.021 Burial0.6786 2 Source: Dunne et al. (2007)

3. NACP-OCB Coastal Synthesis Activity Objective: “Stimulate the synthesis and publication of recent observational and modeling results on carbon cycle fluxes and processes along the North American continental margin” Phase 1: Regional carbon budgets Phase 2: Community modeling & database development NASA & NSF support for regional workshops and post-doc One workshop held (2012 East coast), one scheduled (Gulf of Mexico, March 27-28, 2013 in St. Petersburg, FL) Get involved! NACP web site  Synthesis Activities 3

4. 4 Nationalatlas.gov ( Mathis ) (Cai, Freidrichs, Najjar) (Alin, Hales) (Coble, Lohrenz)

5. Tidal wetlandsEstuaries Continental shelf NPPDegassing Burial River input BPP Air-water exchange POC export The carbon cycle of the coastal ocean POC DOC DIC Respiration (R) Resuspension NPP, R POC DOC DIC Sediments Advective exchange Open Ocean

6. Coastal zone of the eastern U.S.: Head-of-tide to shelf break (~200 m) 6 % Area Tidal wetlands 3 Estuaries14 Shelf waters 83 Gulf of Maine (GoM) Georges Bank + Nantucket Shoals (GB + NS) Mid-Atlantic Bight (MAB) South Atlantic Bight (SAB) See workshop report on NACP web site (Najjar et al. 2012)

7. River input USGS statistical models 7 TOC Tg C yr -1 DIC Tg C yr -1 GoM0.570.30 MAB1.451.63 SAB1.860.56 East Coast3.92.5 Also using process-based model (DLEM—see Tian et al. poster) SPARROW (Shih et al. 2010) LOADEST (Stets and Striegl 2012)

8. Tidal wetlands 8 Delaware Bay New Jersey Delaware Estuarine and marine wetlands Current approach: NWI Break up wetlands by subregion and salinity Literature survey of burial & lateral export Average Two estimates of NPP www.smithtrail.net

9. Tidal wetlands budget (Tg C yr -1 ) 9 NPP 13-24 Degassing 3-19 Burial 1-2 2DIC 2-6 DOC ?POC Respiration (R) = 5-21 Lateral export NPP – R = TOC export + Burial R – NPP = DIC export + Degassing Net uptake 5-10 Empirical model (Childers et al. 2002) being adopted/refined

10. Estuarine processes See Herrmann et al. poster Net ecosystem production (NEP = NPP – R) function of riverine DIN:TOC loading ratio Burial function of estuarine residence time 10 64 estuaries Based on NOAA’s National Estuarine Eutrophication Assessment survey (Bricker et al. 2007)

11. 11 Integrate East coast estuarine NEP = -1.9 Tg C yr -1 Estuarine organic C budget (Tg C yr -1 ) 3.4 0.6 0.9 -1.9 NEP Canada not included yet!

12. 12 Gulf of Maine (GoM) Georges Bank + Nantucket Shoals (GB + NS) Mid-Atlantic Bight (MAB) South Atlantic Bight (SAB) Currently a literature synthesis Also using satellite algorithms and numerical models Respiration poorly constrained 120 ± 30 Tg C yr -1 primary production on continental shelf 47 ± 20 34 ± 10 35 ± 10

13. Continental shelf air-sea exchange (Signorini et al. poster) 13 Surface pCO 2 algorithm exploiting satellite data Observed pCO 2 Algorithm pCO 2 Uptake Tg C yr -1 GoM-0.1 GB+NS1.3 MAB2.1 SAB1.0 East Coast4.3 Flux = f(  pCO 2, wind, SST)

14. Continental shelf sediments 14 DIC flux from sediments DIC flux: estimated from water depth  Similar approach taken with DOC flux Particle flux, resuspension, burial data synthesized See Pilskaln et al. poster Surface water POC export Resuspension flux Benthic DIC + DOC flux POC burial >812141

15. Cross-shelf transport Tracer-based approach: Vlahos et al. poster MAB a DOC source and DIC sink (net autotrophic) 15  Numerical modeling approach: Friedrichs et al. poster Gives similar OC results but IC budget not in balance

16. Tidal wetlandsEstuaries Continental shelf NPP 13-24 Degassing 3-19 Burial 1-2 River input 3.9 TOC 2.5 DIC BPP Air-water exchange POC export >8 Overall US east coast budget POC 1 DOC+DIC 14 Respiration (R) 5-21 Resuspension 12 -1.9 NEP 120 NPP, ? R Burial 0.9 Sediments Advective exchange Open Ocean 2 DIC 2-6 DOC 3-7 TOC ? 4.3

17. Lots of progress made, but still much to do Constrain air-water CO 2 flux for estuaries  close inorganic C budget Burial measurements Tracer techniques to get NEP on shelf and cross-shelf transport Numerical model evaluation and application 17

18. Thank you 18

19. References 19 Bricker, S.B., Longstaff, B., Dennison, W., Jones, A., Boicourt, K., Wicks, C., Woerner, J., 2007. Effects of nutrient enrichment in the nation’s estuaries: A decade of change, NOAA Coastal Ocean Program Decision Analysis Series No. 26. National Centers for Coastal Ocean Science, Silver Spring, MD. 328 pp. Childers, D.L., J.W. Day Jr, H. N. Mckellar (2002). Twenty More Years of Marsh and Estuarine Flux Studies: Revisiting Nixon (1980), M. P. Weinstein and D. A. Kreeger (eds), Concepts and Controversies in Tidal Marsh Ecology, Springer, Netherlands, 391-423. Dunne, J. P., J. L. Sarmiento, and A. Gnanadesikan (2007), A synthesis of global particle export from the surface ocean and cycling through the ocean interior and on the seafloor, Global Biogeochem. Cycles, 21, GB4006, doi:10.1029/2006GB002907. Najjar, R.G., Friedrichs, M.A.M., Cai, W.-J. (Editors), 2012. Report of the U.S. East Coast Carbon Cycle Synthesis Workshop, January 19-20, 2012, Ocean Carbon and Biogeochemistry Program and North American Carbon Program, 34 pp. Shih, J.S., Alexander, R.B., Smith, R.A., Boyer, E.W., Schwarz, G.E., Chung, S., 2010. An Initial SPARROW Model of Land Use and In-Stream Controls on Total Organic Carbon in Streams of the Conterminous United States, U.S. Geological Survey Open-File Report 2010–1276, 22 pp. Stets, E.G. and R.G. Striegl (2012). Carbon export by rivers draining the conterminous United States. Inland Waters, vol. 2., pp. 177-184.