U.S. ECoS U.S. Eastern Continental Shelf Carbon Budget: Modeling, Data Assimilation, and Analysis

1. U.S. ECoSU.S. Eastern Continental Shelf Carbon Budget:Modeling, Data Assimilation, and Analysis A project of the NASA Earth System Enterprise Interdisciplinary Science Program Ocean Color Research Team Meeting Newport, RI, April 2006

2. U.S. ECoSScience Team Eileen Hofmann (ODU) project oversight, 1D modeling Marjorie Friedrichs (ODU) 1D modeling and data assimilation Chuck McClain (GSFC) project oversight, remote sensing data Sergio Signorini (GSFC) satellite data analysis Antonio Mannino (GSFC) carbon cycling Cindy Lee (SUNY-SB) carbon cycling Jay O’Reilly (NOAA) satellite data analysis Dale Haidvogel (RU) circulation modeling John Wilkin (RU) circulation modeling Katja Fennel (RU) biogeochemical modeling Sybil Seitzinger (RU) food web and nutrient dynamics Jim Yoder (URI) food web and nutrient dynamics Ray Najjar (PSU) oxygen data, climate modeling David Pollard (PSU) climate modeling

3. U.S. ECoS Goal: To develop carbon budgets for the U.S. east coast continental shelf (Mid-Atlantic Bight and South Atlantic Bight) Research Questions: 1. What are the relative carbon inputs to the MAB and SAB from terrestrial run-off and in situ biological processes? 2. What is the fate of DOC input to the continental shelf from estuarine and riverine systems? 3. What are the dominant food web pathways that control carbon cycling and flux in this region? 4. Are there fundamental differences in the manner in which carbon is cycled on the continental shelves of the MAB and SAB? 5. Is the carbon cycle of the MAB and SAB sensitive to climate change?

4. Outline of Presentation • Theme 1:Development and implementation of circulation, biogeochemistry, and carbon cycling models for the east coast of the U.S. • Theme 2: Data analysis effort – includes historical in situ measurements and satellite-derived data • Theme 3: Limited field measurement effort • Theme 4: Implementation of data assimilative models • Theme 5: Interfacing circulation and biogeochemical models with climate models

5. Theme 1: Circulation and biogeochemical modeling Northeast North American shelf model (NENA)

6. Theme 1: Circulation and biogeochemical modeling Simulated Salinity WOA98 Salinity 10m August 4m August 2002 North-south gradients agree, simulations produce mesoscale variability Wilkin, Haidvogel

7. Theme 1: Circulation and biogeochemical modeling Freshwater budgets- tides Boundary forcing – cold bias in Hycom solutions Forcing fields for wind, heat flux, shortwave radiation Wilkin, Haidvogel

8. Theme 1: Circulation and biogeochemical modeling Nitrification Water column Mineralization NH4 NO3 Uptake Phytoplankton Grazing Chlorophyll Zooplankton Mortality Large detritus Small detritus Nitrification Fennel et al., in press, GBC N2 NH4 NO3 Denitrification Aerobic mineralization Organic matter Sediment

9. Theme 1: Circulation and biogeochemical modeling Sources and sinks of nitrogen Role of shelf denitrification Fennel et al., in press, GBC

10. Theme 1: Circulation and biogeochemical modeling Simulated annual air-sea flux of CO2 Explicit inorganic carbon cycling Positive values indicate uptake by ocean Outer Mid-Atlantic Bight continental shelf is a sink for atmospheric CO2 Two regions of no net uptake off NJ due to outgassing during summer that results from intermittent upwelling of carbon-rich water from below seasonal thermocline Fennel

11. Theme 2: Satellite and in situ data analyses Intercomparison of Chlorophyll-a Algorithms: May 14, 2000 OC4v4 Clark Carder GSM01 O’Reilly, Signorini, McClain

12. Theme 2: Satellite and in situ data analyses In situ productivity measurements Satellite productivity measurements O’Reilly

13. Annual Ecosystem Variability O’Reilly

14. Theme 2: Satellite and in situ data analyses Analyses of forcing functions and chlorophyll (response) Top- size of North Atlantic Subtropical gyre Middle- Cape Fear River discharge Bottom- Chlorophyll Signorini, McClain

15. Theme 2: Satellite and in situ data analyses Analyses of forcing functions and response Sea surface height anomaly and NASG size Signorini, McClain

16. Theme 2: Satellite and in situ data analyses Air-Sea Flux of Oxygen – NODC historical data SAB MAB MAB- net ingassing in inner shelf, net outgassing over mid and outer shelf SAB- net outgassing in spring, summer, fall Siewert, Najjar

17. Themes 1 and 2: Modeling and satellite analyses Fennel, Wilkin, O’Reilly, Signorini, McClain

18. Themes 1 and 2: Modeling and satellite analyses Model-data comparisons Fennel, Wilkin, O’Reilly

19. Themes 1 and 2: Modeling and satellite analyses Fennel, Wilkin, O’Reilly

20. Themes 1 and 2: Modeling and satellite analyses Satellite-derived primary production (PP) using VGPM2 VGPM2 applied to NENA-simulated fields Modeled PP using NENA Fennel, Wilkin, O’Reilly

21. Themes 1 and 2: Modeling and satellite analyses Model-data comparison Wilkin, O’Reilly

22. Theme 3: Field measurements Chesapeake Bay and adjacent coastal waters – ODU monthly cruises and NASA NIP (Mannino) • ODU cruises - one day, 8 hour cruise, 4 stations • NIP – grid of stations, 3-4 day cruises • Carbon, nutrients, chl a, pigments, absorb., … •Estimate fluxes - model •Algorithm development ARCHIVED SAMPLES 2002 to present

23. Theme 4: Biogeochemical data assimilation Developed a 1-D data assimilative ‘Modeling Testbed’ This framework includes: mixing, advection, diffusion, attenuation, sinking subroutines This framework requires: forcing fields: T, MLD, PAR, w, Kv boundary and initial conditions ecosystem model subroutine adjoint of ecosystem model subroutine biogeochemical data for validation/assimilation This framework will be used to: Perform parameter sensitivity/optimization analyses Test new parameterizations and formulations Compare multiple models at a single site Compare model performance at various sites

24. Theme 4: Biogeochemical data assimilation Comparison of simulated nitrate from 1D and 3D models at a site on MAB continental shelf 5 m 3D 55 m 115 m 1D Friedrichs

25. Theme 4: Biogeochemical data assimilation Identical Twin Numerical Experiments - Use SeaWiFS and in situ data Chl2C_m PhyIS PhyMR Vp0 ZooGR CoagR Sremin 7 (of 18) parameters can be independently estimated Friedrichs

26. Theme 5: Climate Modeling How will coastal regions respond to climate change, and what are the feedbacks on the carbon cycle? Force the circulation/biogeochemical model with climate change scenarios: Present day scenario: 1980-2000 100 years later scenario: 2080-2100 Using RegCM3

27. Theme 5: Climate Modeling Simulated surface air temperature Observed surface air temperature from climatology Pollard, Najjar

28. Theme 5: Climate Modeling Six-hourly precipitation fields from a 10-year simulation using present conditions Pollard, Najjar

29. Summary • Numerous results from all components of program • Model-data comparisons are well developed • Construct carbon budgets for MAB and SAB • No component by itself can do this – synthesis approach • Requires modeling effort coupled with satellite and in situ data analyses • Ongoing effort - observationalists and modelers working together in an interactive manner U.S. ECoS Goal: To develop carbon budgets for the U.S. east coast continental shelf waters