U.S. ECoS U.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

U.S. ECoS Science 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

U.S. ECoS 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? Goal: To develop carbon budgets for the U.S. east coast continental shelf (Mid-Atlantic Bight and South Atlantic Bight) Research Questions:

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

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

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

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

Theme 1 : Circulation and biogeochemical modeling NO 3 Chlorophyll Large detritus Organic matter N2N2 NH 4 NO 3 Water column Sediment Phytoplankton NH 4 Mineralization Uptake Nitrification Grazing Mortality Zooplankton Small detritus Aerobic mineralization Denitrification Fennel et al., in press, GBC

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

Theme 1 : Circulation and biogeochemical modeling Simulated annual air-sea flux of CO 2 Explicit inorganic carbon cycling Positive values indicate uptake by ocean Outer Mid-Atlantic Bight continental shelf is a sink for atmospheric CO 2 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

Theme 2 : Satellite and in situ data analyses OC4v4Clark CarderGSM01 Intercomparison of Chlorophyll-a Algorithms: May 14, 2000 O’Reilly, Signorini, McClain

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

Annual Ecosystem Variability O’Reilly

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

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

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

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

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

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

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

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

Theme 3 : Field measurements 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 Chesapeake Bay and adjacent coastal waters – ODU monthly cruises and NASA NIP (Mannino)

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

Theme 4 : Biogeochemical data assimilation 5 m 55 m115 m 3D 1D Comparison of simulated nitrate from 1D and 3D models at a site on MAB continental shelf Friedrichs

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

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: years later scenario: Using RegCM3

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

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

Summary U.S. ECoS Goal: To develop carbon budgets for the U.S. east coast continental shelf waters 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