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

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U.S. ECoSU.S. Eastern Continental Shelf Carbon
BudgetModeling, Data Assimilation, and Analysis

• A project of the NASA Earth System Enterprise
• Interdisciplinary Science Program
• Ocean Carbon Biogeochemistry Workshop
• Woods Hole, MA, July 2006

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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 OReilly (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

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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?

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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

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Theme 1 Circulation and biogeochemical modeling
Northeast North American shelf model (NENA)
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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
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Theme 1 Circulation and biogeochemical modeling
Hindcasts 2002 onward Boundary forcing
cold bias in HyCOM solutions Tides make a
difference Georges Bank, reduced gradients
Wilkin, Haidvogel
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Theme 1 Circulation and biogeochemical modeling
Nitrification
Water column
Mineralization
NH4
NO3
Uptake
Phytoplankton
Grazing
Chlorophyll
Zooplankton
Mortality
Large detritus
Small detritus
Fennel et al., in press, GBC
Nitrification
N2
NH4
NO3
No DOM yet
Denitrification
Aerobic mineralization
Organic matter
Sediment
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Theme 1 Circulation and biogeochemical modeling
Sources and sinks of nitrogen Role of
shelf denitrification
Fennel et al., in press, GBC
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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 No net uptake off NJ due to outgassing
during summer from upwelling
Fennel
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MAB atmospheric CO2 uptake estimates
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Theme 2 Satellite and in situ data analyses
Intercomparison of Chlorophyll-a Algorithms May
14, 2000
OC4v4
Clark
First coastal intercom-parison Inner shelf
differences
Carder
GSM01
OReilly, Signorini, McClain
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Theme 2 Satellite and in situ data analyses
In situ productivity measurements
Phase good, models differ, models too high. SAB
tough due to intrusions.
Satellite productivity measurements
OReilly
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Annual PP, mean and ratio to mean
OReilly
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Maxmin annual PP(1998-2005)
OReilly
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Theme 2 Satellite and in situ data analyses
SAB variability Analyses of forcing functions
and chlorophyll (response), 1998-2005 Top- size
of North Atlantic Subtropical gyre
(chl-based) Middle- Cape Fear River
discharge Bottom- Chlorophyll
Signorini, McClain
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Theme 2 Satellite and in situ data analyses
Analyses of forcing functions and response at 3
sites Sea surface height anomaly (green) and
NASG size (blue) May reflect seasonal migration
of Gulf Stream frontoffshore in spring, onshore
in fall
Signorini, McClain
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SST trend Chl trend
OReilly
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Theme 2 Satellite and in situ data analyses
Analyses of World Ocean Database for study
region focus on MLD and dissolved O2.
Siewert, Najjar
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Theme 2 Satellite and in situ data analyses
MLD based on ?T 0.2C
Siewert, Najjar
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Theme 2 Satellite and in situ data analyses
MAB outer shelf annual cycles of the oxygen
anomaly
0-30 m
30-60 m
60-100 m
Siewert, Najjar
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Theme 2 Satellite and in situ data analyses
MAB Sea-to-air oxygen flux
Outer Shelf
Slope
Mid-Shelf
Inner Shelf
Siewert, Najjar
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Themes 1 and 2 Modeling and satellite analyses
Fennel, Wilkin, OReilly, Signorini, McClain
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Themes 1 and 2 Modeling and satellite analyses
Model-data comparisons
? Model crashes in summer (no tides)
Fennel, Wilkin, OReilly
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Themes 1 and 2 Modeling and satellite analyses
Fennel, Wilkin, OReilly
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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, OReilly
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Themes 1 and 2 Modeling and satellite analyses
Model-data comparison
Wilkin, OReilly
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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
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Theme 3 Field measurements
From cruises in Southern MAB, including lower
Chesapeake Bay. 30 Mar 1 Apr cruise
? Spring conditions well mixed except where
influenced by rivers.
Mannino
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Theme 3 DOC CDOM field measurements
From cruises in Southern MAB, including lower
Chesapeake Bay. Seasonal algorithms needed.
Offset due to net community production of DOC and
bleaching from spring to summer.
Mannino
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Themes 2 3 Satellite and field measurements
Aqua-MODIS-based CDOM
Mannino
Based on in situ aCDOM and in situ reflectance
ratios
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Themes 2 3 Satellite and field measurements
Aqua-MODIS-based DOC (mM)
Mannino
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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 evaluation/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
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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
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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
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DOM modeling
Jean-Noel Druon
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1-D MAB results
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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
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Theme 5 Climate Modeling
Winter Summer
Simulated precipitation
Observed precipitation
Pollard, Najjar
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Theme 5 Climate Modeling
Six-hourly precipitation fields from a
10-year simulation using present conditions
Pollard, Najjar
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Summary
U.S. ECoS Goal To develop carbon budgets for the
U.S. east coast continental shelf waters

• Circulation model shows observed features for
  SSS, SST. More evaluation (e.g., MLD) needed.
  Tides, BCs make a difference.
• Biogeochemical model captures chl variability.
  Chl too low in gyre. More tracer evaluation
  needed (e.g., oxygen)
• Denitrification significantly influences air-sea
  carbon flux in model. MAB air-sea flux agrees
  with observations.
• Satellite productivity algorithms give MAB
  results close to observed. Issues in SAB.
• Interannual variability and long-term trends in
  chl, PP, SST.

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

• Riverine gyre influences on chl seen in SAB.
• Field data have allowed development of CDOM and
  DOC products for MAB
• Model and satellite productivity issues need
  resolution.
• 1D models and data allow parameters for 3D models
  to be constrained.
• DOM poised to be included in 3D model.
• Regional climate model set up and ready for
  climate change runs

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

• No component can do this by itselfsynthesis
  approach
• Requires modeling effort coupled with satellite
  and in situ data analysis
• Ongoing effortobservationalists and modelers
  working together