Transcript Slide 1

U.S. Eastern Continental Shelf Carbon Budget: Modeling,
Data Assimilation, and Analysis
ABSTRACT. The U.S. Eastern Continental Shelf Carbon Budget
(U.S. ECoS) Program, which began in summer 2004, is funded as
part of the NASA Interdisciplinary Science Program. The overall
goal of this project is to develop carbon budgets for the MidAtlantic Bight (MAB) and South Atlantic Bight (SAB) along the
eastern U.S. coast. The U.S. ECoS program is structured around
five themes which are focused on: 1) development and
implementation of circulation, biogeochemistry, and carbon cycling
models for the east coast of the U.S.; 2) analyses of historical in
situ measurements and satellite-derived data; 3) a limited field
measurement effort designed to provide measurements for input
to the biogeochemistry and carbon cycling models; 4) development
and implementation of data assimilative biogeochemical and carbon
cycling models; and 5) interfacing the circulation, biogeochemistry
and carbon cycling models with climate models. Our research is
particularly germane to NASA’s carbon cycle research focus topic
and coastal research initiative and the U.S. Climate Change
Research Program, all of which emphasize the North American
Carbon Program.
U.S. ECoS Science Team*
*U.S. ECoS Science Team
Eileen Hofmann (ODU)
Project oversight, 1D modeling
Marjorie Friedrichs (ODU) Modeling, data assimilation
Chuck McClain (GSFC)
Project oversight, satellite data
Sergio Signorini (GSFC)
Satellite data analyses
Antonio Mannino (GSFC)
Carbon cycling
Cindy Lee (Stony Brook) Carbon cycling
Jay O’Reilly (NOAA)
Satellite data analyses
Dale Haidvogel (Rutgers) Circulation modeling
John Wilkin (Rutgers)
Circulation modeling
Katja Fennel (Rutgers)
Biogeochemical modeling
Sybil Seitzinger (Rutgers) Food web, nutrient dynamics
Jim Yoder (WHOI)
Food web, nutrient dynamics
Ray Najjar (Penn State) Data climatology, climate modeling
David Pollard (Penn State) Climate modeling
RESEARCH QUESTIONS
1) What are the relative carbon inputs to the MAB and SAB from
terrestrial sources 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 MAB and SAB continental shelf?
5) Is the carbon cycle of the MAB and SAB sensitive to climate
change?
Figure 4
Sink
Figure 2
Simulated
Chlorophyll
Latitude (North)
Source
Figure 1
Figure 5
Figure 2
SeaWiFS
Chlorophyll
Figure 3
Longitude (West)
Comparisons of simulated, in situ, and SeaWiFS-derived monthly-averaged chlorophyll
concentrations at sites in the MAB (Figure 4). The biogeochemical model captures the
chlorophyll annual cycle. The simulated annual air-sea CO2 flux shows that the MAB and
SAB provide a net sink for carbon (Figure 5). Additional simulations are ongoing to
investigate carbon and nutrient cycling processes in the MAB and SAB.
The biogeochemical model used in this
project (Figure 1) is coupled to a
circulation model (Regional Ocean Modeling
System, ROMS v.3) that has been
implemented for the continental shelf and
adjacent deep ocean of the U.S. east
coast (Northeast North American (NENA)
Shelf Model). Comparisons of simulated
chlorophyll distributions obtained with the
coupled circulation-biogeochemical model
show features that are similar to those
seen in chlorophyll distributions obtained
from SeaWiFS measurements (Figures
2,3). The biogeochemical model is
currently being modified to include data
assimilation capability.
Figure 7
Figure 9
Figure 6
Satellite data analyses are an integral
part of the project and provide inputs
and verifications for the simulated
distributions obtained from the
coupled model, such as the Western
North Atlantic POC composite (mg C
L-1, log scale is 0.01 to 5.0) for
April 1998 (Figure 6) derived from
SeaWiFS normalized water leaving
radiances and the Clark empirical
algorithm (D. Clark, unpublished).
The nearshore sources (yellow-red
high values) originate from rivers and
estuaries. Lowest values are in the
Sargasso Sea and patchiness south of
the Gulf Stream may be due to POC
advection by cold core eddies.
The field sampling component of the U.S. ECoS project
is focused on Chesapeake Bay (Figure 9) and provides
data sets that are critical for the biogeochemical model.
Initial results show lower DOC variability in summer-fall
than in winter-spring (Figure 9).
Satellite-derived data sets
provide distributions of seasonal
and interannual variability in
primary production (Figures 7, 8)
and estimates of primary
production obtained from
different algorithms (Figure 7).
In situ data sets, such as the
MARMAP data, provide
calibration for the satellitederived values (Figure 7).
Figure 8
Interannual Ecosystem
Variability
J. O’Reilly, NMFS, NOAA
This project is supported by
the NASA Interdisciplinary
Science Program