REGIONAL AND CONTINENTAL NORTH AMERICAN CARBON EXCHANGE IN 2003 AND 2004 USING AIRCRAFT AND ...
Description:
We quantify atmosphere-biosphere carbon exchange at
the continental scale across North America
during the summers of 2003 and 2004. The 2003 campaign features continental
transects across the northern portion of North America with significant
influence from biomass burning, while the 2004 study focuses on the greater New
England and Quebec
region. We use a Lagrangian, adjoint atmospheric model [Gerbig et al. 2003a,b; Lin et
al. 2003] coupled to a biosphere model derived from the Vegetation
Photosynthesis Model [Xiao et al.,
2004]. Our analysis of the 2004 airborne data demonstrates the progression of
increasing carbon uptake through the boreal zone during the seasonal transition
from early spring to late summer. Data from the coast-to-coast transects of the
2003 campaign allow us to quantify large scale carbon exchange across the
continent.
Author's Names: D.M. Matross, M. Pathmathevan, C. Gerbig, et al
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INTERANNUAL VARIATIONS OF CARBON DIOXIDE IN THE UPPER TROPOSPHERE OBSERVED OVER THE WESTERN ...
Description:
The spatial and temporal variations of atmospheric CO2
at 8-13 km from April 1993 to March 2005 were observed by measuring CO2
concentrations in samples collected biweekly from a commercial airliner between
Australia and Japan.
The 12-year record between 30N and 30S revealed several characteristics for CO2
interannual variabilities in the upper troposphere. The most significant
year-to-year change was found in a large increase in the growth rate during
1997/98 and 2002/03 that were associated with the ENSO
events. During these years, changes in north-to-south gradient of latitudinal
distribution and seasonal cycle were observed compared to data during the
normal years.
Author's Names: H. Matsueda, Y. Sawa, A. Wada, and S. Taguchi
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PACIFIC DOMINANCE TO GLOBAL AIR-SEA CO2 FLUX VARIABILITY: A NOVEL ATMOSPHERIC INVERSION AGREES ...
Description:
We
address an ongoing debate regarding the geographic distribution of interannual
variability in ocean - atmosphere carbon exchange. We find that, for 1983-1998,
both novel high-resolution atmospheric inversion calculations and global ocean
biogeochemical models place the primary source of global CO2 air-sea
flux variability in the Pacific Ocean. In ocean biogeochemical models, this
variability is clearly associated with the El Niño / Southern Oscillation
cycle. Both inversion and models indicate that the Southern Ocean is the
second-largest source of air-sea CO2 flux variability, and that
variability is small throughout the Atlantic, including the North Atlantic, in
contrast to previous studies.
Author's Names: G.A. McKinley, C. Rödenbeck, M. Gloor, et al
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AN EMPIRICAL ESTIMATE OF THE SOUTHERN OCEAN AIR-SEA CO2 FLUX
Description:
A discrepancy exists between current estimates of the
Southern Ocean air-sea flux of CO2.
The most recent estimate using a combination of direct and
climatologically-derived pCO2 measurements [Takahashi et al.,
2002] (herein referred to as T02) suggests a
Southern Ocean CO2 sink that is nearly two times greater that that
suggested from general circulation models, atmospheric inverse models [Gurney et al.,
2002] and oceanic inverse models [Gloor et al.,
2003]. Here we employ an independent method
to estimate the Southern ocean air-sea flux of CO2. Our method exploits all available surface
measurements for Dissolved Inorganic Carbon (DIC) and total alkalinity (ALK) from 1986 to 1996. We show that surface
age-normalized DIC can be predicted to within ~8mmol/kg and ~10mmol/kg for ALK
using standard hydrographic properties, independent of season. The predictive equations are used in
conjunction with World Ocean Atlas (2001) climatologies to estimate an annual
cycle of DIC and ALK, while the
pCO2 distribution is calculated using standard carbonate
chemistry. For consistency we use the
same gas transfer relationship and wind product from Takahashi et
al, [2002] however, we include the effects of sea-ice. We estimate a
Southern Ocean CO2 sink (>40°S) of -0.19±0.26 Pg C for 1995. Our estimates are
smaller than those estimated by Takahashi et al,
[2002], but consistent with atmospheric / oceanic inverse methods, general
circulation models and provides further evidence that the Southern Ocean CO2
sink in relation to its oceanic surface area, is moderate on a global scale.
Author's Names: B. I. McNeil, N. Metzl, R. M. Key and R. J. Matear
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SPACE AND TIME VARIABILITY OF TOTAL INORGANIC CARBON AND AIR-SEA FLUX OF CO2 IN THE NORTH-EAST ...
Description:
Four CARIOCA Lagrangian buoys
drifted in the North-East Atlantic Ocean
between 38° and 45°N between February and August 2001. Daily cycles of pCO2, SST and DIC are
observed even in winter. Biological rates of carbon consumption, gross and net
primary production,are determined in situ from the amplitude of the diel cycles
and the time evolution of surface dissolved inorganic carbon. Over the 6 months
period, February-August, the ocean in the studied area is a sink for atmospheric
CO2.The mean absorbed flux is equal to 3.8 mmoles/ m2/ day.
Author's Names: L. Merlivat, G.Caniaux, J.Boutin, et al
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INTERANNUAL VARIABILITY OF THE CARBON DIOXIDE SYSTEM AND AIR-SEA CO2 FLUXES IN THE HIGH ...
Description: Since 1993, regular seasonal water sampling has been conducted along a
ship-track between Island and Newfoundland in the
open ocean of the North Atlantic subpolar gyre in the
frame of the long-term SURATLANT program. In this study, we
analyse the interannual variation of the carbon dioxide system, including
seawater fugacity (fCO2)
and air-sea CO2 fluxes for the period 1993-2004. During
1993-1997, the data present a clear seasonality in this region marked by a
strong CO2 sink in summer and near-equilibrium in winter. For recent
years, 2001-2004, we observed a dramatic change of the source/sink seasonality.
An extreme case was observed in 2003 when oceanic fCO2 was above equilibrium during all
seasons. This strong anomaly was driven by ocean warming.
Author's Names: A. Corbière, N. Metzl, G. Reverdin , C. Brunet , et al
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DECADAL RISING OF OCEAN SURFACE CO2 IN THE SOUTHERN INDIAN OCEAN (20°S-60°S).
Description:
The decadal
variability of air-sea CO2 fluxes is poorly known in the southern
hemisphere. To evaluate the changes or stability of these fluxes over several
years, we compare seasonal observations obtained in 1991 and 2000 the Southern Indian Ocean. For summer and winter, we observed
a significant increase of ocean fugacity (fCO2) in subtropical
waters (20°-35°S), about the same rate as in the atmosphere. In polar waters
south of 40°S where meso-scale biological activity is high in summer, the
rising of oceanic fCO2 is only well detected when comparing austral
winter data. The decadal evolution of fCO2 observed in the cold
waters certainly results from anthropogenic CO2 emissions, but is
also probably modulated by variations of primary production.
Author's Names: N.Metzl, C.Brunet, C.Lo Monaco, and A. Poisson
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APPLICATION OF A GEOSTATISTICAL KALMAN SMOOTHER TO THE ESTIMATION OF MONTHLY GRIDSCALE FLUXES OF ...
Description: Inverse modeling methods are now commonly used for
estimating surface fluxes of carbon dioxide, using atmospheric mass fraction
measurements combined with a numerical atmospheric transport model. Michalak et al. [2004] recently developed a
geostatistical approach to flux estimation that takes advantage of the spatial
and/or temporal correlation in fluxes and does not require prior flux
estimates. In this work, a
geostatistical implementation of a fixed-lag Kalman smoother is developed and
applied to the recovery of gridscale carbon dioxide fluxes for 1997 – 2001 using
data from the NOAA-CMDL Cooperative
Air Sampling Network.
Author's Names: A.M. Michalak, K. Mueller, S. Gourdji, et al
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INTERANNUAL VARIATIONS OF WINTER OCEANIC pCO2 AND AIR-SEA CO2 FLUX IN THE WESTERN NORTH PACIFIC
Description:
We report the
interannual variations of winter CO2
partial pressure in surface waters (pCO2sea)
and overlying air (pCO2air)
and air-sea CO2 flux in the
extensive area (3-34°N) from subtropical to equatorial along 137°E during the period of 1983-2003. The pCO2sea varied largely in
the equatorial region of 3-6°N, depending on the variations of the
oceanographic conditions related to the El Niño-Southern Oscillation (ENSO) events. The pCO2sea variations in the subtropical gyre north of 23°N were small due to highly
counteracting effects between anti-correlated sea surface temperature (SST)
and dissolved inorganic carbon (DIC) anomalies through the entrainment
process, irrespective of large variations of SST. By contrast, it was
found that there occurred a low negative correlation between SST and DIC in the
region restricted around 15-18°N in the North Equatorial Current, which resulted
in a large amplitude of variations of pCO2sea
and hence CO2 influx. The interannual
variations of CO2 flux depended predominantly on those of the
difference between pCO2sea
and pCO2air (ΔpCO2) south
of 18°N but on those of wind speed in the northern region.
Author's Names: T. Midorikawa, M. Ishii, K. Nemoto, H. Kamiya, et al
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THE ROLE OF SOUTHERN HEMISPHERE WINDS IN CONTROLLING THE OCEANIC UPTAKE AND STORAGE OF ...
Description:
Physical processes in the Southern Ocean are
known to profoundly impact the global carbon cycle, but this region is one of
the most difficult to simulate consistently in ocean general circulation models
(OGCMs). Here we show that Southern Hemisphere winds, by altering the volume of
light, actively-ventilated ocean water as well as the relative contribution to
this volume from Ekman transport, exert strong control over both the magnitude
and distribution of anthropogenic carbon uptake in an OGCM. These results are
provocative in suggesting that climate warming, by increasing the magnitude of
the wind stress at high southern latitudes, may act as a negative feedback on
the global carbon cycle.
Author's Names: B.K. Mignone, A. Gnanadesikan, J. L. Sarmiento, et al
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