Changes in the Atmospheric Methane Concentration in the Arctic and Antarctic Regions for the Last...
Description: Variations of the atmospheric CH4 concentration for the last 110 kyrs
were deduced from deep ice cores drilled at NGRIP, Greenland and Dome
Fuji, Antarctica. The CH4 concentration was higher in the Arctic than
in the Antarctica throughout the period. The interpolar difference of
the CH4 concentration was variable with time, showing that larger and
smaller differences appeared in warmer and colder periods,
respectively. In order to examine the CH4 concentration variations in
terms of its source strength, the CH4 data obtained from both cores
were analyzed using a three-box model. The results suggested that the
CH4 concentration variations during the last ice age were mainly caused
by changes in CH4 sources in northern middle and high latitudes. On the
other hand, the CH4 concentration variations during the Termination I
and the Holocene were expected to ascribe mainly to tropical CH4
sources.
Author's Names: S. Aoki
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GLOBAL CARBON FLUXES INFERRED FROM THE CSIRO GLOBAL FLASK NETWORK: 1983-2004
Description:
Stable isotope measurements of atmospheric carbon
dioxide from the CSIRO global flask sampling program with improved traceability
to the international primary reference material VPDB (Vienna Pee Dee Belemnite),
and with improved uncertainty estimates, are presented. The measurements have
been used with an improved time dependent inversion model to reassess
terrestrial and oceanic contributions to the interannual variability in
atmospheric CO2.
Author's Names: C. Allison, R. Francey, R. Law, and P. Rayner
Filesize: 84.77 Kb
Added on: 10-Aug-2005 Downloads: 38
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SHORT-TERM VARIATION OF ATMOSPHERIC CARBON DIOXIDE AT MT. WALIGUAN: IMPLICATION FOR SOURCE, SINK ...
Description:
This
presentation describes in-situ atmospheric CO2 measurements at Waliguan
Observatory (WLG, 36°17'N, 100°54'E, 3816m asl) since 1994, together with 5-day isobaric
back trajectory analysis. We also use the
Hybrid Single-Particle Lagrangian Integrated Trajectory (Hysplit-4) transport/diffusion
model to simulate the CO2 variation at WLG in January 1999 and
compared with observations. A case study for polluted air mass transport event with
a short-term elevated CO2 has been conducted to further investigate the
impact of source, sink and long-range transport of atmospheric CO2.
Author's Names: L.X. Zhou, X.C. Zhang, P. Yan, and Y.P. Wen
Filesize: 222.64 Kb
Added on: 09-Aug-2005 Downloads: 24
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CALIBRATION AND PROPAGATION OF THE WMO MOLE FRACTION SCALE FOR CARBON DIOXIDE IN AIR
Description:
The current WMO
CO2 Mole Fraction Scale consists of a set of fifteen CO2 –in-air
primary standard calibration gases ranging in CO2 mole fraction from
250 to 520 micromol/mol. Since the WMO
CO2 Expert Group transferred responsibility for maintaining the WMO Scale from the Scripps Institute of
Oceanography (SIO) to the Climate Monitoring and Diagnostics Laboratory (CMDL) in 1995, the fifteen WMO
primary standards have been calibrated at regular interval, between one and two
years, by the CMDL manometric
system. From mid-1996 to 2001, the assigned CO2 values of the WMO Primaries have been jointly based on the SIO
and CMDL manometric measurements,
and completely on the CMDL
manometric measurements alone from 2001 to present. The uncertainty of the 15
primary standards is estimated to be 0.07 micromol/mol in the one-sigma
absolute scale. Manometric calibration results indicated that there is no
evidence of overall drift of the Primaries from 1996 to 2004. In order to
lengthen the useful life of the Primary standards, CMDL
has always transferred the WMO
Scale to the Secondaries via NDIR analyzers. The uncertainties arising from the
analyzer random error and the propagation error due to the uncertainty of the
reference gas concentration are discussed. Precision of NDIR transfer
calibrations is about 0.01 micromol/mol from 1979 to present. Propagation of
the uncertainty is calculated theoretically. In the case of interpolation, the
propagation error is estimated to be between 0.05 and 0.07 micromol/mol when
the Primaries are used as the reference gases via NDIR transfer calibrations.
Author's Names: C. Zhao, and P. Tans
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Added on: 09-Aug-2005 Downloads: 23
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TEMPORAL VARIATIONS OF THE ATMOSPHERIC CO2 CONCENTRATION IN THE SOUTHERNMOST PART OF JAPAN
Description:
To
examine concentration variations of atmospheric CO2 in the
sub-tropical region of East Asia, systematic air sampling with subsequent
laboratory analysis has been made in the southernmost part of Japan since June 1993. A time
series of measured CO2 concentrations was analyzed for long-term
trend, seasonal cycle and interannual variability, and the temporal CO2 variations deduced were interpreted in
terms of atmospheric transport and CO2 flux regions.
Author's Names: X. Zhang, T. Nakazawa, S. Aoki, S. Nakaoka, et al
Filesize: 125.82 Kb
Added on: 09-Aug-2005 Downloads: 22
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OBSERVATIONAL DATA SCREENING TECHNIQUE USING ATMOSPHERIC TRANSPORT MODEL AND INVERSE MODEL IN ...
Description:
We
have developed a new data screening technique using an atmospheric transport
model and an inverse model. Using this technique, we can use original (not
smoothed) observational data for the inversion method. This means that we can
enlarge the number of observational data for inversion method and we can
estimate carbon dioxide (CO2) flux history consistently in long period
in accordance with the number of the observational sites.
Author's Names: T. Maki, K. Kamide and Y. Tsutsumi
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Added on: 09-Aug-2005 Downloads: 27
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RETRIEVAL ALGORITHM OF CO2 COLUMN DENSITY BY USING SIMULATION DATA OF THE ‘GOSAT’ SWIR FTS UNDER
Description:
Greenhouse gases Observing SATellite (GOSAT) of Japan is planned to be launched in
2008. GOSAT will be equipped with a FTS to monitor CO2 column
density globally. The FTS has three near infrared bands which cover 0.76 µm, 1.6
µm, and 2.0 µm spectral regions, respectively. Retrieval algorithms to estimate
CO2 and CH4 column densities from these bands data are
now being developed. We have investigated retrieval algorithms under the
non-clear sky conditions. As one of these cases, a cirrus cloud parameter
estimation was researched. The cirrus vertical profile (i.e., existing height)
is estimated from the 0.76 µm band data. Strong water vapor absorption area is included
in the 2.0 µm spectral band, so that the reflected radiance from a ground
surface is absorbed completely by H2O in this area. Thus the signal
in this area is considered as path radiance caused by the cirrus clouds
reflection, because there is little water vapor above the cirrus cloud top. By
using this signal, the cirrus optical depth can be estimated, and then column
densities of CO2, CH4 and H2O are retrieved
precisely.
Author's Names: T. Yokota, A. Higurashi, T. Aoki, I. Morino, H. Oguma, et al
Filesize: 160.62 Kb
Added on: 09-Aug-2005 Downloads: 23
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A SIMULATION OF CARBON CYCLE EMPLOYED BY A 2-D ATMOSPHERIC TRANSPORT MODEL
Description:
Carbon flux distribution was
simulated between 90°S and 90°N during from 1981 to 1997. It was confirmed there was a terrestrial C
sink in the area of mid-high latitude of north hemisphere. Some effect factors
to Carbon flux, as ENSO, volcano
activity, surface temperature etc. were analyzed also.
Author's Names: L. Xu, C. Li, M. Shao, R.J. Zhang and M.A.K., Khalil
Filesize: 95.35 Kb
Added on: 09-Aug-2005 Downloads: 39
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ANTHROPOGENIC CO2 IN THE OCEANS ESTIMATED USING TRANSIT-TIME DISTRIBUTIONS
Description:
Quantifying
the uptake of anthropogenic carbon by the oceans is a crucial component of
understanding the global carbon cycle. Accordingly there has been considerable
research in the area, and recently global estimates of the inventory and
decadal uptake of anthropogenic carbon have been made using carbon measurements
[Sabine et al., 2004] and CFC
measurements [McNeil et al., 2003]. However, these methods introduce several
assumptions that may introduce systematic biases. In particular, both methods assume that
mixing plays a negligible role in the transport. Here we estimate the ocean uptake, inventory,
and distribution of anthropogenic carbon (Cant) in the oceans using
the transit-time distribution (TTD) method (see Hall et al. 2004, Waugh et al.
2004), which avoids the assumption of weak mixing.
Author's Names: D.W. Waugh , T.M. Hall, and B.I McNeil
Filesize: 71.36 Kb
Added on: 08-Aug-2005 Downloads: 27
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INITIAL RESULTS FROM THE TOTAL CARBON COLUMN OBSERVING NETWORK
Description:
The
Total Carbon Column Observing Network is a new network of ground-based solar
observatories, dedicated to column measurements of greenhouse gases. We present CO2 column abundances
observed in Park Falls, Wisconsin
and Lauder, New Zealand
during May 2004 – June 2005. In Park Falls, Wisconsin,
the peak-to-peak variation of column-average CO2 is approximately 13
ppmv. In Lauder, New Zealand, the peak-to-peak
variation of column-average CO2 is approximately 4 ppmv. Assuming a secular trend of 2 ppmv yr-1,
we infer a peak-to-peak seasonal amplitude of 11 ppmv and 2 ppmv for Park Falls
and Lauder respectively. These values
are higher than model predictions by Olsen and Randerson [2003].
Author's Names: R.A. Washenfelder, V. Sherlock, B.J. Connor, et al
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