FREQUENT MEASUREMENTS OF ATMOSPHERIC CO2 AND OTHER TRACE SPECIES USING COMMERCIAL AIRLINES
Description:
A
new research project has started in 2003 to develop Continuous CO2
Measurement Equipment (CME) and
Automatic Air Sampling Equipment (ASE)
for commercial airlines. CMEs are planning to be installed on five aircrafts
and fly to South East Asia, East Asia, Europe, North America, Pacific and Australia.
Routine air sampling by ASE will
be done twice a month between Japan
and Australia.
After issuing the certification, first observation flight by Boeing 747-400
will be conducted in October, 2005. Preliminary observation by small research
aircraft indicates that CME
produces reasonable results.
Author's Names: T. Machida, H. Matsueda, Y. Nakagawa, M. Tomosawa, et al
Filesize: 77.95 Kb
Added on: 01-Aug-2005 Downloads: 194
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DECADAL CHANGES IN OCEAN CARBON UPTAKE
Description:
There
is growing evidence that the rate of anthropogenic CO2 uptake in the
ocean is changing over time. Several programs are poised to assess current and
future ocean CO2 uptake rates, but there are issues with how to
extrapolate these measurements to decadal-scale changes over entire ocean
basins. One possibility is to exploit the growing network of ARGO floats that
are collecting profiles throughout the global oceans. We explore the viability
of this approach and make recommendations for how the ARGO network might be
made more useful for biogeochemical applications.
Author's Names: C.L. Sabine, R.A. Feely, G.C. Johnson, R. Wanninkhof, et al
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Added on: 04-Aug-2005 Downloads: 193
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TOP-DOWN REGIONAL CO2 FLUXES FOR NORTH AMERICA ESTIMATED FROM NOAA-CMDL CO2 OBSERVATIONS
Description:
We present an analysis of terrestrial net CO2 fluxes from North America for the period 2000-2004. These fluxes
consist of hourly maps at ~70km×100km resolution that are consistent with
observed atmospheric CO2 mixing ratios, as well as with varying
climatic conditions across different ecosystems as observed from space. The
flux maps are created in a newly developed ensemble data assimilation system
that consists of the atmospheric Transport Model v5 (TM5), the Vegetation
Photosynthesis Respiration Model (VPRM), and an efficient Bayesian
least-squares algorithm to optimize the fluxes from different biomes in VPRM
against CO2 mixing ratios from the NOAA-CMDL
observing network. The stochastic nature of the ensemble data assimilation
system allows us to consistently include uncertainty on net CO2 fluxes from the neighboring oceans and more distant continents
in the flux estimates for North America.
Author's Names: Wouter Peters, Lori Bruhwiler, John Miller, et al
Filesize: 364.14 Kb
Added on: 03-Aug-2005 Downloads: 168
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A DECREASING TREND IN NORTHERN HEMISPHERE CARBON UPTAKE SINCE 1992
Description: Increases in the north-south gradient of
atmospheric CO2
at Northern Hemisphere measurement sites of the NOAA/CMDL Global Air Sampling
Network reveal a shrinking carbon sink.
14 of 16 low altitude sites show differences with South Pole increasing
at a faster rate than can be explained by fossil fuel emissions, resulting in
an average north-south difference at remote marine sites nearly 1 ppm larger in
2003 than in 1992. Regardless of whether
this trend will persist, it shows that large changes in the carbon cycle can
occur rapidly and is a strong indication of the tenuous nature of terrestrial
carbon sinks.
Author's Names: J.B. Miller, P.P. Tans, J.W.C. White, et al
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Added on: 02-Aug-2005 Downloads: 166
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ESTIMATION OF ATMOSPHERIC CO2 FROM AIRS INFRARED SATELLITE RADIANCES IN THE ECMWF DATA ASSIMILATION
Description:
Atmospheric
CO2 concentrations have been obtained from the Atmospheric Infrared
Sounder (AIRS) radiance data within the European Centre for Medium-Range
Weather Forecasts (ECMWF) data assimilation system. In a first explorative
configuration, a subset of channels from the AIRS instrument has been
assimilated providing estimates of tropospheric column-averaged CO2
mixing ratios representative of a layer between the tropopause and about 700
hPa at observation locations only. Results show considerable geographical and
temporal variability with values ranging between 370 and 382 ppmv. The 5-day
mean estimated random error is about 1%, which is confirmed by comparisons with
flask observations on board flights of Japanese airliners in the west-Pacific
region. This study demonstrates the feasibility of global CO2
estimation using high spectral resolution infrared satellite data in a
numerical weather prediction data assimilation system. Currently, the system is
being improved to treat CO2 as a full three-dimensional atmospheric
variable included in the forecast model. This allows more flexibility in the
constraints on the CO2 estimation as well as the possibility of
assimilating other data sources (e.g., near-infrared satellite data and
flasks). The CO2 fields provided by the data assimilation system
have great potential to assist the surface flask network in constraining
current top-down carbon flux estimates.
Author's Names: Richard J. Engelen
Filesize: 217.21 Kb
Added on: 28-Jul-2005 Downloads: 164
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A 50 YEAR RECORD OF THE EVOLUTION OF THE MERIDIONAL GRADIENT IN ATMOSPHERIC CO2 AND ITS ...
Description:
Measurements of atmospheric CO2 began in
1957-1958 at a wide range of locations, including at fixed stations, on ice
floes, on oceanic expeditions, and on aircraft flights, with logistical and
financial support provided by the International Geophysical Year (IGY) program.
Although the measurement effort was reduced in scope immediately following the
IGY, today, measurements are made at more than 100 locations. Over this same time interval, emissions of CO2
from fossil fuel combustion increased from 2.3 thousand million metric tons per
year (GtC/yr) in 1958 to 7.1 GtC/yr in 2003 [Marland et
al., 2005, and personal communication]. More than 90% of this CO2 was
released into the northern hemisphere where it lingered before mixing fully
world-wide. The atmospheric CO2
concentration, in response, rose faster in the northern hemisphere than in the
southern, the interhemispheric difference increasing from near zero during the
IGY to about 3 parts per million (ppm) in 2003. For all northern hemisphere
stations where our program has measured CO2, the gradient changes
relative to the South Pole are generally proportional to the rate of fossil
fuel CO2 emissions, disregarding seasonal and short term interannual
variability in the CO2 data.
Here, we use this fact to diagnose how the carbon cycle has evolved over
the past half century.
Author's Names: C.D. Keeling, S.C. Piper, and T.P. Whorf
Filesize: 40.33 Kb
Added on: 01-Aug-2005 Downloads: 164
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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
Filesize: 119.45 Kb
Added on: 02-Aug-2005 Downloads: 155
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A DIRECT CARBON BUDGETING APPROACH TO STUDY CO2 SOURCES AND SINKS
Description:
For the purpose of
exploiting upcoming measurements of atmospheric CO2 vertical
profiles by aircrafts and continuous CO2 data recorded along tall
towers as part of the North American Carbon Plan (NACP), a direct carbon
budgeting approach is being developed.
Author's Names: C. Crevoisier, E. Gloor, J. Sarmiento, L. Horowitz, et al
Filesize: 70.64 Kb
Added on: 28-Jul-2005 Downloads: 154
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SIMULATING THE GLOBAL BOMB RADIOCARBON CYCLE: CLOSING THE BUDGET
Description:
We estimated the production of bomb radiocarbon using available
information on atmospheric nuclear bomb tests, the simple (radio-)carbon cycle
model GRACE (Global RadioCarbon Exploration Model) and atmospheric observations
as constraints. Subsequent forward simulations of the bomb radiocarbon
inventory in the different carbon reservoirs turned out to be in very good
agreement with recent observation-based estimates, therewith for the very first
time allowing to close the global bomb radiocarbon budget. Besides confirming
original stratospheric bomb 14C data published in the reports of the
Health and Safety Laboratories [Telegadas,
1971, and references therein], our results confirm recent observation-based
ocean bomb radiocarbon inventory estimates for the time of GEOSECS (1970s) and
WOCE (1990s) from Peacock [2004] and Key et al. [2004], but refute the GEOSECS ocean inventory
estimates from Broecker et al. [1985, 1995].
Author's Names: T. Naegler, V. Hesshaimer, and I. Levin
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Added on: 03-Aug-2005 Downloads: 147
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NEW VIEWS OF THE OCEANIC CARBON CYCLE FROM AUTONOMOUS EXPLORERS
Description: A new paradigm for ocean carbon observations is
emerging with the rapid advances in autonomous measurements of carbon systems
with the success of robotic ocean profiling Carbon Explorers, autonomous
sensors for particulate organic and inorganic carbon (POC and PIC), and new instruments which will measure
year-long high frequency records of POC and PIC
sedimentation in the very observation-poor but biologically-active upper
kilometers of the ocean. The new observing capability described here is
critical for improved prediction of the substantial biotic carbon flows in the
ocean. There are excellent prospects for an enhanced ocean carbon observing
system fully capable of autonomous real time monitoring, measurement, and
verification of ocean carbon sequestration.
Author's Names: J.K.B. Bishop
Filesize: 400.83 Kb
Added on: 26-Jul-2005 Downloads: 144
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