MODELING ATMOSPHERIC CO2 CONCENTRATION PROFILES AND FLUXES ABOVE SLOPING FORESTED TERRAIN
Description: CO2
profiles were simulated in the atmospheric boundary layer above sloping terrain
using a three dimensional transport model coupled with a vegetation sub-model.
WMO/GAW concentration monitoring site and ecosystem flux measurement site were
located inside the modeled region at the top of a hill and at boreal forest,
respectively. According to model results, the concentration measurement at hill
site was representative for continental background. However, concentration at few
meters above active vegetation represented mainly local variation.
Concentration difference between hill site and forest site was about 5 ppm
during afternoon according to both model and measurements. The hill site was
above boundary layer during night and inside boundary layer during daytime. The
regional CO2 signal dominated in both cases. The average flux to the
whole model region was about 40 % of the local flux at the forest site.
Author's Names: T. Aalto, J. Hatakka, M. Aurela, T. Thum and A. Lohila
Filesize: 40.81 Kb
Added on: 22-Jul-2005 Downloads: 40
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DETERMINING CO2 FLUX COMPONENTS IN THE DENVER URBAN ECOSYSTEM
Description: Within urban ecosystems are strong anthropogenic
emissions of CO2 as well as significant CO2 sinks
associated with vegetation. CO2 profiles and net flux of CO2
(NEE) over Denver
was measured over a multi-year period and compared with certain component
fluxes (soil surface net flux, and emissions from fossil fuel combustion). CO2
concentration and NEE typically exhibits a diurnal trend, apparently due to
emissions from transportation and sequestration by vegetation.
Author's Names: D. E. Anderson and T. Thienelt
Filesize: 22.21 Kb
Added on: 25-Jul-2005 Downloads: 38
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MONTHLY RESOLUTION FOSSIL-FUEL-DERIVED CARBON DIOXIDE EMISSIONS FOR THE COUNTRIES...
Description: Examination of national statistical databases has
allowed for the widely-used data set on annual, fossil-fuel-derived, carbon
dioxide emissions (maintained by the Carbon Dioxide Information Analysis Center
(CDIAC)) to be subdivided into monthly time intervals. This analysis focused on
statistical parameters that represent the solid, liquid, and gaseous fuels
consumed in each country at monthly time scales. An intermediate product of
this analysis was the fraction of the annual total consumption occurring in
each month for each fuel. Monthly fractions were multiplied by the annual carbon
dioxide emission value to obtain monthly emission estimates. A benefit of this
approach is monthly and annual emissions time series that are mutually
consistent. This presentation will give
monthly emissions for multiple years for the United
States, Canada,
and Mexico.
All data have been updated since the Fall 2004 AGU
presentation of this work. The monthly data by state and province provide
enough detail to begin to describe how the annual cycle of emissions varies
spatially (i.e., whether emissions peak in the summer, in the winter, or are
relatively uniform throughout the year).
Author's Names: R.J. Andres, J.S. Gregg, L.M. Losey, and G. Marland
Filesize: 40.59 Kb
Added on: 25-Jul-2005 Downloads: 29
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TOWARDS A NEW ISOPYCNIC OCEAN CARBON CYCLE MODEL
Description: Numerical
ocean carbon cycle models are the primary tools to predict the ocean's response
to increasing atmospheric CO2 concentration. So far most of these
have been based of physical components with geometric vertical levels. While
permitting an accurate computation of the horizontal pressure gradient driving
geostrophic flow, vertical discretization on z-levels leads to spurious
diapycnal mixing and upwelling. Isopycnic ocean models have an advantage over
those with geometric vertical layers in that their vertical coordinate mimics
the real structure of the water column as stratified layers of constant
density, and thus avoid artificial mixing and advection in the ocean interior.
Their disadvantages include the problem of massless layers, the necessity to
add a mixed layer model to adequately represent surface processes, and the
induction of a horizontal pressure gradient error by the sloping density
surfaces. Models with different vertical schemes thus complement each other and
can be used as one basis for an uncertainty assessment.
Author's Names: K.M. Assmann, C. Heinze, H. Drange, M. Bentsen, and K. Lygre
Filesize: 19.62 Kb
Added on: 25-Jul-2005 Downloads: 37
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VARIATIONAL DATA ASSIMILATION OF HIGH DENSITY ATMOSPHERIC CO2 DATA:...
Description: High-frequency atmospheric CO2 measurements
should become increasingly available by the end of this decade from a variety
of sources, including low-Earth orbiting satellites. If of sufficient accuracy,
these should allow the functioning of the global carbon cycle to be monitored
at fine time/space resolutions using atmospheric transport inversions. Since
traditional direct inversion methods (e.g., Bayesian synthesis) become
computationally infeasible at these resolutions, we use an approximate method,
variational data assimilation, to estimate surface CO2 fluxes at
spatial resolutions ranging from 10x10 degrees to 1x1 degrees and at time
resolutions ranging from 2 weeks to 1 hour. We assess its performance using simulated
data, including the effects of realistic transport and data errors.
Author's Names: D.F. Baker, S. Doney, and D. Schimel
Filesize: 12.88 Kb
Added on: 25-Jul-2005 Downloads: 34
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THE IMPACT OF TRANSPORT AND ESTIMATION ERRORS ON THE SIGNIFICANCE OF INTERANNUAL CO2 FLUX...
Description: Transport-based
inversions of atmospheric CO2 concentration measurements have been
used by several groups [e.g., Bousquet, et al.,
2000; Rödenbeck, et al., 2003; Baker, et al., 2005] to estimate monthly regional CO2
fluxes from the 1980s to the present.
When compared at the scale of broad latitude bands, the inter-annual
variability (IAV) of these results is broadly consistent. This agreement breaks down, however, when the
fluxes are partitioned regionally inside these latitude bands, or even into
global land/ocean totals. We show here that this disagreement can largely be
explained by random estimation errors and transport model errors affecting the
estimates.
Author's Names: D.F. Baker, R. Law, and K.R. Gurney
Filesize: 197.31 Kb
Added on: 25-Jul-2005 Downloads: 38
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CONTROLS ON THE OCEANIC CO2 SINK NEAR THE CROZET PLATEAU IN THE SOUTHERN INDIAN OCEAN...
Description: The CROZEX cruises (November 2004 to January 2005) had the objective to
test whether natural iron fertilisation from the Crozet plateau promotes algal
blooms. Results from the cruises show that algal blooms created an oceanic CO2
sink downstream of the Crozet plateau. Vertical advection of water into the
mixed layer occurred close to two islands on the plateau. Data from 18 cruises
between 1991 and 2002 are used to quantify the seasonal variability of surface
pCO2 and CO2 air-sea exchange in the region.
Author's Names: D.C.E. Bakker, M.C. NielsdottÃr, J.T. Allen, et al
Filesize: 22.21 Kb
Added on: 25-Jul-2005 Downloads: 29
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CH4 TOTAL COLUMNS FROM SCIAMACHY - COMPARISON WITH ATMOSPHERIC MODELS
Description: A
detailed comparison of global atmospheric CH4 retrievals from the
space-borne spectrometer SCIAMACHY onboard the European environmental satellite
ENVISAT is presented with the atmospheric transport models TM4 and TM5.
Author's Names: P. Bergamaschi, C. Frankenberg, J.F. Meirink, et al
Filesize: 224.71 Kb
Added on: 25-Jul-2005 Downloads: 126
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A TEST OF THE REPRESENTATION OF CONVECTIVE CLOUD TRANSPORT IN A MODEL OF CO2 TRANSPORT
Description: We present here a test of convection uncertainty
within a single model framework driven by the same meteorological fields. Our
primary goal is to explore to what extent do convection schemes impact atmospheric
CO2 distribution, by testing three referred cloud convection schemes
ranging from a very simple to a relatively complex form [Table 1]. Our second
goal is to examine the sensitivity of atmospheric CO2 to its
regional emission/sink uncertainty [Fig. 1] constrained by IPCC 2001 at a “fixed”
convection scheme to clarify the pros and cons of the convection schemes.
Author's Names: H. Bian, S. R. Kawa, M. Chin, S. Pawson, et al
Filesize: 107.46 Kb
Added on: 25-Jul-2005 Downloads: 23
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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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