SPATIAL PATTERNS OF CARBON RESIDENCE TIMES AND SEQUESTRATION CAPACITY IN ECOSYSTEM OF THE ...
Description:
To properly model carbon (C) sequestration capacity and its spatial
pattern in the conterminous USA,
the model parameters of C turnover times should be identified. In this study,
we inversed the C turnover times based on a process-based model that combining
Carnegie-Ames-Stanford Approach (CASA
model) and vegetation and soil carbon transfer (VAST)
model. The genetic algorithm was used in this study to search for optimal parameters
of C turnover times. After inversing the spatial pattern of C turnover times,
we modeled the carbon sequestration capacity by using a forward model under
current NPP increase trend that derived from satellite data.
Author's Names: T. Zhou, and Y. Luo
Filesize: 174.10 Kb
Added on: 09-Aug-2005 Downloads: 25
Home Page | Comment on Proceeding | Details
SOIL CO2 CONCENTRATIONS AND FLUXES IN A PLOW-MANAGED AGRICULTURAL FIELD, A GRASS FIELD AND A FOREST
Description:
In this paper we briefly introduce our results
of soil CO2 concentrations in an arable field in the campus of
NIAES, a grass field and a pine forest in central mountaneous area in Japan. The soil CO2 concentrations
seasonally variated with soil temperature changes at all the three sites. Temporal variations in CO2
concentrations in the arable and the grass field were more linked to changes in
soil moisture than those in the forest. Soil CO2 concentrations were
generally largest in the grass field. CO2 concentrations at the
grass field and pine forest under snow cover showed positive relationship with
snow depth.
Author's Names: S. Yonemura, M. Yokozawa, Y. Shirato, S. Sekikawa, et al
Filesize: 482.89 Kb
Added on: 09-Aug-2005 Downloads: 19
Home Page | Comment on Proceeding | Details
SPATIO-TEMPORAL EVALUATION OF SOIL CARBON STORAGE OF CROPLANDS IN JAPAN
Description:
We evaluated the current
status and the future projection of soil organic carbon (SOC) storage in
Japanese croplands (paddy and upland), using a soil carbon turnover model. The
model based on the RothC involves the modification after verification of
turnover processes of SOC for the main soil type in Japan, Andosols. The objectives of
this study are to i) evaluate the spatial distribution of SOC storage, ii)
estimate the annual input organic matter for reaching the equilibrium, and iii)
simulate time changes of SOC storage with changing agricultural practices as
well as climate conditions.
Author's Names: M. Yokozawa, Y. Shirato, S. Yonemura and T. Sakamoto
Filesize: 59.58 Kb
Added on: 09-Aug-2005 Downloads: 24
Home Page | Comment on Proceeding | Details
LINKS BETWEEN GLOBAL CO2 VARIABILITY AND CLIMATE ANOMALIES OF BIOMES
Description:
The
global rate of fossil fuel combustion continues to rise, but the amount of CO2
accumulating in the atmosphere has not increased accordingly (Tans et al., 1990; Conway et al., 1994; Wofsy,
2001). The causes for this discrepancy
are widely debated (Houghton,
2003). In particular, the location and
drivers for the interannual variability of atmospheric CO2 are
highly uncertain. Here we examine links
between global atmospheric CO2 growth rate (CGR) and the climate anomalies
of biomes based on ten years (1986-1995) of global climate data and
accompanying satellite data sets. Our
results show that four biomes, the tropical rainforest, tropical savanna, C4
grassland and boreal forest, and their responses to climate anomalies, are the
major climate-sensitive CO2 sinks/sources that control the CGR. The nature and magnitude by which these
biomes respond to climate anomalies are generally not the same. However, one common influence did emerge from
our analysis; the extremely high CGR that was observed for the one extreme El
Niño year was caused by the response of the tropical biomes (rainforest,
savanna and C4 grassland) to temperature.
Author's Names: C. Yi, T. Zhou, P. S. Bakwin, L. Zhu and R. K. Monson
Filesize: 43.61 Kb
Added on: 09-Aug-2005 Downloads: 29
Home Page | Comment on Proceeding | Details
EFFECT OF INCLUDING CO2 VERTICAL PROFILES ON PARTITIONING CARBON SOURCES AND SINKS BETWEEN ...
Description:
Understanding the geographical distribution of
carbon uptake by the terrestrial biosphere is critical for predicting future
trends of atmospheric CO2.
With inverse techniques, atmospheric CO2 measurements can be
used to estimate this uptake. The results from this approach, however, depend
on the accuracy of the transport model(s).
Because of the covariance between the seasonally-varying biosphere
exchange and the strength of vertical mixing (the rectifier effect), using only
the surface CO2 observations for this analysis yields an inferred
carbon flux that is highly sensitive to the details of the boundary-layer
dynamics in the transport model [Gurney
et al., 2004]. One possible way to reduce the sensitivity of these
inversions to poorly-represented boundary-layer dynamics is to use CO2
vertical profiles (and/or column CO2 measurements) in addition to
surface observations. In theory, multi-level aircraft CO2
measurements from several well-positioned sites are capable of improving the
estimate of the true annual mean inter-hemisphere CO2 gradient and
thereby improving the estimate of the partitioning of carbon sinks between the
two hemispheres.
Author's Names: Z. Yang, N. Krakauer, P. Wennberg, J. Randerson
Filesize: 23.84 Kb
Added on: 09-Aug-2005 Downloads: 24
Home Page | Comment on Proceeding | Details
SATELLITE-BASED MODELING OF GROSS PRIMARY PRODUCTION OF DECIDUOUS FOREST AND GRASSLAND SITES ...
Description: The
satellite-based Vegetation Photosynthesis Model (VPM) that estimates seasonal
dynamics of gross primary production (GPP) of vegetation was applied to 5
European forest and grassland sites. The relatively simple VPM model is based
upon light absorption by leaf chlorophyll, leaf water content and leaf age. The
current version of the VPM model relates the Enhanced Vegetation Index (EVI) to
light absorption by leaf chlorophyll and the Land Surface Water Index (LSWI) to
leaf water content, modifying implied functional relationships within the model
according to daily air temperature and photo-synthetically active radiation
input. We used site-specific climate data and CO2 flux data of the
year 2002 from three beech forest sites and two grassland/cropland sites of the
CARBOEUROPE network for testing.
Author's Names: Xiangming Xiao
Filesize: 11.46 Kb
Added on: 09-Aug-2005 Downloads: 25
Home Page | Comment on Proceeding | Details
CARBON FLUXES AND LAI EVOLUTION IN THE ECMWF LAND SURFACE SCHEME
Description:
The
Ags parameterization of canopy conductance from ISBA-Ags is implemented in
TESSEL, the ECMWF land surface scheme. We present first results of the
investigation of the model behavior in view of an operational use in a data
assimilation system. It is shown that the performance of the Ags module is
sensitive to the land surface model in which it is embedded.
Author's Names: M.H. Voogt, L. Jarlan and B.J.J.M. van den Hurk
Filesize: 100.53 Kb
Added on: 08-Aug-2005 Downloads: 29
Home Page | Comment on Proceeding | Details
INTERANNUAL VARIABILITY IN TERRESTRIAL CARBON EXCHANGE USING AN ECOSYSTEM FIRE MODEL
Description: We have incorporated a
semi-mechanistic fire model into the SEVER Dynamic Global Vegetation Model (DGVM).
The model produces estimates of net primary productivity (NPP), heterotrophic
respiration (HR) and fire carbon emission (FE) for the globe. This model was
run for the period 1957-2002 with the NCEP climate reanalysis data as an input.
Results were compared with the ATSR area burnt maps and a Time Dependent
Inverse (TDI) model fluxes of CO2. We find that on interannual time
scales NPP variability explains major part of flux variability simulated by the
TDI model, followed by the HR and FE contributions.
Author's Names: Sergey Venevsky, Prabir K. Patra, Shamil Maksyutov, et al
Filesize: 64.05 Kb
Added on: 08-Aug-2005 Downloads: 162
Home Page | Comment on Proceeding | Details
ACCURATE SIMULATION OF LOCAL DAILY CARBON FLUXES USING LARGE SCALE CLIMATE DATA SETS: EXAMPLE ...
Description: A Dynamic Global Vegetation Model
SEVER [Venevsky, Maksyutov, 2005] was
applied for the fourteen EUROFLUX sites [Valentini,
2003] with a large scale daily NCEP climate data as an input (0.5º x 0.5º
degree spatial resolution) for years 1997-2000 and net ecosystem exchange (NEE)
calculated and observed were compared. Requirements for accurate estimate of
local daily NEE flux from a large scale climate data set were found.
Author's Names: Sergey Venevsky, Shamil Maksyutov, Gen Inoue
Filesize: 42.02 Kb
Added on: 08-Aug-2005 Downloads: 69
Home Page | Comment on Proceeding | Details
REGIONAL-SCALE CHARACTERIZATION OF SUMMERTIME CO2 SOURCES AND SINKS OVER THE CONTERMINOUS ...
Description:
Fast-response
(1-s resolution) CO2 measurements were recorded aboard the NASA DC-8
during the Intercontinental Chemical Transport Experiment – North
America (INTEX-NA) mission.
Utilizing a non-dispersive infrared gas analyzer-based sampling
system, measurements were obtained over sparsely sampled areas of North America and adjacent ocean basins providing
valuable regional-scale information on carbon sources and sinks.
Author's Names: S.A. Vay, Y. Choi, J.-H. Woo, and K. Prasad
Filesize: 369.00 Kb
Added on: 08-Aug-2005 Downloads: 41
Home Page | Comment on Proceeding | Details