TOWARDS A NEW UNDERSTANDING OF RECENT CARBON CYCLE VARIABILITY COMBINING ATMOSPHERIC INVERSION, ...
Description:
We present a comprehensive
analysis of the recent inter-annual variation of the atmospheric CO2
growth rate, with a special focus on the 2002-2003 period, using a state of the
art atmospheric inversion, process driven model simulations (land and ocean),
and recent biomass burning estimates. The inverse estimates compare favourably well
with the model simulations over North Asia and
indicate a large contribution of the fire anomaly to the total anomaly, for
that region in 2003. Over Europe, the spatial distribution of the inverse and
bottom-up flux anomalies for 2003 have similarities but the time evolution of
the total fluxes still need to be reconciled.
Author's Names: P. Peylin, N. Viovy, C. Carouge, et al
Filesize: 45.91 Kb
Added on: 03-Aug-2005 Downloads: 24
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UNCERTAINTIES IN TERRESTRIAL CARBON CYCLE INTERACTION WITH A WARMER CLIMATE
Description:
Results from recent models in the coupled carbon cycle
climate model intercomparison project (C4MIP) indicate a positive feedback to
global warming from the interactive carbon cycle, but the magnitude varies
widely. A typical model simulates an additional increase of 90 ppmv in the
atmospheric CO2, and 0.6 degree additional warming due to this
feedback, but some model can be as large as 250ppm. Using a liner perturbation
framework, we analyze what might have caused such large discrepancy in the
models, with a focus on land where the largest uncertainties lie. Change in NPP
such as different sensitivity to the CO2 fertilization effect is one
where in some models it is modest largely due to the multiple limiting factors
constraining terrestrial productivity and carbon loss. The large differences
among the models are also manifestations of other poorly constrained processes
such as the turnover time and rates of soil decomposition.
Author's Names: N. Zeng, H. Qian, E. Munoz and R. Iacono
Filesize: 11.58 Kb
Added on: 09-Aug-2005 Downloads: 29
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WHAT ARE THE MOST IMPORTANT FACTORS FOR CLIMATE CARBON CYCLE COUPLING
Description: Data
from long-term measurements of carbon balance in boreal, mid-latitude and
tropical ecosystems are used to assess the mechanisms that drive changes in
ecosystem carbon balance in response to a changing climate. We find that most
model parameterizations overestimate the temperature sensitivity of ecosystem
respiration and underestimate the role of soil water balance in controlling
respiration and flammability. We conclude that model assessments of
climate—carbon feedbacks must carefully simulate regional precipitation,
evaporation, evapotranspiration, and water balance, including factors leading
to fires (e.g. sources of ignition), in addition to assessing changes in
temperature. Covariances among these drivers of ecosystem respiration and
vegetation change may be critically important for these simulations.
Author's Names: S. C. Wofsy, J. W. Munger, S. P. Urbanski, et al
Filesize: 686.66 Kb
Added on: 09-Aug-2005 Downloads: 159
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