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Partitioning of ocean and land uptake of CO2 as inferred by delta C-13 measurements from the NOAA Climate Monitoring and Diagnostics Laboratory Global Air Sampling NetworkUsing delta C-13 measurements in atmospheric CO2 from a cooperative global air sampling network, we determined the partitioning of the net uptake of CO2 between ocean and land as a function of latitude and time. The majority of delta C-13 measurements were made at the Institute of Arctic and Alpine Research (INSTAAR) of the University of Colorado. We perform an inverse deconvolution of both CO2 and delta C-13 observations, using a two-dimensional model of atmospheric transport. Also, the discrimination against C-13 by plant photosynthesis, as a function of latitude and time, is calculated from global runs of the simple biosphere (SiB) model. Uncertainty due to the longitudinal structure of the data, which is not represented by the model, is studied through a bootstrap analysis by adding and omitting measurement sites. The resulting error estimates for our inferred sources and sinks are of the order of 1 GTC (1 GTC = 10(exp 15) gC). Such error bars do not reflect potential systematic errors arising from our estimates of the isotopic disequilibria between the atmosphere and the oceans and biosphere, which are estimated in a separate sensitivity analysis. With respect to global totals for 1992 we found that 3.2 GTC of carbon dissolved into the ocean and that 1.5 GTC were sequestered by land ecosystems. Northern hemisphere ocean gyres north of 15 deg N absorbed 2.7 GTC. The equatorial oceans between 10 deg S and 10 deg N were a net source to the atmosphere of 0.9 GTC. We obtained a sink of 1.6 GTC in southern ocean gyres south of 20 deg S, although the deconvolution is poorly constrained by sparse data coverage at high southern latitudes. The seasonal uptake of CO2 in the northern gyres appears to be correlated with a bloom of phytoplankton in surface waters. On land, northern temperate and boreal ecosystems between 35 deg N and 65 deg N were found to be a major sink of CO2 in 1992, as large as 3.5 GTC. Northern tropical ecosystems (equator-30 deg N) appear to be a net source to the source to the atmosphere of 2 GTC which could reflect biomass burning. A small sink, 0.3 GTC, was inferred for southern tropical ecosystems (30 deg S-equator).
Document ID
19950048914
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ciais, Philippe
(University of Colorado, Boulder, CO United States)
Tans, Pieter P.
(NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO United States)
White, James W. C.
(University of Colorado, Boulder, CO United States)
Trolier, Michael
(University of Colorado, Boulder, CO United States)
Francey, Roger J.
(CSIRO Victoria, Australia)
Berry, Joe A.
(Carnegie Institution of Washington, Stanford, CA United States)
Randall, David R.
(Colorado State University Fort Collins, CO, United States)
Sellers, Piers J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Collatz, James G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Schimel, David S.
(National Center for Atmospheric Research, Boulder, CO United States)
Date Acquired
August 16, 2013
Publication Date
March 20, 1995
Publication Information
Publication: Journal of Geophysical Research
Volume: 100
Issue: D3
ISSN: 0148-0227
Subject Category
Meteorology And Climatology
Accession Number
95A80513
Distribution Limits
Public
Copyright
Other

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