Bakeretal2006-IAV - GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 20,...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO 2 fluxes, 1988–2003 D. F. Baker, 1,2 R. M. Law, 3 K. R. Gurney, 4,5 P. Rayner, 3,6 P. Peylin, 7 A. S. Denning, 4 P. Bousquet, 7 L. Bruhwiler, 8 Y.-H. Chen, 9 P. Ciais, 7 I. Y. Fung, 10 M. Heimann, 11 J. John, 10 T. Maki, 12 S. Maksyutov, 13 K. Masarie, 8 M. Prather, 14 B. Pak, 14,15 S. Taguchi, 16 and Z. Zhu 17 Received 28 December 2004; revised 23 August 2005; accepted 11 October 2005; published 7 January 2006. [ 1 ] Monthly CO 2 fluxes are estimated across 1988–2003 for 22 emission regions using data from 78 CO 2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P ± 0.05 when the fluxes are grouped into land and ocean components for three broad latitude bands, but is much less so when grouped into continents and basins. The transport errors have the largest impact in the extratropical northern latitudes. A third of the 22 emission regions have significant IAV, including the Tropical East Pacific (with physically plausible uptake/release across the 1997–2000 El Nin ˜o/La Nin ˜a) and Tropical Asia (with strong release in 1997/1998 coinciding with large-scale fires there). Most of the global IAV is attributed robustly to the tropical/southern land biosphere, including both the large release during the 1997/1998 El Nin ˜o and the post-Pinatubo uptake. Citation: Baker, D. F., et al. (2006), TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO 2 fluxes, 1988–2003, Global Biogeochem. Cycles , 20 , GB1002, doi:10.1029/2004GB002439. 1. Introduction [ 2 ] The concentration of CO 2 in the atmosphere has been monitored continuously since 1958 [ Keeling et al. , 1989] at a growing number of sites. When deseasonalized, these records show that global CO 2 levels have increased mono- tonically for the last 45 years, but at a rate that varies strongly from year to year. Two human activities that add large amounts of carbon to the atmosphere are thought to be the main drivers of the increase: fossil fuel burning and deforestation. Comparing this anthropogenic input to the observed increase rate, it is found that about 55% of the input does not stay in the atmosphere, but is apparently taken up by sinks in the ocean and land biosphere. Since fossil fuel burning has increased relatively smoothly across this span, the large interannual swings in atmospheric CO 2 1 Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey, USA.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/07/2011 for the course EAS 8803 taught by Professor Staff during the Spring '08 term at Georgia Institute of Technology.

Page1 / 17

Bakeretal2006-IAV - GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 20,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online