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<article language="en">
	<journal>
		<journal_title>Atmospheric Chemistry and Physics Discussions</journal_title>
		<journal_url>www.atmos-chem-phys-discuss.net</journal_url>
		<issn>1680-7367</issn>
		<eissn>1680-7375</eissn>
		<volume_number>9</volume_number>
		<issue_number>3</issue_number>
		<publication_year>2009</publication_year>
	</journal>
	<doi>10.5194/acpd-9-11783-2009</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/9/11783/2009/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/9/11783/2009/acpd-9-11783-2009.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/9/11783/2009/acpd-9-11783-2009.pdf</fulltext_pdf>
	<start_page>11783</start_page>
	<end_page>11810</end_page>
	<publication_date>2009-05-12</publication_date>
	<article_title content_type="html">Error correlation between CO&lt;sub&gt;2&lt;/sub&gt; and CO as constraint for CO&lt;sub&gt;2&lt;/sub&gt; flux inversions using satellite data</article_title>
	<authors>
		<author numeration="1" affiliations="1,2">
			<name>H. Wang</name>
			<email>hwang@cfa.harvard.edu</email>
		</author>
		<author numeration="2" affiliations="1">
			<name>D. J. Jacob</name>
		</author>
		<author numeration="3" affiliations="1">
			<name>M. Kopacz</name>
		</author>
		<author numeration="4" affiliations="3">
			<name>D. B. A. Jones</name>
		</author>
		<author numeration="5" affiliations="4">
			<name>P. Suntharalingam</name>
		</author>
		<author numeration="6" affiliations="1">
			<name>J. A. Fisher</name>
		</author>
		<author numeration="7" affiliations="3,5">
			<name>R. Nassar</name>
		</author>
		<author numeration="8" affiliations="6">
			<name>S. Pawson</name>
		</author>
		<author numeration="9" affiliations="6">
			<name>J. E. Nielsen</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA</affiliation>
		<affiliation numeration="2" content_type="html">Harvard-Smithsonian Center For Astrophysics, Cambridge, MA, USA</affiliation>
		<affiliation numeration="3" content_type="html">Department of Physics, University of Toronto, Toronto, Ontario, Canada</affiliation>
		<affiliation numeration="4" content_type="html">School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom</affiliation>
		<affiliation numeration="5" content_type="html">Department of Geography, University of Toronto, Toronto, Ontario, Canada</affiliation>
		<affiliation numeration="6" content_type="html">NASA Goddard Space Flight Center, Global Modeling and Assimilation Office, Greenbelt, MD, USA</affiliation>
	</affiliations>
	<abstract content_type="html">Inverse modeling of CO&lt;sub&gt;2&lt;/sub&gt; satellite observations to better quantify carbon
surface fluxes requires a forward model such as a chemical transport model
(CTM) to relate the fluxes to the observed column concentrations. Model
transport error is an important source of observational error. We investigate
the potential of using CO satellite observations as additional constraints in
a joint CO&lt;sub&gt;2&lt;/sub&gt;–CO inversion to improve CO&lt;sub&gt;2&lt;/sub&gt; flux estimates, by exploiting
the CTM transport error correlations between CO&lt;sub&gt;2&lt;/sub&gt; and CO. We estimate the
error correlation globally and for different seasons by a paired-model method
(comparing CTM simulations of CO&lt;sub&gt;2&lt;/sub&gt; and CO columns using different
assimilated meteorological data sets for the same meteorological year) and a
paired-forecast method (comparing 48- vs. 24-h CTM forecasts of CO&lt;sub&gt;2&lt;/sub&gt; and
CO columns for the same forecast time). We find strong positive and negative
error correlations (&lt;i&gt;r&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt;&amp;gt;0.5) between CO&lt;sub&gt;2&lt;/sub&gt; and CO columns over much of
the world throughout the year, and strong consistency between different
methods to estimate the error correlation. Application of the averaging
kernels used in the retrieval for thermal IR CO measurements weakens the
correlation coefficients by 15% on average (mostly due to variability in the
averaging kernels) but preserves the large-scale correlation structure.
Results from a testbed inverse modeling application show that CO&lt;sub&gt;2&lt;/sub&gt;–CO
error correlations can indeed significantly reduce uncertainty on surface
carbon fluxes in a joint CO&lt;sub&gt;2&lt;/sub&gt;–CO inversion vs. a CO&lt;sub&gt;2&lt;/sub&gt;–only inversion.</abstract>
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</article>

