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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>7</volume_number>
		<issue_number>5</issue_number>
		<publication_year>2007</publication_year>
	</journal>
	<doi>10.5194/acpd-7-14295-2007</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/7/14295/2007/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/7/14295/2007/acpd-7-14295-2007.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/7/14295/2007/acpd-7-14295-2007.pdf</fulltext_pdf>
	<start_page>14295</start_page>
	<end_page>14330</end_page>
	<publication_date>2007-10-09</publication_date>
	<article_title content_type="html">Aerosol-cloud interactions in the NASA GMI: model development and indirect forcing assessments</article_title>
	<authors>
		<author numeration="1" affiliations="1,4">
			<name>N. Meskhidze</name>
		</author>
		<author numeration="2" affiliations="1">
			<name>R. E. P. Sotiropoulou</name>
		</author>
		<author numeration="3" affiliations="1,2">
			<name>A. Nenes</name>
			<email>nenes@eas.gatech.edu</email>
		</author>
		<author numeration="4" affiliations="3">
			<name>J. Kouatchou</name>
		</author>
		<author numeration="5" affiliations="3">
			<name>B. Das</name>
		</author>
		<author numeration="6" affiliations="3">
			<name>J. M. Rodriguez</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA</affiliation>
		<affiliation numeration="2" content_type="html">Schools of Chemical &amp; Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA</affiliation>
		<affiliation numeration="3" content_type="html">NASA Goddard Space Flight Center, Greenbelt, Washington, USA</affiliation>
		<affiliation numeration="4" content_type="html">now at: School of Marine Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA</affiliation>
	</affiliations>
	<abstract content_type="html">This study uses the NASA Global Modeling Initiative (GMI) 3-D
chemical transport model (CTM) for assessments of indirect forcing and its
sensitivity to the treatment of aerosol, aerosol-cloud interactions and meteorological fields.
Three different meteorological datasets from NASA Data Assimilation
Office (DAO), NASA finite volume GCM (FVGCM) and the Goddard
Institute for Space Studies version II&apos; (GISS II&apos;) GCM were used.
GMI is ideal for this study as different model components (such as
meteorological fields and chemical mechanisms) can easily be
interchanged under the same model framework to capture the first
aerosol indirect effect (AIE), and its sensitivity to
parameterizations and meteorological fields. Cloud droplet number
concentration was calculated by implementing both diagnostic and
physically based droplet parameterizations. Derived cloud
properties, such as cloud optical thickness and effective radius
were compared with the remotely sensed data from Moderate Resolution
Imaging Spectroradiometer (MODIS). GMI was able to capture the
spatial variability and the land-ocean contrast
observed in the satellite record. Depending on the meteorological
field and droplet parameterization used, the annual mean first AIE
ranged from &amp;minus;0.99 to &amp;minus;1.48 W m&lt;sup&gt;&amp;minus;2&lt;/sup&gt;. It is found that, roughly
80% of the variation is attributed to changes in the meteorology
(primarily from variations in liquid water path), while the remaining
20% is attributed to different cloud droplet parameterizations.</abstract>
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