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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>2</issue_number>
		<publication_year>2009</publication_year>
	</journal>
	<doi>10.5194/acpd-9-6979-2009</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/9/6979/2009/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/9/6979/2009/acpd-9-6979-2009.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/9/6979/2009/acpd-9-6979-2009.pdf</fulltext_pdf>
	<start_page>6979</start_page>
	<end_page>7032</end_page>
	<publication_date>2009-03-16</publication_date>
	<article_title content_type="html">Ozone budget in the West African lower troposphere during the AMMA (African Monsoon Multidisciplinary Analysis) campaign</article_title>
	<authors>
		<author numeration="1" affiliations="1,2">
			<name>M. Saunois</name>
			<email>marielle.saunois@aero.obs-mip.fr</email>
		</author>
		<author numeration="2" affiliations="3">
			<name>C. E. Reeves</name>
		</author>
		<author numeration="3" affiliations="1,2">
			<name>C. Mari</name>
		</author>
		<author numeration="4" affiliations="3,4">
			<name>J. G. Murphy</name>
		</author>
		<author numeration="5" affiliations="3">
			<name>D. J. Stewart</name>
		</author>
		<author numeration="6" affiliations="3">
			<name>G. P. Mills</name>
		</author>
		<author numeration="7" affiliations="3">
			<name>D. E. Oram</name>
		</author>
		<author numeration="8" affiliations="5,6">
			<name>R. M. Purvis</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Université de Toulouse, UPS, LA (Laboratoire d&apos;Aérologie), 14 avenue Edouard Belin, 31400 Toulouse, France</affiliation>
		<affiliation numeration="2" content_type="html">CNRS, LA (Laboratoire d&apos;Aérologie), 31400 Toulouse, France</affiliation>
		<affiliation numeration="3" content_type="html">School of Environmental Sciences, University of East Anglia, Norwich, UK</affiliation>
		<affiliation numeration="4" content_type="html">Department of Chemistry, University of Toronto, Toronto, Canada</affiliation>
		<affiliation numeration="5" content_type="html">Facility for  Airborne Atmospheric Measurement, National Centre for Atmospheric Science, Cranfield, UK</affiliation>
		<affiliation numeration="6" content_type="html">now at: Facility for Ground Atmospheric Measurements, National Centre for Atmospheric Science, University of York, Heslington, York, UK</affiliation>
	</affiliations>
	<abstract content_type="html">A bi-dimensional latitudinal-vertical meterological model coupled with O&lt;sub&gt;3&lt;/sub&gt;-NO&lt;sub&gt;x&lt;/sub&gt;-VOC
chemistry is used to reproduce the distribution of ozone and precursors in the boundary layer over West Africa during the
African Monsoon Multidisciplinary Analysis (AMMA) campaign as observed on board the Facility for Airborne
Atmospheric Measurements (FAAM) BAe 146 Atmospheric Research Aircraft. The model reproduces the increase of
ozone mixing ratios in the boundary layer observed between the forested region south of 13&amp;deg; N and the
Sahelian area northward. Sensitivity and budget analysis reveals that the intertropical convergence zone is a
moderate source of O&lt;sub&gt;3&lt;/sub&gt; rich-air in
the boundary layer due to convective downdrafts. Dry deposition drives the ozone minimum over the vegetated area.
The combination of high NO&lt;sub&gt;x&lt;/sub&gt; emissions from soil north of 13&amp;deg; N and northward advection by the monsoon
flux of VOC-enriched air masses contributes to the ozone maximum simulated at higher latitudes. Simulated OH exhibit a
well marked latitudinal gradient with minimum concentrations over the vegetated region where the reactions with
biogenic compounds predominate. The model underestimates the observed OH mixing ratios, however this model
discrepancy has slight effect on ozone budget and does not alter the conclusions.</abstract>
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</article>

