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<article language="en">
	<journal>
		<journal_title>Atmospheric Measurement Techniques</journal_title>
		<journal_url>www.atmos-meas-tech.net</journal_url>
		<issn>1867-1381</issn>
		<eissn>1867-8548</eissn>
		<volume_number>3</volume_number>
		<issue_number>4</issue_number>
		<publication_year>2010</publication_year>
	</journal>
	<doi>10.5194/amt-3-1113-2010</doi>
	<article_url>http://www.atmos-meas-tech.net/3/1113/2010/</article_url>
	<abstract_html>http://www.atmos-meas-tech.net/3/1113/2010/amt-3-1113-2010.html</abstract_html>
	<fulltext_pdf>http://www.atmos-meas-tech.net/3/1113/2010/amt-3-1113-2010.pdf</fulltext_pdf>
	<start_page>1113</start_page>
	<end_page>1128</end_page>
	<publication_date>2010-08-24</publication_date>
	<article_title content_type="html">Continuous low-maintenance  CO&lt;sub&gt;2&lt;/sub&gt;/CH&lt;sub&gt;4&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;O measurements at the  Zotino Tall Tower Observatory (ZOTTO) in Central Siberia</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>J. Winderlich</name>
			<email>jan.winderlich@bgc-jena.mpg.de</email>
		</author>
		<author numeration="2" affiliations="1">
			<name>H. Chen</name>
		</author>
		<author numeration="3" affiliations="1">
			<name>C. Gerbig</name>
		</author>
		<author numeration="4" affiliations="1">
			<name>T. Seifert</name>
		</author>
		<author numeration="5" affiliations="1">
			<name>O. Kolle</name>
		</author>
		<author numeration="6" affiliations="1,2">
			<name>J. V. Lavrič</name>
		</author>
		<author numeration="7" affiliations="2">
			<name>C. Kaiser</name>
		</author>
		<author numeration="8" affiliations="1">
			<name>A. Höfer</name>
		</author>
		<author numeration="9" affiliations="1">
			<name>M. Heimann</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745 Jena, Germany</affiliation>
		<affiliation numeration="2" content_type="html">Laboratoire des Sciences du Climat et de l&apos;Environnement, Orme des Merisiers, 91191 Gif-sur-Yvette, France</affiliation>
	</affiliations>
	<abstract content_type="html">To monitor the continental carbon cycle, a fully automated low maintenance
measurement system is installed at the Zotino Tall Tower Observatory in
Central Siberia (ZOTTO, 60°48&apos; N, 89°21&apos; E) since April 2009. A
cavity ring-down spectroscopy (CRDS) analyzer continuously measures carbon
dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) and methane (CH&lt;sub&gt;4&lt;/sub&gt;) from six heights up to 301 m a.g.l. Buffer volumes in each air line remove short term CO&lt;sub&gt;2&lt;/sub&gt; and
CH&lt;sub&gt;4&lt;/sub&gt; mixing ratio fluctuations associated with turbulence, and allow
continuous, near-concurrent measurements from all tower levels. Instead of
drying the air sample, the simultaneously measured water vapor is used to
correct the dilution and pressure-broadening effects for the accurate
determination of dry air CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; mixing ratios. The stability
of the water vapor correction was demonstrated by repeated laboratory and
field tests. The effect of molecular adsorption in the wet air lines was
shown to be negligible. The low consumption of four calibration tanks that
need recalibration only on decadal timescale further reduces maintenance.
The measurement precision (accuracy) of 0.04 ppm (0.09 ppm) for CO&lt;sub&gt;2&lt;/sub&gt; and
0.3 ppb (1.5 ppb) for CH&lt;sub&gt;4&lt;/sub&gt; is compliant with the WMO recommendations.
The data collected so far (until April 2010) reveals a seasonal cycle
amplitude for CO&lt;sub&gt;2&lt;/sub&gt; of 30.4 ppm at the 301 m level.</abstract>
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