<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE article SYSTEM "http://www.atmos-chem-phys-discuss.net/inc/acpd/copernicus.dtd">
<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>8</volume_number>
		<issue_number>6</issue_number>
		<publication_year>2008</publication_year>
	</journal>
	<doi>10.5194/acpd-8-19791-2008</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/8/19791/2008/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/8/19791/2008/acpd-8-19791-2008.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/8/19791/2008/acpd-8-19791-2008.pdf</fulltext_pdf>
	<start_page>19791</start_page>
	<end_page>19818</end_page>
	<publication_date>2008-11-19</publication_date>
	<article_title content_type="html">Intercomparison of ammonia measurement techniques at an intensively managed grassland site (Oensingen, Switzerland)</article_title>
	<authors>
		<author numeration="1" affiliations="1,4">
			<name>M. Norman</name>
			<email>michael.norman@slb.nu</email>
		</author>
		<author numeration="2" affiliations="2">
			<name>C. Spirig</name>
		</author>
		<author numeration="3" affiliations="3">
			<name>V. Wolff</name>
		</author>
		<author numeration="4" affiliations="3">
			<name>I. Trebs</name>
		</author>
		<author numeration="5" affiliations="2,5">
			<name>C. Flechard</name>
		</author>
		<author numeration="6" affiliations="1">
			<name>A. Wisthaler</name>
		</author>
		<author numeration="7" affiliations="1">
			<name>R. Schnitzhofer</name>
		</author>
		<author numeration="8" affiliations="1">
			<name>A. Hansel</name>
		</author>
		<author numeration="9" affiliations="2">
			<name>A. Neftel</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria</affiliation>
		<affiliation numeration="2" content_type="html">Agroscope Reckenholz Tänikon Research Station (ART), Zürich, Switzerland</affiliation>
		<affiliation numeration="3" content_type="html">Max Planck Institute for Chemistry, Biogeochemistry Department, Mainz, Germany</affiliation>
		<affiliation numeration="4" content_type="html">now at: Environment and Health Administration, Stockholm City, Sweden</affiliation>
		<affiliation numeration="5" content_type="html">now at: Institut National de la Recherche Agronomique (INRA), Rennes, France</affiliation>
	</affiliations>
	<abstract content_type="html">As part of a field campaign in the framework of the NitroEurope project,
three different instruments for atmospheric ammonia (NH&lt;sub&gt;3&lt;/sub&gt;) measurements
were operated side-by-side on a managed grassland site in Switzerland: a
modified Proton Transfer Reaction Mass Spectrometer (PTR-MS), a GRadient of
AErosol and Gases Online Registrator (GRAEGOR), and an Automated Ammonia
Analyzer (AiRRmonia). The modified PTR-MS approach is based on chemical
ionization of NH&lt;sub&gt;3&lt;/sub&gt; using O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt; instead of H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt; as
ionizing agent, GRAEGOR and AiRRmonia measure NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt; in liquids
after absorption of gaseous NH&lt;sub&gt;3&lt;/sub&gt; in a rotating wet-annular denuder and
through a gas permeable membrane, respectively. Bivariate regression slopes
using uncorrected data from all three instruments ranged from 0.78 to 0.97
while measuring ambient NH&lt;sub&gt;3&lt;/sub&gt; levels between 2 and 25 ppbv during a 5
days intercomparison period. Correlation coefficients &lt;i&gt;r&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt; were in the
range of 0.79 to 0.94 for hourly average concentrations. Observed
discrepancies could be partly attributed to temperature effects on the
GRAEGOR calibration. Bivariate regression slopes using corrected data
ranged 0.92 to 0.95 with offsets ranging from 0.22 to 0.58 ppbv. The intercomparison
demonstrated the potential of PTR-MS to resolve short-time NH&lt;sub&gt;3&lt;/sub&gt;
fluctuations which could not be measured by the two other slow-response
instruments. During conditions favoring condensation in inlet lines, the
PTR-MS underestimated NH&lt;sub&gt;3&lt;/sub&gt; concentrations, underlining the importance of
careful inlet designs as an essential component for any inlet-based
instrument.</abstract>
	<references>
		<reference numeration="1" content_type="text"> Ammann, C., Flechard, C., Fuhrer, J., and Neftel, A.: Greenhouse gas budget of intensively and extensively managed grassland, in: Land Use Systems in Grassland Dominated Regions, Grassland Science in Europe, edited by: Lüscher, A., et al., vdf Hochschulverlag, Zürich, Switzerland, 9, 130–132, 2004. </reference>
		<reference numeration="2" content_type="text"> Ammann, C., Flechard, C.R., Leifeld, J., Neftel, A., and Fuhrer, J.: The carbon budget of newly established temperate grassland depends on management intensity, Agr. Ecosyst. Environ., 121, 5–20, 2007. </reference>
		<reference numeration="3" content_type="text"> Asman, W. A. H., Sutton, M. A., and Schjorring, J. K.: Ammonia: emission, atmospheric transport and deposition, New Phytol., 139, 27–48, 1998. </reference>
		<reference numeration="4" content_type="text"> Bouwman, A. F., Lee, D. S., Asman, W. A. H., Dentener, F. J., Van der Hoek, K. W., and Olivier, J. G. J.: A global high resolution emission inventory for ammonia, Global Biogeochem. Cy., 11, 561–587, 1997. </reference>
		<reference numeration="5" content_type="text"> Charlson, R. J. and Rodhe, H.: Factors controlling the acidity of natural rainwater, Nature, 295, 683–685, 1982. </reference>
		<reference numeration="6" content_type="text"> Dasgupta, P. K.: Automated measurements of atmospheric trace gases: Diffusion based collection and analysis, in: Measurements Challenges in Atmospheric Analysis, edited by: Newman, L., Adv. Chem. Ser., 232, 41–90, American Chemical Society, Washington, DC, 1993. </reference>
		<reference numeration="7" content_type="text"> Dentener, F. J. and Crutzen, P. J.: A three-dimensional model of the global ammonia cycle, J. Atmos. Chem., 19, 331–369, 1994. </reference>
		<reference numeration="8" content_type="text"> Decuq, C., Loubet, B., Personne, E., Ferrara, R., Masson, S., Flura, D., and Génermont, S.: Effect of temperature on ammonia measurements by semi-permeable membrane coupled with conductivity, NitroEurope-IP Open Science Conference, Ghent, Belgium, 20–21 February 2008. </reference>
		<reference numeration="9" content_type="text"> Erisman, J. W., Otjes, R., Hensen, A., Jongejan, P., van den Bulk, P., Khlystov, A., Möls, H., and Slanina, S.: Instrument development and application in studies and monitoring of ambient ammonia, Atmos. Environ., 35, 1913–1922, 2001. </reference>
		<reference numeration="10" content_type="text"> Fangmeier, A. F., Hadwiger-Fangmeier, A., Van der Eerden, L., and Jager, H. J.: Effects of atmospheric ammonia on vegetation: A review, Environ. Pollut., 86, 43–82, 1994. </reference>
		<reference numeration="11" content_type="text"> Fehsenfeld, F. C., Huey, L. G., Leibrock, E., Dissly, R., Williams, E., Ryerson, T. B., Norton, R., Sueper, D. T., and Hartsell, B.: Results from an informal intercomparison of ammonia measurement techniques, J. Geophys. Res., 107(D24), 4812, doi:10.1029/2001JD001327, 2002. </reference>
		<reference numeration="12" content_type="text"> Ferm, M.: Method for determination of atmospheric ammonia, Atmos. Environ., 13, 1385–1393, 1979. </reference>
		<reference numeration="13" content_type="text"> Flechard, C. R., Neftel, A., Jocher, M., Ammann, C., and Fuhrer, J.: Bi-directional soil/atmosphere N&lt;sub&gt;2&lt;/sub&gt;O exchange over two mown grassland systems with contrasting management practices, Glob. Change Biol., 11, 2114–2127, 2005. </reference>
		<reference numeration="14" content_type="text"> Gall, R., Perner, D., and Ladstatter-Weissenmayer, A.: Simultaneous determination of NH&lt;sub&gt;3&lt;/sub&gt;, SO&lt;sub&gt;2&lt;/sub&gt;, NO and NO&lt;sub&gt;2&lt;/sub&gt; by direct UV-absorption in ambient air, Fresen. J. Anal. Chem., 340, 646–649, 1991. </reference>
		<reference numeration="15" content_type="text"> Gang, L.: Catalytic oxidation of ammonia to nitrogen, Ph.D thesis, Technische Universiteit Eindhoven, ISBN 90-386-2653-3, NUGI 813, 2002. </reference>
		<reference numeration="16" content_type="text"> Genfa, Z., Dasgupta, P. K., and Dong S.: Measurements of atmospheric ammonia, Environ. Sci. Technol., 23, 1467–1474, 1989. </reference>
		<reference numeration="17" content_type="text"> Genfa, Z., Slanina, F., Boring, S. C. B., Jongejan, P. A. C., and Dasgupta, P. K.: Continuous wet denuder measurements of atmospheric nitric and nitrous acids during the 1999 Atlanta Supersite, Atmos. Environ., 37, 1351–1364, 2003. </reference>
		<reference numeration="18" content_type="text"> Hansel, A., Jordan, A., Holzinger, R., Prazeller, P., Vogel W., and Lindinger, W.: Proton transfer reaction mass spectrometry: On-line trace gas analysis at the ppb level, Int. J. Mass Spectrom., 149/150, 609–619, 1995. </reference>
		<reference numeration="19" content_type="text"> Jäggi, M., Ammann, C., Neftel A., and Fuhrer J.: Environmental control of profiles of ozone concentration in a grassland canopy, Atmos. Environ., 40, 5496–5507, 2006. </reference>
		<reference numeration="20" content_type="text"> Lindinger, W., Hansel, A., and Jordan, A.: Proton-transfer reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev., 27, 347–375, 1998. </reference>
		<reference numeration="21" content_type="text"> Mennen, M. G., van Elzakker B. G., van Putten E. M., Uiterwijk J. W., Regts T. A., van Hellenmond J., Wyer G. P., Otjes R. P., Verhage A. J. L., Wouters L. W., Heffels C. J. G, Römer F. G., van den Beld L., and Tetteroo, J. E. H.: Evaluation of automatic ammonia monitors for application in an air quality monitoring network, Atmos. Environ., 30, 3239–3256, 1996. </reference>
		<reference numeration="22" content_type="text"> Milford, C., Sutton, M. A., Allen, A. G., Karlsson, A., Davison, B. M., James J. D., Rosman, K., Harrison, R. M., and Snape J. N.: Marine and land-based influence on atmospheric ammonia and ammonium over Tenerife, Tellus B, 52, 273–289, 2000. </reference>
		<reference numeration="23" content_type="text"> Mozurkewich, M.: The Dissociation-Constant of Ammonium-Nitrate and Its Dependence on Temperature, Relative-Humidity and Particle-Size, Atmos. Environ. A-Gen., 27, 261–270, 1993. </reference>
		<reference numeration="24" content_type="text"> Neftel, A., Flechard, C., Ammann, C., Conen, F., Emmenegger, L., and Zeyer, K.: Experimental assessment of N&lt;sub&gt;2&lt;/sub&gt;O background fluxes in grassland systems, Tellus, 59B, 470–482, 2007. </reference>
		<reference numeration="25" content_type="text"> Neuman, J. A., Huey, L. G., Ryerson, T. B., and Fahey, D. W.: Study of Inlet Materials for Sampling Atmospheric Nitric Acid, Environ. Sci. Technol., 33, 1133–1136, 1999. </reference>
		<reference numeration="26" content_type="text"> Norman, M., Hansel, A., and Wisthaler, A.,: O$_2^+$ as primary reagent ion in the PTR-MS instrument: Detection of gas-phase ammonia, Int. J. Mass Spectrom., 265, 382–387, 2007. </reference>
		<reference numeration="27" content_type="text"> Nowak, J. B., Huey, L. G., Eisele, F. L., Tanner, D. J., Mauldin III, R. L., Cantrell, C., Kosciuch, E., and Davis, D. D.: Chemical ionization mass spectrometry technique for detection of dimethylsulfoxide and ammonia, J. Geophys. Res., 107(D18), 4363, doi:10.1029/2001JD001058, 2002. </reference>
		<reference numeration="28" content_type="text"> Nowak, J. B., Huey, L. G., Russell, A. G., Tian, D., Neuman, J. A., Orsini, D., Sjostedt, S. J., Sullivan, A. P., Tanner, D. J., Weber, R. J., Nenes, A., Edgerton, E., and Fehsenfeld, F. C.: Analysis of urban gas phase ammonia measurements from the 2002 Atlanta Aerosol Nucleation and Real-Time Characterization Experiment (ANARChE), J. Geophys. Res., 111, D17308, doi:10.1029/2006JD007113, 2006. </reference>
		<reference numeration="29" content_type="text"> Otjes, R. P. and Erisman, J. W.: Haalbaarheidstudie miniaturisering ammoniak analyser (Feasibility study on the diminution of ammonia analyser), Report ECN-CX-99-015, ECN, Petten, The Netherlands, 1999 (in Dutch). </reference>
		<reference numeration="30" content_type="text"> Parrish, D. D. and Fehsenfeld, F. C.: Methods for gas-phase measurements of ozone, ozone precursors and aerosol precursors, Atmos. Environ., 34, 1921–1957, 2000. </reference>
		<reference numeration="31" content_type="text"> Pushkarsky, M. B., Webber, M. E., Baghdassarian, O., Narasimhan, L. R., and Patel, C. K. N.: Laserbased photoacoustic ammonia sensor for industrial applications, Appl. Phys. B-lasers special issue: Trends in Laser Sources, Spectroscopic Techniques and Their Applications to Trace Gas Detection, 75, 391–396, 2002. </reference>
		<reference numeration="32" content_type="text"> Slanina, J., ten Brink, H. M., Otjes, R. P., Even, A., Jongejan, P., Khlystov, A., Waijers-Ijpelaan, A., and Hu, M.: The continuous analysis of nitrate and ammonium in aerosols by the steam jet aerosol collector (SJAC): extension and validation of the methodology, Atmos. Environ., 35, 2319–2330, 2001. </reference>
		<reference numeration="33" content_type="text"> Sutton, M. A., Tang, Y. S., Miners, B., and Fowler, D.: A New Diffusion Denuder System for Long-Term, Regional Monitoring of Atmospheric Ammonia and Ammonium, Water Air Soil Poll.: Focus, 1, 145–156, 2001. </reference>
		<reference numeration="34" content_type="text"> Trebs, I., Meixner, F. X., Slanina, J., Otjes, R., Jongejan, P., and Andreae, M. O.: Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin, Atmos. Chem. Phys., 4, 967–987, 2004. </reference>
		<reference numeration="35" content_type="text"> Warland, J. S., Dias, G. M., and Thurtell, G. W.: A tunable diode laser system for ammonia flux measurements over multiple plots, Environ. Pollut., 114, 215–221, 2001. </reference>
		<reference numeration="36" content_type="text"> Wells, M., Choularton, T. W., and Bower, K. N.: A modeling study of the interaction of ammonia with cloud, Atmos. Environ., 32, 359–363, 1998. </reference>
		<reference numeration="37" content_type="text"> Wiebe, H. A., Anlauf, K. G., Tuazon, E. C., Winer, A. M., Biermann, H. W., Appel, B. R., Solomon, P. A., Cass, G. R., Ellestad, T. G., Knapp, K. T., Peake, E., Spicer, C. W., and Lawson, D. R.: A Comparison of Measurements of Atmospheric Ammonia by Filter Packs, Transition-Flow Reactors, Simple and Annular Denuders and Fourier-Transform Infrared-Spectroscopy, Atmos. Environ. A-Gen., 24, 1019–1028, 1990. </reference>
		<reference numeration="38" content_type="text"> Wyers, G. P., Otjes, R. P., and Slanina, J.: A continuous-flow denuder for the measurement of ambient concentration and surface-exchange fluxes of ammonia, Atmos. Environ, 27A, 2085–2090, 1993. </reference>
		<reference numeration="39" content_type="text"> Yokelson, R. J., Christian T. J., Bertschi, I. T., and Hao, W. M.: Evaluation of adsorption effects on measurements of ammonia, acetic acid and methanol, J. Geophys. Res., 108, 4649, doi:10.1029/2003JD003549, 2003. </reference>
	</references>
</article>

