<?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>7</volume_number>
		<issue_number>4</issue_number>
		<publication_year>2007</publication_year>
	</journal>
	<doi>10.5194/acpd-7-10235-2007</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/7/10235/2007/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/7/10235/2007/acpd-7-10235-2007.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/7/10235/2007/acpd-7-10235-2007.pdf</fulltext_pdf>
	<start_page>10235</start_page>
	<end_page>10285</end_page>
	<publication_date>2007-07-17</publication_date>
	<article_title content_type="html">The high Arctic in extreme winters: vortex, temperature, and MLS and  ACE-FTS trace gas evolution</article_title>
	<authors>
		<author numeration="1" affiliations="1,2">
			<name>G. L. Manney</name>
			<email>manney@mls.jpl.nasa.gov</email>
		</author>
		<author numeration="2" affiliations="3">
			<name>W. H. Daffer</name>
		</author>
		<author numeration="3" affiliations="4">
			<name>K. B. Strawbridge</name>
		</author>
		<author numeration="4" affiliations="5,6">
			<name>K. A. Walker</name>
		</author>
		<author numeration="5" affiliations="6">
			<name>C. D. Boone</name>
		</author>
		<author numeration="6" affiliations="6,7">
			<name>P. F. Bernath</name>
		</author>
		<author numeration="7" affiliations="5">
			<name>T. Kerzenmacher</name>
		</author>
		<author numeration="8" affiliations="1">
			<name>M. J. Schwartz</name>
		</author>
		<author numeration="9" affiliations="5">
			<name>K. Strong</name>
		</author>
		<author numeration="10" affiliations="8">
			<name>R. J. Sica</name>
		</author>
		<author numeration="11" affiliations="9">
			<name>K. Krüger</name>
		</author>
		<author numeration="12" affiliations="10">
			<name>H. C. Pumphrey</name>
		</author>
		<author numeration="13" affiliations="1">
			<name>L. Froidevaux</name>
		</author>
		<author numeration="14" affiliations="1">
			<name>A. Lambert</name>
		</author>
		<author numeration="15" affiliations="1">
			<name>M. L. Santee</name>
		</author>
		<author numeration="16" affiliations="1">
			<name>N. J. Livesey</name>
		</author>
		<author numeration="17" affiliations="11">
			<name>E. E. Remsberg</name>
		</author>
		<author numeration="18" affiliations="11">
			<name>M. G. Mlynczak</name>
		</author>
		<author numeration="19" affiliations="12">
			<name>J. R. Russell III</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA</affiliation>
		<affiliation numeration="2" content_type="html">New Mexico Institute of Mining and Technology, Socorro, NM, USA</affiliation>
		<affiliation numeration="3" content_type="html">Columbus Technologies Inc., Pasadena, CA, USA</affiliation>
		<affiliation numeration="4" content_type="html">Science and Technology Branch, Environment Canada, Ontario, Canada</affiliation>
		<affiliation numeration="5" content_type="html">University of Toronto, Toronto, Ontario, Canada</affiliation>
		<affiliation numeration="6" content_type="html">University of Waterloo, Waterloo, Ontario, Canada</affiliation>
		<affiliation numeration="7" content_type="html">University of York, Heslington, York, UK</affiliation>
		<affiliation numeration="8" content_type="html">University of Western Ontario, London, Ontario, Canada</affiliation>
		<affiliation numeration="9" content_type="html">Leibniz-Institute for Marine Sciences at Kiel University  (IFM-GEOMAR), Kiel, Germany</affiliation>
		<affiliation numeration="10" content_type="html">University of Edinburgh, Edinburgh, UK</affiliation>
		<affiliation numeration="11" content_type="html">NASA Langley Research Center, Hampton, Virginia, USA</affiliation>
		<affiliation numeration="12" content_type="html">Hampton University, Hampton, Virginia, USA</affiliation>
	</affiliations>
	<abstract content_type="html">The first three Canadian Arctic Atmospheric Chemistry Experiment (ACE)
Validation Campaigns at Eureka (80&amp;deg; N, 86&amp;deg; W)
were during two extremes of Arctic winter variability:
Stratospheric sudden warmings (SSWs) in 2004 and 2006 were among the strongest,
most prolonged on record; 2005 was a record cold
winter. New satellite measurements from ACE-Fourier Transform Spectrometer (ACE-FTS),
Sounding of the Atmosphere using Broadband Emission Radiometry,
and Aura Microwave Limb Sounder (MLS), with
meteorological analyses and Eureka lidar and radiosonde temperatures,
are used to detail the meteorology in these winters, to
demonstrate its influence on transport and chemistry, and to provide a
context for interpretation of campaign observations.
During the 2004 and 2006 SSWs, the vortex broke down throughout
the stratosphere, reformed quickly in the upper stratosphere, and remained
weak in the middle and lower stratosphere.
The stratopause
reformed at very high altitude, above where it could be accurately
represented in the meteorological analyses.
The 2004 and 2006 Eureka campaigns were during the recovery
from the SSWs, with the redeveloping vortex over Eureka.
2005 was the coldest winter on record in the lower
stratosphere, but with an early final warming in mid-March.
The vortex was over Eureka at the start of the 2005 campaign,
but moved away as it broke up. Disparate
temperature profile structure and vortex evolution resulted in
much lower (higher) temperatures in the upper (lower) stratosphere
in 2004 and 2006 than in 2005. Satellite temperatures agree well with Eureka
radiosondes, and with lidar data up to
50&amp;ndash;60 km. Consistent with a strong, cold upper stratospheric vortex and
enhanced radiative cooling after the SSWs,
MLS and ACE-FTS trace gas measurements show strongly enhanced descent in the
upper stratospheric vortex during the
2004 and 2006 Eureka campaigns compared to that in 2005.</abstract>
	<references>
		<reference numeration="1" content_type="text"> Barrett, B., Ricaud, P., Santee, M. L., et~al.: Intercomparisons of Trace Gas Profiles from the Odin/SMR and Aura/MLS Limb Sounders, J. Geophys. Res., 111, D21302, doi:10.1029/2006JD007305, 2006, 2006. </reference>
		<reference numeration="2" content_type="text"> Bernath, B F., McElroy, C. T., Abrams, M. C., et~al.: Atmospheric Chemistry Experiment (ACE): mission overview, Geophys. Res. Lett., 32, L15S01, doi:10.1029/2005GL022386, 2005. </reference>
		<reference numeration="3" content_type="text"> Bloom, S C., McElroy, C. T., Abrams, M. C., et~al.: The Goddard Earth Observing Data Assimilation System, GEOS DAS Version 4.0.3: Documentation and Validation, Tech. Rep. 104606 V26, NASA, 2005. </reference>
		<reference numeration="4" content_type="text"> Boone, C D., Nassar, R., Walker, K A., Rochon, Y., McLeod, S D., Rinsland, C P., and Bernath, P F.: Retrievals for the Atmospheric Chemistry Experiment Fourier-Transform Spectrometer, Appl. Opt., 44, 7218&amp;ndash;7231, 2005. </reference>
		<reference numeration="5" content_type="text"> Braathen, G., Grunow, K., Kivi, R., Kyrö, E., Raffalski, U., Kopp, G., Urban, J., Hochschild, G., Goutail, F., Manney, G. L., Rösevall, J., and Murtagh, D.: Joint WMO/EU Arctic ozone bulletin, winter/spring summary, Tech. Rep. 2006-1, World Meteorological Organization/European Ozone Research Coordinating Unit, 2006. %</reference>
		<reference numeration="6" content_type="text"> %Carleer, M., \blackbox\bf please name at least 3 authors before using et al., et~al.: %ACE-FTS water vapor validation, Atmos. Chem. Phys. Discuss., %in preparation, 2007. </reference>
		<reference numeration="7" content_type="text"> Carswell, A I., Donovan, D P., Bird, J C., Duck, T J., Pal, S R., and Whiteway, J A.: Measurements at the Eureka Arctic NDSC station with a Raman DIAL system, in: Advances in atmospheric remote sensing with lidar, edited by Ansmann, A. and Neuber, R., pp. 521&amp;ndash;524, Springer-Verlag, Berlin, 1996. </reference>
		<reference numeration="8" content_type="text"> Clerbaux, C., Coheur, P.-F., Hurtmans, D., Barret, B., Carleer, M., Semeniuk, K., McConnell, J C., Boone, C., and Bernath, P.: Carbon monoxide distribution from the ACE-FTS solar occultation measurements, Geophys.\ Res. Lett., 32, L16S01, doi:10.1029/2005GL022394, 2005. %</reference>
		<reference numeration="9" content_type="text"> %Clerbaux, C., George, M., et~al.: CO measurements from the ACE-FTS mission: %Validation using ground-based, airbourne and satellite observations, Atmos.\ %Chem. Phys. Discuss., in preparation, 2007. </reference>
		<reference numeration="10" content_type="text"> Davies, T., Cullen, M. J P., Malcolm, A J., Mawson, M H., Staniforth, A., White, A A., and Wood, N.: A new dynamical core for the Met Office&apos;s global and regional modelling of the atmosphere, Q. J. R. Meteorol. Soc., 131, 1759&amp;ndash;1782, 2005. </reference>
		<reference numeration="11" content_type="text"> Duck, T J. and Greene, M D.: High Arctic observations of mesospheric inversion layers, Geophys. Res. Lett., 31, L02105, doi:10.1029/2003GL018481, 2004. </reference>
		<reference numeration="12" content_type="text"> Dunkerton, T J. and Delisi, D P.: Evolution of potential vorticity in the winter stratosphere of January-February 1979, J. Geophys. Res., 91, 1199&amp;ndash;1208, 1986. %</reference>
		<reference numeration="13" content_type="text"> %Fraser, A., \blackbox\bf please name at least 3 authotrs beofre using et al., et~al.: UV-Visible measurements of ozone and NO\sub2 at PEARL, %Eureka, Nunavut 2004-2007, Atmos. Chem. Phys. Discuss., in preparation, 2007. </reference>
		<reference numeration="14" content_type="text"> Froidevaux, L., Livesey, N. J., Read, W. G., et~al.: Early Validation analyses of atmospheric profiles from EOS MLS on the Aura Satellite, IEEE Trans. Geosci. Remote Sens., 44, 1106&amp;ndash;1121, 2006. %</reference>
		<reference numeration="15" content_type="text"> %Froidevaux, L., \blackbox\bf please name at least 3 authors beofre using et al., et~al.: Validation of EOS MLS HCl measurements, J.\ %Geophys. Res., submitted\blackbox\bf status?, available at http://mls.jpl.nasa.gov, %2007a. %</reference>
		<reference numeration="16" content_type="text"> %Froidevaux, L., \blackbox\bf please name at least 3 authors beofre using et al., et~al.: Validation of EOS MLS stratospheric ozone %measurements, J. Geophys. Res., submitted\blackbox\bf status?, available at %http://mls.jpl.nasa.gov, 2007b. %</reference>
		<reference numeration="17" content_type="text"> %Fu, D., Mittermeier, R., Sung, K., Walker, K A., Bernath, P F., Fast, H., and %Strong, K.: Simultaneous atmospheric remote sensing using Fourier transform %Infrared spectrometers at Polar Environment Atmospheric Research %Laboratory (PEARL) during spring 2006, Atmos. Chem. Phys. Discuss., in preparation, 2007. </reference>
		<reference numeration="18" content_type="text"> Fussen, D., Vanhellemont, F., Dodion, J., Bingen, C., Walker, K A., Boone, C D., McLeod, S D., and Bernath, P F.: Initial intercomparison of ozone and nitrogen dioxide number density profiles retrieved by the ACE-FTS and GOMOS occultation experiments, Geophys. Res. Lett., 32, L16S02, doi:10.1029/2005GL022468, 2005. </reference>
		<reference numeration="19" content_type="text"> Gross, M R., McGee, T J., Ferrare, R A., Singh, U N., and Kimvilakani, P.: Temperature measurements made with a combined Rayleigh-Mie and Raman lidar, Applied Optics, 36, 5987&amp;ndash;5995, 1997. </reference>
		<reference numeration="20" content_type="text"> Hauchecorne, A. and Chanin, M L.: Density and temperature profiles obtained by lidar between 35 and 70 km, Geophys. Res. Lett., 8, 565&amp;ndash;569, 1980. </reference>
		<reference numeration="21" content_type="text"> Highwood, E J. and Berrisford, P.: Properties of the Arctic tropopause, Q.\ J. R. Meteorol. Soc., 126, 1515&amp;ndash;1532, 2000. </reference>
		<reference numeration="22" content_type="text"> Hitchman, M H., Gille, J C., Rodgers, C D., and Brasseur, G.: The separated polar stratopause: A gravity wave driven climatological feature, J.\ Atmos. Sci., 46, 410&amp;ndash;422, 1989. </reference>
		<reference numeration="23" content_type="text"> Ivanov, A., Kats, A., Kurnosenko, S., Nash, N., and Zaitseva, N.: International Radiosonde Intercomparison Phase~III (Dzhambul, USSR 1989) final report, Tech. Rep. WMO/TD-No 451, World Meteorological Organization, Instruments and Observing Methods Report 40, 1991. </reference>
		<reference numeration="24" content_type="text"> Jin, J J., Semeniuk, K., Jonsson, A. I., et~al.: Co-located ACE-FTS and Odin/SMR stratospheric-mesospheric CO 2004 measurements and comparison with a GCM, Geophys. Res. Lett., 32, L15S03, doi:10.1029/2005GL022433, 2005. </reference>
		<reference numeration="25" content_type="text"> Kerzenmacher, T E., Walker, K. A., Strong, K., et~al.: Measurements of O&lt;sub&gt;3&lt;/sub&gt;, NO&lt;sub&gt;2&lt;/sub&gt; and Temperature During the 2004 Canadian Arctic ACE Validation Campaign, Geophys.\ Res. Lett., 32, L16S07, doi:10.1029/2005GL023032, 2005. </reference>
		<reference numeration="26" content_type="text"> Kutepov, A., Feofilov, A., Marshall, B., Gordley, L., Pesnell, W., Goldberg, R., and Russell~III, J.: SABER temperature observations in the summer polar mesosphere and lower thermosphere: Importance of accounting for the CO&lt;sub&gt;2&lt;/sub&gt; $\nu_2$ quanta V&amp;ndash;V exchange, Geophys. Res. Lett., 33, L21809, doi:10.1029/2006GL026591, 2006. </reference>
		<reference numeration="27" content_type="text"> Labitzke, K.: Temperature changes in the mesosphere and stratosphere connected with circulation changes in winter, J. Atmos. Sci., 29, 756&amp;ndash;766, 1972. %</reference>
		<reference numeration="28" content_type="text"> %Lambert, A., \blackbox\bf please name at least 3 authors before using et al., et~al.: Validation of the Aura Microwave Limb Sounder %stratospheric water vapor and nitrous oxide measurements, J. Geophys.\ %Res., submitted\blackbox\bf status?, available at http://mls.jpl.nasa.gov, 2007. </reference>
		<reference numeration="29" content_type="text"> Livesey, N J., Read, W. J., Filipiak, M. J., et~al.: MLS Version~1.5 Level~2 data quality and description document, Tech. Rep. JPL D-32381, Jet Propulsion Laboratory, 2005. </reference>
		<reference numeration="30" content_type="text"> Lorenc, A C., Ballard, S. P., Bell, R. S., et~al.: The Met. Office global three-dimensional variational data assimilation scheme, Q. J. R. Meteorol. Soc., 126, 2991&amp;ndash;3012, 2000. </reference>
		<reference numeration="31" content_type="text"> Mahieu, E. and Fels, S B.: Comparisons between ACE-FTS and ground-based measurements of stratospheric HCl and ClONO\sub2 loadings at northern latitudes, Geophys. Res. Lett., 32, L15S08, doi:10.1029/2005GL022396, 2005. </reference>
		<reference numeration="32" content_type="text"> Manney, G L., Zurek, R W., O&apos;Neill, A., and Swinbank, R.: On the motion of air through the stratospheric polar vortex, J. Atmos. Sci., 51, 2973&amp;ndash;2994, 1994. </reference>
		<reference numeration="33" content_type="text"> Manney, G L., Krüger, K., Sabutis, J L., Sena, S A., and Pawson, S.: The remarkable 2003-2004 winter and other recent warm winters in the Arctic stratosphere since the late 1990s, J. Geophys. Res., 110, D04107, doi:10.1029/2004JD005367, 2005. </reference>
		<reference numeration="34" content_type="text"> Manney, G L., Livesey, N J., Jimenez, C J., Pumphrey, H C., Santee, M L., MacKenzie, I A., Froidevaux, L., and Waters, J W.: EOS MLS observations of &quot;frozen-in&quot; anticyclonic air in Arctic summer, Geophys.\ Res. Lett., 33, L06810, doi:10.1029/2005GL025418, 2006a. </reference>
		<reference numeration="35" content_type="text"> Manney, G L., Santee, M L., Froidevaux, L., Hoppel, K., Livesey, N J., and Waters, J W.: EOS MLS observations of ozone loss in the 2004-2005 Arctic winter, Geophys. Res. Lett., 33, L04802, doi:10.1029/2005GL024494, 2006b. %</reference>
		<reference numeration="36" content_type="text"> %Manney, G L. et~al.: Solar Occultation Satellite Data and Derived %Meteorological Products: Sampling Issues and Comparisons with Aura MLS, % J. Geophys. Res., submitted\blackbox\bf status?, available at %http://mls.jpl.nasa.gov, 2007a. %</reference>
		<reference numeration="37" content_type="text"> %Manney, G L., \blackbox\bf please name at least 3 authors before using et al., et~al.: The evolution of the stratopause during the 2006 major %warming: Satellite Data and Assimilated Meteorological Analyses, %Geophys. Res. Lett., submitted\blackbox\bf status?, available at http://mls.jpl.nasa.gov, %2007b. </reference>
		<reference numeration="38" content_type="text"> McHugh, M., Magill, B., Walker, K A., Boone, C D., Bernath, P F., and Russell~III, J M.: Comparison of atmospheric retrievals from ACE and HALOE, Geophys. Res. Lett., 32, L15S10, doi:10.1029/2005GL022403, 2005. </reference>
		<reference numeration="39" content_type="text"> Mlynczak, M. and Russell, J.: An overview of the SABER experiment for the TIMED mission, NASA Langley Research Center, Optical Remote Sensing of the Atmosphere, 2, 5&amp;ndash;7, 1995. </reference>
		<reference numeration="40" content_type="text"> Nash, J. and Schmidlin, F J.: International Radiosonde Intercomparison (U.K., 1984, U.S.A., 1985) final report, Tech. Rep. WMO/TD-No 195, World Meteorological Organization, Instruments and Observing Methods Report 30, 1987. </reference>
		<reference numeration="41" content_type="text"> Petelina, S V., Llewellyn, E J., Walker, K A., Degenstein, D A., Boone, C D., Bernath, P F., Haley, C S., von Savigny, C., Lloyd, N D., and Gattinger, R L.: Validation of ACE-FTS stratospheric ozone profiles against Odin/OSIRIS measurements, Geophys. Res. Lett., 32, L15S06, doi:10.1029/2005GL022377, 2005. %</reference>
		<reference numeration="42" content_type="text"> %Pumphrey, H C., \blackbox\bf please name at least 3 authors before using et al., et~al.: Validation of the Aura Microwave Limb Sounder %stratospheric and mesospheric CO measurements, J. Geophys. Res., %submitted\blackbox\bf status?, available at http://mls.jpl.nasa.gov, 2007. </reference>
		<reference numeration="43" content_type="text"> Randall, C E., Harvey, V L., Singleton, C S., Bernath, P F., Boone, C D., and Kozyra, J U.: Enhanced NO&lt;sub&gt;x&lt;/sub&gt; in 2006 linked to strong upper stratospheric Arctic vortex, Geophys. Res. Lett., 33, L18811, doi:10.1029/2006GL027160, 2006. </reference>
		<reference numeration="44" content_type="text"> Randall, C E. , Harvey, V. L., Manney, G. L., et~al.: Stratospheric effects of energetic particle precipitation in 2003&amp;ndash;2004, Geophys. Res. Lett., 32, L05802, doi:10.1029/2004GL022003, 2005. </reference>
		<reference numeration="45" content_type="text"> Reichler, T., Dameris, M., and Sausen, R.: Determining the tropopause height from gridded data, Geophys. Res. Lett., 30, 2042, doi:10.1029/2003GL018240, 2003. </reference>
		<reference numeration="46" content_type="text"> Reinecker, M M., Suarez, M. J., Todling, R., et~al.: The GEOS-5 Data Assimilation System: A Documentation of GEOS-5.0, Tech. Rep. 104606 V27, NASA, 2007. </reference>
		<reference numeration="47" content_type="text"> Remsberg, E E., Lingenfelser, G., Harvey, V L., Grose, W., III, J R., Mlynczak, M., Gordley, L., and Marshall, B T.: On the verification of the quality of SABER temperature, geopotential height, and wind fields by comparison with Met Office assimilated anylyses, J. Geophys. Res., 108, 4628, doi:10.1029/2003JD003720, 2003. </reference>
		<reference numeration="48" content_type="text"> Remsberg, E E., Deaver, L., Wells, J. , et~al.: An assessment of the quality of HALOE temperature profiles in the mesosphere based on comparisons with Rayleigh backscatter lidar and inflatable falling sphere measurements, J. Geophys. Res., 107, 4447, doi:10.1029/2001JD001521, 2002. %</reference>
		<reference numeration="49" content_type="text"> %Santee, M L., \blackbox\bf please name at least 3 authors before using et al., et~al.: A study of stratospheric chlorine partitioning based on %new satellite measurements and modeling, J. Geophys. Res., submitted\blackbox\bf status?, %available at http://mls.jpl.nasa.gov, 2007a. %</reference>
		<reference numeration="50" content_type="text"> %Santee, M L., \blackbox\bf please name at least 3 authors before using et al., et~al.: Validation of the Aura Microwave Limb Sounder %HNO&lt;sub&gt;3&lt;/sub&gt; measurements, J. Geophys. Res., submitted\blackbox\bf status?, available %at http://mls.jpl.nasa.gov, 2007b. </reference>
		<reference numeration="51" content_type="text"> Schoeberl, M R.: Extratropical stratosphere-troposphere mass exchange, J.\ Geophys. Res., 109, D13303, doi:10.1029/2004JD004525, 2004. %</reference>
		<reference numeration="52" content_type="text"> %Schwartz, M J., \blackbox\bf please name at least 3 authors before using et al., et~al.: Validation of the Aura Microwave Limb Sounder %temperature and geopotential height measurements, J. Geophys. Res., %submitted, available at http://mls.jpl.nasa.gov, 2007. %</reference>
		<reference numeration="53" content_type="text"> %Sica, R J., \blackbox\bf please name at least 3 authors before using et al., et~al.: Validation of ACE temperature using ground-based and %space-based meassurements, Atmos. Chem. Phys. Discuss., in preparation, 2007. </reference>
		<reference numeration="54" content_type="text"> Simmons, A J., Hortal, M., Kelly, G., McNally, A., Untch, A., and Uppala, S.: ECMWF analyses and forecasts of stratospheric winter polar vortex break-up: September~2002 in the southern hemisphere and related events, J. Atmos.\ Sci., 62, 668&amp;ndash;689, 2005. </reference>
		<reference numeration="55" content_type="text"> Siskind, D E., , Eckermann, S D., Coy, L., and McCormack, J P.: On recent interannual variability of the Arctic winter mesosphere: Implications for tracer descent, Geophys. Res. Lett., 34, L09806, doi:10.1029/2007GL029293, 2007. </reference>
		<reference numeration="56" content_type="text"> Sung, K., Skelton, R., Walker, K A., Boone, C D., Fu, D., and Bernath, P F.: N\sub2O and O\sub3 Arctic column amounts from PARIS-IR observations: Retrievals, characterization and error analysis, J. Quant. Spectrosc.\ Rad. Transfer, in press, 2007, 2007a. %</reference>
		<reference numeration="57" content_type="text"> %Sung, K., \blackbox\bf please name at least 3 authors before using et al., et~al.: Partial and total column SFIT2 retrievals from Eureka %DA8 spectra in spring 2004 and 2005, including comparisons with PARIS-IR %and ACE Satellite measurements, Atmos. Chem. Phys. Discuss., in preparation, 2007b. </reference>
		<reference numeration="58" content_type="text"> Swinbank, R. and O&apos;Neill, A.: A stratosphere-troposphere data assimilation system, Mon. Weather Rev., 122, 686&amp;ndash;702, 1994. </reference>
		<reference numeration="59" content_type="text"> Swinbank, R., Ingleby, N B., Boorman, P M., and Renshaw, R J.: A 3D variational data assimilation system for the stratosphere and troposphere, Tech. Rep 71, Met Office Numerical Weather Prediction Forecasting Research Scientific Paper, 2002. </reference>
		<reference numeration="60" content_type="text"> Swinbank, R., Keil, M., Jackson, D R., and Scaife, A A.: Stratospheric Data Assimilation at the Met Office - progress and plans, in: ECMWF workshop on Modelling and Assimilation for the Stratosphere and Tropopause 23-26-June, 2003, ECMWF, 2004. </reference>
		<reference numeration="61" content_type="text"> Untch, A., Miller, M., Hortal, M., Buizza, R., and Janssen, P.: Towards a global meso-scale model: The high resolution system T799L91 and T399L62 EPS, ECMWF Newsletter, 108, 6&amp;ndash;13, 2006. </reference>
		<reference numeration="62" content_type="text"> Walker, K A., Randall, C E., Trepte, C R., Boone, C D., and Bernath, P F.: Initial validation comparisons for the Atmospheric Chemistry Experiment (ACE), Geophys. Res. Lett., 32, L16S04, doi:10.1029/2005GL022 388, 2005. </reference>
		<reference numeration="63" content_type="text"> Waters, J W., Froidevaux, L., Harwood, R. S., et~al.: The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura satellite, IEEE Trans. Geosci. Remote Sens., 44, 1075&amp;ndash;1092, 2006. </reference>
		<reference numeration="64" content_type="text"> WMO: \upshape Scientific assessment of stratospheric ozone depletion: 2006, U N Environ Program, Geneva, Switzerland, 2007. </reference>
		<reference numeration="65" content_type="text"> Wu, W.-S., Purser, R J., and Parish, D F.: Three-dimensional variational analyses with spatially inhomogeneous covariances, Mon. Weather Rev., 130, 2905&amp;ndash;2916, 2002. </reference>
	</references>
</article>

