<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE article SYSTEM "http://www.atmos-meas-tech-discuss.net/inc/amtd/copernicus.dtd">
<article language="en">
	<journal>
		<journal_title>Atmospheric Measurement Techniques Discussions</journal_title>
		<journal_url>www.atmos-meas-tech-discuss.net</journal_url>
		<eissn>1867-8610</eissn>
		<volume_number>3</volume_number>
		<issue_number>4</issue_number>
		<publication_year>2010</publication_year>
	</journal>
	<doi>10.5194/amtd-3-3877-2010</doi>
	<article_url>http://www.atmos-meas-tech-discuss.net/3/3877/2010/</article_url>
	<abstract_html>http://www.atmos-meas-tech-discuss.net/3/3877/2010/amtd-3-3877-2010.html</abstract_html>
	<fulltext_pdf>http://www.atmos-meas-tech-discuss.net/3/3877/2010/amtd-3-3877-2010.pdf</fulltext_pdf>
	<start_page>3877</start_page>
	<end_page>3906</end_page>
	<publication_date>2010-08-26</publication_date>
	<article_title content_type="html">Retrieval of macrophysical cloud parameters from MIPAS: algorithm description and preliminary validation</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>J. Hurley</name>
			<email>hurley@atm.ox.ac.uk</email>
		</author>
		<author numeration="2" affiliations="1">
			<name>A. Dudhia</name>
		</author>
		<author numeration="3" affiliations="1">
			<name>R. G. Grainger</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Department of Physics, Parks Road, Oxford</affiliation>
	</affiliations>
	<abstract content_type="html">The Michelson Interferometer for Passive Atmospheric Sounding
      (MIPAS) onboard ENVISAT has the potential to be particularly
      useful for studying high, thin clouds, which have been
      difficult to observe in the past. This paper details the
      development, implementation and testing of an
      optimal-estimation-type retrieval for three macrophysical
      cloud parameters (cloud top height, cloud top temperature and
      cloud extinction coefficient) from infrared spectra measured
      by MIPAS, employing additional information derived to improve
      the choice of a priori. The retrieval is applied and initially
      validated on MIPAS data. From application to MIPAS data, the
      retrieved cloud top heights are assessed to be accurate to
      within 50 m, the cloud top temperatures to within 0.5 K and
      extinction coefficients to within a factor of 15%. This
      algorithm has been adopted by the European Space Agency&apos;s
      &apos;&apos;MIPclouds&apos;&apos; project, which itself recognises the
      potential of MIPAS beyond monitoring atmospheric chemistry and
      seeks to study clouds themselves rigorously using MIPAS.</abstract>
	<references>
		<reference numeration="1" content_type="text"> Barton,~I.: Upper-level cloud climatology from an orbiting satellite, J. Atmos. Sci., 40, 435–447, 1983. </reference>
		<reference numeration="2" content_type="text"> Bernath,~P.: The Atmospheric Chemistry Experiment (ACE): An Overview, Geoscience and Remote Sensing Symposium, IGARSS &apos;02, 2002. </reference>
		<reference numeration="3" content_type="text"> CLAES: Website on SPASCI CLAES Mission, www.spasci.com/CLAES/mission.html, 2007. </reference>
		<reference numeration="4" content_type="text"> Dudhia,~A.: Website on the Reference Forward Model (RFM): Software User&apos;s Manual (SUM), http://www.atm.ox.ac.uk/RFM/sum/, 2005. </reference>
		<reference numeration="5" content_type="text"> Dudhia,~A., Jay,~V L., and Rodgers,~C D.: Microwindow selection for high-spectral-resolution sounders, Appl. Optics, 41, 3665–3673, 2002. </reference>
		<reference numeration="6" content_type="text"> European~Space Agency: website on ESA ENVISAT, http://envisat.esa.int/instruments/images/MIPAS_Interferometer.gif, 2005. </reference>
		<reference numeration="7" content_type="text"> Ewen,~G.: Infrared Limb Observations of Cloud, DPhil thesis in Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK, 2005.  </reference>
		<reference numeration="8" content_type="text"> Global Change~Master Directory: Website on ISAMS, BADC Datasets: ISAMS Welcome, http://badc.nerc.ac.uk/data/isams/, 2010. </reference>
		<reference numeration="9" content_type="text"> Hervig,~M. and Deshler,~T.: Evaluation of aerosol measurements from SAGE II, HALOE, and balloonborne optical particle counters, J. Geophys. Res., 107, AAC3.1–AAC3.12, 2002. </reference>
		<reference numeration="10" content_type="text"> Hurley, J., Dudhia, A., and Grainger, R. G.: Cloud detection for MIPAS using singular vector decomposition, Atmos. Meas. Tech., 2, 533–547, doi:10.5194/amt-2-533-2009, 2009. </reference>
		<reference numeration="11" content_type="text"> IMK: website on IMK Karlsruhe Optimized and Precise Radiative transfer Algorithm, http://www-imk.fzk.de/asf/ame/publications/kopra_docu/, 2008. </reference>
		<reference numeration="12" content_type="text"> Intergovernmental Panel on~Climate Change: Fourth Assessment Report Climate Change 2007 – The Physical Science Basis, Cambridge University Press, Cambridge, 2008. </reference>
		<reference numeration="13" content_type="text"> ISCCP: website on ISCCP, http://isccp.giss.nasa.gov/index.html, 2008. </reference>
		<reference numeration="14" content_type="text"> Kahn,~B., Eldering,~A., Irion,~F., Mills,~F., Sen,~B., and Gunson,~M.: Cloud identification in atmospheric trace molecule spectroscopy infrared occultation measurement, Appl. Optics, 41, 2768–2780, 2002. </reference>
		<reference numeration="15" content_type="text"> Lambert,~A., Bailey,~B., Edwards,~D., Gille,~J., and Johnson,~B.: High Resolution Dynamics Limb Sounder Level-2 Algorithm Theoretical Basis Document 2, Tech. rep., 1999. </reference>
		<reference numeration="16" content_type="text"> Mantovani,~R.: ENVISAT MIPAS Report: Mar 2004–Feb 2005, ENVI-SPPA-EOPG-TN-05-0006, Tech. rep., European Space Agency, 2005. </reference>
		<reference numeration="17" content_type="text"> Moore,~D.: Website on University of Leicester Cloud Top Height product, http://www.leos.le.ac.uk/mipas/data/nrt_ci.html, 2008. </reference>
		<reference numeration="18" content_type="text"> NASA: Website on GES Distributed Active Archive Center LIMS User&apos;s Guide, ftp://disc1.sci.gsfc.nasa.gov/data/lims/Documentation/, 2007. </reference>
		<reference numeration="19" content_type="text"> Prabhakara,~C., Fraser,~R., Dalu,~G., Wu,~M., Curran,~R., and Styles,~T.: Thin cirrus clouds: seasonal distribution over oceans deduced from NIMBUS-4 IRIS, J. Appl. Meteorol., 27, 379–399, 1988. </reference>
		<reference numeration="20" content_type="text"> Rodgers,~C.: Inverse Methods for Atmospheric Sounding: Theory and Practice, World Scientific Publishing Co Pte Ltd, 2000. </reference>
		<reference numeration="21" content_type="text"> SAGE-III-ATBD-Team: SAGE III Algorithm Theoretical Basis Document (ATBD) Cloud Data Products, LaRC 475-00-106, 1.2, Tech. rep., 2002. %</reference>
		<reference numeration="22" content_type="text"> %Sayer,~A M., Campmany,~E., Dean,~S., Ewen,~G., Poulsen,~C A., %Arnold,~C., Thomas,~G E., Grainger,~R G., Siddans,~R., Lawrence,~B., %and Watts,~P.: Validation of GRAPE ORAC ATSR-2 cloud products, in %preparation, 2009.\blackbox\bfPlease update if possible. </reference>
		<reference numeration="23" content_type="text"> Thomas, G. E., Poulsen, C. A., Siddans, R., Sayer, A. M., Carboni, E., Marsh, S. H., Dean, S. M., Grainger, R. G., and Lawrence, B. N.: Validation of the GRAPE single view aerosol retrieval for ATSR-2 and insights into the long term global AOD trend over the ocean, Atmos. Chem. Phys., 10, 4849–4866, doi:10.5194/acp-10-4849-2010, 2010. </reference>
		<reference numeration="24" content_type="text"> Spang,~R., Remedios,~J., and Barkley,~M.: Colour indices for the detection and differentiation of cloud types in infra-red limb emission spectra, Adv. Space Res., 33, 1041–1047, 2004. </reference>
		<reference numeration="25" content_type="text"> Spang,~R., Griessbach,~S., Hopfner,~M., Dudhia,~A., Hurley,~J., Siddans,~R., Waterfall,~A., Remedios,~J., and Sembhi,~H.: Technical Note: Retrievability of MIPAS cloud parameter, ESA-ITT AO/1-5255/06/I-OL, Tech. rep., European Space Agency, 2008. </reference>
		<reference numeration="26" content_type="text"> Warren,~S., Hahn,~C., and London,~J.: Simultaneous occurrence of different cloud types, J. Clim. Appl. Meteorol., 24, 658–667, 1985. </reference>
		<reference numeration="27" content_type="text"> Woodbury,~G. and McCormick,~M.: Global distributions of cirrus clouds determined from SAGE data, Geophys. Res. Lett., 10, 1180–1183, 1983. </reference>
		<reference numeration="28" content_type="text"> Wylie,~D. and Menzel,~W.: Two years of cloud cover statistics using VAS, J. Clim. Appl. Meteorol., 2, 380–392, 1989. </reference>
		<reference numeration="29" content_type="text"> Wylie,~D., Menzel,~W., Woolf,~H., and Strabala,~K.: Four years of global cirrus cloud statistics using HIRS, J. Climate, 7, 1972–1986, 1994. </reference>
		<reference numeration="30" content_type="text"> Wylie,~D., Jackson,~D., Menzel,~W., and Bates,~J.: Trends in global cloud cover in two decades of HIRS observations, J. Climate, 130, 3021–3033, 2005. </reference>
	</references>
</article>

