Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.400 IF 3.400
  • IF 5-year value: 3.841 IF 5-year
  • CiteScore value: 3.71 CiteScore
  • SNIP value: 1.472 SNIP 1.472
  • IPP value: 3.57 IPP 3.57
  • SJR value: 1.770 SJR 1.770
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 70 Scimago H
    index 70
  • h5-index value: 49 h5-index 49
Volume 9, issue 10 | Copyright
Atmos. Meas. Tech., 9, 4977-4995, 2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 11 Oct 2016

Research article | 11 Oct 2016

Cloud information content analysis of multi-angular measurements in the oxygen A-band: application to 3MI and MSPI

Guillaume Merlin1, Jérôme Riedi1, Laurent C. Labonnote1, Céline Cornet1, Anthony B. Davis2, Phillipe Dubuisson1, Marine Desmons1, Nicolas Ferlay1, and Frédéric Parol1 Guillaume Merlin et al.
  • 1Laboratoire d'Optique Atmosphérique, Université de Lille 1, Sciences et Technologies, Villeneuve d'Ascq, France
  • 2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

Abstract. Information content analyses on cloud top altitude (CTOP) and geometrical thickness (CGT) from multi-angular A-band measurements in the case of monolayer homogeneous clouds are conducted. In the framework of future multi-angular radiometer development, we compared the potential performances of the 3MI (Multi-viewing, Multi-channel and Multi-polarization Imaging) instrument developed by EUMETSAT, which is an extension of POLDER/PARASOL instrument and MSPI (Multiangle SpectroPolarimetric Imager) developed by NASA's Jet Propulsion Laboratory. Quantitative information content estimates were realized for thin, moderately opaque and opaque clouds for different surface albedo and viewing geometry configurations. Analyses show that retrieval of CTOP is possible with a high accuracy in most of the cases investigated. Retrieval of CGT is also possible for optically thick clouds above a black surface, at least when CGT > 1–2km and for thin clouds for CGT > 2–3km. However, for intermediate optical thicknesses (COT≃ 4), we show that the retrieval of CGT is not simultaneously possible with CTOP. A comparison between 3MI and MSPI shows a higher information content for MSPI's measurements, traceable to a thinner filter inside the oxygen A-band, yielding higher signal-to-noise ratio for absorption estimation. Cases of cloud scenes above bright surfaces are more complex but it is shown that the retrieval of CTOP remains possible in almost all situations while the information content on CGT appears to be insufficient in many cases, particularly for COT < 4 and CGT< 2–3km.

Publications Copernicus
Short summary
The vertical distribution of cloud cover has a significant impact on a large number of meteorological and climatic processes. Cloud top altitude (CTOP) and cloud geometrical thickness (CGT) are essential for understanding these processes. Previous studies established the possibility of retrieving those parameters from multi-angular oxygen A-band measurements. Here we perform a study and comparison of the performance of future instruments.
The vertical distribution of cloud cover has a significant impact on a large number of...