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  • 1.
    Aires, Filipe
    et al.
    Estellus, Paris.
    Prigent, Catherine
    Estellus, Paris.
    Orlandi, Emiliano
    Cologne university.
    Milz, Mathias
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Eriksson, Patrick
    Chalmers University of Technology.
    Crewell, Susanne
    Cologne university.
    Lin, Chung-Chi
    ESA, ESTEC.
    Kangas, Ville
    ESA, ESTEC.
    Microwave hyperspectral measurements for temperature and humidity atmospheric profiling from satellite: The clear-sky case2015In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 120, no 21, p. 11334-11351Article in journal (Refereed)
    Abstract [en]

    This study investigates the benefits of a satellite HYper-spectral Microwave Sensor (HYMS) for the retrieval of atmospheric temperature and humidity profiles, in the context of Numerical Weather Prediction (NWP). In the infrared, hyper-spectral instruments have already improved the accuracy of NWP forecasts. Microwave instruments so far only provide observations for a limited number of carefully selected channels. An information content analysis is conducted here to assess the impact of hyper-spectral microwave measurements on the retrieval of temperature and water vapor profiles under clear-sky conditions. It uses radiative transfer simulations over a large variety of atmospheric situations. It accounts for realistic observation (instrument and radiative transfer) noise and for a priori information assumptions compatible with NWP practices. The estimated retrieval performance of the HYMS instrument is compared to those of the microwave instruments to be deployed on board the future generation of European operational meteorological satellites (MetOp-SG). The results confirm the positive impact of a HYMS instrument on the atmospheric profiling capabilities compared to MetOp-SG. Temperature retrieval uncertainty, compared to a priori information, is reduced by 2 to 10%, depending on the atmospheric height, and improvement rates are much higher than what will be obtained with MetOp-SG. For humidity sounding these improvements can reach 30%, a significant benefit as compared to MetOp-SG results especially below 250 hPa. The results are not very sensitive to the instrument noise, under our assumptions. The main impact provided by the hyper-spectral information originates from the higher resolution in the O2 band around 60 GHz. The results are presented over ocean at nadir but similar conclusions are obtained for other incidence angles and over land

  • 2.
    Clarmann, T. Von
    et al.
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    Ceccherini, S.
    Istituto di Fisica Applicata “Nello Carrara,”, Florence.
    Doicu, A.
    Deutsches Zentrum für Luft-und Raumfahrt (DLR).
    Dudhia, A.
    Atmospheric, Oceanic, and Planetary Physics, Oxford University.
    Funke, B.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Grabowski, U.
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    Hilgers, S.
    Deutsches Zentrum für Luft-und Raumfahrt (DLR).
    Jay, V.
    Rutherford Appleton Laboratory, Oxfordshire.
    Linden, A.
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    López-Puertas, M.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Martin-Torres, Javier
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe, Analytical Services and Materials Inc., Hampton.
    Payne, V.
    Atmospheric, Oceanic, and Planetary Physics, Oxford University.
    Reburn, J.
    Rutherford Appleton Laboratory, Oxfordshire.
    Ridolfi, M.
    Dipertemento di Chimica Fisica e Inorganica, Universitá di Bologna.
    Schreier, F.
    Deutsches Zentrum für Luft-und Raumfahrt (DLR).
    Schwarz, G.
    Deutsches Zentrum für Luft-und Raumfahrt (DLR).
    Siddans, R.
    Rutherford Appleton Laboratory, Oxfordshire.
    Steck, T.
    Institut für Meteorologie und Klimaforschung, Universität Karlsruhe.
    A blind test retrieval experiment for infrared limb emission spectrometry2003In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 108, no D23Article in journal (Refereed)
    Abstract [en]

    The functionality and characteristics of six different data processors (i.e., retrieval codes in their actual software and hardware environment) for analysis of high-resolution limb emission infrared spectra recorded by the space-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have been validated by means of a blind test retrieval experiment based on synthetic spectra. For this purpose a self-consistent set of atmospheric state parameters, including pressure, temperature, vibrational temperatures, and abundances of trace gases and aerosols, has been generated and used as input for radiative transfer calculations for MIPAS measurement geometry and configuration. These spectra were convolved with the MIPAS field of view, spectrally degraded by the MIPAS instrument line shape, and, finally, superimposed with synthetic measurement noise. These synthetic MIPAS measurements were distributed among the participants of the project “Advanced MIPAS level-2 data analysis” (AMIL2DA), who performed temperature and species abundance profile retrievals by inverse radiative transfer calculations. While the retrieved profiles of atmospheric state parameters reflect some characteristics of the individual data processors, it was shown that all the data processors under investigation are capable of producing reliable results in the sense that deviations of retrieved results from the reference profiles are within the margin that is consistent with analytical error estimation.

  • 3.
    Isoz, Oscar
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Buehler, Stefan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Eriksson, Per
    Chalmers University of Technology, Department of Earth and Space Sciences.
    Intercalibration of microwave temperature sounders using radio occultation measurements2015In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 120, no 9, p. 3758-3773Article in journal (Refereed)
    Abstract [en]

    This is a study of the usefulness of radio occultation (RO) data for intercomparing different microwave temperature (MWT) sounding instruments. The RO data used are from the Global Navigational Satellite System Receiver for Atmospheric Sounding on the Metop-A and B satellites. The MWT sounders investigated are the Advanced Microwave Sounding Unit-A instruments on the satellites NOAA 15, 16, and 18 and Metop-A. We collocate RO and MWT data and then use these collocations to study various aspects of the MWT instruments. In addition, two different versions of the MWT data are compared: standard operational data (OPR) and the NOAA Integrated Microwave Intercalibration Approach data (IMICA). The time series of monthly mean differences shows that there are robust patterns for each satellite and data version, which mostly drift only slowly over time. The intersatellite spread, measured by the standard deviation of the yearly mean values by all satellites, is between 0.1 and 0.4 K, depending on channel, with no significant differences between OPR and IMICA data. The only notable exception is Channel 8 of NOAA 16, which appears to have a time-varying offset of 0.5–1 K relative to the other instruments. At this point it is not clear whether this deviation is real or a sampling artifact, so further study is needed. Due to the large number of collocations used, it is possible to also investigate the scene brightness and scan angle dependence of the MWT bias (relative to RO). First results of such an analysis are presented and discussed. Particularly, the investigation of the scan angle dependence is novel, since this bias pattern is difficult to assess without RO data. Further work is needed on these angular dependences, before conclusions are robust enough to include in data recalibration efforts, but our overall conclusion is that RO collocations are a powerful tool for intercomparing MWT sounders.

  • 4.
    Mlynczak, Martin G.
    et al.
    NASA Langley Research Center, Hampton.
    Hunt, Linda A.
    Science Systems and Applications Inc., Hampton.
    Mast, Jeffrey C.
    Science Systems and Applications Inc., Hampton.
    Marshall, B. Thomas
    G & A Technical Software, Newport News.
    III, James M. Russell
    Hampton University.
    Smith, Anne K.
    National Center for Atmospheric Research, Boulder, Colorado.
    Siskind, David E.
    Naval Research Laboratory, Washington, DC.
    Yee, Jen-Hwa
    Johns Hopkins University Applied Physics Laboratory, Laurel.
    Mertens, Christopher J.
    NASA Langley Research Center, Hampton.
    Martin-Torres, Javier
    Centro de Astrobiologia, INTA-CSIC, Madrid.
    Thompson, R. Earl
    G & A Technical Software, Newport News.
    Drob, Douglas P.
    Naval Research Laboratory, Washington, DC.
    Gordley, Larry L.
    G & A Technical Software, Newport News.
    Atomic oxygen in the mesosphere and lower thermosphere derived from SABER: Algorithm theoretical basis and measurement uncertainty2013In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 118, no 11, p. 5724-5735Article in journal (Refereed)
    Abstract [en]

    Atomic oxygen (O) is a fundamental component in chemical aeronomy of Earth's mesosphere and lower thermosphere region extending from approximately 50 km to over 100 km in altitude. Atomic oxygen is notoriously difficult to measure, especially with remote sensing techniques from orbiting satellite sensors. It is typically inferred from measurements of the ozone concentration in the day or from measurements of the Meinel band emission of the hydroxyl radical (OH) at night. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite measures OH emission and ozone for the purpose of determining the O-atom concentration. In this paper, we present the algorithms used in the derivation of day and night atomic oxygen from these measurements. We find excellent consistency between the day and night O-atom concentrations from daily to annual time scales. We also examine in detail the collisional relaxation of the highly vibrationally excited OH molecule at night measured by SABER. Large rate coefficients for collisional removal of vibrationally excited OH molecules by atomic oxygen are consistent with the SABER observations if the deactivation of OH(9) proceeds solely by collisional quenching. An uncertainty analysis of the derived atomic oxygen is also given. Uncertainty in the rate coefficient for recombination of O and molecular oxygen is shown to be the largest source of uncertainty in the derivation of atomic oxygen day or night.

  • 5.
    Mlynczak, Martin G.
    et al.
    NASA Langley Research Center, Hampton.
    Marshall, B. Thomas
    G & A Technical Software, Newport News.
    Martin-Torres, Javier
    Analytical Services and Materials Inc., Hampton.
    III, James M. Russell
    Department of Atmospheric and Planetary Sciences, Hampton University.
    Thompson, R. Earl
    G & A Technical Software, Newport News.
    Remsberg, Ellis E.
    NASA Langley Research Center, Hampton.
    Gordley, Larry L.
    G & A Technical Software, Newport News.
    Sounding of the Atmosphere using Broadband Emission Radiometry observations of daytime mesospheric O2(1Δ) 1.27 μm emission and derivation of ozone, atomic oxygen, and solar and chemical energy deposition rates2007In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 112, no D15, article id D15306Article in journal (Refereed)
    Abstract [en]

    We report observations of the daytime O2(1Δ) airglow emission at 1.27 μm recorded by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. The measured limb radiances are inverted to yield vertical profiles of the volume emission rate of energy from the O2 molecule. From these emission rates we subsequently derive the mesospheric ozone concentrations using a nonlocal thermodynamic equilibrium (non-LTE) radiative and kinetic model. Rates of energy deposition due to absorption of ultraviolet radiation in the Hartley band of ozone are also derived, independent of knowledge of the ozone abundance and solar irradiances. Atomic oxygen concentrations are obtained from the ozone abundance using photochemical steady state assumptions. Rates of energy deposition due to exothermic chemical reactions are also derived. The data products illustrated here are from a test day (4 July 2002) of SABER Version 1.07 data which are now becoming publicly available. This test day illustrates the high quality of the SABER O2(1Δ) airglow and ozone data and the variety of fundamental science questions to which they can be applied.

  • 6.
    Remsberg, E.E.
    et al.
    Science Directorate, NASA Langley Research Center, Hampton.
    Marshall, B.T.
    G & A Technical Software, Inc., Hampton.
    Garcia-Comas, M.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Kreuger, D.
    Department of Physics, Colorado State University, Fort Collins.
    Lingenfelser, G.S.
    Science Systems and Applications Inc., Hampton.
    Martin-Torres, Javier
    Science Systems and Applications Inc., Hampton.
    Mlynczak, M.G.
    Science Directorate, NASA Langley Research Center, Hampton.
    III, J.M. Russell
    Center for Atmospheric Sciences, Hampton University.
    Smith, A.K.
    National Center for Atmospheric Research, Boulder, Colorado.
    Zhao, Y.
    Center for Atmospheric and Space Sciences, Utah State University, Logan.
    Brown, C.
    G & A Technical Software, Inc., Hampton.
    Gordley, L.L.
    G & A Technical Software, Inc., Hampton.
    Lopez-Gonzalez, M.J.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    López-Puertas, M.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    She, C.-Y.
    Department of Physics, Colorado State University, Fort Collins.
    Taylor, M.J.
    Center for Atmospheric and Space Sciences, Utah State University, Logan.
    Thompson, R.E.
    G & A Technical Software, Inc., Hampton.
    Assessment of the quality of the Version 1.07 temperature-versus-pressure profiles of the middle atmosphere from TIMED/SABER2008In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 113, no D17, article id D17101Article in journal (Refereed)
    Abstract [en]

    The quality of the retrieved temperature-versus-pressure (or T(p)) profiles is described for the middle atmosphere for the publicly available Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) Version 1.07 (V1.07) data set. The primary sources of systematic error for the SABER results below about 70 km are (1) errors in the measured radiances, (2) biases in the forward model, and (3) uncertainties in the corrections for ozone and in the determination of the reference pressure for the retrieved profiles. Comparisons with other correlative data sets indicate that SABER T(p) is too high by 1–3 K in the lower stratosphere but then too low by 1 K near the stratopause and by 2 K in the middle mesosphere. There is little difference between the local thermodynamic equilibrium (LTE) algorithm results below about 70 km from V1.07 and V1.06, but there are substantial improvements/differences for the non-LTE results of V1.07 for the upper mesosphere and lower thermosphere (UMLT) region. In particular, the V1.07 algorithm uses monthly, diurnally averaged CO2 profiles versus latitude from the Whole Atmosphere Community Climate Model. This change has improved the consistency of the character of the tides in its kinetic temperature (Tk). The Tk profiles agree with UMLT values obtained from ground-based measurements of column-averaged OH and O2 emissions and of the Na lidar returns, at least within their mutual uncertainties. SABER Tk values obtained near the mesopause with its daytime algorithm also agree well with the falling sphere climatology at high northern latitudes in summer. It is concluded that the SABER data set can be the basis for improved, diurnal-to-interannual-scale temperatures for the middle atmosphere and especially for its UMLT region.

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