• Allan, R. P., and Ringer M. A. , 2003: Inconsistencies between satellite estimates of longwave cloud forcing and dynamical fields from reanalyses. Geophys. Res. Lett., 30, 1491, doi:10.1029/2003GL017019.

    • Search Google Scholar
    • Export Citation
  • Allan, R. P., Slingo A. , and Ramaswamy V. , 2002: Analysis of moisture variability in the European Centre for Medium-Range Weather Forecasts 15-year reanalysis over the tropical oceans. J. Geophys. Res., 107, 4230, doi:10.1029/2001JD001132.

    • Search Google Scholar
    • Export Citation
  • Allan, R. P., Ringer M. A. , and Slingo A. , 2003: Evaluation of moisture in the Hadley Centre climate model using simulations of HIRS water-vapour channel radiances. Quart. J. Roy. Meteor. Soc., 129, 33713389.

    • Search Google Scholar
    • Export Citation
  • Allan, R. P., Ringer M. A. , Pamment J. A. , and Slingo A. , 2004: Simulation of the Earth's radiation budget by the European Centre for Medium-Range Weather Forecasts 40-year reanalysis (ERA40). J. Geophys. Res., 109, D18107, doi:10.1029/2004JD004816.

    • Search Google Scholar
    • Export Citation
  • Atkinson, N. C., 2001: Calibration, monitoring and validation of AMSU-B. Adv. Space Res., 28, 117126.

  • Bates, J. J., and Jackson D. L. , 2001: Trends in upper tropospheric humidity. Geophys. Res. Lett., 28, 16951698.

  • Bates, J. J., Wu X. , and Jackson D. L. , 1996: Interannual variability of upper-tropospheric water vapor band brightness temperature. J. Climate, 9, 427438.

    • Search Google Scholar
    • Export Citation
  • Bates, J. J., Jackson D. L. , Bréon F.-M. , and Bergen Z. D. , 2001: Variability of tropical upper tropospheric humidity 1979–1998. J. Geophys. Res., 106 (D23), 32 27132 281.

    • Search Google Scholar
    • Export Citation
  • Buehler, S. A., and John V. O. , 2005: A simple method to relate microwave radiances to upper tropospheric humidity. J. Geophys. Res., 110, D02110, doi:10.1029/2004JD005111.

    • Search Google Scholar
    • Export Citation
  • Buehler, S. A., Eriksson P. , Kuhn T. , von Engeln A. , and Verdes C. , 2005a: ARTS, the atmospheric radiative transfer simulator. J. Quant. Spectrosc. Radiat. Transfer, 91, 6593.

    • Search Google Scholar
    • Export Citation
  • Buehler, S. A., Kuvatov M. , and John V. O. , 2005b: Scan asymmetries in AMSU-B data. Geophys. Res. Lett., 32, L24810, doi:10.1029/2005GL024747.

    • Search Google Scholar
    • Export Citation
  • Buehler, S. A., Kuvatov M. , Sreerekha T. R. , John V. O. , Rydberg B. , Eriksson P. , and Notholt J. , 2007: A cloud filtering method for microwave upper tropospheric humidity measurements. Atmos. Chem. Phys., 7, 55315542.

    • Search Google Scholar
    • Export Citation
  • Buehler, S. A., Kuvatov M. , John V. O. , Milz M. , Soden B. J. , Jackson D. L. , and Notholt J. , 2008: An upper tropospheric humidity data set from operational satellite microwave data. J. Geophys. Res., 113, D14110, doi:10.1029/2007JD009314.

    • Search Google Scholar
    • Export Citation
  • Cao, C., Xu H. , Sullivan J. , McMillin L. , Ciren P. , and Hou Y.-T. , 2005: Intersatellite radiance biases for the High-Resolution Infrared Radiation Sounders (HIRS) on board NOAA-15,-16, and -17 from simultaneous nadir observations. J. Atmos. Oceanic Technol., 22, 381395.

    • Search Google Scholar
    • Export Citation
  • Cao, C., Goldberg M. , and Wang L. , 2009: Spectral bias estimation of historical HIRS using IASI observations for improved fundamental climate data records. J. Atmos. Oceanic Technol., 26, 13781387.

    • Search Google Scholar
    • Export Citation
  • Chevallier, F., 2001: Sampled databases of 60-level atmospheric profiles from the ECMWF analyses. EUMETSAT/ECMWF SAF Programme Research Rep. 4, 27 pp.

  • Chung, E.-S., Sohn B. J. , Schmetz J. , and Koenig M. , 2007: Diurnal variation of upper tropospheric humidity and its relations to convective activities over tropical Africa. Atmos. Chem. Phys., 7, 24892502.

    • Search Google Scholar
    • Export Citation
  • Chung, E.-S., Sohn B. J. , and Schmetz J. , 2009: Diurnal variation of outgoing longwave radiation associated with high cloud and UTH changes from Meteosat-5 measurements. Meteor. Atmos. Phys., 105, 109119.

    • Search Google Scholar
    • Export Citation
  • Chung, E.-S., Soden B. J. , Sohn B.-J. , and Schmetz J. , 2011: Model-simulated humidity bias in the upper troposphere and its relation to the large-scale circulation. J. Geophys. Res., 116, D10110, doi:10.1029/2011JD015609.

    • Search Google Scholar
    • Export Citation
  • Chung, E.-S., Soden B. J. , Sohn B.-J. , and Schmetz J. , 2013: An assessment of the diurnal variation of upper tropospheric humidity in reanalysis data sets. J. Geophys. Res. Atmos., 118, 3425–3430, doi:10.1002/jgrd.50345.

    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553597.

    • Search Google Scholar
    • Export Citation
  • Eriksson, P., Rydberg B. , Johnston M. , Murtagh D. P. , Struthers H. , Ferrachat S. , and Lohmann U. , 2010: Diurnal variations of humidity and ice water content in the tropical upper troposphere. Atmos. Chem. Phys., 10, 11 51911 533.

    • Search Google Scholar
    • Export Citation
  • Greenwald, T. J., and Christopher S. A. , 2002: Effect of cold clouds on satellite measurements near 183 GHz. J. Geophys. Res., 107, 4170, doi:10.1029/2000JD000258.

    • Search Google Scholar
    • Export Citation
  • Held, I. M., and Soden B. J. , 2000: Water vapor feedback and global warming. Annu. Rev. Energy Environ., 25, 441475.

  • Hocking, J., Rayer P. , Saunders R. , Matricardi M. , Geer A. , and Brunel P. , 2011: RTTOV v10 users guide. NWP SAF Doc. NWPSAF-MO-UD-023, EUMETSAT, 92 pp.

  • Hong, G., Heygster G. , Miao J. , and Kunzi K. , 2005: Detection of tropical deep convective clouds from AMSU-B water vapor channels measurements. J. Geophys. Res., 110, D05205, doi:10.1029/2004JD004949.

    • Search Google Scholar
    • Export Citation
  • Jackson, D. L., and Soden B. J. , 2007: Detection and correction of diurnal sampling bias in HIRS/2 brightness temperatures. J. Atmos. Oceanic Technol., 24, 14251438.

    • Search Google Scholar
    • Export Citation
  • John, V. O., and Buehler S. A. , 2004: The impact of ozone lines on AMSU-B radiances. Geophys. Res. Lett., 31, L21108, doi:10.1029/2004GL021214.

    • Search Google Scholar
    • Export Citation
  • John, V. O., and Soden B. J. , 2007: Temperature and humidity biases in global climate models and their impact on climate feedbacks. Geophys. Res. Lett., 34, L18704, doi:10.1029/2007GL030429.

    • Search Google Scholar
    • Export Citation
  • John, V. O., Holl G. , Allan R. P. , Buehler S. A. , Parker D. E. , and Soden B. J. , 2011: Clear-sky biases in satellite infrared estimates of upper tropospheric humidity and its trends. J. Geophys. Res., 116, D14108, doi:10.1029/2010JD015355.

    • Search Google Scholar
    • Export Citation
  • John, V. O., Holl G. , Buehler S. A. , Candy B. , Saunders R. W. , and Parker D. E. , 2012: Understanding intersatellite biases of microwave humidity sounders using global simultaneous nadir overpasses. J. Geophys. Res., 117, D02305, doi:10.1029/2011JD016349.

    • Search Google Scholar
    • Export Citation
  • John, V. O., Allan R. P. , Bell W. , Buehler S. A. , and Kottayil A. , 2013a: Assessment of intercalibration methods for satellite microwave humidity sounders. J. Geophys. Res. Atmos., 118, 4906–4918, doi:10.1002/jgrd.50358.

    • Search Google Scholar
    • Export Citation
  • John, V. O., Holl G. , Atkinson N. , and Buehler S. A. , 2013b: Monitoring scan asymmetry of microwave humidity sounding channels using simultaneous all angle collocations (SAACs). J. Geophys. Res. Atmos., 118, 1536–1545, doi:10.1002/jgrd.50154.

    • Search Google Scholar
    • Export Citation
  • Kleespies, T. J., and Watts P. , 2006: Comparison of simulated radiances, Jacobians and linear error analysis for the Microwave Humidity Sounder and the Advanced Microwave Sounding Unit-B. Quart. J. Roy. Meteor. Soc., 132, 30013010.

    • Search Google Scholar
    • Export Citation
  • Mears, C. A., and Wentz F. J. , 2009: Construction of the Remote Sensing Systems V3.2 atmospheric temperature records from the MSU and AMSU microwave sounders. J. Atmos. Oceanic Technol., 26, 10401056.

    • Search Google Scholar
    • Export Citation
  • Mears, C. A., Schabel M. C. , and Wentz F. J. , 2003: A reanalysis of the MSU channel 2 tropospheric temperature record. J. Climate, 16, 36503664.

    • Search Google Scholar
    • Export Citation
  • Paltridge, G., Arking A. , and Pook M. , 2009: Trends in middle- and upper-level tropospheric humidity from NCEP reanalysis data. Theor. Appl. Climatol., 98, 351359.

    • Search Google Scholar
    • Export Citation
  • Schröder, M., König M. , and Schmetz J. , 2009: Deep convection observed by the Spinning Enhanced Visible and Infrared Imager on board Meteosat 8: Spatial distribution and temporal evolution over Africa in summer and winter 2006. J. Geophys. Res., 114, D05109, doi:10.1029/2008JD010653.

    • Search Google Scholar
    • Export Citation
  • Sherwood, S. C., Roca R. , Weckwerth T. M. , and Andronova N. G. , 2010: Tropospheric water vapor, convection, and climate. Rev. Geophys., 48, RG2001, doi:10.1029/2009RG000301.

    • Search Google Scholar
    • Export Citation
  • Shi, L., and Bates J. J. , 2011: Three decades of intersatellite-calibrated High-Resolution Infrared Radiation Sounder upper tropospheric water vapor. J. Geophys. Res., 116, D04108, doi:10.1029/2010JD014847.

    • Search Google Scholar
    • Export Citation
  • Shi, L., Bates J. J. , and Cao C. , 2008: Scene radiance-dependent intersatellite biases of HIRS longwave channels. J. Atmos. Oceanic Technol., 25, 22192229.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., 2000: The diurnal cycle of convection, clouds, and water vapor in the tropical upper troposphere. Geophys. Res. Lett., 27, 21732176.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., and Bretherton F. P. , 1993: Upper tropospheric relative humidity from the GOES 6.7 μm channel: Method and climatology for July 1987. J. Geophys. Res., 98 (D9), 16 66916 688.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., and Bretherton F. P. , 1996: Interpretation of TOVS water vapor radiances in terms of layer-average relative humidities: Method and climatology for the upper, middle, and lower troposphere. J. Geophys. Res., 101 (D5), 93339343, doi:10.1029/96JD00280.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., Jackson D. L. , Ramaswamy V. , Schwarzkopf M. D. , and Huang X. , 2005: The radiative signature of upper tropospheric moistening. Science, 310, 841844.

    • Search Google Scholar
    • Export Citation
  • Sohn, B.-J., and Bennartz R. , 2008: Contribution of water vapor to observational estimates of longwave cloud radiative forcing. J. Geophys. Res., 113, D20107, doi:10.1029/2008JD010053.

    • Search Google Scholar
    • Export Citation
  • Tian, B., Soden B. J. , and Wu X. , 2004: Diurnal cycle of convection, clouds, and water vapor in the tropical upper troposphere: Satellite versus a general circulation model. J. Geophys. Res., 109, D10101, doi:10.1029/2003JD004117.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., Stepaniak D. P. , Hurrell J. W. , and Fiorino M. , 2001: Quality of reanalyses in the tropics. J. Climate, 14, 14991510.

    • Search Google Scholar
    • Export Citation
  • Uppala, S., and Coauthors, 2008: Towards a climate data assimilation system: Status update of ERA-Interim. ECMWF Newsletter, No. 115, ECMWF, Reading, United Kingdom, 12–18.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 5 5 5
PDF Downloads 3 3 3

Intercalibrating Microwave Satellite Observations for Monitoring Long-Term Variations in Upper- and Midtropospheric Water Vapor

View More View Less
  • 1 Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida
  • | 2 Met Office Hadley Centre, Exeter, United Kingdom
Restricted access

Abstract

This paper analyzes the growing archive of 183-GHz water vapor absorption band measurements from the Advanced Microwave Sounding Unit B (AMSU-B) and Microwave Humidity Sounder (MHS) on board polar-orbiting satellites and document adjustments necessary to use the data for long-term climate monitoring. The water vapor channels located at 183.31 ± 1 GHz and 183.31 ± 3 GHz are sensitive to upper- and midtropospheric relative humidity and less prone to the clear-sky sampling bias than infrared measurements, making them a valuable but underutilized source of information on free-tropospheric water vapor. A method for the limb correction of the satellite viewing angle based upon a simplified model of radiative transfer is introduced to remove the scan angle dependence of the radiances. Biases due to the difference in local observation time between satellites and spurious trends associated with satellite orbital drift are then diagnosed and adjusted for using synthetic radiative simulations based on the Interim European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim). The adjusted, cloud-filtered, and limb-corrected brightness temperatures are then intercalibrated using zonal-mean brightness temperature differences. It is found that these correction procedures significantly improve consistency and quantitative agreement between microwave radiometric satellite observations that can be used to monitor upper- and midtropospheric water vapor. The resulting radiances are converted to estimates of the deep-layer-mean upper- and midtropospheric relative humidity, and can be used to evaluate trends in upper-tropospheric relative humidity from reanalysis datasets and coupled ocean–atmosphere models.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JTECH-D-13-00001.s1.

Corresponding author address: Eui-Seok Chung, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149. E-mail: echung@rsmas.miami.edu

Abstract

This paper analyzes the growing archive of 183-GHz water vapor absorption band measurements from the Advanced Microwave Sounding Unit B (AMSU-B) and Microwave Humidity Sounder (MHS) on board polar-orbiting satellites and document adjustments necessary to use the data for long-term climate monitoring. The water vapor channels located at 183.31 ± 1 GHz and 183.31 ± 3 GHz are sensitive to upper- and midtropospheric relative humidity and less prone to the clear-sky sampling bias than infrared measurements, making them a valuable but underutilized source of information on free-tropospheric water vapor. A method for the limb correction of the satellite viewing angle based upon a simplified model of radiative transfer is introduced to remove the scan angle dependence of the radiances. Biases due to the difference in local observation time between satellites and spurious trends associated with satellite orbital drift are then diagnosed and adjusted for using synthetic radiative simulations based on the Interim European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim). The adjusted, cloud-filtered, and limb-corrected brightness temperatures are then intercalibrated using zonal-mean brightness temperature differences. It is found that these correction procedures significantly improve consistency and quantitative agreement between microwave radiometric satellite observations that can be used to monitor upper- and midtropospheric water vapor. The resulting radiances are converted to estimates of the deep-layer-mean upper- and midtropospheric relative humidity, and can be used to evaluate trends in upper-tropospheric relative humidity from reanalysis datasets and coupled ocean–atmosphere models.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JTECH-D-13-00001.s1.

Corresponding author address: Eui-Seok Chung, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149. E-mail: echung@rsmas.miami.edu
Save