• Beer, R., 1992: Remote Sensing by Fourier Transform Spectroscopy. Academic Press, 153 pp.

  • Cady-Pereira, K. E., Shephard M. W. , Turner D. D. , Mlawer E. J. , Clough S. A. , and Wagner T. J. , 2008: Improved daytime column-integrated precipitable water vapor from Vaisala radiosonde humidity sensors. J. Atmos. Oceanic Technol., 25 , 873883.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Clough, S. A., Shephard M. W. , Mlawer E. J. , Delamere J. S. , Iacono M. J. , Cady-Pereira K. , Boukabara S. , and Brown P. D. , 2005: Atmospheric radiative transfer modeling: A summary of the AER codes. J. Quant. Spectrosc. Radiat. Transfer, 91 , 233244.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Comstock, J. M., Ackerman T. P. , and Turner D. D. , 2004: Evidence of high ice supersaturation in cirrus clouds using ARM Raman lidar measurements. Geophys. Res. Lett., 31 .L11106, doi:10.1029/2004GL019705.

    • Search Google Scholar
    • Export Citation
  • Conway, T. J., Tans P. P. , Waterman L. S. , Thoning K. W. , Kitzis D. R. , Masarie K. A. , and Zhang N. , 1994: Evidence for interannual variability of the carbon cycle from the NOAA/CMDL global air sampling network. J. Geophys. Res., 99 , 2283122855.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dlugokencky, E. J., Walter B. P. , Masarie K. A. , Lang P. M. , and Kasischke E. S. , 2001: Measurements of an anomalous global methane increase during 1998. Geophys. Res. Lett., 28 , 499502.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ferrare, R. A., and Coauthors, 2004: Characterization of upper tropospheric water vapor measurements during AFWEX using LASE. J. Atmos. Oceanic Technol., 21 , 17901808.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gettelman, A., Walden V. P. , Miloshevich L. M. , Roth W. L. , and Halter B. , 2006: Relative humidity over Antarctica from radiosondes, satellites, and a general circulation model. J. Geophys. Res., 111 .D09S13, doi:10.1029/2005JD006636.

    • 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.

  • Hudson, S. R., Town M. S. , Walden V. P. , and Warren S. G. , 2004: Temperature, humidity, and pressure response of radiosondes at low temperatures. J. Atmos. Oceanic Technol., 21 , 825836.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jensen, E. J., and Coauthors, 2001: Prevalence of ice-supersaturated regions in the upper troposphere: Implications for optically thin ice cloud formation. J. Geophys. Res., 106 , 1725317266.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knuteson, R. O., and Coauthors, 2004a: Atmospheric Emitted Radiance Interferometer. Part I: Instrument design. J. Atmos. Oceanic Technol., 21 , 17631776.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knuteson, R. O., and Coauthors, 2004b: Atmospheric Emitted Radiance Interferometer. Part II: Instrument performance. J. Atmos. Oceanic Technol., 21 , 17771789.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McClatchey, R. A., Fenn R. W. , Selby J. E. A. , Volz F. E. , and Garing J. S. , 1972: Optical properties of the atmosphere. 3rd ed. Tech. Rep. AFCRL-72-0497, Air Force Geophysical Laboratories, 108 pp.

  • Miloshevich, L. M., Vömel H. , Paukkunen A. , Heymsfield A. J. , and Oltmans S. J. , 2001: Characterization and correction of relative humidity measurements from Vaisala RS80-A radiosondes at cold temperatures. J. Atmos. Oceanic Technol., 18 , 135156.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Miloshevich, L. M., Paukkunen A. , Vömel H. , and Oltmans S. J. , 2004: Development and validation of a time-lag correction for Vaisala radiosonde humidity measurements. J. Atmos. Oceanic Technol., 21 , 13051327.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Miloshevich, L. M., Vömel H. , Whiteman D. N. , Lesht B. M. , Schmidlin F. J. , and Russo F. , 2006: Absolute accuracy of water vapor measurements from six operational radiosonde types launched during AWEX-G and implications for AIRS validation. J. Geophys. Res., 111 .D09S10, doi:10.1029/2005JD006083.

    • Search Google Scholar
    • Export Citation
  • Paukkunen, A., Antikainen V. , and Jauhiainen H. , 2001: Accuracy and performance of the new Vaisala RS90 radiosonde in operational use. Preprints. 11th Symp. on Meteorological Observations and Instrumentation, Albuquerque, NM, Amer. Meteor. Soc., 4.5.

    • Search Google Scholar
    • Export Citation
  • Revercomb, H. E., Buijs H. , Howell H. B. , LaPorte D. D. , Smith W. L. , and Sromovsky L. A. , 1988: Radiometric calibration of IR Fourier transform spectrometers: Solution to a problem with the High-Resolution Interferometer Sounder. Appl. Opt., 27 , 32103218.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rothman, L. S., and Coauthors, 2005: The HITRAN 2004 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transfer, 96 , 139204.

  • Rowe, P. M., 2004: Measurements of the foreign-broadened continuum of water vapor in the 6.3-micron band at −30° Celsius. Ph.D. thesis, University of Washington, 278 pp.

  • Rowe, P. M., Walden V. P. , and Warren S. G. , 2006: Measurements of the foreign-broadened continuum of water vapor in the 6.3-μm band at −30°C. Appl. Opt., 45 , 43664382.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sinha, A., and Harries J. E. , 1995: Water vapour and greenhouse trapping: The role of far infrared absorption. Geophys. Res. Lett., 22 , 21472150.

  • Tobin, D. C., and Coauthors, 1999: Downwelling spectral radiance observations at the SHEBA ice station: Water vapor continuum measurements from 17 to 26 μm. J. Geophys. Res., 104 , D2. 20812092.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Turner, D. D., Lesht B. M. , Clough S. A. , Liljegren J. C. , Revercomb H. E. , and Tobin D. C. , 2003: Dry bias and variability in Vaisala RS80-H radiosondes: The ARM experience. J. Atmos. Oceanic Technol., 20 , 117132.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Turner, D. D., and Coauthors, 2004: The QME AERI LBLRTM: A closure experiment for downwelling high spectral resolution infrared radiance. J. Atmos. Sci., 61 , 26572675.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Twomey, S., 1977: Introduction to the Mathematics of Inversion in Remote Sensing and Indirect Measurements. Elsevier, 243 pp.

  • Vömel, H., and Coauthors, 2007: Radiation dry bias of the Vaisala RS92 humidity sensor. J. Atmos. Oceanic Technol., 24 , 953963.

  • Walden, V. P., Warren S. G. , and Murcray F. J. , 1998: Measurements of the downward longwave radiation spectrum over the Antarctic Plateau and comparisons to a line-by-line radiative transfer model for clear skies. J. Geophys. Res., 103 , 38253846.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Walden, V. P., Town M. S. , Halter B. , and Storey J. W. V. , 2005: First measurements of the infrared sky brightness at Dome C, Antarctica. Publ. Astron. Soc. Pacific, 117 , 300308.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Walden, V. P., Roth W. L. , Stone R. S. , and Halter B. , 2006: Radiometric validation of the Atmospheric Infrared Sounder over the Antarctic Plateau. J. Geophys. Res., 111 .D09S03, doi:10.1029/2005JD006357.

    • Search Google Scholar
    • Export Citation
  • Wang, J., Cole H. L. , Carlson D. J. , Miller E. R. , Beierle K. , Paukkunen A. , and Laine T. K. , 2002: Corrections of humidity measurement errors from the Vaisala RS80 radiosonde: Application to TOGA COARE data. J. Atmos. Oceanic Technol., 19 , 9811002.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 141 84 4
PDF Downloads 77 41 1

Dry Bias in Vaisala RS90 Radiosonde Humidity Profiles over Antarctica

View More View Less
  • 1 Department of Geography, University of Idaho, Moscow, Idaho
  • | 2 National Center for Atmospheric Research, Boulder, Colorado
  • | 3 University of Wisconsin—Madison, Madison, Wisconsin
  • | 4 Department of Geography, University of Idaho, Moscow, Idaho
Restricted access

Abstract

Middle to upper tropospheric humidity plays a large role in determining terrestrial outgoing longwave radiation. Much work has gone into improving the accuracy of humidity measurements made by radiosondes. Some radiosonde humidity sensors experience a dry bias caused by solar heating. During the austral summers of 2002/03 and 2003/04 at Dome C, Antarctica, Vaisala RS90 radiosondes were launched in clear skies at solar zenith angles (SZAs) near 83° and 62°. As part of this field experiment, the Polar Atmospheric Emitted Radiance Interferometer (PAERI) measured downwelling spectral infrared radiance. The radiosonde humidity profiles are used in the simulation of the downwelling radiances. The radiosonde dry bias is then determined by scaling the humidity profile with a height-independent factor to obtain the best agreement between the measured and simulated radiances in microwindows between strong water vapor lines from 530 to 560 cm−1 and near line centers from 1100 to 1300 cm−1. The dry biases, as relative errors in relative humidity, are 8% ± 5% (microwindows; 1σ) and 9% ± 3% (line centers) for SZAs near 83°; they are 20% ± 6% and 24% ± 5% for SZAs near 62°. Assuming solar heating is minimal at SZAs near 83°, the authors remove errors that are unrelated to solar heating and find the solar-radiation dry bias of 9 RS90 radiosondes at SZAs near 62° to be 12% ± 6% (microwindows) and 15% ± 5% (line centers). Systematic errors in the correction are estimated to be 3% and 2% for microwindows and line centers, respectively. These corrections apply to atmospheric pressures between 650 and 200 mb.

Corresponding author address: Penny M. Rowe, 1515 N. Prospect St., Tacoma, WA 98406. Email: prowe@harbornet.com

Abstract

Middle to upper tropospheric humidity plays a large role in determining terrestrial outgoing longwave radiation. Much work has gone into improving the accuracy of humidity measurements made by radiosondes. Some radiosonde humidity sensors experience a dry bias caused by solar heating. During the austral summers of 2002/03 and 2003/04 at Dome C, Antarctica, Vaisala RS90 radiosondes were launched in clear skies at solar zenith angles (SZAs) near 83° and 62°. As part of this field experiment, the Polar Atmospheric Emitted Radiance Interferometer (PAERI) measured downwelling spectral infrared radiance. The radiosonde humidity profiles are used in the simulation of the downwelling radiances. The radiosonde dry bias is then determined by scaling the humidity profile with a height-independent factor to obtain the best agreement between the measured and simulated radiances in microwindows between strong water vapor lines from 530 to 560 cm−1 and near line centers from 1100 to 1300 cm−1. The dry biases, as relative errors in relative humidity, are 8% ± 5% (microwindows; 1σ) and 9% ± 3% (line centers) for SZAs near 83°; they are 20% ± 6% and 24% ± 5% for SZAs near 62°. Assuming solar heating is minimal at SZAs near 83°, the authors remove errors that are unrelated to solar heating and find the solar-radiation dry bias of 9 RS90 radiosondes at SZAs near 62° to be 12% ± 6% (microwindows) and 15% ± 5% (line centers). Systematic errors in the correction are estimated to be 3% and 2% for microwindows and line centers, respectively. These corrections apply to atmospheric pressures between 650 and 200 mb.

Corresponding author address: Penny M. Rowe, 1515 N. Prospect St., Tacoma, WA 98406. Email: prowe@harbornet.com

Save