• Albrecht, B., and S. K. Cox, 1977: Procedures for improving pyrgeometer performance. J. Appl. Meteor., 16 , 188197.

  • Caughey, S. J., J. C. Wyngaard, and J. C. Kaimal, 1979: Turbulence in the evolving stable boundary layer. J. Atmos. Sci., 36 , 10411052.

    • Search Google Scholar
    • Export Citation
  • Cerni, T. A., and T. R. Parish, 1984: A radiative model of the stable nocturnal boundary layer with application to the polar night. J. Climate Appl. Meteor., 23 , 15631572.

    • Search Google Scholar
    • Export Citation
  • Fleagle, R. G., 1953: A theory of fog formation. J. Mar. Res., 12 , 4350.

  • Forrer, J., and M. W. Rotach, 1997: On the turbulence structure in the stable boundary layer over the Greenland ice sheet. Bound.-Layer Meteor., 85 , 111136.

    • Search Google Scholar
    • Export Citation
  • Funk, J. P., 1960: Measured radiative flux divergence near the ground at night. Quart. J. Roy. Meteor. Soc., 86 , 382389.

  • Funk, J. P., 1962: Radiative flux divergence in radiation fog. Quart. J. Roy. Meteor. Soc., 88 , 233248.

  • Garratt, J. R., and R. A. Brost, 1981: Radiative cooling effects within and above the nocturnal boundary layer. J. Atmos. Sci., 38 , 27302746.

    • Search Google Scholar
    • Export Citation
  • Kondratyev, K. Ya, 1969: Radiation in the Atmosphere. International Geophysics Series, Vol. 12, Academic Press, 912 pp.

  • Kraus, H., 1958: Untersuchungen über den nächtlichen energietransport und energiehaushalt in der bodennahen luftschicht bei der bildung von strahlungsnebeln. Ber. Dtsch. Wetterdienstes, 7 , 125.

    • Search Google Scholar
    • Export Citation
  • Lieske, B. J., and L. A. Stroschein, 1967: Measurements of radiative flux divergence in the Arctic. Arch. Meteorol. Geophys. Bioklimatol., 15B , 6781.

    • Search Google Scholar
    • Export Citation
  • Long, C. N., and T. P. Ackerman, 2000: Identification of clear skies from broadband pyranometer measurements and calculation of downwelling shortwave cloud effects. J. Geophys. Res., 105 , 1560915626.

    • Search Google Scholar
    • Export Citation
  • Marty, C., 2000: Surface radiation, cloud forcing and greenhouse effect in the Alps. Ph.D. thesis, Swiss Federal Institute of Technology ETH, 11 pp.

  • Marty, C., R. Philipona, J. Delamere, E. G. Dutton, J. Michalsky, K. Stamnes, R. Storvold, T. Stoffel, S. A. Clough, and E. J. Mlawer, 2003: Downward longwave irradiance uncertainty under arctic atmospheres: Measurements and modeling. J. Geophys. Res., 108 .4358, doi:10.1029/2002JD002937.

    • Search Google Scholar
    • Export Citation
  • Nieuwstadt, F. T. M., 1984: The turbulent structure of the stable, nocturnal boundary layer. J. Atmos. Sci., 41 , 22022216.

  • Parish, T. R., and D. H. Bromwich, 1986: The inversion wind pattern over West Antarctica. Mon. Wea. Rev., 114 , 849860.

  • Philipona, R., C. Fröhlich, and C. Betz, 1995: Characterization of pyrgeometers and the accuracy of atmospheric long-wave radiation measurements. Appl. Opt., 34 , 15981605.

    • Search Google Scholar
    • Export Citation
  • Philipona, R., and Coauthors, 2001: Atmospheric longwave irradiance uncertainty: Pyrgeometers compared to an absolute sky-scanning radiometer, atmospheric emitted radiance interferometer, and radiative transfer model calculations. J. Geophys. Res., 106 , 2812928141.

    • Search Google Scholar
    • Export Citation
  • Sala, A., 1986: Radiant Properties of Materials: Tables of Radiant Values for Black Body and Real Materials. Elsevier, 479 pp.

  • Stull, R. B., 1988: An Introduction to Boundary Layer Meteorology. Kluwer Academic, 666 pp.

  • Sun, J., S. P. Burns, A. C. Delany, S. P. Oncley, T. W. Horst, and D. H. Lenschow, 2003: Heat balance in the nocturnal boundary layer during CASES-99. J. Appl. Meteor., 42 , 16491666.

    • Search Google Scholar
    • Export Citation
  • Timanovskaya, R. G., and G. P. Faraponova, 1967: Measurement of the radiative heat influx in the atmospheric ground layer. Izv. Acad. Sci. USSR, Atmos. Oceanic, 3 , 12591270.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 195 99 0
PDF Downloads 122 55 0

Year-Round Observation of Longwave Radiative Flux Divergence in Greenland

View More View Less
  • 1 Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
  • | 2 Physikalisch-Meteorologisches Observatorium Davos, and World Radiation Center, Davos Dorf, Switzerland
  • | 3 Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Restricted access

Abstract

Longwave radiative flux divergence within the lowest 50 m of the atmospheric boundary layer was observed during the Eidgenössische Technische Hochschule (ETH) Greenland Summit experiment. The dataset collected at 72°35′N, 38°30′W, 3203 m MSL is based on longwave radiation measurements at 2 and 48 m that are corrected for the influence of the supporting tower structure. The observations cover all seasons and reveal the magnitude of longwave radiative flux divergence and its incoming and outgoing component under stable and unstable conditions. Longwave radiative flux divergence during winter corresponds to a radiative cooling of −10 K day−1, but values of −30 K day−1 can persist for several days. During summer, the mean cooling effect of longwave radiative flux divergence is small (−2 K day−1) but exhibits a strong diurnal cycle. With values ranging from −35 K day−1 around midnight to 15 K day−1 at noon, the heating rate due to longwave radiative flux divergence is of the same order of magnitude as the observed temperature tendency. However, temperature tendency and longwave radiative flux divergence are out of phase, with temperature tendency leading the longwave radiative flux divergence by 3 h. The vertical variation of the outgoing longwave flux usually dominates the net longwave flux divergence, showing a strong divergence at nighttime and a strong convergence during the day. The divergence of the incoming longwave flux plays a secondary role, showing a slight counteracting effect. Fog is frequently observed during summer nights. Under such conditions, a divergence of both incoming and outgoing fluxes leads to the strongest radiative cooling rates that are observed. Considering all data, a correlation between longwave radiative flux divergence and the temperature difference across the 2–48-m layer is found.

* Current affiliation: Department of Meteorology, University of Utah, Salt Lake City, Utah

Corresponding author address: S. Hoch, Department of Meteorology, University of Utah, 135 S. 1450 E., Rm. 819, Salt Lake City, UT 84112. Email: sebastian.hoch@utah.edu

Abstract

Longwave radiative flux divergence within the lowest 50 m of the atmospheric boundary layer was observed during the Eidgenössische Technische Hochschule (ETH) Greenland Summit experiment. The dataset collected at 72°35′N, 38°30′W, 3203 m MSL is based on longwave radiation measurements at 2 and 48 m that are corrected for the influence of the supporting tower structure. The observations cover all seasons and reveal the magnitude of longwave radiative flux divergence and its incoming and outgoing component under stable and unstable conditions. Longwave radiative flux divergence during winter corresponds to a radiative cooling of −10 K day−1, but values of −30 K day−1 can persist for several days. During summer, the mean cooling effect of longwave radiative flux divergence is small (−2 K day−1) but exhibits a strong diurnal cycle. With values ranging from −35 K day−1 around midnight to 15 K day−1 at noon, the heating rate due to longwave radiative flux divergence is of the same order of magnitude as the observed temperature tendency. However, temperature tendency and longwave radiative flux divergence are out of phase, with temperature tendency leading the longwave radiative flux divergence by 3 h. The vertical variation of the outgoing longwave flux usually dominates the net longwave flux divergence, showing a strong divergence at nighttime and a strong convergence during the day. The divergence of the incoming longwave flux plays a secondary role, showing a slight counteracting effect. Fog is frequently observed during summer nights. Under such conditions, a divergence of both incoming and outgoing fluxes leads to the strongest radiative cooling rates that are observed. Considering all data, a correlation between longwave radiative flux divergence and the temperature difference across the 2–48-m layer is found.

* Current affiliation: Department of Meteorology, University of Utah, Salt Lake City, Utah

Corresponding author address: S. Hoch, Department of Meteorology, University of Utah, 135 S. 1450 E., Rm. 819, Salt Lake City, UT 84112. Email: sebastian.hoch@utah.edu

Save