Boundary-Layer Meteorology

, Volume 163, Issue 3, pp 497–522

Inversion Build-Up and Cold-Air Outflow in a Small Alpine Sinkhole

  • Manuela Lehner
  • C. David Whiteman
  • Manfred Dorninger
Research Article

DOI: 10.1007/s10546-017-0232-7

Cite this article as:
Lehner, M., Whiteman, C.D. & Dorninger, M. Boundary-Layer Meteorol (2017) 163: 497. doi:10.1007/s10546-017-0232-7
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Abstract

Semi-idealized model simulations are made of the nocturnal cold-air pool development in the approximately 1-km wide and 100–200-m deep Grünloch basin, Austria. The simulations show qualitatively good agreement with vertical temperature and wind profiles and surface measurements collected during a meteorological field expedition. A two-layer stable atmosphere forms in the basin, with a very strong inversion in the lowest part, below the approximate height of the lowest gap in the surrounding orography. The upper part of the stable layer is less strongly stratified and extends to the approximate height of the second-lowest gap. The basin atmosphere cools most strongly during the first few hours of the night, after which temperatures decrease only slowly. An outflow of air forms through the lowest gap in the surrounding orography. The outflow connects with a weak inflow of air through a gap on the opposite sidewall, forming a vertically and horizontally confined jet over the basin. Basin cooling shows strong sensitivity to surface-layer characteristics, highlighting the large impact of variations in vegetation and soil cover on cold-air pool development, as well as the importance of surface-layer parametrization in numerical simulations of cold-air-pool development.

Keywords

Basin meteorology Cold-air pools Katabatic winds Numerical modelling 

Copyright information

© Springer Science+Business Media Dordrecht 2017

Authors and Affiliations

  1. 1.Department of Atmospheric SciencesUniversity of UtahSalt Lake CityUSA
  2. 2.Institute of Atmospheric and Cryospheric SciencesUniversity of InnsbruckInnsbruckAustria
  3. 3.Department of Meteorology and GeophysicsUniversity of ViennaViennaAustria

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