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Boundary-Layer Meteorology

, Volume 34, Issue 4, pp 357–375 | Cite as

Lidar measurements of the atmospheric entrainment zone and the potential temperature jump across the top of the mixed layer

  • R. Boers
  • E. W. Eloranta
Article

Abstract

Lidar measurements of the thickness of the atmospheric entrainment zone are presented. The measurements were obtained in central Illinois during 6 days of clear-air convection.

A new method was developed to monitor the potential temperature jump across the entrainment zone. A single early morning temperature sounding and continuous lidar measurements of the mixed-layer height provide potential temperature jump values which agree well with in situ observations.

Lidar measurements of the thickness of the entrainment zone normalized by mixed-layer depth are presented as a function of a ‘convective’ Richardson number; these values show reasonable agreement with published laboratory results. The lidar observations span a wider range of mixed-layer depths and contain higher values of the normalized entrainment rate (dh/dt)/w* than those observed in tank studies. Both lidar and tank results show that simple parcel theory does not properly predict entrainment-zone thickness. During this experiment which examined mostly high entrainment conditions, the normalized entrainment-layer thickness was linearly dependent on entrainment rate.

Keywords

Convection Lidar Mixed Layer Richardson Number Entrainment Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© D. Reidel Publishing Company 1986

Authors and Affiliations

  • R. Boers
    • 1
  • E. W. Eloranta
    • 2
  1. 1.Laboratory for Atmospheres NASA/Goddard Space Flight CenterGreenbeltUSA
  2. 2.Department of MeteorologyMadisonUSA

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