Modeling of Cloud-Top Entrainment

Abstract

Our long term goals are to understand the dynamics of atmospheric motions on scales of order 10 m - 10 km in sufficient detail to be able to provide a consistent subgrid scale turbulent closure for models across a range of scales, and to be able to utilize simulated variances as a measure of forecast predictability. Boundary layer entrainment is a critical, much studied, yet relatively poorly understood element of the dynamics of the atmospheric boundary layer. The entrainment fluxes of heat and moisture across the capping inversion strongly affect both the dynamics and cloud structure within the boundary layer. The chief objective of the present grant is to better understand the physical processes which control the rate of this entrainment, and to formulate a closure model for cloud-top entrainment that is consistent for a broad range of boundary layer conditions and forcings. Ideally, this closure model would allow one to produce a simulation at any desired level of resolution, with the results of lower resolution simulations being approximately similar to results obtained by appropriate spatial filtering of the higher resolution simulation.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1998
Accession Number
ADA542598

Entities

People

  • David C. Lewellen
  • W. S. Lewellen

Organizations

  • West Virginia University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Atmospheric Motion
  • Atmospheric Sciences
  • Boundaries
  • Boundary Layer
  • Climate Change
  • Dynamics
  • Electronic Mail
  • Entrainment
  • Heat Energy
  • Heat Flux
  • Heat Transfer
  • High Resolution
  • Inversion
  • Latent Heat
  • Layers
  • Turbulence
  • West Virginia

Fields of Study

  • Environmental science

Readers

  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers