Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Importance of Using Observations of Mixing Depths in order to Avoid Large Prediction Errors by a Transport and Dispersion Model

Importance of Using Observations of Mixing Depths in order to Avoid Large Prediction Errors by a... The mixing depth of the boundary layer is an input to most atmospheric transport and dispersion (ATD) models, which obtain mixing depths in one of four ways: 1) observations by radiosondes, sodars, or other devices; 2) simulations by regional or mesoscale meteorological models; 3) parameterizations based on boundary layer similarity theory; or 4) climatological averages. This paper describes a situation during a field experiment when exceptionally low mixing depths persisted in the morning and led to relatively high observed tracer concentrations. The low mixing depths were caused by synoptic effects associated with a nearby stationary front and the outflow from a mesoscale thunderstorm complex located 20–50 km away. For the same time period, the ATD model-parameterized mixing depth was a factor of 5–10 higher, leading to predicted concentrations that were less than the observations by a factor of 5–10. The synoptic situation is described and local radiosonde and radar observations of mixing depth are presented, including comparisons with other more typical days. Time series of local observations of near-surface sensible heat fluxes are also plotted to demonstrate the suppression of turbulence by negative sensible heat fluxes during the period in question. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Atmospheric and Oceanic Technology American Meteorological Society

Importance of Using Observations of Mixing Depths in order to Avoid Large Prediction Errors by a Transport and Dispersion Model

Download PDF
11 pages

Loading next page...
 
/lp/american-meteorological-society/importance-of-using-observations-of-mixing-depths-in-order-to-avoid-r7CUz1THAR

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
American Meteorological Society
Copyright
Copyright © 2008 American Meteorological Society
ISSN
1520-0426
DOI
10.1175/2008JTECHA1134.1
Publisher site
See Article on Publisher Site

Abstract

The mixing depth of the boundary layer is an input to most atmospheric transport and dispersion (ATD) models, which obtain mixing depths in one of four ways: 1) observations by radiosondes, sodars, or other devices; 2) simulations by regional or mesoscale meteorological models; 3) parameterizations based on boundary layer similarity theory; or 4) climatological averages. This paper describes a situation during a field experiment when exceptionally low mixing depths persisted in the morning and led to relatively high observed tracer concentrations. The low mixing depths were caused by synoptic effects associated with a nearby stationary front and the outflow from a mesoscale thunderstorm complex located 20–50 km away. For the same time period, the ATD model-parameterized mixing depth was a factor of 5–10 higher, leading to predicted concentrations that were less than the observations by a factor of 5–10. The synoptic situation is described and local radiosonde and radar observations of mixing depth are presented, including comparisons with other more typical days. Time series of local observations of near-surface sensible heat fluxes are also plotted to demonstrate the suppression of turbulence by negative sensible heat fluxes during the period in question.

Journal

Journal of Atmospheric and Oceanic Technology – American Meteorological Society

Published: Mar 10, 2008

References

  • Overview of Joint Urban 2003—An atmospheric dispersion study in Oklahoma City.
    Allwine
  • Evaluation of the NCEP mesoscale Eta Model convective boundary layer for air quality applications.
    Angevine
  • Boundary-layer depth and entrainment zone characterization with a boundary-layer profiler.
    Angevine
  • Air Pollution Meteorology and Dispersion.
    Arya
  • Convective boundary layer depth: Improved measurement by Doppler radar wind profiler using fuzzy logic methods.
    Bianco
  • Joint Urban 2003 (JU2003) SF6 atmospheric tracer field tests.
    Clawson
  • Boundary layer height and entrainment zone thickness measured by lidars and wind profiling radars.
    Cohn
  • HPAC Version 4.04.04.
    DTRA
  • User’s guide for the AERMOD Meteorological Preprocessor (AERMET).
    EPA
  • Analysis of the evolution of an urban boundary layer as detected by a frequency modulated-continuous wave radar.
    Gallagher
  • Use of a large crane for wind and tracer profiles in an urban setting.
    Gouveia
  • Evaluation of the HPAC dispersion model with the Joint Urban 2003 (JU2003) tracer observations.
    Hanna
  • Observed winds, turbulence, and dispersion in built-up downtown areas of Oklahoma City and Manhattan.
    Hanna
  • Verification of a mesoscale data assimilation and forecasting system for the Oklahoma City area during the Joint Urban 2003 field project.
    Liu
  • Observations of turbulent kinetic energy dissipation rate in the urban environment.
    Lundquist
  • SCIPUFF version 2.3.
    Sykes
  • Comparisons of transport and dispersion model predictions of the Joint Urban 2003 field experiment.
    Warner
  • Sonic anemometer tilt correction algorithms.
    Wilczak