Record Display for the EPA National Library Catalog


Main Title Characteristics of Vertical Turbulent Velocities in the Urban Convective Boundary Layer.
Author Godowitch, J. M. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.
Year Published 1986
Report Number EPA/600/J-86/354;
Stock Number PB87-196515
Additional Subjects Air masses ; Meteorology ; Turbulent boundary layer ; Statistical analysis ; Urban areas ; Velocity ; Convection ; Air pollution ; Reprints ; CBL(Convective Boundary Layer) ; St Louis(Missouri)
Library Call Number Additional Info Location Last
NTIS  PB87-196515 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 23p
Time series of vertical velocity fluctuations from horizontal aircraft flight segments made in the lower part of and near the middle of the convective boundary layer (CBL) over St. Louis, Missouri, and surrounding region were subjected to various statistical and objective analyses. The higher order vertical velocity moments, and positive and negative velocity statistics, were computed. The horizontal dimensions of updrafts and downdrafts, and related properties of these turbulent eddies were derived by conditional sampling analysis. Statistical results show that the means and standard deviations of positive and negative velocity fluctuations were greater over the urban area. The urban vertical velocity variance was 50% greater than rural values, and power spectra revealed greater production of vertical turbulent energy in the urban area over a wide frequency range. Convective similarity scaling parameters appeared to order both the urban and rural measurements.