Stability-class determination: a comparison for one site

Conference · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6533544

Bowen, B M; Dewart, J M; Chen, A I

The Pasquill method of determining stability class at a site with irregular terrain with other commonly used methods: vertical temperature difference (..lambda..T); Richardson number (Ri) and Bulk Richardson number (Ri/sub B/); and horizontal standard deviation of wind and vertical standard deviation of wind. Also, the indirect methods of measuring turbulence, such as the Pasquill method, are compared to direct measures of turbulence. The various methods for determining stability class are analyzed and compared with the Pasquill classification scheme at 2 sites with irregular terrain. The Pasquill categories were estimated objectively and compared with other stability indicators for 15-minute periods over a year. The results show that near-surface ..lambda..T distinguishes the neutral category very well. However, it does not differentiate the specific stable and unstable categories very well. Both the Ri and Ri/sub B/, indicators of both thermal and mechanical turbulence, correlate very well with and distinguish the different stability categories. Due to the irregular terrain, the various methods of determining stability may be even better indicators of turbulence and diffusion if the wind direction were taken into account. It is suggested that further study investigate the methods by wind direction.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6533544
• Report Number(s): LA-UR-82-3382; CONF-830307-6; ON: DE83003532
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
AEROSOLS
COLLOIDS
COMPARATIVE EVALUATIONS
DIFFUSION
DISPERSIONS
ENVIRONMENTAL TRANSPORT
MASS TRANSFER
MATHEMATICAL MODELS
RADIOACTIVE AEROSOLS
RADIONUCLIDE MIGRATION
SOLS
STABILITY
TOPOGRAPHY
TURBULENCE
WIND