An evaluation of a solar radiation/delta-T method for estimating Pasquill-Gifford (P-G) stability categories

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:28719

Coulter, C T ^[1]

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1. Environmental Protection Agency, Research Triangle Park, NC (United States)

There has been a continuing need to develop robust methods for determining Pasquill-Gifford (P-G) stability categories using solely on-site meteorological instrumentation. The Revised EPA Guideline on Air Quality Models recommends several such methods. Experience with these suggests that, since they rely on turbulence measurements, they can be unduly influenced by local effects such as mesoscale circulation (e.g., upslope/downslope flows, land/sea breeze), wakes from tree barriers or buildings, etc. to such an extent as to diminish their practical usefulness. In the following discussion, a methodology is proposed for estimating P-G stability categories that employs on-site meteorological measurements (10m wind speed coupled with solar radiation during the day and temperature difference, {Delta}T, at night) in lieu of cloud cover and ceiling height observations. The proposed method was adapted from Bowen and is herein referred to as the solar radiation/delta-T (SRDT) method. To evaluate the method, an attempt was made to acquire data bases from diverse geographical areas. Data bases with {Delta}T measurements from 2-10m above ground level were of primary interest for characterizing the boundary layer; other intervals were considered for evaluation, as available. To document the consequence of implementing the method in practical applications, an analysis was needed of the effect on design concentration ratios.

• OSTI ID: 28719
• Report Number(s): CONF-940115--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR QUALITY
CLIMATE MODELS
EARTH ATMOSPHERE
METEOROLOGY
SOLAR RADIATION
STABILITY
THERMODYNAMICS
TURBULENCE
WIND