Atmospheric dispersion in mountain valleys and basins

Technical Report · Wed Jan 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/5814419· OSTI ID:5814419

Allwine, K J

The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ventilation rate'' of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

• Research Organization: Pacific Northwest Lab., Richland, WA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5814419
• Report Number(s): PNL-7922; ASCOT--91-8; ON: DE92006635
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
540210 -- Environment
Terrestrial-- Basic Studies-- (1990-)
58 GEOSCIENCES
580000 -- Geosciences
AIR FLOW
AIR POLLUTION
ATMOSPHERIC CIRCULATION
CLIMATE MODELS
CLIMATES
COMPILED DATA
COMPLEX TERRAIN
DAILY VARIATIONS
DATA
DISPERSIONS
FLOW MODELS
FLUID FLOW
GAS FLOW
INFORMATION
MATHEMATICAL MODELS
METEOROLOGY
MICROCLIMATES
MOUNTAINS
NUMERICAL DATA
POLLUTION
TEMPERATURE INVERSIONS
TOPOGRAPHY
VALLEYS
VARIATIONS
VENTILATION