Exam 3 Flashcards
stability class
classifies atmospheric conditions depending on wind speed and quantity of daylight
dispersion coefficient
represent the standard deviations of the concentration in the downwind, crosswind, and vertical directions
convective boundary layer conditions
A, B, C,D
stable boundary layer conditions
D, E, F
what does stability class indicate? Why is it important?
stability class indicates how turbulent the atmosphere is. it’s important because
what time of day can stable atmospheric conditions typically occur?
Night
what is the difference between unstable, neutral, and stable atmospheric conditions, particularly with regard to the level of mixing in the atmosphere?
unstable conditions have the most mixing, while stable conditions have the least mixing
what is surface roughness? how is the surface roughness related to the mean obstacle height?
surface roughness represents the obstacles that can affect wind speed. Since height affects
what causes plume meander?
meander occurs when the atmospheric conditions have been altered, if there is surface roughness, or if the wind varies in direction and/or speed. Meander only affects plumes, but not puffs position
all other things being equal, how is the concentration of a passive contaminant at a given location related to the mass release rate?
higher release rate will cause a higher concentration at a given time
all other things being equal, how is the concentration of a passive contaminant at a given location related to the wind speed?
plume: wind speed and concentration are inversely proportional
all other things being equal, how is the concentration of a passive contaminant at a given location related to the atmospheric stability?
higher stability (A to F) correlates to higher concentration
how are passive atmospheric dispersion coefficients related to atmospheric stability? For increased atmospheric stability, do dispersion coefficients increase or decrease?
higher stable classes correlates to lower dispersion coefficients.
