Abstract HTML Views: 607 PDF Downloads: 210 Total Views/Downloads: 991
Abstract HTML Views: 400 PDF Downloads: 169 Total Views/Downloads: 684
Long-term wind and turbulence profiles were analyzed for all stability conditions at three tall, multi-level towers
located at the Los Alamos National Laboratory (LANL), Rocky Flats Environmental Plant (RF), and the Boulder Atmospheric
Observatory (BAO). The LANL and RF sites are located in complex terrain and the BAO is located over relatively
simple terrain, but within 3 to 5 km of an abrupt 20 to 30 m increase in terrain. Results indicate that normalized turbulence
parameter profiles at all three sites agree well with widely used empirical relationships during unstable conditions.
During near neutral conditions, σu parameter profiles are also well behaved at all three sites while σw increases with
height for complex fetch (BAO downwind of bluff, LANL, and RF) while σw remains nearly constant up to 200 m AGL
at BAO with simple fetch. The σw /u* values at 10-m AGL are close to one at all sites and they increase by an order of
50% in the lowest 60 to 200 m for complex fetch and remain approximately constant in the lowest 200 m with simple
During very stable conditions, typical values of σu and σ v range between 0.4 to 0.6 ms-1 and increase slightly with
height while median σw values nearly double from about 0.1 to 0.2 ms-1 between the 10- and 100 to 200-m levels. A
comparison of predicted with measured u* values at two of the sites shows generally good agreement over 6 stability categories.
It is suggested that M-O similarity theory will usually greatly underestimate vertical diffusivity and dispersion during
very stable conditions, especially at larger heights, based on idealized Kz profiles calculated from measured σw values.
Finally, rules of thumb are formulated to describe departure from similarity theory during near-neutral and stable