Wind characteristics at the Boulder Atmospheric Observatory

Schotz, Steven; Panofsky, H. A.

doi:10.1007/bf00117217

Cited by 14 publications

(4 citation statements)

References 10 publications

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“…As soon as either the surface becomes rugged and inhomogeneous or one tries to apply the theory to higher levels, possibly outside the surface layer, the roughness length has to be increased from its local value to a larger value, the so-called effective roughness length (ERL) (see e.g., Fiedler and Panofsky (1972) and Schotz and Panofsky (1980) for more up-to-date measurements). The ERL depends not only on neighbouring mesoscale terrain properties.…”

Section: Introduction and Motivationsmentioning

confidence: 99%

On the effective roughness length for use in numerical three-dimensional models

André

Blondin

1986

Boundary-Layer Meteorol

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We present analytical and numerical calculations of the effective roughness length (ERL) over a flat surface with varying roughness elements, for use in large-scale models. It is shown that ERL is mostly determined by the roughest elements present inside the averaging domain and that, more surprisingly, the ERL increases as the first level of the numerical model gets closer to the surface and its altitude approaches the value of the largest local roughness length. This effect further increases the drag coefficient, in addition to the well-known increase due to the lowering of the first model level.

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Section: Introduction and Motivationsmentioning

confidence: 99%

On the effective roughness length for use in numerical three-dimensional models

André

Blondin

1986

Boundary-Layer Meteorol

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“…Wind profiles over rolling farmland (Dutton et a1. 1979, also Schotz andPanofsky 1980) tend to remain logarithmic under near-neutral conditions. However, there is some indication that the "effective" roughness length is not just a measure of ground cover, but may be increased by larger-scale topography.…”

Section: Characteristics Over Rolling Farmlandmentioning

confidence: 91%

Spectra over complex terrain in the surface layer

Panofsky¹,

Dutton²,

Larko³

et al. 1982

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This report was prepared as an account of work sponso red by an agency of the United States Government. Neither the Un ited States Govern m en t nor any agency t hereof, nor any of their employees, makes any warranty, express o r implied. o r assumes any legal li abi l ity or respo nsibi li ty for t he accuracy, completeness, or usefulness of an y i nformation, appa ratu s, prod uct, o r process disclosed, or represents that its use would no t infringe private ly owned r ights. Reference herein to an y specif ic commercial product, process, or serv ice b y trade name, t rademark , manufacturer, o~ otherwise, does not necessa rily cons t itute o r imply its endo rseme nt, recomme"da tion, or favo ri ng by the United States Government or any agency thereof. The views and o pinions o f au t hors expressed herein do not necessarily state or reflect those o f the United St ates Government or any agency thereo f.

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“…The vegetation is sparse at RF while ponderosa trees are widespread at LANL. The local terrain at BAO is simple, located in slightly rolling farmland with ground cover of wheat or wheat stubble with 0.25 to 0.5 m height [14]. The low relief, with slopes of 20 m km -1 or less, extends at least 10 km to the north, east, and south of this site.…”

Section: Description Of Sites and Instrumenta-tionmentioning

confidence: 99%

Analysis of Turbulence Profiles from Three Tall Towers: Departure from Similarity Theory in Near-Neutral and Stable Conditions

Bowen¹

2008

TOASCJ

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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 fetch. 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 conditions.

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Wind characteristics at the Boulder Atmospheric Observatory

Cited by 14 publications

References 10 publications

On the effective roughness length for use in numerical three-dimensional models

On the effective roughness length for use in numerical three-dimensional models

Spectra over complex terrain in the surface layer

Analysis of Turbulence Profiles from Three Tall Towers: Departure from Similarity Theory in Near-Neutral and Stable Conditions

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