Shapes of annual frequency distributions of wind speed observed on high meteorological masts

Abstract

Annual wind distributions from six masts are used to investigate the annual variability of hourly-average wind. A variability extremum occurs at the height where the average diurnal cycle of wind reverses its phase from a nocturnal minimum to a nocturnal maximum. A simple profile model shows that in non-complex terrain, this reversal height varies approximately between 50 m at coasts and 90 m inland. The Weibull distribution shape factor k has a maximum at the reversal height, and with decreasing height, k decreases approximately as a linear function of height. Therefore estimation of wind distribution shape from surface data is possible in the surface layer. In the upper PBL, however, such estimation is not very feasible, because no simple methods are available to estimate the reversal height from routine surface observations.

Resolving Nonstationary Spectral Information in Wind Speed Time Series Using the Hilbert–Huang Transform

“…In summer, a midday minimum in wind speed is observed, which is likely to be part of the observed pattern, where a midday maximum in surface wind speed is accompanied by a minimum in wind speed just above the surface as the wind profile adjusts to the daytime heating and destabilizes (Holtslag 1984;Wieringa 1989). It is interesting to note that a minimum in wind variability lags the minimum in wind speed by around 3 h. This may occur once the surface heating has existed long enough for the layer of surface air to become well mixed; in this case, turbulence will be at a maximum but larger-scale fluctuations may be equalized by the increasingly even distribution of momentum.…”

A comparative study of field measurements of the turbulence characteristics of typhoon and hurricane winds

“…For brevity, the structure system and the setups of towers will not specify for other towers in the following parts. The effects of flow distorted by the mast is insignificant (Britter et al, 1979;Wieringa, 1989;Kaimal and Finnigan, 1994). The wind speed range of the WindMaster ™ Pro anemometer is between 0 and 65 m/s with the resolution of 0.01 m/s and the accuracy of smaller than 1.5% of RMS at 12 m/s.…”

Regime Transitions in Near-Surface Temperature Inversions: A Conceptual Model

“…At intermediate heights (some decameters above the surface), a ''crossing level'' exists where the wind remains relatively constant in magnitude. At Cabauw, wind speeds are relatively constant at levels between 40 and 60 m above the ground [a climatology is provided in VH15 and in Wieringa (1989)]. In the following we assume the wind speed to be constant during the night at z r .…”