Determine Wind Frequency Distributions Through the Surface Layer of Baghdad City

Abstract

This study is made for determining wind speed frequency distributions at any height within Surface Layer SL (SL has height about 250m above ground) ,where wind speed is measured at low reference level (usually 10m) which is considered a routine meteorological data recorded hourly. This study needs to know in detail the roughness characteristics of the terrain surrounding the location study, that important to calculate the rate of growth of internal boundary layers resulting from discontinuities in roughness as well as the shape of wind profile in various layers. The shape characteristics of the wind profile are determined as a function of roughness length and stability and the result of this profile is compared with measurements from radiosonde, at height 10, 50,100,150, 200m. This study tested frequency percent for wind speed at 10m, 50m, 200m for the observed and calculated at July– month 1990 and at the 12:00 hour only. The calculated wind frequency has weak at 10m wind speed and all the frequency is concentrated at the (2-6) m/s, while the observed has high frequency at the wind speed reached to 8m/s. This case is changed at the height 50m, and 200m where the calculated have high frequency at the wind speed concentrated at (6-10) m/s. This study refers to the possibility of installing turbine in this layer to generate electricity at least in this period of this year.