Estmation of the Function of Surface Roughness and Stability (p) in Defrrent Air Conditions Over Baghdad City

In this work the function of surface roughness and stability (P) has been measured using horizontal wind velocity for different levels by radio sound over Baghdad city for Stable and unstable condition has been evaluated in every month., as well , in a neutral condition we found a relation between the function of surface roughness and stability (p) and the roughness length ,that lead to practical equation can be used under specific condition .The power law, which calculates the change in horizontal wind speed with height has been corrected for stable and unstable condition.