Seasonal variation of wind direction fluctuations vs Pasquill stabilities in complex terrain

The authors have studied the seasonal variation of Σ_θ (the standard deviation of wind direction fluctuations) vs Pasquill stabilities over complex terrain. It is found that the values of Σ_θ are quite high in the month of April in contrast with other months. Values are also high when compared with those estimated over flat terrain and at a coastal site.