Seasonal variation of the structure of the atmospheric boundary layer over a Suburban area

The long-term observational data of wind and temperature obtained from a 213-m instrumented tower in a suburban area were analyzed to investigate the seasonal variation of the structure of the atmospheric boundary layer.It was found from the daily variations of wind and temperature and the seasonal variation of the power spectrum of wind that in the summer the atmospheric boundary layer below 200 m is well mixed by convective turbulence, but in the winter the inversion layer near the ground suppresses the turbulent mixing, and the diurnal variation caused by turbulent mixing is confined to below 50–100 m height.Power spectra of wind speed were computed for different seasons of the year. In the summer season there is no significant variation of the shape of the spectrum with height. However, in winter the spectrum varies with height. The spectrum also varies annually and the characteristic of the long period (a few days) spectral peak of wind is related closely to the synoptic weather situation, and this suggests the possibility of a spectrum climatology.