Abstract/Summary

Measurements have been made of the three components of velocity and of the static pressure in the lowest 10 ​m of the atmospheric boundary layer. The measurements reported here were made on two occasions: the first with a single 10 ​m mast and the second with four 6 ​m masts. One-hour duration measurements at a sampling rate of 10 samples s−1 were processed for statistical properties including an assessment of the mean static pressure, and the time series processed for spectral properties. The mean velocity profile followed the expected boundary-layer log-region. An estimate of the mean static pressure compared to that above the boundary layer has been made and shows a dependency on the RMS (Root Mean Square) of dynamic pressure. The spectra of wind velocity and wind dynamic pressure follow the expected n−5/3 power-law decay rate in the inertial subrange, whereas static pressure spectra followed a decay rate close to n−4/3 - a result that was not predicted by published theory. Limited comparisons have been made with measurements from wind-tunnel boundary-layer flows, and with one other full-scale experiment. There is evidence from these comparisons that the static pressure spectra has a decay rate close to n−4/3 but there is also evidence of Reynolds-number sensitive. These measurements were made as part of a study of wind effects on buildings. The distinct spectral pattern of static pressure compared to that of dynamic pressure is a potential aid to identifying their separate contribution to wind loading and natural ventilation.