Development of a new wind‐rose for the British Isles using radiosonde data, and application to an atmospheric transport model

A six-hourly dataset of radiosonde ascents spanning a ten-year period from four stations in the British Isles has been used to generate a set of wind frequency roses and wind speed roses for the pressure level range 950–900 hPa. The wind frequency rose showed close agreement with the long-term series of the Jenkinson classification scheme. Small but significant inter-station and interannual variations were observed. Seasonal analysis of the data revealed the higher incidence of north-easterlies during spring months whilst the stronger wind speeds associated with the winter months were also evident. The use of a harmonic mean was found to be appropriate for calculating a directionally dependent wind speed for use in an atmospheric transport model. A harmonic mean wind speed value of 7.5 m s−1 was generated from the entire dataset, the same as that which has previously been used in other transport models. This is also the same value as the ‘optimized wind speed’ that was generated by Singles et al. The radiosonde wind frequency rose and wind speed rose were input to the FRAME atmospheric transport model. This resulted in an improved correlation with measurements of SO2 concentrations from a national monitoring network when compared to a model simulation using the earlier dataset of Jones. Copyright © 2006 Royal Meteorological Society