Assessing the power of geostrophic winds A EU funded research project tests geostrophic winds with the use of radiosonde data derived from coastal stations to forecast sea surface and temperature conditions. Energy © PhotoDisc Geostrophic winds, namely winds flowing parallel to isobars, are considered a rare phenomenon, mainly because isobars are not always straight or independent of other frictional forces. Geostrophic winds are neither new on this earth, as signs of sea level pressures were witnessed in European coastal waters already since the 1870s. Scientists from the Climatic Research Unit of the POWER project in recent years used that evidence to calculate geostrophic wind speed and power offshore of the Dutch and English coasts. Their aim was to highlight those sea areas where hazardous wind or wave conditions exist. Data of a period of ten years observation and analysis was selected and studied, divided into whether wind was approaching from over the sea or the land. If coming from the sea, wind was found to be forming small daily cycles. If approaching from the land, the daily cycle of the wind was producing variations in wind speed, more intense than the climatic seasonal changes. These changes took place in the North Norfolk coast for two summer months. They allowed researchers also to examine the height of the daily cycle of geostrophic winds as well as the speed of gusts in extreme circumstances. To forecast such storm and geostrophic wind intensities, scientists invented datasets. These datasets served to recreate geostrophic wind conditions as a means of observing how such conditions were originally developed. Interpolated atmospheric pressure data was collected with the use of bi-cubic spline interpolation to calculate the sea level pressure changes in longitude and latitude in the westerly and southerly directions, while the pressure gradient was used to calculate the geostrophic wind speed and direction for each point and time frame. An additional, independent estimation method was developed to measure the reliability of the project's wind speed estimates using twelve sets of simulated wind speeds with 100 speeds per bin. Results of all-related data analysis can be found in a CD-ROM with a user-friendly GIS interface. Such data will allow users to discover long-term wind power resources, examine whether their area of interest is suitable for offshore wind farming and predict any potentially harmful coastal climatic changes.
