WIND CHARACTERISTICS AND INFLUENCES ON SEA-STATES WITHIN AND AROUND PLYMOUTH SOUND

In the attempt to investigate the pattems of winds around Plymouth, surveys were carried out from five designated stations within Plymouth Sound. These surveys lasted for a total of 44 days and involved manual measurements of the wind speed with aid of hand-held anemometer and wind directions with hand-held GPS. The limited data acquired from these surveys were augmented by the integration of data from three weather stations from open sea, coastal area and from inland. The results from the field observations were used to analyse the local characteristics of the winds within Plymouth. The results from the weather station were used in the analyses of the daily, monthly and seasonal variations of the winds in the different environments and the implications these will have in the occurrence of various wind forces within Plymouth Sound. The comparison of the data from the different environments showed that frictional forces on winds increased as winds moved landwards from the open seas. The headlands surrounding the Sound were seen as exerting the greatest influence on the wind as it was seen to contribute mostly to these frictional forces by limiting wind speeds. The analyses showed an increase in wind speed around Plymouth during the day with maxima at about 3pm and a decrease at night with minima at about 3am. The windiest months were seen to be the winter months with maximum wind speeds in January while the summer months were seen to have the lowest wind speeds. The survey also showed that the winds with the highest speeds are from south-western direction and this is because winds blowing from the direction have the longest fetch.Faculty of Scienc