Located on the north-western fringe of Europe, the Highlands and Islands of Scotland have a wind climate characterised by high average wind speeds and the frequency of strong winds and gales is higher than in other parts of the United Kingdom. In addition, the wind flow over the region is significantly influenced by the complex topography. Recognising variations in the dynamic but small scale structure of the wind field and its extremes is important when considering the regional impact of climate variability for the Scottish Highlands and Islands. However, although several regional climate change studies have been conducted for the region, little effort has been invested in understanding the regional wind field as compared to that invested in understanding changes in precipitation and temperature, whilst all three are considered key variables in the global warming scenarios.
This research aims to increase our understanding of the current and future wind regime in the Highlands and Islands. Wind observations from airport meteorological stations were obtained from the UK Met. Office for the period 1960-2004. Changes in prevailing wind strength and direction are separated into seasonal and inter annual variability to look for indicators of multi annual periodicity and long term drift. A potential NAO related winter variability is also investigated.
For the stations studied, we show that annual and monthly mean wind speeds and directions exhibit very little pattern in variability over this period. However, winter time high winds in the prevailing wind direction show a good correlation with the NAO index. A diagnostic model is used to show how island topography deflects the prevailing wind field and may make simple correlations difficult to determine.