ABSTRACT

We are all very familiar with the notion that climate varies from place to place. The south of England is usually warmer than northern Scotland, and considerably cooler than the south of Spain. The earth’s climate system is driven by energy from the sun, which warms the surface and evaporates water. Differences in climate arise not only because the amount of energy received varies from place to place, but also because the earth’s atmosphere and oceans transport energy and water from one place to another. The weather we experience on any one day is therefore determined by the interaction between time of year and the movement of these two fluids. The weather across the British Isles is typically characterised by a sequence of low pressure depressions moving eastwards from the Atlantic Ocean, bringing rain and cloud, and the warm waters of the Atlantic flowing from the south west keeping temperatures mild. The amount of rain that falls varies depending on how intense these depressions are, and how far

north they track. Sometimes the weather of the British Isles is dominated by high pressure over Europe and Asia. In winter this tends to produce cold, dry weather, whilst in summer it usually produces hot, dry weather.