ABSTRACT

This chapter examines the underlying mechanisms and defining character of the weather and climate of mid-latitude continental interiors with specific reference to North America. The impacts of anthropogenic climate change on the water sector must be viewed alongside the historic legacies of river regulation and groundwater exploitation. The dynamic climatology of North America may be explained at different scales. At a macro scale, semi-permanent pressure systems act to drive air masses across the continent. Local factors such as topography and the moderating influence of inland water bodies such as the Great Lakes embellish further the climatic mosaic at a smaller scale. Two semi-permanent pressure systems control the flow of Pacific air into the continent. The Californian High is the subtropical high created as a result of the descending limb of the Hadley cell over the north Pacific, and becomes most pronounced in the summer season when it extends on land over the south-western USA.