The polar easterlies
This term is applied to winds that occur between polar high pressure and subpolar low pressure. The polar high, as has already been pointed out, is by no means a quasi-permanent feature of the Arctic circulation. Easterly winds occur mainly on the poleward sides of depressions over the North Atlantic and North Pacific (Figure 7.12). If average wind directions are calculated for entire high-latitude belts there is found to be little sign of a coherent system of polar easterlies. The situation in high latitudes of the southern hemisphere is complicated by the presence of Antarctica, but anticyclones appear to be frequent over the high plateau of eastern Antarctica, and easterly winds prevail over the Indian Ocean sector of the Antarctic coastline. For example, in 1902 to 1903 the expedition ship Gauss, at 66°S, 90°E, observed winds between northeast and south-east for 70 per cent of the time, and at many coastal stations the constancy of easterlies may be compared with that of the trades. However, westerly components predominate over the seas off west Antarctica.
Continue reading here: The General Circulation
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