Factors Affecting Climate

The variation of received solar intensity with latitude drives a simple air movement where air rises at the equator and sinks at the poles (Hadley cell), causing the polar high-pressure areas of cold, sinking air that inhibits precipitation. A second external factor affecting polar climate is the extreme seasonal variation in incoming solar radiation over the course of a year, from near-continuous insolation in summer to months of almost total darkness in winter. As a result, temperatures fluctuate less diurnally than they do between winter and summer. The daily temperature range may be only 3-6°C. Winters are sustained and extremely cold, while summers are short and cool.

The high albedo of snow and ice ensures that even in summer much incoming solar radiation is reflected (negative energy balance), leading to surface cooling and air temperatures that can reach as low as -60°C (see Albedo; Energy Balance).

The Arctic differs from the Antarctic in being an ocean surrounded by continental landmasses and open seas rather than a landmass surrounded by seas. Warm North Atlantic water flowing into the Arctic Ocean keeps temperatures to +2 to +4°C in the Fram Strait area and near 0°C even after reaching the other side of the Arctic Ocean. The climate of coastal Arctic areas is moderated by this maritime influence, while continental interiors have much more severe winters.

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