Ecoregions of the Continents: The Polar Ecoregions

Abstract

Polar and arctic air masses chiefly control climates of the polar domain, located at high latitudes. With the exception of the icecap climates, they lie entirely in the Northern Hemisphere. In general, climates in the polar domain have low temperatures, severe winters, and small amounts of precipitation, most of which falls in summer. Polar systems are dominated by a periodic fluctuation of solar energy and temperature, in which the annual range is far greater than the diurnal range (see Figure 4.2, p. 35). This contrasts with the tropics, where the major periodic fluctuation is the diurnal one, and the mid-latitude systems, which we will see, are subject to fluctuations in both annual and diurnal energy patterns.