Ice Cap
Ice capsare found mostly on Greenland and Antarctica, about 9% of the Earth’s land area
(Figure17.26). Ice caps may be thousands of meters thick. Ice cap areas have extremely
low average annual temperatures, e.g. -29°C (-20°F) at Eismitte, Greenland. Precipitation is
low, since the air is too cold to hold much moisture. Snow occasionally falls in the summer.
Figure 17.26: A composite satellite image of Antarctica. Almost all the continent is covered
with an ice cap. ( 6 )
Microclimates
When climate conditions in a small area are different from those of the surroundings, the
climate of the small area is called amicroclimate. The microclimate of a valley may be
cool relative to its surroundings since cold air sinks. The ground surface may be hotter
or colder than the air a few feet above it, since rock and soil gain and lose heat readily.
Different sides of a mountain will have different microclimates. In the Northern Hemisphere,
a south-facing slope receives more solar energy than a north-facing slope, and so each side
supports different amounts and types of vegetation.
Altitude mimics latitude in climate zones. Climates and biomes typical of higher latitudes