Climatic
Zones
The world
has several climatic zones. These are summarised on the map below.
(Image
curtesy of the UK Meteorlogical Office)
The classification
is based on maximum and minimum temperatures and the temperature
range as well as the total and seasonal distribution of precipitation.
Simple summary
of climatic zones:
Polar - very
cold and dry all year
Temperate - cold winters and mmild summers
Arid - dry, hot all year
Tropical - hot and wet all year
Mediterranean - mild winters, dry hot summers
Mountains (tundra) very cold all year
What
factors affect climate?
There are
5 factors which affect climate. These are summerised below:
Latitude
Tempature
range increases with distance from the equatot. Also, temperatures
decrease as you move away from the equator. This is because the
suns rays are dispersed over a larger area of land as you move
away from the equator. This is due to the curved surface of the
earth. In addition polar regions are colder because the suns rays
have further to travel compared to place on the equator.
Altitude
Temperatures
decrease with height. The air is less dense and cannot hold heat
as easily.
Winds
If winds are
warm - they have been blown from a hot area - they will raise
temperatures. If winds have been blown from cold areas they will
lower temperatures.
Distance
from the sea (continentality)
Land heats
and cools faster than the sea. Therefore coastal areas have a
lower temperature range than those areas inland. On the coast
winters are mild and summers are cool. In inland areas temperatures
are high in the summer and cold in the winter.
Aspect
Slopes facing
the sun are warmer than those that are not. Thus south facing
slopes in the northern hemisphere are usually warm whereas slopes
facing north in the southern hemisphere are warmest.
Climate
Graphs
Climate can
be displayed on a graph. A climate graph contians two pieces of
information. The amount of rainfall and the temperature of an
area. The temperature is shown as a line and the rainfall is displayed
as bars. The figures are usually calculated as an avergae over
a number of years. This reduces the impact of any anomolies in
the weather affecting the statistics.
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