Download Climate: Causes and World Climates

Climate
Causes and Zones
Climate

Climate of a region is dependent on:
◦ Latitude
◦ Atmospheric circulation cells
◦ Topography/Elevation
Latitude



The main factor influencing the climate of a region
because different latitudes receive different amounts of
solar radiation.
Equator receives the most solar radiation.
Polar regions receive the least solar radiation.
Atmospheric Circulation Cells
The position of a region relative to the
circulation cells and wind belts has a great effect
on its climate.
 In an area where the air is mostly rising or
sinking, there is not much wind.

Intertropical Convergence
Zone (ITCZ)

the low pressure area
near the equator in
the boundary between
the two Hadley Cells.
◦ air rises, cools and
condenses to create
clouds and rain

Climate along the
ITCZ is warm and wet.
Cell Boundaries

Hadley and Ferrell
◦ 30°N and 30°S
latitude
◦ air is warm and dry, it
came from the
equator where it lost
most of its moisture at
the ITCZ
◦ air is descending
◦ air warms and causes
evaporation

Ferrell and Polar
◦ 50° to 60°N and S
◦ cold air from the poles
meets warmer air
from the tropics
◦ polar jet stream, shifts
due to change in
incoming sunlight
◦ South of jet stream =
warmer and moister
Prevailing Winds
At the bases of the Hadley, Ferrell, and
Polar Cells.
 Influence the climate of a region by bring
the weather from the locations they
come from.

Continental Position


A maritime climate is strongly influenced by the
nearby sea.
A continental climate is more extreme, with greater
temperature differences between day and night and
between summer and winter.
The ocean’s influence in
moderating climate can be
seen in the following
temperature comparisons.
Each city is located at 37°N
latitude, within the westerly
winds.
Ocean Currents

The temperature of the water
offshore influences the
temperature of a coastal
location, particularly if the
winds come off the sea.
◦ cool waters of the California
Current bring cooler
temperatures to the California
coastal region.
◦ in southern Alaska, the upwelling
actually raises the temperature of
the surrounding land because the
ocean water is much warmer than
the land.
Altitude

Air pressure and air temperature decrease with
altitude.
◦ At higher altitudes, the air is less dense and air
molecules are more spread out and less likely to
collide and give off heat.

A location in the mountains has lower average
temperatures than one at the base of the
mountains.
Mountain Ranges

Have two effects on climate of
surrounding regions:
◦ Rainshadow effect- brings a warm, dry climate
to the leeward side of a mountain range.
◦ Separation of the coastal region from the rest
of the continent.
 The coastal region keeps a maritime climate, the
inland/leeward side keeps a continental climate.
The Bonneville Salt Flats
are part of the very dry
Great Basin of the Sierra
Nevada of California. The
region receives little
rainfall.
Climate Zones
Climate zones are classified by the Köppen
classification system.
 Based on:

◦ Temperature
◦ Amount of precipitation
◦ Times of year when precipitation occurs
Vegetation is used as an indicator of climate
type.
 Köppen

Biomes
An intro to Biomes
 Are regions of the world with similar climate,
animals, and plants.
 Organisms in a biome share certain
characteristics around the world.
 They have adapted to that environment in
similar ways over time.

◦ Different species of cactus live on different continents,
but they have adapted to the desert biome in similar
ways.
Köppen classification system
Five major climate groups, A through E.
 Subcategories are:

◦ forest (f)
◦ monsoon (m)
◦ wet/dry (w)