Transcript Climate -overall view of a region`s weather conditions over a long

Two characteristics of Climate that are most
important:
1)The
2)The
average temperature over the year
annual temperature range (difference
between the average temperature of the hottest
month and the average temperature of the
coldest month)
 Arid or Dry = a region in which the average total
precipitation during the year is less than the average
yearly potential evapotranspiration (evaporation and
transpiration)
 Humid or Wet = an area that has an average
precipitation for the year is greater than the average
potential evapotranspiration
 Deserts = regions where the potential evapotranspiration
is much greater than the precipitation
 Sub-Arid or Sub-Humid = an area that has equal
amounts of precipitation and potential
evapotranspiration
Latitude
Planetary wind and pressure belts
Oceans and other large bodies of
water
Ocean currents
Elevation
Mountains
Amount of cloud cover
Vegetation
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Latitude has an influence on both temperature
and moisture
At low latitudes, there is very little temperature
variation because the angle of insolation is always
high
At high latitudes, the temperatures are low
because the angle of insolation is never large
♦ Moisture condition vary with latitudes because of
the location of the planetary wind and moisture
belts (ESRT – pg 14)
♦ Where there is a low pressure, air rises – the
cooling of this air creates clouds and precipitation
(humid climates)
♦ Where there is a high pressure, air sinks – the air
warms creating a dry or arid climate
**The combo if Latitude and Moisture creates a
latitudinal climate pattern**
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If land mass is near a large body of water, its temperatures
will be moderated by the slow heating and cooling off of the
water
An area that is moderated by a body of water is said to have a
maritime climate
Ex: Long Island
Maritime climates have cooler summers and warmer winters
Inland areas away from water are called continental climates
Ex: Central North America
Continental climates have warmer summers and cooler
winters
o Prevailing winds are caused by air pressure
differences (from unequal heating of the Earth by
the sun) and the effects of Earth’s rotation
o Most of the United States is located in the
prevailing southwesterly wind belt for much of
the year
o This allows most of the weather conditions to
move from the southwest to the northeast
o The west coast of the US has more of a maritime
climate than the east coast because the west coast’s
winds are from the ocean
• Currents flowing away from the equator carry
warm water to higher latitudes, while currents
flowing toward the equator carry cool water to
lower latitudes
• A cool ocean current will cause a coastal area to
have cooler temperatures and less precipitation
• A warm ocean current will cause a coastal are to
have warmer temperatures and more
precipitation
***ESRT pg. 4 : Surface Currents***
 The higher the altitude at and given latitude,
the cooler the climate
--because air rises, expands and cools
 Areas at higher altitudes generally have more
precipitation than lower areas
Mountains that intersect prevailing winds and force the winds up the
mountain.
The side of the mountain in which the prevailing winds blow up, is
called the windward side.
As the prevailing wind travels up the side of the mountain, it expands
and cools. When it cools to its dew point, condensation occurs which
forms clouds and precipitation. As a result the windward side is cooler
and more humid.
The opposite side of the mountain in which the winds descend is called
the leeward side.
As the air descends it is compressed and
warmed. As a result, the leeward side is
warmer and drier.
Arid Climate = has desert vegetation
Hot/Humid Climate = has a tropical rainforest
**When rainforests are cut down (deforestation),
and converted into farms or grazing land, the
climate often becomes hotter and less
humid.**
Without clouds = the atmosphere is more
transparent and more of the sun’s energy can
reach and heat Earth’s surface
With clouds = the sun’s rays are absorbed or
reflected back into space
**Although the equator is seems hot, they have
many thunderstorms which produce large
clouds. Deserts on the other hand, rarely
have clouds, allowing temperatures to be
high**