Download Climate

Ch. 13 Section 1
Objective
 Compare and contrast weather and
climate.
 List and describe factors that influence
them and analyze their impact.
Weather
 Is the state of the atmosphere at a
particular place at a particular moment.
Climate
 Is the long term prevailing weather
conditions at a particular place based
upon records taken.
New York vs Aiken
 Two cities may experience the same weather, but their
climate is different.
Gets below zero
Aiken 2/12/2010
What factors determine climate?
 1. Latitude
 2. Atmospheric circulation patterns
 3. Oceanic circulation patterns
 4. Geography
 5. Solar activity
 6. Volcanic activity
1. Latitude
 The distance from the equator measured in
degrees north or south.
 The most northerly
latitude would be the
North pole at
90 degrees North.
LATITUDES
Low latitudes
High latitudes
 On either side of the
equator.
 Closer to the poles.
 More solar energy falls
here. Sun is
concentrated on
smaller surface area.
 Night and day are
about 12 hours each.
 Temperatures are high
year round.
 Sun is at oblique angle
and spreads over larger
surface area.
 Day and night vary
more.
 Temperature range is
greater.
Lattitudes
DNC Equator markers
DNC- Brasilia Brazil
 Climate is Tropical savanna climate .
 The individual seasons are defined according to the
degree of humidity of the air: one season is dry, while
the other one is comparatively humid.
 September, at the end of the dry season, has the
highest average maxi temp,82 °F, and July has the
lowest average max temp, 77 °F.
The lowest average minimum
temperature is in July 55 °F.
DNC Siberia
 The by far most common climate in Siberia is
continental subarctic, with the annual average
temperature about 23 °F and roughly −13 °F average in
January and 62.6 °F in July.
 there is a very short
(about one-month-long)
summer
2. Atmospheric Circulation
 Large scale movement of air.
 As cold air sinks it compresses and warms.
 As warm air rises it expands and cools.
 Warm air holds more water vapor than
cool air so as it cools the vapor may
condense into rain, snow or fog.
 The movement of air is called wind.
2. Atmospheric circulation cont
 Due to the amount of sun the areas
around the equator receive there is a lot
of evaporation.
 Remember the warm air will rise and
cool.
 Areas around the equator tend to have
large amounts of rain.
Prevailing winds
 Movement of air causes wind. Winds that
blow predominantly in one direction are
prevailing winds.
 Trade winds are belts of prevailing winds.
 Northern Hemisphere blow from NE
 Southern Hemisphere blow from SE
Examples of prevailing winds are westerlies
and polar easterlies.
Global Air Circulation
3. Ocean Circulation Patterns
 El Nino Southern Oscillation (ENSO)
 El Nino- short term (16-18 month period)
Periodic Change in the warm and cold
water masses in Pacific Ocean.
 El Nino and La Nina are opposite phases
of ENSO cycle. El Nino-warm phase, La
Nina- cold phase.
Oceanic Circulation Patterns Cont.
Pacific Decadal Oscillation
Long term change (20-30 years)
Affects Ocean surface
temperatures, air temperatures
and precipitation patterns
4. Geographic-Topography
 Rain shadow
 Mountains influence the distribution
of precipitation.
 As air rises up the mountain it cools
and rains. When it reaches the other
side of the mountain it is dry.
Rain Shadow
4. Geographic-Topography
Solar activity
 At a solar maximum, the sun emits an increased
amount of ultraviolet (UV) radiation.
 UV radiation produces more ozone, which warms the
stratosphere.
 The increased solar radiation can also warm the lower
atmosphere and surface of Earth a little.
6 .Volcanic Eruptions
 Releases sulfur dioxide into air.
 Stays in atmosphere up to 3 years.
 Reacts and forms layer of haze that deflects
sunlight and reduces global temperature.
Glaciers
flood when
they melt
He is
standing
on a
road.
Seasonal Changes in Climate
 The seasons result from the tilt of Earth’s axis, which is
about 23.5° relative to the plane of its orbit.
 Because of this tilt the angle at which the sun’s rays
strike Earth changes as Earth moves around the sun.
Seasonal Changes in Climate
Seasonal Changes in Climate
 During summer in the Northern Hemisphere, the
Northern Hemisphere tilts toward the sun and receives
direct sunlight.
 Therefore, the amount of time available for the sun to
warm Earth becomes greater.
 During summer in the Southern Hemisphere tilts
away from the sun and receives less direct sunlight.
 But, during the summer in the Southern Hemisphere,
the situation is reversed.