Transcript Unit 6 Chapter 22 Climate

Unit 6 Chapter 22 Climate
Section 1 Factors that Affect
Climate
Climate
It is an area’s long-term pattern of weather.
It is the overall weather conditions of an
environment. It will depend mainly on
Temperature & Rainfall. Other factors that
affect the climate are the hours of sunlight;
duration, speed and steadiness of the
wind and whether the area has severe
weather.
Temperature and Precipitation
It is usually described as the average temperature and precipitation.
To get the average temp or precip, you must add the high(s) and low(s) and divide
by two.
Average Temperature
Daily – Highs and Lows
Monthly – daily averages averaged together
Annually – Monthly averages averaged together
Temperature Range –
The number of degrees from the warmest temperature
to the coldest for an area.
NYC –
high 89o
average 52o
Low 10o
range 79
Chicago
High 110o
average 55o
Low
range 110o
Rainfall – how much precipitation an area receives
Seattle – rains most days – 40” of rain per year; light and steady
NY – approx. 50” per year -Clear most days; changes quickly to heavy
storms
Latitude
This is a factor because different areas receive different amounts of solar energy, at different times.
TEMPERATURE
PRECIPITATION
Latitude
Colder at the poles
Low pressure areas have rain (ITCZ &
mid lats.)
No rain at poles & horse lats.
Elevation
Colder at high altitudes
Higher elevations, less water
Nearby Water
Near water the temp changes
are small so coastal areas have
small range too
Precip most likely downwind of large
bodies of water
Ocean Currents
Warm ocean currents, warm by
coast; cold currents, cool by
coast
Some currents cause fog
Topography
Leeward side is warmer.
Mountains can act as barriers to
air masses
Windward side is wetter. Mountains
can act as barriers to masses
Prevailing Winds
May determine whether air
masses arrive from hot or cold
regions
May determine whether air masses
arrive from hot or cold regions
Vegetation
Can control how much insolation
is absorbed and how quickly it is
heated
Releases water vapor into the air
Solar Energy
Latitude –
The closer to the equator, the warmer the climate will be, because the angle
of insolation is greater.
The further from the equator, the cooler the climate because the angle of
insolation is less.
Global Wind Patterns
Where the wind belts come together, there will be moist climates. Where the
wind belts drift apart, there will be dry climates.
Heat Absorption and Balance
The land will warm up faster and lose the heat faster. The oceans will take a longer
time to heat up and cool down. This has a great effect on the climate of the area.
Specific Heat and Evaporation
Different objects have a different specific heat. Land (granite) has a lower specific heat
than the oceans (liquid water). This creates areas that are heated differently.
Ocean Currents
The temperature of the current that comes into contact of the land will affect the
climate. Warm currents will make an area temperate, while colder currents can make
an area cooler than inland
El Niño – Southern Oscillation
This is a cycle of the changing patterns of the wind and water currents in the
Pacific Ocean. It occurs every 3-10 years. It is the warm water phase of the
ENSO which causes the surface water temperatures to rise. It is followed by an
increase in the occurrence of typhoons, cyclones and floods in the area. In
Indonesia and Asia severe droughts can occur.
La Niña is the cool water phase of the ENSO. This can cause an increase of
hurricanes in the Atlantic.
Seasonal Winds
Because of the uneven heating of the land and water during seasonal changes,
they create seasonal winds. A monsoon is one such seasonal wind. A
monsoon is a wind that blows toward the land in summer. It brings heavy rains
during the summer months.
Topography
Altitude –
Height above sea level
The closer to the sea, the warmer the climate
The higher the elevation, the cooler the climate
Areas that receive the most precipitation are the ones where there
is warm, moist air rising in large quantities.
Ex.
•Florida- daily thunderstorms
•Atlantic Coast – storm areas including hurricanes
•Mountainous areas
Elevation
The height above sea level will produce distinct temperature
changes. As you go up in elevation, the temperature goes down.
Rain Shadows
As air rises it cools condensation occurs, clouds form the water droplets grow
and gravity pulls them down in the form of rain. The windward side is cool and
moist.
As the air continues its journey down the back side of the slope, it becomes
warm and dry. The probability of precipitation goes down. The leeward side is
warm and dry.
Foehn – flows down the Alps
Chinooks – flow down the Rocky Mountains
Section 2 Climate Zones
The Earth has three main climate zones: they are Topical, Middle-latitude, and
Polar. These zones are effected by the amount of precipitation in each areas.
Tropical Climates
Middle-Latitude Climates
•Polar Climates
Local Climates
Microclimates are the climates of small areas. They are influenced by
vegetation, elevation and proximity to water. Long Island has a microclimate.
Heat Island
A heat island is created when a cities pavement and buildings absorbs radiation
and reradiates it as heat.
Effects of Elevation
Highland Climates
This is mountainous regions. The climate will be effected by the height above
sea level.
Effects of Large Bodies of Water
The water will keep us temperate. Warmer winters because it takes all winter
to cool down the water; Cooler summers because it takes all summer to heat
up.
Section 3 Climate Change
Climatologist
A climatologist is a scientist that studies the climate
Studying Climate Changes
Modeling Climates
Computers are generally used for this because variables can
change often.
Potential Causes of Climate Change
By studying computer based models, climatologists have determined that there
are a few potential causes to climate changes.
Plate Tectonics
The change in position of the continents has changed the wind and water
current patterns. Land masses lower the air temperatures due to more snow
reflecting the sunlight, not absorbing it. There are also areas that did not have
land, that have it now.
Orbital Changes
Milankovitch Theory
Human Activity
Humans can affect the climate through deforestation and the
burning of fossil fuels. They both add to the amounts of CO2 in to
the atmosphere which is causing Global Warming.
Volcanic Activity
Volcanoes not only increase in the dust in the air but it also
increases the greenhouse gases (CO2 & H20) which will lower the
temperature.
Sun Spot Activity
Sun spots – areas of intense heat on the surface, therefore a lot
of sun spots, and a lot of heat. Around 1400 – 1800 there was
almost no sun spots which gave us about ¼ the energy from the
sun, cooler climate, glaciers grew
Potential Impacts of Climate Change
Because everything is so intertwined and dependant, when one variable
(climate) changes, it can influence other areas.
Global Warming
Global warming is the gradual increase in the average global temperature. This
is usually associated with an increase in the greenhouse gases. This creates an
increase in temperatures in areas that will increase evaporation, causing
droughts. It can also raise temperatures in areas that usually have ice and
snow, causing significant melting and flooding. The average global
temperatures have increased by 1o C since the 1800’s. It is possible that this is
occurring naturally.
Possible side effects:
Rising sea levels due to melting polar ice caps
Increasing frequency & severity of storms and hurricanes
More frequent heat waves and droughts
Relocation of major crops due to the change in growing areas
Sea-Level Changes
The melting of the polar ice caps can bring about a rise in sea level due to the
addition of water and by the thermal expansion of the water itself. This can
submerge coastlines.
What Humans Can Do
Many countries are working together to reduce Global Warming
Individual Efforts
A few ideas could be reduce Carbon Dioxide, use electricity sparingly, don’t use
throw away products, and recycle. There are many more ways to do this
Transportation Solutions
Use public transportation, use electric cars or fuel efficient ones, walk, bike,
etc.