Date post: | 04-Jan-2016 |
Category: |
Documents |
Upload: | thomasine-white |
View: | 216 times |
Download: | 1 times |
Earth ScienceEarth Science
Chapter 9Chapter 9
Chapter 9Chapter 9
Weather and Climate
Lesson 1Lesson 1What Factors Affect What Factors Affect
Climate?Climate?• Climate is the
normal pattern of weather in an area over many years.
• Climate in an area is affected by:– Earth’s shape– Tilt of its axis– Geographic
features
Uneven HeatingUneven Heating
• The Sun’s rays strike Earth at different angles.
• The closer the angle to the Sun, the warmer the climate in that area.– Example: The Equator
Major Climate ZonesMajor Climate Zones
• Earth has three Major Climate Zones– Tropical, Temperate, and Polar
• Their differences are:– Average temperature– Amount of precipitation (rain,
sleet, snow, or hail)
Tropical Climate ZonesTropical Climate Zones
• Occur at the Equator, or areas just North and South of it
• Warm temperatures all year round
• Often very rainy
Temperate Climate ZonesTemperate Climate Zones
• North and South of the tropics
• Warm summers, with rain as precipitation.
• Winter is cool- very cold, and precipitation falls as snow
• We live in a temperate climate
• Have 4 seasons
Polar ClimatesPolar Climates
• Located close to Earth’s North Pole and South Pole.
• Very cold year round.• Most precipitation falls as snow.
Land and Sea BreezesLand and Sea Breezes
• Unequal heating of land and water causes Land and Sea Breezes.
• Sea Breezes- flow from the WATER towards the land.
• Land Breezes- flows from the LAND toward the water.
Mountain EffectMountain Effect
• Mountains can affect precipitation.
• Most air flows up the windward side of a mountain.– The windward side
receives more precipitation than the leeward side.
Ocean and ClimatesOcean and Climates
• Ocean Currents – Caused by the wind pushing against the
ocean’s surface, moving streams of water.
• Warm ocean currents move warm water away from the equator toward the poles.
• Cold ocean currents move cold water away from the poles and toward the equator.
El NiñoEl Niño
• The name given to a periodic change in the direction of warm ocean currents across the Pacific Ocean.– Occurs every 5-7
years– Can cause change in
climate around the world
Lesson 2Lesson 2How Are Weather Forecasts Made?How Are Weather Forecasts Made?
• Earth’s atmosphere is a mixture of gases that surrounds the planet.
• Changes in the air causes changes in weather.
Structure of the AtmosphereStructure of the Atmosphere
• Divided into four main layers.
• Troposphere- – Closest to Earth– Where almost all
weather occurs– Thinnest layer– Contains 75% of
gases that make up the atmosphere.
StratosphereStratosphere
• Lies above the Troposphere• Air is much colder and drier• Contains most of the Planet’s Ozone layer• Absorbs radiation from the Sun
MesosphereMesosphere• Lies above
Stratosphere
• Coldest layer of Earth’s atmosphere
ThermosphereThermosphere
• Thin layer of Earth’s atmosphere
• First layer struck by sunlight
Air MassesAir Masses
An AIR MASS is a huge volume of air that affects weather in a certain area
– Can be dry OR humid, and warm OR cold, depending on where it forms
FrontsFronts • A front is a boundary between two air masses • When two DIFFERENT air masses meet, they
create a front. – Warm fronts form when warm air moves into an area,
causes light rains – Cold fronts form when cold air moves into an area,
usually has heavy rains
Observing Observing WeatherWeather• Weather is the overall
condition of the atmosphere at a given time and place. – Meteorologists are
scientists who study weather.
– Weather maps display atmospheric conditions.
RADARRADAR• Radar is a useful tool
for observing and forecasting weather
• Can be used to create an image of a storm.– Size, direction, amount
of precipitation and speed of the storm can be determined
Other Weather InstrumentsOther Weather Instruments
Satellites orbiting the Earth measure data in the atmosphere and relay it to Earth
• Thermometers- measure temperature in Celsius or Fahrenheit
• Anemometers- measure wind speed• Barometers- measure air pressure• Rain Gauges- collect and measure amount of
rain, snow, sleet or hail.• Weather Vane- indicates the direction the wind
is blowing