1. Section 1: Factors That Affect Climate
Chapter 25 – Climate
Section 1: Factors That Affect Climate

2. Section 1 Objectives
Identify two major factors used to describe climate
Explain how latitude determines the amount of solar energy received on Earth
Describe how the different rates at which land and water are heated affect climate
Explain the effects of topography on climate

3. Factors that Affect Climate
What is climate?
How does it differ from weather?
Climates are described using average temp and precipitation.
Daily: high and low of day / 2
Monthly & yearly average temps
Yearly temperature range
Latitude, heat absorption and release, and topography affect temp and precipitation

4. Latitude
The higher the latitude, the smaller the angle of incoming solar radiation on Earth’s surface (equator receives more, translates to higher temps)
Also tilt of Earth leads to seasonal climate change
Different temperatures different pressures wind belts
Different wind belts lead to different climates ~ affect temp, precip., & cloud cover

5. Global Wind Belts
Doldrums – warm air rises and cools, water vapor condenses, resulting in large amounts of precipitation
Subtropical highs (20-30) – air is sinking, it warms and dries, little precipitation, most of the world’s deserts here
Middle latitudes (45-60) – warm tropical air meets cold polar, belts of greater precip. due to fronts
Polar – cold, dry with avg. low precip.

6. Heat Absorption & Release
Land heats faster than water and can reach higher temps in the same amount of time
Ocean waters, waves, and currents circulate, and as they warm the can move around and be replaced by cooler water, takes longer for overall ocean temps to increase or decrease
Temp of land or ocean can affect how much heat that the air above them absorbs or releases and that air temp can affect climate directly

7. Specific Heat & Evaporation
What is specific heat?
Water has a higher sp. heat than land, therefore it takes more energy to heat a given mass of water to a certain temperature than it does the same mass of land
Also, evaporation also affects water surfaces at a much higher rate than land, and evaporation cools the water and absorbs energy away from water surface

8. Ocean Currents & El Niña
Temp of ocean current affects air above water surface
El Niño-Southern Oscillation (ENSO) – a cycle of changing wind and water-current patterns in the Pacific
El Niño: the warm-water phase (La Niña, cool- water phase)
Water temps along west coast of S. America rise
Affects weather around the globe – typhoons, cyclones, and floods or droughts
Warm water keeps cold, nutrient-rich bottom water from upwelling along coast. This in turn affects fishing industries dramatically

9. Seasonal Winds
Winds between land and ocean can change direction during different seasons due to changing temperature imbalances
Monsoons
What direction do they blow in the summer?
What type of weather do they bring?
What about during winter?

10. Topography What is topography? What is a rain shadow?
How does it form?

11. Section 2: Climate Zones
Chapter 25 – Climate
Section 2: Climate Zones

12. Section 2 Objectives Describe the three types of tropical climates
Describe the five types of middle-latitude climates
Describe the three types of polar climates
Explain why city climates may differ from rural climates

13. Three Major Climate Zones
Tropical
Middle-latitude
Polar
Each zone has distinct range of temps
Several types of climates per zone because of various amounts of precipitation.

14. Tropical Climates
Climates with high temperatures in the equatorial region
Three types of tropical climates
Tropical rain-forest
Tropical desert
Savanna

15. Middle-Latitude Climates
Marine west coast
Steppe
Humid continental
Humid subtropical
Mediterranean

16. Polar Climates
Subarctic
Tundra
Polar icecaps

17. Local Climates Microclimates What is a highland climate?
Density of vegetation
Elevation
Proximity to large bodies of water
How do cities and rural areas differ in microclimate?
Why?
What is a highland climate?
What is the climate like near a large body of water?

18. Section 3: Climate Change
Chapter 25 – Climate
Section 3: Climate Change

19. Section 3 Objectives Compare four methods used to study climate change
Describe four factors that may cause climate change
Identify potential impacts of climate change
Identify ways that humans can minimize their effect on climate change

20. Studying Climate Change
Climatologists – study climate change and the cause of it
They collect current climate conditions and also use data from the past to predict future changes
Ice cores – concetration of CO2
Sea-floor sediment – concentration of 18O
Fossils – pollen type and leaf shapes; animal body adaptations
Tree rings – ring width (temp and precipitation)

21. Modeling Climates
Massive amounts of data are handled by computers to help make models of climate conditions
General circulation models (GCMs)
Can isolate variables and help us understand how changes in individual factors may affect future climates
Very complex b/c they take into account interactions between land, clouds, ocean, wind, and vegetation

22. Potential Causes of Climate Change
Plate tectonics – changing wind flow and ocean currents
Orbital changes – Milankovitch theory
Shape – distance from sun
Tilt – difference in seasons
Wobble – direction of tilt, reverses seasons
Human activity – pollution and deforestation
Increases CO2
Volcanic activity – releases sulfur and ash into atmosphere
Decrease temps by reflecting solar radiation

23. Potential Impacts of Climate Change
Domino affect - one area’s climate change could cause other to change.
Affects not only humans, but all living things such as plants and animals
Global warming – gradual increase in global temps due to increased concentration of certain gases in atmosphere
Positive and negative effects, depending on location
Sea-level changes – coastal cities might no longer be habitable
50 % of the world population lives along coasts

24. What Can We Do? Laws have been passed to reduce pollution
Industrial processes are now monitored for compliance with pollution laws
Reduce use of fossil fuels
Turn off lights and appliances when not in use
Reduce use of AC and heaters
Recycle
Carpool
Hybrid cars