1. Climate: Causes and Classification

2. What is CLIMATE?
Long-term weather patterns for an area (climatology)
Variations in temperature, precipitation, and winds throughout the year

4. What causes CLIMATE?
An area’s climate is caused by a combination of three factors:
Latitude
Topographic Effects
Air masses

5. 1st Cause of Climate: Latitude
Most important cause!
The latitude (how far North or South of the equator) determines how much solar radiation an area receives due to Earth’s tilt.
Equator = little tilt = high solar radiation
Poles = high tilt = little solar radiation

6. 2nd Cause of Climate: Topographic Effects
Land vs. Water . . .
Coastal areas = wetter and moderate temperatures
Inland areas = drier and more extreme temperatures
Elevation . . .
Mountains = cooler
Lower elevations = warmer

7. 3rd Cause of Climate: Air Masses
Same types of air masses move into the same area at the same time each year.
Air masses bring the characteristics of their source regions (cP, mT, etc).
Air masses moving in interact with the air masses present to influence climate.

8. Koppen Classification System

9. Koppen Classification System
Uses mean monthly and annual values of temperature, precipitation, and vegetation to classify climates

10. Koppen Classification System
Contains ~5 main divisions:
Humid Tropical
Dry
Humid Mid-Latitude
Continental
Polar

11. Koppen Classification System: Humid Tropical Climates
Constant high temperatures
Constant high humidity
High amounts of precipitation

12. Koppen Classification System: Dry Climates
Little to no precipitation
Hot summers and cool winters
Subtypes:
Arid
Semi-arid

13. Koppen Classification System: Humid Mid-Latitude Climates
Mild winters & warm, humid summers
Abundant rainfall
Subtypes:
Marine
Humid subtropical
Mediterranean

14. Koppen Classification System: Continental
Severe winters and mild summers
Primarily located north of the equator
Subtypes:
Temperate
Highlands

15. Koppen Classification System: Polar Climates
Coldest regions on Earth (year-round)
Little precipitation
Winter days are (almost) all darkness; summer days (almost) all daylight