Earth’s Climate Systems

What is the difference between weather and climate?

• Weather is the condition of the atmosphere at any given place.

• Climate is the consistent, long-term behavior of weather over time.

Climate Factors

• H Statistical Analysis of 30 years of data

• Insolation• Temperature• Pressure• Air Masses• PrecipitationH L

5 Climate Regions

1. Tropical

2. Dry

3. Mid latitude

4. High Latitude

5. Highlands

Tropical ClimatesA. Tropical Wet

• Avg temp 80 degrees F• Daily rain• 80 in/year• Wildlife abundant• Tropical rainforest veg• Amazon Basin, S. Am, Asia Caribbean, Africa

B. Tropical Dry• Dry winters, wet summers• High yearly temps• Savannas• Africa, central - S Am., Australia

Dry Climates

A. Desert• < 10 in. rain/yr• Day/night temps vary• 1/3 of world’s land• Veg = scrub, cactus• Dunes, rocky surfaces• Where???

B. Steppes• Dry, treeless• 10 – 20 in. rain/year• Where???

Mid latitude ClimatesA. Marine West Coast

• 30 - 60 N/S• Western coastlines• Cool summers, cool damp winters• Veg = Coniferous, Deciduous, mixed forest

B. Mediterranean• Mild, rainy winters• hot., sunny summers• Veg = woody bushes, short trees,• Where?

C. Humid Subtropical• Short, mild winters• Year round rain, high humidity

b/c of oceans• Veg = prairies, forests• Where?

D. Humid Continental• Inland locations, further N, longer harsher winters• Veg = Mixed forests – but evergreens out# in N

High LatitudeA. Subarctic

• Bitter-cold winters• Summers short/cool• > temp vary variation• permafrost• Veg = needles evergreens

B. Tundra• Winter darkness• No roots• Veg = Low shrub, short grasses, mosses

C. Ice Caps• Snow, ice 2 miles thick!

Highland

• Natural vegetation varies with elevation

• High Mountain areas

The Köppen System

What is the Köppen System?

• Widely used system that classifies climate according to:– annual and monthly averages of temperature– annual and monthly averages of precipitation

• Devised by Walter Köppen (1846-1940); updated and modified by Köppen until his death.

• Continues to be modified by geographers today!

Köppen’s major climates:

• Tropical Climates (A)• Dry Arid and Semiarid Climates (B)• Mesothermal Climates (C) – mild winter• Microthermal Climates (D) – severe winter• Polar Climates (E) • Highland (H)

http://www.uwmc.uwc.edu/geography/100/koppen_web/koppen_map.htm

Climate subcategories

• Each category is further divided into sub-categories based on temperature and precipitation.

• For example, in a Dfa climate:• D = microthermal climate• f = feucht (German for “moist”)• a = warmest avg. summer month above 22° C• Dfa = humid-continental, hot-summer climate in

the microthermal D category.

The Köppen System: Pros & Cons

Pros:• Uses temperature

and precipitation which are easy to measure

• Temperature and precipitation directly affect humans.

• Corresponds with vegetation regions.

Cons:• Only uses averages

which does not take into account subtle changes from place to place.

• Ignores wind, cloud cover, intensity of precipitation, and humidity.

Climographs

• Graphic means of giving info on mean monthly temperature and rainfall for a select location or station

• Usually two parts– Annual temperature curve (red)– Precipitation bars (blue)

Annual Climatology: Green Bay, WI (GRB)Elev: 687 ft    Lat: 44o 29'N    Long: 88o 08'W

Figure 1: Average Temperatures and Precipitation 1971-2000. (NCDC Data)