Climate Regions

What is Climate?

Weather is the day-to-day changes in atmospheric conditions

Climate is long-term weather conditions Temperature and precipitation are the most

important expressions of climate

What aspects of the environment are influenced by climate?

Vegetation Animal life Soils Landforms Water resources

Ecosystems What is an ecosystem? An area of interaction between plants,

animals,and their environment Unique ecosystems evolve as a result of

differing climate conditions Climatology studies the climate regions that

have evolved in response to different moisture and temperature conditions

Does Climate Repeat Itself?

Koppen’s Climate Region Map

Can we make any generalizations? Latitude

Single most important factor-Why?

Maritime versus continental locations Windward coasts have cooler summers and warmer

winters

Precipitation related to pressure and wind belts

High pressure – dry, Converging winds - rainy

Mountains have different climates Mountains are cooler than lowlands

Greek’s Climate Regions

Frigid

Frigid

Temperate

Temperate

Torrid

Latitude

Maritime and Continental Climates

Crescent City

Chicago

New York

Maritime climates are under the influence of westerly winds

Continental climate dominated by continental temperatures

Continental climates are under the influence of winds from the continental interior

Cold California Current brings cooler temperatures to the coast in summer

Herbertson’s Climate Regions

Pressure and Wind Belts

Polar High Polar Easterlies Polar Front Westerlies Subtropical

High N E Trade

Winds Intertropical

Convergence Zone SE Trades

What is the climate of each of these pressure and wind belts?

What happens to all these pressure and wind belts?

They shift north and south with the overhead sun

Do they shift as far north and south as the Tropics of Cancer and Capricorn?

No, about 5º N and 5º S

Where in the World is it Raining Today ?

The world’s rainy places coincide with global pressure and wind belts

Three Major Rain Belts

The Northern Hemisphere Polar Front Midlatitude Cyclonic Storms - low pressure

The Intertropical Convergence Zone (ITCZ) Trade winds converge along the equatorial low Convectional lifting produces cumulus clouds

The Southern Hemisphere Polar Front Midlatitude Cyclonic Storms - low pressure

Animation Showing Monthly Rainfall

Mean Annual Precipitation

STH STH

STH STH STH

Africa’s Climate Regions

Tropic of Cancer

Equator

North America Climates

Koppen’s Climate Classification Most widely used map of climate regions Empirical-quantitative approach that uses climate

statistics compiled over 30 years Designed with plants in mind Each climate is defined according to set values of

mean monthly precipitation and mean monthy temperature

Koppen’s Climate Regions

Koppen Classification

(A) Tropical rainy climates Every month over 64.4 F

(B) Dry climates Evaporation exceeds precipitation

Koppen Classification

(C) Mild, humid climates Coldest month below 64.4 F but above 26.6 F

(D) Snowy-forest climates Coldest month below 26.6 F but warmest month over

50F (E) Polar climates

Warmest month below 50 F

Why is the Bay Area rainy in winter and dry in summer?

The jet stream and the Polar Front move into the Bay Area in winter

The Subtropical High dominates our weather in Summer

Global Regions of Mediterranean and Marine west-coast “C” climates.

Mediterranean Climate Zones: West coasts ~30-40° Latitude

Global Regions of Moist Subtropical ClimateGlobal Regions of Moist Subtropical Climate

East coasts ~25-35° Latitude.

East vs. West Coast ClimatesEast vs. West Coast Climates

Mediterranean Climate in Monterey, CA

Moist subtropical climate in Charleston, South Carolina.

West Coast PrecipitationWest Coast Precipitation

Dry all year ~20-30°

Dry summer wet winter ~30-40°

Dry summer wet winter ~30-40°

Reality Check Most climates between the

tropics of Cancer and Capricorn are:

Which major climate group is not in the Southern hemisphere?

Which major group forms the cold summer climates of the Arctic?

Which climates are dry? What climate dominates

Australia?

Does the U.S. have any A (tropical moist) climates?

Does the U.S. have a BWh (hot desert)?

What major climate group dominates Canada and Russia?

What climate makes up most of Western Europe?

What climate is not classified using Koppen?

Berkeley and San Jose Climographs

Annual rainfall – 14.6 inchesAnnual rainfall – 22.3 inches

Review QuestionsReview Questions

1. What do clouds need in addition to saturation?

2. Consider the topographic profile diagrammed below.

Cloud condensation nuclei

Ocean

Prevailing windsA

C

B

   

This would induce what “type” of lifting?

What is the process that causes condensation?

How would the amount of precipitation at A, B, and C compare?

Ocean

Prevailing windsA

C

B

   

Point B above is said to be in the ________________ of the mountain shown.

What type of local wind is commonly experienced at B? Is it a hot or cold wind?

rain shadow

Chinook wind. It’s a hot wind.

What is the cause of the seasons?

Tilt of earth’s axis as it orbits the sun Revolution Parallelism