World Climates Chapter 21 Section 2 The Kppen

World Climates Chapter 21, Section 2

The Köppen Climate Classification System l l The Köppen climate classification system uses mean monthly and annual values of temperature and precipitation to classify climates The Köppen system has five principle groups: humid tropical climates, dry climates, humid midlatitude climates, polar climates, and highland climates All of these, except dry climates, are defined by temperature Dry climates are classified according to the amount of precipitation

Climates of the World

Concept Check What is the Köppen climate classification system? l The Köppen system uses mean monthly and annual values of temperature and precipitation to classify climates. l

Humid Tropical Climates Humid tropical climates are climates without winters l Every month in such a climate has a mean temperature above 18ºC 18 l The amount of precipitation can exceed 200 cm per year l Wet Tropical Climate – high temperatures and much annual precipitation (Rainforests) l Tropical Wet and Dry Climate – temperatures and precipitation similar to the wet tropics, but experience distinct periods of low precipitation (Savannas) l

Rainforests vs. Savannas

Concept Check Describe the characteristics of humid tropical climates. l Humid tropical climates have no winters. Every month has a mean temperature above 18ºC and has a lot of precipitation. l

Humid Mid-Latitude Climates with mild winters have an average temperature in the coldest month that is below 18ºC but above -3ºC l Climates with severe winters have an average temperature in the coldest month that is below -3ºC l Humid mid-latitude climates include: humid subtropical, marine west coast, dry-summer subtropical, humid continental, and subarctic l

l l Humid Subtropical Climate – generally located on the eastern side of a continent and characterized by hot, sultry summers and cool winters Marine West Coast Climate – found on the windward coasts from 40º and 65º latitude and dominated by maritime air masses; winters are mild, and summers are cool Dry-Summer Subtropical Climate – located on the west sides of continents between 30º and 45º latitude; the only humid climate with a strong winter precipitation max Subarctic Climate – found north of the humid continental climate and south of the polar climate; bitterly cold winters and short cool summers; highest annual temperature range

Humid Mid-Latitude with Mild Winters

Humid Mid-Latitude with Severe Winters

Concept Check What type of climate does LA have? Explain. l LA has a dry-summer subtropical climate. It is on the west-side of the continent, located between 30º and 45º latitude, and experiences all of its precipitation in the winter. l

Dry Climates l l l l A dry climate is one in which the yearly precipitation is not as great as the potential loss of water by evaporation Dryness is not only related to annual rainfall, but is also a function of evaporation Evaporation is closely dependent upon temperature There are two types of dry climates: arid (desert) and semi-arid (steppe) The steppe is a marginal more humid variant of the desert, separating the desert from the humid climates Dry climates exist as the result of the global distribution of air pressure and winds Other dry climates are a result of rain shadows off of large mountain chains Some of Earth’s driest climates occur where a cold ocean current affects the west coast of a continent

Extent of Dry Climate Zones

Concept Check What defines a dry climate? l Both the amount of precipitation that falls and the amount that can be lost as the result of evaporation. l

Polar Climates l l l Polar climates are those in which the mean temperature of the warmest month is below 10ºC Polar winters are periods of perpetual night, making temperatures extremely cold In the summer, temperatures remain cool despite the long days Very little precipitation falls in polar regions There are two types of polar climates: the tundra climate (treeless region) and the ice cap climate (permanent ice and snow)

Two Types of Polar Climates

Concept Check What are the characteristics of polar climates? l Polar climates are extremely cold, even in the summer months. Very little precipitation falls in polar regions, and evaporation is limited. l

Highland Climates Highland climates are localized l They are much different than their surrounding climates l The conditions vary abruptly from one place to another l South-facing slopes are warmer than north -facing slopes l In general, highland climates are cooler and wetter than nearby areas at lower elevations l

Concept Check How do highland climates compare with nearby lowland climates? l Highland climates are usually cooler and wetter than nearby places at lower elevations. l

Assignment Read Chapter 21, Section 2 (pg. 592 -599) l Do Chapter 21 Assessment #1 -32 (pg. 609610) l