Objectives Recognize limits associated with the use of normals. Explain why climates vary. Compare and contrast temperatures in different regions on Earth

ObjectivesRecognize limits associated with the use of normals.

Explain why climates vary.

Compare and contrast temperatures in different regions on Earth.

Defining ClimateSection 14.1

Review Vocabulary

jet stream: a high-altitude, narrow, westerly wind band that occurs above large temperature changes

Climate is affected by several factors including latitude and elevation.


New Vocabulary

climatology

normal

tropics

temperate zones

polar zones


Climatology is the study of Earth’s climate and the factors that affect past, present, and future climatic changes.

Climate describes the long-term weather patterns of an area.

Annual Averages and Variations



The data used to describe an area’s climate include daily high and low temperatures, amounts of rainfall, wind speed and direction, humidity, and air pressure.


Normals


The data are averaged on a monthly or annual basis for a period of at least 30 years to determine the normals, which are the standard values for a location.


Normals


Normals apply only to the specific place where the meteorological data were collected.

Changes in elevation and other factors, such as proximity to large bodies of water, can cause climates to vary.

Normals


Causes of Climate

Latitude has a great effect on climate. The amount of solar radiation received on Earth decreases from the equator to the poles.

1.Latitude


Causes of Climate

The area between 23.5° S and 23.5° N of the equator is known as the tropics.

Tropical areas receive the most solar radiation and are generally warm year-round.

Latitude



Causes of Climate

The temperate zones lie between 23.5° and 66.5° north and south of the equator.

As their name implies, temperatures in these regions are moderate.

Latitude


Causes of Climate

The polar zones are located from 66.5° north and south of the equator to the poles.

Polar temperatures tend to be cold.

Latitude


Causes of Climate

Water heats up and cools down more slowly than land. Thus, large bodies of water affect the climates of coastal areas.

Temperatures in the lower atmosphere generally decrease with altitude. Thus, mountain climates are usually cooler than those at sea level.

2.Topographic effects


Causes of Climate

Orographic lifting leads to rain on the windward side of a mountain. The leeward side is usually dry and warm.

Topographic effects


Causes of Climate3.Air masses

Air masses affect regional climates by transporting the temperature and humidity of their source regions.

ObjectivesDescribe the criteria used to classify climates.

Compare and contrast different climates.

Explain and give examples of microclimates.

Climate ClassificationSection 14.2

Review Vocabulary

precipitation: all solid and liquid forms of water—including rain, snow, sleet, and hail—that fall from clouds

Climates are categorized according to the average temperatures and precipitation amounts.


New Vocabulary

Köppen classification system

microclimate

heat island

Köppen Classification System – 5 divisions

The Köppen classification system is a classification system for climates that is based on the average monthly values of temperature, precipitation and vegetation..

Developed by German climatologist Wladimir Köppen, the system also takes into account the distinct vegetation found in different climates.


Köppen Classification SystemThese graphs show temperature and precipitation for two different climates—a desert in Reno, Nevada, and a tropical rain forest in New Guinea.


Visualizing Worldwide Climates

Köppen’s classification system is made up of five main divisions based on temperature and precipitation.



Please click the image above to view the video.


Köppen Classification System

Year-round high temperatures characterize tropical climates. In tropical wet climates, high temperatures are accompanied by up to 600 cm of rain each year.

Tropical regions are almost continually under the influence of maritime tropical air.

1.Tropical climates



The areas that border the rainy tropics to the north and south of the equator are transition zones, known as the tropical wet and dry zones.

These areas have distinct dry winter seasons as a result of the occasional influx of dry continental air masses.

Tropical climates



Dry climates, which cover about 30 percent of Earth’s land area, make up the largest climatic zone.

In these climates, continental tropical air dominates, precipitation is low, and vegetation is scarce.

2.Dry climates(between 20 and 30 degree latitudes)



There are two subtypes of dry climates: a)arid regions, called deserts

b)semiarid regions, called semideserts.

Semideserts are usually more humid than deserts. They generally separate arid regions from bordering wet climates.

Dry climates



Mild climates can be classified into three subtypes:

a)humid subtropical climate – In S.E USA due to subtropical high pressure systems.

b)marine west-coast climates- due to constant inland flow of air off the ocean.

c)Mediterranean climates – warm,dry summers and cool, rainy winters.

3.Mild climates



Humid subtropical climates are influenced by the subtropical high-pressure systems that are normally found over oceans in the summer.

The marine west-coast climates are dominated by the constant inland flow of air off the ocean.

Mild climates



Summers in Mediterranean climates are generally warm and dry because of their nearness to the dry midlatitude climates from the south. Winters are cool and rainy as a result of the midlatitude weather systems that bring storm systems from the north.

Mild climates



Continental climates are classified into three subtypes:

a)warm summer climates,

b)cool summer climates, and

c)subarctic climates.

4.Continental climates- in the interior of continents.


Tropical and polar air masses often form fronts where they meet in continental climates.

Thus, these zones experience rapid and sometimes violent changes in weather, including severe thunderstorms or tornadoes.


Continental climates



5.Polar climates

To the north of the subarctic climate lies one of the polar climates— the tundra.

The tundra is known for its low temperatures. There are no trees in the tundra and precipitation is generally low.



Polar climates

The ice-cap polar climate, found at the highest latitudes in both hemispheres, does not have a single month in which average temperatures rise above 0°C.



Polar climates

A variation of the polar climate, called a highland climate, is found at high elevations.


Microclimates

A localized climate that differs from the main regional climate is called a microclimate.

Many concrete buildings and large expanses of asphalt can create a heat island, where the climate is warmer than in surrounding rural areas.


MicroclimatesHeat islands

CH

14.1 Section Questions

Climate

The normal high temperature for a location is calculated by averaging high temperature data for that location.

a. true

b. false

CH


Climate

Which latitude region on Earth is called the tropics?

a. between 10° N and 10° S

b. between 23.5° N and 23.5° S

c. between 28.5° N and 28.5° S

d. between 30° N and 30° S

CH


Climate

What happens as air rises on the windward side of a mountain range?

a. The air cools and water condenses.

b. The air cools and water resists condensation.

c. The air warms and water condenses.

d. The air warms and water resists condensation.

CH


Climate

Which two measures of climate form the basis of the Köppen classification system?

a. temperature and wind speed

b. precipitation and temperature

c. humidity and precipitation

d. wind speed and humidity

CH


Climate

Which landmass has mostly an ice cap climate?

a. Europe

b. South America

c. North America

d. Greenland

CH


Climate

Why is the climate of a large city usually different from the climate of the surrounding region?

CH

Answer: Large cities are heat islands, microclimates in which the average temperature is higher than that of surrounding areas and in which the average precipitation might differ. Buildings, roadways, and parking lots contribute to the heat island by absorbing more solar energy than vegetated land would.


Climate

CH

Chapter Assessment Questions

Climate

In which latitude zone are dry climates most common?

a. 0° to 10°

b. 20° to 30°

c. 40° to 50°

d. 60° to 70°

CH

Chapter Assessment Questions

Climate

Examine the graph. Which climate type is shown?

a. tundra

b. highland

c. tropical wet

d. tropical wet and dry

CH

Which type of air mass brings the most frigid winter air to the central United States?

a. continental polar

b. maritime polar

c. arctic

d. maritime tropical

Standardized Test Practice

Climate

CH

a. winter

b. spring

c. summer

d. autumn

Examine the illustration. Which season is occurring in the northern hemisphere?


Climate

CH


Climate

a. tundra

b. Mediterranean

c. highland

d. subarctic

Which climate is a type of mild climate?

Documents

Objectives Recognize limits associated with the use of normals. Explain why climates vary. Compare and contrast temperatures in different regions on Earth