Chapter 14 - Climate14.1 – Defining Climate

ClimatologyStudy of Earth’s climate and the

factors that affect past, present, and future climate changes

Long-term weather patterns of an area

http://www.geography.learnontheinternet.co.uk/images/weather/worldclimatesmall.gif

Normals Data used to describe an area’s

climateIncluded daily high and low temperaturesAmount of rainfallWind speed and directionHumidityAir pressure

Averaged on a monthly or annual basis for at least 30 years

Standard values for a location

 NormalsApply only to the specific place where data is collected

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

 LatitudeAmount of solar radiation received decreases from the equator to the poles

The amount of solar energy received depends on the angle at which the sun’s rays hit a location and the number of daylight hours the location receives

Angle of sun’s rays is determined by latitude and tilt of the Earth’s axis

http://www.physicalgeography.net/fundamentals/images/earth_sun_angles.gif

Tropic ZoneArea between 23.5° S and 23.5 ° N

of equatorImmediately around the equator

Receive most solar radiationGenerally warm year-round

Average monthly temperature above 64ºF (18ºC)

Influenced by continental and maritime tropical air masses

Temperate ZoneArea between 23.5° to 66.5°Temperatures are moderate

Average monthly temperature is no warmer than 64°F (18°C) in coldest month and no cooler than 50°F (10°C) in warmest month

Weather changes often because of air masses moving across regionFrequently exposed to wave cyclones

with strong winds and heavy rains

Polar Zone66.5° latitude to the polesTend to be cold

Average monthly temperature is never higher than 50°F (10°C)

Continental and maritime air masses start in these areas

 Topographic effectsWater heats up and cools down more

slowly than landLarge bodies of water affect climates

of coastal areas

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Temperature in the lower atmosphere generally decreases with altitude

Mountain climates are usually cooler than those at sea level

MountainsOrographic lifting leads to rains on the windsideLeeward side is usually dry and warm

Air massesAffect regional climates by transporting the temperature and humidity

In-Class Assignment/HomeworkMountains and Climate WKT