ClimateClimate

A climate is the pattern of weather that occurs A climate is the pattern of weather that occurs in an area over many years.in an area over many years.

1. Determines the types of plants or 1. Determines the types of plants or animals that can survive and animals that can survive and influences how people live.influences how people live.

2. Elements that are averaged to 2. Elements that are averaged to determine climate: temperature, determine climate: temperature,

precipitation, air pressure, humidity, precipitation, air pressure, humidity, and days of sunshine.and days of sunshine.

Factors that affect climateFactors that affect climate

1. Latitude – distance north or south of the 1. Latitude – distance north or south of the equator.equator.

TropicsTropics Regions between latitudes 23 N and 23 SRegions between latitudes 23 N and 23 S Sun shines almost directly overhead, keeping Sun shines almost directly overhead, keeping

temperatures hightemperatures high

Polar ZonesPolar Zones

extend from 66 N and 66 S to the poles – sun extend from 66 N and 66 S to the poles – sun shines at a low angle, keeping temperatures shines at a low angle, keeping temperatures lowlow

Temperate ZonesTemperate Zones between the tropics and the polar zones – between the tropics and the polar zones –

moderate temperaturesmoderate temperatures

Why are isotherms not parallel with latitude?

Large bodies of water affect the Large bodies of water affect the climate of coastal areas by absorbing climate of coastal areas by absorbing

or giving off heator giving off heat

Ocean currents can bring cool or Ocean currents can bring cool or warm temperatures and moisture to warm temperatures and moisture to

coastal areascoastal areas

Mountains affect their own climate Mountains affect their own climate as well as the climates of nearby as well as the climates of nearby

areasareas

At the same latitude, the climate of At the same latitude, the climate of on a mountain is colder than the on a mountain is colder than the

climate at sea levelclimate at sea level

Mountains cause air to rise, cool, and Mountains cause air to rise, cool, and condense, creating a wetter climate on the condense, creating a wetter climate on the windward side of the mountain and a much windward side of the mountain and a much drier climate on the leeward side.drier climate on the leeward side.

Because of their large areas of solar radiation – Because of their large areas of solar radiation – absorbing asphalt and concrete, cities absorbing asphalt and concrete, cities frequently have higher temperatures than frequently have higher temperatures than surrounding areas.surrounding areas.

Section II – Climate TypesSection II – Climate Types

AdaptationAdaptation

any structure or behavior that helps an any structure or behavior that helps an organism survive in its environmentorganism survive in its environment

Structural adaptations are body Structural adaptations are body structures that help organisms structures that help organisms

survive in certain climates.survive in certain climates. a – the fur of mammals insulates them from a – the fur of mammals insulates them from

cold temperaturescold temperatures b – a cactus’s thick, fleshy stem helps it hold b – a cactus’s thick, fleshy stem helps it hold

waterwater

Behavioral adaptationsBehavioral adaptations

a – hibernation – a period of greatly reduced a – hibernation – a period of greatly reduced activity during cold monthsactivity during cold months

b – estivation – similar to hibernation, an b – estivation – similar to hibernation, an inactive state that occurs during periods of inactive state that occurs during periods of intense heatintense heat

Section III - Climate ChangesSection III - Climate Changes

SeasonsSeasons

short periods of climatic change caused by short periods of climatic change caused by changes in the amount of solar radiation an changes in the amount of solar radiation an area receivesarea receives

1. As Earth revolves around the Sun, different 1. As Earth revolves around the Sun, different areas of Earth are tilted toward the sun.areas of Earth are tilted toward the sun.

2. The tropics do not experience much 2. The tropics do not experience much seasonal temperature change.seasonal temperature change.

3. High latitudes near the poles experience 3. High latitudes near the poles experience great seasonal temperature change.great seasonal temperature change.

El Nino – an occasional climatic El Nino – an occasional climatic event in which strong Pacific winds event in which strong Pacific winds

weaken and sometimes reverse.weaken and sometimes reverse.

Effects of El NinoEffects of El Nino

a – Ocean temperatures near Peru heat upa – Ocean temperatures near Peru heat up

b – The position and strength of one of the jet b – The position and strength of one of the jet streams may be altered, changing wind and streams may be altered, changing wind and precipitation patterns around the world.precipitation patterns around the world.

c - Africa and Australia may experience c - Africa and Australia may experience drought.drought.

La Nina – The winds blowing across La Nina – The winds blowing across the pacific are stronger than normalthe pacific are stronger than normal

At times in the past, Earth’s climate At times in the past, Earth’s climate was much warmer or colder than was much warmer or colder than

now.now.

Causes of climatic change can Causes of climatic change can operate over short or very long operate over short or very long

periods of timeperiods of time

1. Solar radiation is blocked by larger 1. Solar radiation is blocked by larger numbers of solid and liquid particles entering numbers of solid and liquid particles entering the atmospherethe atmosphere

a. Catastrophic events such as a. Catastrophic events such as volcanic eruptions and meteorite volcanic eruptions and meteorite

collisions can cause climatic changecollisions can cause climatic change

Pollution can also cause climatic changePollution can also cause climatic change

4. The movement of Earth’s crustal plates 4. The movement of Earth’s crustal plates affects the transfer of heat on Earth.affects the transfer of heat on Earth.

Climatic Changes TodayClimatic Changes Today

Greenhouse Effect – a natural heating process Greenhouse Effect – a natural heating process that occurs when certain gasses such as carbon that occurs when certain gasses such as carbon dioxide, methane, and water vapor in earth’s dioxide, methane, and water vapor in earth’s atmosphere trap heat.atmosphere trap heat.

Global Warming – Earth’s average global Global Warming – Earth’s average global surface temperature is rising, possibly due to surface temperature is rising, possibly due to the increase in greenhouse gasses in our the increase in greenhouse gasses in our atmosphere.atmosphere.

Human activities affect the air on Human activities affect the air on Earth’s surfaceEarth’s surface

a. burning fossil fuels increases the amount of a. burning fossil fuels increases the amount of carbon dioxide in the atmosphere.carbon dioxide in the atmosphere.

Deforestation results in fewer trees to absorb Deforestation results in fewer trees to absorb carbon dioxide from the atmosphere.carbon dioxide from the atmosphere.

Individuals CAN help reduce the Individuals CAN help reduce the amount of carbon dioxide in the amount of carbon dioxide in the

atmosphere.atmosphere.