Chapter Three Climate and Vegetation. SEASONS How many season are there? Winter Spring Summer Fall

Chapter ThreeChapter ThreeClimate and VegetationClimate and Vegetation

SEASONSSEASONS

How many season are there?WinterSpringSummer Fall

WHERE DO SEASONS COME WHERE DO SEASONS COME FROM?FROM?

Earth’s tilt on it’s axis at a Earth’s tilt on it’s axis at a 23.5 23.5 degreedegree angleangle in relation to the in relation to the sunsun

Earth rotates once every 24 hrs Earth rotates once every 24 hrs Earth makes one Earth makes one revolutionrevolution

around the sun every 365.25 daysaround the sun every 365.25 days

SEASONSSEASONS

Earth’s axis always points to Earth’s axis always points to the same spot in the skythe same spot in the sky

Revolution and tilt cause the Revolution and tilt cause the seasonsseasons

(different parts of the earth receive (different parts of the earth receive direct rays from the sun for more direct rays from the sun for more hours at certain times of the year) hours at certain times of the year)

Season DiagramSeason Diagram

SEASONSSEASONS

SummerSummer: days are longer and sun’s energy : days are longer and sun’s energy is strongeris stronger

WinterWinter: days are shorter and sun’s energy is : days are shorter and sun’s energy is weakerweaker

Spring & FallSpring & Fall: daylight and darkness are : daylight and darkness are equal length sun’s energy is evenly equal length sun’s energy is evenly distributeddistributed

SOLSTICESSOLSTICES

The two times a The two times a year that the year that the earth’s poles point earth’s poles point at their greatest at their greatest angle toward or angle toward or away from the sunaway from the sun

SOLSTICESSOLSTICES

Summer Solstice:Summer Solstice: June 21 June 21stst . . Beginning of Summer, longest day of Beginning of Summer, longest day of the year the year

Winter Solstice:Winter Solstice: December 21 December 21stst Beginning of Winter, shortest day of Beginning of Winter, shortest day of the yearthe year

EQUINOXEQUINOX

Twice a year Twice a year Days and Days and

nights are nights are equal in lengthequal in length

Sun’s rays are Sun’s rays are directly on the directly on the equator equator

EQUINOXEQUINOX

Vernal (spring) equinoxVernal (spring) equinox about about March 21 signals the beginning of March 21 signals the beginning of SpringSpring

Autumnal equinoxAutumnal equinox about September about September 22 signals the beginning of autumn22 signals the beginning of autumn

WHAT CAUSES WEATHER?WHAT CAUSES WEATHER?

Amount of Amount of solar energysolar energy How air masses absorb and distribute How air masses absorb and distribute

the energythe energy Landforms / bodies of waterLandforms / bodies of water Water Vapor (determines if there will be Water Vapor (determines if there will be

precipitation)precipitation) Cloud coverCloud cover ElevationElevation

CLIMATECLIMATE

Climate reflects the seasonal patterns Climate reflects the seasonal patterns of weather for a location over a long of weather for a location over a long period of timeperiod of time

Global climatic changes may be Global climatic changes may be natural or man-madenatural or man-made

FACTORS AFFECTING CLIMATEFACTORS AFFECTING CLIMATE

I. I. Wind CurrentsWind Currents

Because of earth’s rotation the winds Because of earth’s rotation the winds blow at an angle.blow at an angle. Northern hemisphere to the rightNorthern hemisphere to the right Southern hemisphere to the leftSouthern hemisphere to the left

Coriolis Effect – bending of the windCoriolis Effect – bending of the wind

CLIMATE FACTORSCLIMATE FACTORS

Trade Winds: Low lat. – Southeasterly Trade Winds: Low lat. – Southeasterly & Northeasterly & Northeasterly

Westerlies: Mid Lat. – carry weather Westerlies: Mid Lat. – carry weather across the US from W to Eacross the US from W to E

Polar Easterlies: High Lat. Bring cold Polar Easterlies: High Lat. Bring cold air from the polesair from the poles

CLIMATE FACTORSCLIMATE FACTORS II. II. Ocean CurrentsOcean Currents-- rivers flowing in rivers flowing in

the oceanthe ocean Currents are circularCurrents are circular Warm waters flow away from the Warm waters flow away from the

equator toward the poles & cold water equator toward the poles & cold water flows back toward the equatorflows back toward the equator

affect temperature & amount of affect temperature & amount of precipitation of an area.precipitation of an area.

III. III. Latitude ZonesLatitude Zones - -Biggest effect on Biggest effect on

climate!climate! Low/Tropics Low/Tropics - areas near the equator that - areas near the equator that

remain warm, 23½remain warm, 23½° N - ° N - 23½23½°S°S Mid/Temperate - Mid/Temperate - usually has four different usually has four different

seasons 23½seasons 23½° ° -66-66°° N & 23½ N & 23½° ° – 66– 66°° S S High/Polar -High/Polar - areas near the poles that receive areas near the poles that receive

little solar energy and are cold most of the little solar energy and are cold most of the time. 66time. 66° - 90° N & ° - 90° N & 6666° - 90° S° - 90° S



IV. IV. ElevationElevation- distance above sea - distance above sea levellevel As altitude increases, air temp drops As altitude increases, air temp drops

about 3.5 degrees for every 1000 feetabout 3.5 degrees for every 1000 feet Above 12,000 feet climate Above 12,000 feet climate

is like the Arcticis like the Arctic

CLIMATE FACTORSCLIMATE FACTORS V. V. TopographyTopography

Continental Location – coastline more Continental Location – coastline more stable. Interior more extremes.stable. Interior more extremes.

Landforms have a large influence on Landforms have a large influence on climate.climate. Windward side of mountain wetter & coolerWindward side of mountain wetter & cooler

Leeward side are drier and warmerLeeward side are drier and warmer

El NinEl Ninoo

Warming of the waters off the coast Warming of the waters off the coast of South Americaof South America

Occurs about every 2-7 yearsOccurs about every 2-7 years Prevailing easterly winds slow or Prevailing easterly winds slow or

reverse direction changing the reverse direction changing the ocean’s temperatureocean’s temperature

This affects weather worldwideThis affects weather worldwide

El NinEl Ninoo

Normally easterly winds bring rain Normally easterly winds bring rain and push warm ocean toward Asia and push warm ocean toward Asia and Australiaand Australia

In El NinIn El Nino years, winds push warm o years, winds push warm water and heavy rains toward water and heavy rains toward Americas. We get floods and Americas. We get floods and Australia and Asia get droughtsAustralia and Asia get droughts

La NinLa Ninaa

Occurs when the winds blow Occurs when the winds blow opposite El Ninopposite El Ninoo

Winds blow the warmer water to the Winds blow the warmer water to the lands on the western Pacific Rimlands on the western Pacific Rim

Causes increased rain in Asia & Causes increased rain in Asia & Australia & drought along Pacific Australia & drought along Pacific coast of USAcoast of USA

GLOBAL WARMINGGLOBAL WARMING

Temperature has increased 1 degree Temperature has increased 1 degree since late 1800’ssince late 1800’s

Predicted to increase 3-5 degrees this Predicted to increase 3-5 degrees this centurycentury

GLOBALWARMING

Causes?Causes? Earth’s natural warming and Earth’s natural warming and

cooling cyclescooling cycles Greenhouse effect- layer of gases Greenhouse effect- layer of gases

released by burning of coal and released by burning of coal and petroleum traps solar energy which petroleum traps solar energy which causes higher temperaturescauses higher temperatures

CLIMATE GRAPHSCLIMATE GRAPHS

Climate graphs allow us to see how the Climate graphs allow us to see how the temperature and rainfall (precipitation) for a temperature and rainfall (precipitation) for a particular location have changed on average particular location have changed on average over one whole year. over one whole year.


A climate graph is used to display statistics A climate graph is used to display statistics about temperature (how hot or cold it is) and about temperature (how hot or cold it is) and precipitation (rainfall, snow, sleet etc.) precipitation (rainfall, snow, sleet etc.) gathered for a particular place. The statistics gathered for a particular place. The statistics of individual years of weather can vary greatly of individual years of weather can vary greatly from one year to the next. Therefore these from one year to the next. Therefore these figures are collected over a long period of time figures are collected over a long period of time (often 30 years) and an average is calculated. (often 30 years) and an average is calculated. They are climatic statistics rather than weather They are climatic statistics rather than weather statistics. statistics.


Temperature is always shown on a Temperature is always shown on a climate graph as line graph in red. climate graph as line graph in red. Temperature is a continuous concept. It Temperature is a continuous concept. It moves degree by degree rather than moves degree by degree rather than jumping from temperature to a much jumping from temperature to a much higher higher

or lower one. This is best or lower one. This is best shown by a continuous line.shown by a continuous line.


Precipitation per month is complete. It is Precipitation per month is complete. It is simply a total amount occurring when the simply a total amount occurring when the amount for each day is added up. There is no amount for each day is added up. There is no direct relationship between one month and the direct relationship between one month and the next. This is best shown by a column graph in next. This is best shown by a column graph in blue or black. blue or black.


Climate graphs can then be used to help Climate graphs can then be used to help explain the relationship between climate and explain the relationship between climate and vegetation or climate and landuse by humans. vegetation or climate and landuse by humans. They can also have spaces to describe seasons, They can also have spaces to describe seasons, human activity and many other useful climate human activity and many other useful climate related pieces of information. related pieces of information.

WORLD CLIMATE REGIONSWORLD CLIMATE REGIONS

Geographers use generalizations Geographers use generalizations about weather conditions over a long about weather conditions over a long period of time to define a climate period of time to define a climate region.region.

WORLD CLIMATE REGIONSWORLD CLIMATE REGIONS

Two most significant factors in Two most significant factors in defining different climates are:defining different climates are:

TemperatureTemperature

PrecipitationPrecipitation

CLIMATE REGIONSCLIMATE REGIONS

Other factors:Other factors:

LocationLocation

TopographyTopography

ElevationElevation

CLIMATE PATERNSCLIMATE PATERNS

Geographers use several methods to Geographers use several methods to describe climate patterns.describe climate patterns.

Most common method uses latitude Most common method uses latitude to defineto define

GENERAL CLIMATE REGIONSGENERAL CLIMATE REGIONS

Tropical (low-latitude)Tropical (low-latitude) DryDry Mid-latitudeMid-latitude High-latitudeHigh-latitude HighlandHighland

GENERAL CLIMATE REGIONSGENERAL CLIMATE REGIONS

Dry and Highland climates will occur Dry and Highland climates will occur at several different latitudesat several different latitudes

Geographers divide general regions Geographers divide general regions into sub-regionsinto sub-regions

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS Tropical

Tropical WetTropical Wet- - little variation in temperature over little variation in temperature over

year; always hot, avg temp 80;year; always hot, avg temp 80; sunny mornings and rainy sunny mornings and rainy

afternoons; afternoons; avg rainfall 80+ inches;avg rainfall 80+ inches; found in Central and South found in Central and South

America, Africa and SW AsiaAmerica, Africa and SW Asia

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS Tropical Wet & DryTropical Wet & Dry- rainy season in summer and dry season in

winter; temps cooler in dry season and warmer

in rainy season; rainfall less than tropical wet and

mostly in rainy season; found next to tropical wet climates in

Africa, Central and South America

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS Semi-aridSemi-arid- - very little precipitation (16 inches/year);very little precipitation (16 inches/year); hot summers and mild to cold winters;hot summers and mild to cold winters; found in interior of continents or in a found in interior of continents or in a

zone around deserts;zone around deserts; contains some of the mostcontains some of the most

productive agriculturalproductive agricultural

lands in the worldlands in the world

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS

DesertDesert- - categorized by rainfallcategorized by rainfall and can be hot and can be hot or cool/cold;or cool/cold;

less than 10 inches of rain/year;less than 10 inches of rain/year; hot deserts (Sahara & Arabian) have low hot deserts (Sahara & Arabian) have low

humidity and high temps during day and cold humidity and high temps during day and cold at night; at night;

cool/cold deserts found at mid-latitudes in cool/cold deserts found at mid-latitudes in Northern Hemispheres in rain shadow of Northern Hemispheres in rain shadow of mtns.; summer is warm to hot and winters are mtns.; summer is warm to hot and winters are cool to freezingcool to freezing

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS MediterraneanMediterranean- named for land - named for land

around Med. Sea; also on west around Med. Sea; also on west coast of USA and parts of coast of USA and parts of Australia;Australia;

summers dry and hot and winters summers dry and hot and winters are cool and rainy; are cool and rainy;

supports dense populationsupports dense population and rich agricultureand rich agriculture


Marine West CoastMarine West Coast- - located close to ocean; located close to ocean; mostly cloudy, foggy and damp;mostly cloudy, foggy and damp; temps relatively constant because of temps relatively constant because of

ocean winds;ocean winds; found in parts of US west coast and found in parts of US west coast and

Canada and most of Western Europe;Canada and most of Western Europe; rain is evenly distributed throughout yearrain is evenly distributed throughout year

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS Humid SubtropicalHumid Subtropical- - long periods of summer heat and long periods of summer heat and

humidity; humidity; found on east coast of continents; subject found on east coast of continents; subject

to hurricanes;to hurricanes; winters are mild to cool;winters are mild to cool; SE USA and ChinaSE USA and China are examplesare examples

CLIMATE SUB-REGIONSCLIMATE SUB-REGIONS Humid ContinentalHumid Continental- - great variety of temp and precipitation; found great variety of temp and precipitation; found

in mid-latitude interiors of Northern in mid-latitude interiors of Northern Hemisphere;Hemisphere;

air masses chilled from arctic flow air masses chilled from arctic flow over area and collide with tropical air over area and collide with tropical air masses which causes changing weather masses which causes changing weather conditionsconditions; ;

four seasons are experiencedfour seasons are experienced


SubarcticSubarctic- - covered by evergreen forests called covered by evergreen forests called

taigataiga; ; huge temp shift from winter to summer;huge temp shift from winter to summer; summers short and cool and winters very summers short and cool and winters very

cold; temps at or below freezing 5-8 cold; temps at or below freezing 5-8 months of the yearmonths of the year


TundraTundra- - flat, treeless lands forming a ring around flat, treeless lands forming a ring around

the Arctic Ocean;the Arctic Ocean; exclusive to Northern Hemisphere;exclusive to Northern Hemisphere; less than 15 inches of precipitation per less than 15 inches of precipitation per

year;year; summer lasts only a few weeks and temp summer lasts only a few weeks and temp

may reach 40 degreesmay reach 40 degrees


Ice CapIce Cap- - snow, ice and permanently frozen snow, ice and permanently frozen

climate; climate; so cold it rarely snows; so cold it rarely snows; sometimes sometimes

called polar deserts because they called polar deserts because they receive less than 10 inches of receive less than 10 inches of precipitation per yearprecipitation per year; ;

coldest temp ever recorded -128.6coldest temp ever recorded -128.6


HighlandsHighlands- climate varies with - climate varies with elevation, topography and continental elevation, topography and continental location; could be temperate up to location; could be temperate up to arctic climate depends on elevationarctic climate depends on elevation

SOILS AND VEGETATIONSSOILS AND VEGETATIONS

World’s food supply grows in the World’s food supply grows in the top 6 inches of soil, topsoil. top 6 inches of soil, topsoil.

Type of vegetation is determined Type of vegetation is determined by the depth, mixture and humus by the depth, mixture and humus content of the soil.content of the soil.

VEGETATION REGIONSVEGETATION REGIONS

Vegetation patterns are identified by Vegetation patterns are identified by the ecosystems they support.the ecosystems they support.

The ecosystems of a region, called a The ecosystems of a region, called a biome, are divided into:biome, are divided into:

ForestForest GrasslandGrassland

DesertDesert Tundra Tundra

FORESTSFORESTS

Categorized by the types of trees they Categorized by the types of trees they supportsupport Broadleaf (i.e. Maple & oak called Broadleaf (i.e. Maple & oak called

deciduous)deciduous)Rain forest is covered with Rain forest is covered with broadleafsbroadleafs

Needleleaf (i.e. Pine and fir called Needleleaf (i.e. Pine and fir called coniferous)coniferous)

GRASSLANDSGRASSLANDS

Savannas in tropical regionsSavannas in tropical regions Steppes in Northern HemisphereSteppes in Northern Hemisphere Many names in South America – Many names in South America –

Pampas, Cerrado, LlanosPampas, Cerrado, Llanos

Tundra- plants like lichen and mosses Tundra- plants like lichen and mosses are specially adapted to grow there in are specially adapted to grow there in dry, cold conditionsdry, cold conditions

Desert- plants must be able to Desert- plants must be able to conserve water and withstand heat. conserve water and withstand heat. Plants like cacti and sagebrush are Plants like cacti and sagebrush are good there.good there.

FOR TESTFOR TEST

Be sure to add Global Wind Be sure to add Global Wind Currents map on pg 54 to your Currents map on pg 54 to your notes.notes.

Know how to read a Climate Know how to read a Climate ChartChart

Documents

Chapter Three Climate and Vegetation. SEASONS How many season are there? Winter Spring Summer Fall