climate and terrestrial biodiversity chapter 7. weather: a brief introduction weather result of...
TRANSCRIPT
Climate and Terrestrial Climate and Terrestrial BiodiversityBiodiversity
CHAPTER 7CHAPTER 7
Weather: A Brief IntroductionWeather: A Brief Introduction
WeatherWeather result of the atmospheric conditions in a result of the atmospheric conditions in a
particular area over short periods of time, particular area over short periods of time, typically over hours or daystypically over hours or days
EX:EX:temperature, pressure, moisture content, temperature, pressure, moisture content,
precipitation, sunshine, cloud cover, and wind precipitation, sunshine, cloud cover, and wind directiondirection
OBJ 6.1
CLIMATECLIMATEthe average pattern of the average pattern of
weather for a particular weather for a particular regionregion
LONG TERMLONG TERM
OBJ 6.2
Warm FrontsWarm Fronts
A A warm frontwarm front is the boundary between an is the boundary between an advancing warm air mass and the cooler advancing warm air mass and the cooler one it is replacing.one it is replacing.
Because warm air is less dense than cool Because warm air is less dense than cool air, an advancing warm front rises up over a air, an advancing warm front rises up over a mass of cool air. mass of cool air.
As the warm front rises, its moisture begins As the warm front rises, its moisture begins condensing into droplets to form layers of condensing into droplets to form layers of clouds at different altitudes.clouds at different altitudes.
Cold FrontCold Front
A cold front is the leading edge of an A cold front is the leading edge of an advancing mass of cold air. Since cold air is advancing mass of cold air. Since cold air is more dense than warm air it moves in low to more dense than warm air it moves in low to the ground.the ground.
Jet StreamsJet Streams
These are hurricane force winds that are These are hurricane force winds that are blowing around up near the troposphere, blowing around up near the troposphere, these powerful winds rising and falling these powerful winds rising and falling cause great influence on weather patterns.cause great influence on weather patterns.
What are Highs and Lows? Pressure What are Highs and Lows? Pressure ChangesChanges
Weather is affected by up and down Weather is affected by up and down movements of masses of air with high and movements of masses of air with high and low atmospheric pressure.low atmospheric pressure.
Air pressure results from zillions of tiny Air pressure results from zillions of tiny molecules of gases (mostly nitrogen and molecules of gases (mostly nitrogen and oxygen) in the atmosphere zipping around oxygen) in the atmosphere zipping around at incredible speeds and hitting and at incredible speeds and hitting and bouncing off anything they encounter.bouncing off anything they encounter.
An air mass with high pressure, called a An air mass with high pressure, called a high, contains cool, dense air that descends high, contains cool, dense air that descends toward the earth’s surface and becomes toward the earth’s surface and becomes warmer.warmer.
An air mass with low pressure, called a low, An air mass with low pressure, called a low, produces cloudy and sometimes stormy produces cloudy and sometimes stormy weather.weather.
Weather GodzillasWeather Godzillas
Tornadoes (over land) and tropical storms, Tornadoes (over land) and tropical storms, cyclones, (form over warm ocean waters cyclones, (form over warm ocean waters and sometimes pass over land) are weather and sometimes pass over land) are weather extremes that can cause lots of damage but extremes that can cause lots of damage but can sometimes have beneficial ecological can sometimes have beneficial ecological effects.effects.
TornadoesTornadoes
Tornadoes or twisters are swirling funnel Tornadoes or twisters are swirling funnel shaped clouds that form over land.shaped clouds that form over land.
They can destroy houses and cause other They can destroy houses and cause other serious damage in areas when they touch serious damage in areas when they touch down on the earth’s surface.down on the earth’s surface.
The United States is the world’s most The United States is the world’s most tornado-prone country, followed by tornado-prone country, followed by Australia.Australia.
TornadoesTornadoes
Tornadoes in the plains of the Midwest Tornadoes in the plains of the Midwest usually occur when a large, dry cold air front usually occur when a large, dry cold air front moving southward from Canada runs into a moving southward from Canada runs into a large mass of humid air moving northward large mass of humid air moving northward from the Gulf.from the Gulf.
Most tornadoes occur in the spring when Most tornadoes occur in the spring when fronts of cold air from north penetrate deeply fronts of cold air from north penetrate deeply into the midwestern plains. into the midwestern plains.
Tropical StormsTropical Storms
Large and dangerous storms called tropical Large and dangerous storms called tropical cyclones are spawned by the formation of cyclones are spawned by the formation of low-pressure cells of air over warm tropical low-pressure cells of air over warm tropical seas.seas.
Hurricanes are tropical cyclones the form in Hurricanes are tropical cyclones the form in the Atlantic Ocean; those forming in the the Atlantic Ocean; those forming in the Pacific Ocean usually are called typhoons. Pacific Ocean usually are called typhoons.
Gale force winds circle the eye of the storm Gale force winds circle the eye of the storm at speeds of up to 200 miles per hour.at speeds of up to 200 miles per hour.
Moist surface winds move to the center of Moist surface winds move to the center of the stormthe storm
ClimateClimate
Climate is the long term atmospheric Climate is the long term atmospheric conditions of a region over several decades.conditions of a region over several decades.
The two main factors that determine a The two main factors that determine a regions climate are average temperature regions climate are average temperature and average precipitation.and average precipitation.
Determining Air PatternsDetermining Air Patterns
There are four main factors that determine There are four main factors that determine global air circulation patterns.global air circulation patterns.
1. Uneven heating of the earths surface.1. Uneven heating of the earths surface.
EX: Air at the equator has more direct EX: Air at the equator has more direct sunlight so it is hotter than air below it and sunlight so it is hotter than air below it and above itabove it
OBJ 6.3
2. Seasonal changes in temperature and 2. Seasonal changes in temperature and precipitation precipitation
Ex. The earth is tilted which resulted in Ex. The earth is tilted which resulted in some areas being pushed closer to the sun some areas being pushed closer to the sun and some being pushed farther.and some being pushed farther.
3. Rotation of the earth on its axis3. Rotation of the earth on its axis
Ex. This causes prevailing winds which are Ex. This causes prevailing winds which are major surface winds that are continuously major surface winds that are continuously blowing and distributing moisture over the blowing and distributing moisture over the earthearth
4. properties of air, water, and land also 4. properties of air, water, and land also affect global air circulation.affect global air circulation.
Seasons Seasons Seasons in the N and S Seasons in the N and S
hemispheres are caused by the tilt hemispheres are caused by the tilt of the earths axis. of the earths axis.
The earths tilt is The earths tilt is about 23.5 degrees.about 23.5 degrees.
How does the ocean affect climateHow does the ocean affect climate
Ocean currents and winds influence climate Ocean currents and winds influence climate by redistributing heat received from the sun by redistributing heat received from the sun from one place to anotherfrom one place to another
Oceans absorb heat from air patternsOceans absorb heat from air patterns
OBJ 6.4
WindsWinds
Winds can also affect regional climates and Winds can also affect regional climates and how some forms of ocean life are how some forms of ocean life are distributed.distributed.
The ocean is in a constant flow where the The ocean is in a constant flow where the outgoing surface water gets replaced by the outgoing surface water gets replaced by the upwelling upwelling cold nutrient rich water from the cold nutrient rich water from the bottom.bottom.
Wind Currents in the U.S.Wind Currents in the U.S.
El NinoEl Nino Every few years in the Pacific Ocean normal Every few years in the Pacific Ocean normal
shore upwelling's are affected by changes in shore upwelling's are affected by changes in climate patterns called, climate patterns called, El Nino Southern El Nino Southern OscillationOscillation..
OBJ 6.5
El NinoEl Nino
In an ENSO warmer trade winds prevail and In an ENSO warmer trade winds prevail and warm the ocean waters of the northern and warm the ocean waters of the northern and southern waters of the American coasts. southern waters of the American coasts. This stops the cold nutrient rich waters from This stops the cold nutrient rich waters from reaching the surface and affects marine life reaching the surface and affects marine life populations in the seas.populations in the seas.
A very strong ENSO can bring about extream A very strong ENSO can bring about extream climate changes in two-thirds of the world.climate changes in two-thirds of the world.
The Natural Greenhouse EffectThe Natural Greenhouse Effect
The Naturals Greenhouse Effect is water The Naturals Greenhouse Effect is water vapor, carbon dioxide, and other gases that vapor, carbon dioxide, and other gases that influence climate by warming the lower influence climate by warming the lower troposphere and the earth’s surface.troposphere and the earth’s surface.
OBJ 6.6
The Natural Greenhouse EffectThe Natural Greenhouse Effect
The Natural Greenhouse EffectThe Natural Greenhouse Effect
Small amounts of certain gases play a key Small amounts of certain gases play a key role in determining the earth’s average role in determining the earth’s average temperature and thus its climates.temperature and thus its climates.
These gases include water vapor (H20), These gases include water vapor (H20), Carbon Dioxide (CO2), Methane (CH4), and Carbon Dioxide (CO2), Methane (CH4), and Nitrous Oxide (N20)Nitrous Oxide (N20)
The Natural Greenhouse EffectThe Natural Greenhouse Effect
The Natural Greenhouse EffectThe Natural Greenhouse Effect
Together these gases known as Together these gases known as greenhouse gases, allow mostly visible light greenhouse gases, allow mostly visible light and some infrared radiation and ultraviolet and some infrared radiation and ultraviolet (UV) radiation from the sun to pass through (UV) radiation from the sun to pass through the trosphere.the trosphere.
The Natural Greenhouse EffectThe Natural Greenhouse Effect
The earth’s surface absorbs much of this The earth’s surface absorbs much of this solar energy.solar energy.
This transforms it to longer-wavelength This transforms it to longer-wavelength infrared, which rises into the troposphere.infrared, which rises into the troposphere.
The Natural Greenhouse EffectThe Natural Greenhouse Effect
Some of this infrared radiation escapes into space Some of this infrared radiation escapes into space and some is absorbed by molecules of and some is absorbed by molecules of greenhouse gases and emitted into the greenhouse gases and emitted into the troposphere in all directions as even longer troposphere in all directions as even longer wavelength infrared radiationwavelength infrared radiation
The Natural Greenhouse EffectThe Natural Greenhouse Effect
Some of this released energy is radiation Some of this released energy is radiation into space and some warms the troposphere into space and some warms the troposphere and the earth’s surface. and the earth’s surface.
This natural warming effect of the This natural warming effect of the troposphere is called the troposphere is called the greenhouse greenhouse effect.effect.
Creating Deserts and Warming Creating Deserts and Warming CitiesCities
Mountain and cities affect local and regional Mountain and cities affect local and regional climates.climates.
Creating Deserts and Warming Creating Deserts and Warming CitiesCities
When moist air blowing inland from an When moist air blowing inland from an ocean reaches a mountain range, it cools as ocean reaches a mountain range, it cools as it is forced to rise and expand.it is forced to rise and expand.
This causes the air to los most of its This causes the air to los most of its moisture as rain and snow on the windward moisture as rain and snow on the windward slopes.slopes.
Creating Deserts and Warming Creating Deserts and Warming CitiesCities
As the drier air mass flows down the As the drier air mass flows down the leeward slopes, it draws moisture out of the leeward slopes, it draws moisture out of the plants and soil over which it passes.plants and soil over which it passes.
The lower precipitation and the resulting The lower precipitation and the resulting semiarid or arid conditions on the leeward semiarid or arid conditions on the leeward side of the high mountains are called side of the high mountains are called rain rain shadow effect.shadow effect.
Creating Deserts and Warming Creating Deserts and Warming CitiesCities
Cities also create distinct microclimates.Cities also create distinct microclimates. Bricks, concrete, asphalt, and other building Bricks, concrete, asphalt, and other building
materials absorb and hold heat, and materials absorb and hold heat, and buildings block wind flow.buildings block wind flow.
Creating Deserts and Warming Creating Deserts and Warming CitiesCities
Motor vehicles and the climate control Motor vehicles and the climate control systems of buildings release large quantities systems of buildings release large quantities of heat and pollutants.of heat and pollutants.
As a result, cities tend to have more haze As a result, cities tend to have more haze and smog, higher temperature, and lower and smog, higher temperature, and lower wind speeds than the surrounding wind speeds than the surrounding countryside.countryside.
Tropical TemperaturesTropical Temperatures
The most important factors for producing the The most important factors for producing the tropical and temperate climates is the tropical and temperate climates is the average annual precipitation, temperature average annual precipitation, temperature and soil type.and soil type.
NavigationNavigation
Latitude: the distance from the equatorLatitude: the distance from the equator
Altitude: the elevation above sea levelAltitude: the elevation above sea level
DesertsDeserts
A desert is an area where evaporation A desert is an area where evaporation exceeds precipitation.exceeds precipitation.
Deserts have little precipitation and little Deserts have little precipitation and little vegetation and are found in tropical, vegetation and are found in tropical, temperature, and polar regions.temperature, and polar regions.
Deserts cover about 30% of the earths Deserts cover about 30% of the earths surface.surface.
Deserts are found mostly in tropical and Deserts are found mostly in tropical and subtropical regionssubtropical regions
Desert soils have little vegetation so at night Desert soils have little vegetation so at night the surface rapidly coolsthe surface rapidly cools
3 types of deserts3 types of deserts
Tropical deserts: hot and dry most of the Tropical deserts: hot and dry most of the year, with few plants and hard surfacesyear, with few plants and hard surfaces
Temperate deserts: has high daytime temps Temperate deserts: has high daytime temps in the summer and low daytime temps in the in the summer and low daytime temps in the winter. Vegetation consists of cacti and winter. Vegetation consists of cacti and shrubsshrubs
Cold deserts: winters cold and summers are Cold deserts: winters cold and summers are warm with low precipitation.warm with low precipitation.
In the semiarid zones between deserts and In the semiarid zones between deserts and grasslands, we find semidesert. grasslands, we find semidesert.
This biome is dominated by thorn trees and This biome is dominated by thorn trees and shrubs adapted to long dry spells followed shrubs adapted to long dry spells followed by brief, sometimes heavy rains.by brief, sometimes heavy rains.
Stay Cool and Get Water Any Way Stay Cool and Get Water Any Way You Can!You Can!
Desert plants and animals have a number of Desert plants and animals have a number of strategies for staying cool and getting strategies for staying cool and getting enough water to survive in hot and dry enough water to survive in hot and dry climates. Beat the heat or DIE!!!climates. Beat the heat or DIE!!!
Desert AdaptationsDesert Adaptations
Cactuses don’t have leaves which can Cactuses don’t have leaves which can loose water, also they open their pores loose water, also they open their pores at night when its cooler to intake at night when its cooler to intake oxygen, they store water in inside them oxygen, they store water in inside them for very dry spells, and finally they have for very dry spells, and finally they have deep roots to tap into ground water deep roots to tap into ground water supplies.supplies.
Major Types of GrasslandsMajor Types of GrasslandsHot, Cold, and MildHot, Cold, and Mild
Grasslands have enough precipitation to Grasslands have enough precipitation to support grasses but not enough to support support grasses but not enough to support large stands of trees. large stands of trees.
Grasslands are found in tropical, temperate Grasslands are found in tropical, temperate and polar regions. and polar regions.
Prairies or Grasslands Prairies or Grasslands
Prairies or grasslands are mostly found in Prairies or grasslands are mostly found in the interiors on continents. They are formed the interiors on continents. They are formed because of a combination of drought, because of a combination of drought, precipitation, fire and animals grazing that precipitation, fire and animals grazing that keep large shrubs and trees from growing. keep large shrubs and trees from growing.
Grasslands in CanadaGrasslands in Canada
SavannaSavanna
Are grasslands that experience very warm Are grasslands that experience very warm temperatures year round. Also they have temperatures year round. Also they have two dry spells and then rain the rest of the two dry spells and then rain the rest of the year.year.
They are mainly inhabited by huge herds of They are mainly inhabited by huge herds of hoofed, and grazing animals. hoofed, and grazing animals.
Polar GrasslandsPolar Grasslands
Polar Grasslands are occur south of the Polar Grasslands are occur south of the polar ice caps.polar ice caps.
Treeless plains covered in ice and snow Treeless plains covered in ice and snow most of the year, except for a brief summer most of the year, except for a brief summer period.period.
Has a layer of permafrost just below the soilHas a layer of permafrost just below the soil Inhabited by small herbivores, and small Inhabited by small herbivores, and small
predators.predators.
ChaparralChaparral
Has a very mild climate with a slightly longer Has a very mild climate with a slightly longer winter rainy season.winter rainy season.
Located along the oceans in southern Located along the oceans in southern California and the Mediterranean.California and the Mediterranean.
Subject to many fires during the fall followed Subject to many fires during the fall followed by flooding and mudslides.by flooding and mudslides.
Long, hot, dry summers make fires happen Long, hot, dry summers make fires happen very often.very often.
FloodingFlooding
Chaparral Plant LifeChaparral Plant Life
Consists mostly of dense growths of low Consists mostly of dense growths of low growing evergreen shrubsgrowing evergreen shrubs
Few small trees with leaves that reduce Few small trees with leaves that reduce evaporationevaporation
During summer become dry and flammable.During summer become dry and flammable.
Tropical Rain ForestsTropical Rain Forests
Heavy rainfall most days out of the year.Heavy rainfall most days out of the year. Found near the equator. High humidity.Found near the equator. High humidity. Very diverse forms of life.Very diverse forms of life. Broadleaf evergreen plants are the main Broadleaf evergreen plants are the main
vegetation.vegetation. Soil has very little plant nutrients. Soil has very little plant nutrients. Very little ground plant life.Very little ground plant life.
Temperate DeciduousTemperate Deciduous
Grow in places with moderate temperatures.Grow in places with moderate temperatures. Long warm summers, cold winters, and Long warm summers, cold winters, and
abundant precipitation.abundant precipitation. Oak, Hickory, Maple, Popular, and Beech Oak, Hickory, Maple, Popular, and Beech
trees dominate the plant life. Diverse ground trees dominate the plant life. Diverse ground plant life.plant life.
Nutrient rich soil.Nutrient rich soil.
Temperate DeciduousTemperate DeciduousAnimal LifeAnimal Life
Most popular animal species is the White-Most popular animal species is the White-Tail Deer, along with squirrels, rabbits, Tail Deer, along with squirrels, rabbits, opossums, raccoons, and mice.opossums, raccoons, and mice.
Used to be home to bears, wolves, foxes, Used to be home to bears, wolves, foxes, wildcats, and mountain lions. Most of the wildcats, and mountain lions. Most of the predators have been killed off, or displaced.predators have been killed off, or displaced.
Evergreen Coniferous ForestsEvergreen Coniferous Forests
Found just south of the arctic tundra in the Found just south of the arctic tundra in the northern regions of North America, Asia, northern regions of North America, Asia, and Europe.and Europe.
Long, dry, and extremely cold winters. Long, dry, and extremely cold winters. Where sunlight is available only 6-8 hours a Where sunlight is available only 6-8 hours a day.day.
Summers are short with mild temperatures. Summers are short with mild temperatures. Where the sun shines 19 hours a day.Where the sun shines 19 hours a day.
Evergreen Coniferous ForestEvergreen Coniferous ForestPlant lifePlant life
Mostly populated by a few species of Mostly populated by a few species of coniferous evergreen trees.coniferous evergreen trees.
Spruce, fir, cedar, hemlock, and pine trees.Spruce, fir, cedar, hemlock, and pine trees. Most keep needles all year long, and are Most keep needles all year long, and are
cone bearing.cone bearing.
Evergreen Coniferous ForestsEvergreen Coniferous ForestsAnimal LifeAnimal Life
Many small rabbits and mice.Many small rabbits and mice. Contain animal species such as moose, Contain animal species such as moose,
wolves, owls, and small birdswolves, owls, and small birds
Temperate Rain ForestsTemperate Rain Forests
Coastal region support these forests.Coastal region support these forests. Huge cone bearing trees such as redwoods Huge cone bearing trees such as redwoods
and Douglas firsand Douglas firs Environment must be cool and moist to Environment must be cool and moist to
support temperate rain forests.support temperate rain forests. Cool summers and wintersCool summers and winters Trees depend of frequent rainsTrees depend of frequent rains
Mountain BiomesMountain Biomes
High elevated forests.High elevated forests. Often peaks are snow covered.Often peaks are snow covered. Gradually release water to lower level Gradually release water to lower level
streams and rivers.streams and rivers. Prone to erosion, landslides, and Prone to erosion, landslides, and
avalanchesavalanches Make up one fourth on the worlds land Make up one fourth on the worlds land
surface.surface.
Natural Capital DegradationNatural Capital Degradation
Clearing and degradation of tropical forests Clearing and degradation of tropical forests for agriculture, livestock, gazing, and timber for agriculture, livestock, gazing, and timber harvesting.harvesting.
Clearing of deciduous forests of Europe, Clearing of deciduous forests of Europe, Asia and North America, for timber, Asia and North America, for timber, agriculture, and urban development.agriculture, and urban development.
Converting diverse forest into non diverse Converting diverse forest into non diverse tree plantations. tree plantations.
Natural Capital Degradation Natural Capital Degradation (Mountains)(Mountains)
Landless poor migrating uphill to survive.Landless poor migrating uphill to survive. Timber extractionTimber extraction Mineral resource extractionMineral resource extraction Hydro-electric dams and reservoirsHydro-electric dams and reservoirs Increasing tourism (such as hiking and Increasing tourism (such as hiking and
skiing)skiing) Air pollutionAir pollution Soil damage from off road vehiclesSoil damage from off road vehicles
