chapter 17/21: the atmosphere, climate, and climate change
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Chapter 17/21: The Chapter 17/21: The Atmosphere, Climate, and Atmosphere, Climate, and
Climate ChangeClimate Change
What is the What is the Atmosphere?Atmosphere?
The atmosphere is a The atmosphere is a relatively thin layer of gas relatively thin layer of gas
around our planet that around our planet that protects us from outer space.protects us from outer space.
How was the atmosphere How was the atmosphere formed?formed?
Scientists believe that gases Scientists believe that gases emitted from volcanic emitted from volcanic
eruptions led to the formation eruptions led to the formation of an atmosphere.of an atmosphere.
These gases were primarily These gases were primarily Carbon Dioxide (COCarbon Dioxide (CO22), Sulfur ), Sulfur
Dioxide (SODioxide (SO22), Water Vapor ), Water Vapor
(H(H22O), and Nitrogen (NO), and Nitrogen (N22).).
But where did the Oxygen But where did the Oxygen (O(O22) come from?) come from?
Sunlight splitting HSunlight splitting H22O into HO into H22
and Oand O22
2H2H22O 2HO 2H22 + O + O22
Cyanobacteria (Blue Green Algae) in the Cyanobacteria (Blue Green Algae) in the form of stromatolites photosynthesized form of stromatolites photosynthesized oxygen over 3 billion years ago in the oxygen over 3 billion years ago in the
“Great Oxidation Event.”“Great Oxidation Event.”
Stromatolite Fossil from Glacier National Park
Cyanobacteria as seen under a microscope
Cyanobacterium (Blue Green Algae) became part Cyanobacterium (Blue Green Algae) became part of the eukaryotic plant cell around 543 million of the eukaryotic plant cell around 543 million
years ago early in the Cambrian Period. This is years ago early in the Cambrian Period. This is called endosymbiosis. The cyanobacteria called endosymbiosis. The cyanobacteria
benefited from having a safe place to live and the benefited from having a safe place to live and the plant cell benefited by having a food source.plant cell benefited by having a food source.
Stromatolite Fossil from Glacier National Park
Cyanobacteria as seen under a microscope
Plants take in HPlants take in H22O, COO, CO22, and sunlight and give off , and sunlight and give off
energy (sugar) and Oenergy (sugar) and O22 through photosynthesis. through photosynthesis.
6CO6CO22 + 6H + 6H22O + Sunlight _____CO + Sunlight _____C66HH1212OO66 + 6O + 6O22
Trees, shrubs, grasses, and other plants produce about 50% of the world’s atmospheric oxygen. They are known as a “sink” for atmospheric carbon dioxide.
Plants take in HPlants take in H22O, COO, CO22, and sunlight and give off , and sunlight and give off
energy (sugar) and Oenergy (sugar) and O22 through photosynthesis. through photosynthesis.
6CO6CO22 + 6H + 6H22O + Sunlight _____CO + Sunlight _____C66HH1212OO66 + 6O + 6O22
Different Species of Phytoplankton. These microorganisms produce about 50% of all atmospheric oxygen worldwide. They are known as a “sink” for atmospheric carbon dioxide.
Cellular Respirators like animals take in energy Cellular Respirators like animals take in energy (sugar) and O(sugar) and O2 2 and give off Hand give off H22OO and COand CO22 through through
photosynthesis. photosynthesis. C C66HH1212OO66 + 6O + 6O2 2 _____6CO_____6CO22 + 6H + 6H22O O
Cows, humans, etc. are known as a “source” for atmospheric carbon dioxide.
See graphic on page 367 of See graphic on page 367 of your text for atmospheric your text for atmospheric
pathways.pathways.
Carbon CycleCarbon Cycle
What are the “sources” of atmospheric carbon dioxide? What are the “sinks” for atmospheric carbon dioxide?
Principal Gases of Dry AirPrincipal Gases of Dry AirPrincipal Gases of Dry Air
Nitrogen, 78.08
Oxygen, 20.95
Argon, 0.934
Carbon Dioxide, 0.035
Trace Gases, 0.001
Movement of Heat Energy in Movement of Heat Energy in the Atmospherethe Atmosphere
ConductionConduction: Heat moves : Heat moves through a substance by through a substance by
molecular collisions.molecular collisions.Ex) Burning yourself on a hot Ex) Burning yourself on a hot stove is through conduction.stove is through conduction.
ConvectionConvection: Heat moves : Heat moves through a fluid (gas or liquid) through a fluid (gas or liquid)
by differences in density.by differences in density.Ex) Rising smoke from a Ex) Rising smoke from a
forest fire.forest fire.
RadiationRadiation: Transfer of : Transfer of Energy through empty space Energy through empty space via electromagnetic waves via electromagnetic waves
(spectrum).(spectrum).Ex) UV rays from the sun.Ex) UV rays from the sun.
Structure of AtmosphereStructure of Atmosphere
The layers of the Atmosphere The layers of the Atmosphere are defined by changes in the are defined by changes in the
temperature trend.temperature trend.
TroposphereTroposphere: The : The lowest layer (0-10 lowest layer (0-10 Km). Temperature Km). Temperature
decreases with decreases with height due to height due to decreasing decreasing
pressure. This is pressure. This is where weather where weather
occurs.occurs.
StratosphereStratosphere: : (10-50 Km) (10-50 Km)
Temperature Temperature increases with increases with height. This is height. This is where we find where we find
the the ozone layerozone layer..
MesosphereMesosphere: : (50-90 Km) (50-90 Km)
Temperature Temperature decreases decreases
with height. with height.
ThermosphereThermosphere: (50 : (50 Km to Space) Km to Space) Temperature Temperature
increases with increases with height. Ionosphere height. Ionosphere
and and AurorasAuroras caused caused by by solar wind solar wind occur occur
here.here.
We sample the atmosphere We sample the atmosphere using using radiosonderadiosonde balloons balloons
You can remember the layers of the atmosphere You can remember the layers of the atmosphere from bottom to top by remembering this mnemonic: from bottom to top by remembering this mnemonic: TrTraeger aeger StStudies udies MeMega ga ThThunderstorms understorms ExExuberantly!uberantly!
Troposphere = Traeger
Stratosphere = Studies
Mesosphere = Mega
Thermosphere = Thunderstorms
Exosphere = Exuberantly!
The The greenhouse effect greenhouse effect is is caused by gases that trap caused by gases that trap infrared radiation (heat).infrared radiation (heat).
The The greenhouse effect greenhouse effect is is caused by gases that trap caused by gases that trap infrared radiation (heat).infrared radiation (heat).
One of the primary Greenhouse One of the primary Greenhouse gases is Carbon Dioxide (COgases is Carbon Dioxide (CO22). CO). CO22
molecules absorb and re-radiate molecules absorb and re-radiate infrared (heat) radiation.infrared (heat) radiation.
Carbon
2 Oxygens
An animation showing how An animation showing how ozone is destroyedozone is destroyed
The mechanism for The mechanism for depletion of the ozone layerdepletion of the ozone layer
The The ozone layer hole ozone layer hole is greatest over Antarctica in is greatest over Antarctica in October (Southern Hemisphere Spring). This is due to October (Southern Hemisphere Spring). This is due to
extremely cold temperatures and the return of ultraviolet extremely cold temperatures and the return of ultraviolet radiation as the sun rises again. radiation as the sun rises again.
Why are the temperatures at Why are the temperatures at each location different?each location different?
Heating and Cooling: Light Directly Above Surface
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time in Minutes
Tem
per
atu
re in
Deg
rees
Cel
siu
s
Sand
Water
Soil
Raw Data for Different MaterialsRaw Data for Different Materials
Time 0 1 2 3 4 5 6 7 8 910
11
12
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14
15
16
17
18
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20
Sand
22.0
27.0
28.0
36.0
41.0
42.0
43.0
46.0
47.0
49.0
51.0
49.0
46.0
45.0
43.0
41.0
39.0
38.0
37.0
36.0
35.0
Water
20.0
21.0
21.0
21.0
21.5
21.5
22.0
22.0
22.0
22.0
23.0
23.0
23.0
23.0
23.0
22.5
22.5
22.5
22.5
22.0
22.0
Soil
20.0
22.0
23.0
24.0
25.0
26.0
27.0
27.0
28.0
28.0
29.0
28.0
27.0
27.0
26.0
25.0
25.0
24.0
24.0
24.0
24.0
Why are the temperatures at Why are the temperatures at each location different?each location different?
What happens to the temperature of sand when What happens to the temperature of sand when the lamp is put at a 45 degree angle?the lamp is put at a 45 degree angle?
Effects of Angle of Insolation on Temperature: Sand Only
0.0
20.0
40.0
60.0
80.0
100.0
120.0
0 2 4 6 8 10 12 14 16 18 20
Time (minutes)
Tem
per
atu
re (
Deg
rees
Cel
siu
s)
Overhead
45 Degree Angle
Raw Data for Light at an AngleRaw Data for Light at an Angle
Time 0 1 2 3 4 5 6 7 8 910
11
12
13
14
15
16
17
18
19
20
Overhead
22.8
42.8
59.5
70.6
79.1
86.4
91.3
94.8
98.0
10
1.9
10
5.0
89.8
75.3
65.5
58.4
53.2
49.4
46.3
43.8
41.6
39.9
45 Degree Angle
23.3
26.0
30.6
34.7
38.1
40.8
43.4
45.4
47.1
48.6
50.4
49.1
45.8
42.8
40.2
38.1
36.4
35.1
34.0
33.0
32.3
When the sun’s rays are more direct, we get more When the sun’s rays are more direct, we get more intense rays.intense rays.
We get more solar insolation in the summer We get more solar insolation in the summer months also because the sun has less atmosphere months also because the sun has less atmosphere
to travel through if it is overhead.to travel through if it is overhead.
If there is more atmosphere to travel through, less If there is more atmosphere to travel through, less radiation reaches the surface.radiation reaches the surface.
Earth’s Axis is tilted at 23.5° from the vertical. This Earth’s Axis is tilted at 23.5° from the vertical. This gives way to the seasons.gives way to the seasons.
Table of SeasonsTable of Seasons
SeasonSeason Summer Summer Solstice Solstice (First Day (First Day of of Summer: Summer: around around 6/21)6/21)
Autumnal Autumnal Equinox Equinox (First Day (First Day of Fall: of Fall: around around 9/229/22
Winter Winter Solstice Solstice (First Day (First Day of Winter: of Winter: around around 12/21)12/21)
Vernal Vernal Equinox Equinox (First Day (First Day of Spring: of Spring: around around 3/21)3/21)
Day Day Length at Length at LCHSLCHS
Around 14 Around 14 hourshours
12 hours12 hours Around 10 Around 10 hourshours
12 hours12 hours
Sun Sun Directly Directly overhead:overhead:
23.5° N at 23.5° N at Tropic of Tropic of CancerCancer
0° at 0° at EquatorEquator
23.5° S at 23.5° S at Tropic of Tropic of CapricornCapricorn
0° at 0° at EquatorEquator
Here are two animations for the reasons for our Here are two animations for the reasons for our seasons. Animation 1 and Animation 2seasons. Animation 1 and Animation 2
Air Pollution and SMOGAir Pollution and SMOGSo
urce
: Lo
s An
gele
s Ti
mes
Syn
dica
te
““WEEP SOME MORE, MY LADY” APPEARED TO BE LOS ANGLES’ THEME SONGWEEP SOME MORE, MY LADY” APPEARED TO BE LOS ANGLES’ THEME SONGYESTERDAY DUE TO SMOG. CITY HALL, MERELY ACROSS THE STREET, YESTERDAY DUE TO SMOG. CITY HALL, MERELY ACROSS THE STREET,
IS DIM AS MARION E. LENT GROPES HER WAY TO WORK.IS DIM AS MARION E. LENT GROPES HER WAY TO WORK.--LOS ANGELES TIMES, FEBRUARY 5, 1953--LOS ANGELES TIMES, FEBRUARY 5, 1953
Air Pollution over Downtown Los Angeles on July 13, 2004
““An An air pollutantair pollutant is any airborne gas or particle is any airborne gas or particle that occurs at a concentration capable of that occurs at a concentration capable of
harming humans or the environment.”harming humans or the environment.”
Air Pollution over the San Fernando Valley on July 13, 2004
Common Air Pollutants Common Air Pollutants as defined by the Clean as defined by the Clean Air Act of 1970Air Act of 1970
Air PollutantAir Pollutant Major SourcesMajor Sources EffectsEffects
Carbon Monoxide (CO)Carbon Monoxide (CO) Automobile exhaustAutomobile exhaust Reduces delivery of OReduces delivery of O22 to body to body
tissues; impairs vision and tissues; impairs vision and reflexesreflexes
Nitrogen Dioxide (NONitrogen Dioxide (NO22)) Burning of fossil fuels in power Burning of fossil fuels in power plants and automobilesplants and automobiles
Irritates lungs and lowers Irritates lungs and lowers resistance to respiratory resistance to respiratory infections; contributes to acid infections; contributes to acid rain and SMOGrain and SMOG
Sulfur Dioxide (SOSulfur Dioxide (SO22)) Burning of fossil fuels in power Burning of fossil fuels in power plants, oil refineries, paper plants, oil refineries, paper mills, volcanoesmills, volcanoes
Irritates respiratory system; Irritates respiratory system; contributes to acid raincontributes to acid rain
Particulate Matter (dust, smoke, Particulate Matter (dust, smoke, soot, ash)soot, ash)
Factories, power plants, oil Factories, power plants, oil refineries, paper mills, refineries, paper mills, volcanoesvolcanoes
Contributes to respiratory Contributes to respiratory problems; linked to some forms problems; linked to some forms of cancerof cancer
Lead (Pb)Lead (Pb) Smelters, battery plantsSmelters, battery plants Damages nervous and Damages nervous and digestive systemsdigestive systems
Ground Level Ozone (OGround Level Ozone (O33) ) BadBad
High Altitude Stratospheric High Altitude Stratospheric Ozone protects us from UVOzone protects us from UV
Reactions of nitrogen oxides Reactions of nitrogen oxides and hydrocarbons in the and hydrocarbons in the presence of sunlightpresence of sunlight
Reduces lung function and Reduces lung function and causes inflammationcauses inflammation
SMOG (SMoke + fOG) is made worse by high SMOG (SMoke + fOG) is made worse by high temperatures and sunlight and is the worst during temperatures and sunlight and is the worst during
the summer monthsthe summer months
SMOG over the San Fernando Valley on July 13, 2004
An An inversion layerinversion layer traps the SMOG and does not let it traps the SMOG and does not let it escape in to the upper atmosphere. Warm air above escape in to the upper atmosphere. Warm air above traps cooler air below. Convection and mixing with air traps cooler air below. Convection and mixing with air
above cannot take place due to higher density air below.above cannot take place due to higher density air below.
SMOG over the San Gabriel Valley and La Cañada on July 13, 2004
Warmer Air Above
Cooler Air Below
Why is the air so much worse in the Inland Why is the air so much worse in the Inland Empire?Empire?
The The Air Quality Index Air Quality Index explains the colorsexplains the colors
Go to the following sites to find out more Go to the following sites to find out more about your local air quality and how it about your local air quality and how it
affects your health and the health of the affects your health and the health of the ones you care about!ones you care about!
Environmental Protection Agency
California Air Resources Board
South Coast Air Quality Management District
Air Now
Call 1-800-CUT-SMOG to report polluting vehicles that are smoking like a chimney!
Chapter 21: Climate and Climate ChangeChapter 21: Climate and Climate Change
What is Climate?
Chapter 21: Climate and Climate ChangeChapter 21: Climate and Climate Change
What is Climate?
Climate is the long-term state of Earth’s atmosphere.
Climate CharacteristicsClimate Characteristics
What are the two main characteristics of an area’s climate?
Climate CharacteristicsClimate Characteristics
The two main characteristics of an area’s climate are temperature and precipitation.
Climate CharacteristicsClimate Characteristics
What are three other characteristics of an area’s climate?
Climate CharacteristicsClimate Characteristics1.Number of days and hours of sunlight
2.Direction, speed, and steadiness of the wind
3.Occurrence of severe weather conditions
Controls on Climate
TemperatureTemperature PrecipitationPrecipitation
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Nearby WaterNearby Water Coastal areas have mild climates Coastal areas have mild climates due to WATER!!!due to WATER!!!
More precipitation near large More precipitation near large water bodieswater bodies
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Nearby WaterNearby Water Coastal areas have mild climates Coastal areas have mild climates due to WATER!!!due to WATER!!!
More precipitation near large More precipitation near large water bodieswater bodies
Ocean CurrentsOcean Currents Warm ocean currents warm Warm ocean currents warm nearby coast. Cold ocean nearby coast. Cold ocean
currents cool nearby coast.currents cool nearby coast.
Ocean currents can produce fog.Ocean currents can produce fog.
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Nearby WaterNearby Water Coastal areas have mild climates Coastal areas have mild climates due to WATER!!!due to WATER!!!
More precipitation near large More precipitation near large water bodieswater bodies
Ocean CurrentsOcean Currents Warm ocean currents warm Warm ocean currents warm nearby coast. Cold ocean nearby coast. Cold ocean
currents cool nearby coast.currents cool nearby coast.
Ocean currents can produce fog.Ocean currents can produce fog.
TopographyTopography Leeward side of mountains Leeward side of mountains warmer than windward sidewarmer than windward side
Windward side of mountains are Windward side of mountains are wetter than leeward sidewetter than leeward side
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Nearby WaterNearby Water Coastal areas have mild climates Coastal areas have mild climates due to WATER!!!due to WATER!!!
More precipitation near large More precipitation near large water bodieswater bodies
Ocean CurrentsOcean Currents Warm ocean currents warm Warm ocean currents warm nearby coast. Cold ocean nearby coast. Cold ocean
currents cool nearby coast.currents cool nearby coast.
Ocean currents can produce fog.Ocean currents can produce fog.
TopographyTopography Leeward side of mountains Leeward side of mountains warmer than windward sidewarmer than windward side
Windward side of mountains are Windward side of mountains are wetter than leeward sidewetter than leeward side
Prevailing WindsPrevailing Winds Air masses delivered from hot or Air masses delivered from hot or cold regions determine cold regions determine
temperaturetemperature
Air masses delivered from wet or Air masses delivered from wet or dry regions determine dry regions determine
precipitationprecipitation
Controls on ClimateTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are generally Temperatures are generally colder towards the polescolder towards the poles
Areas near the equator and 60Areas near the equator and 60 N/S latitude are wet. Areas near N/S latitude are wet. Areas near
3030 N/S and the poles are dry N/S and the poles are dry
ElevationElevation Temperatures colder at higher Temperatures colder at higher elevationelevation
Air at higher elevations has less Air at higher elevations has less moisturemoisture
Nearby WaterNearby Water Coastal areas have mild climates Coastal areas have mild climates due to WATER!!!due to WATER!!!
More precipitation near large More precipitation near large water bodieswater bodies
Ocean CurrentsOcean Currents Warm ocean currents warm Warm ocean currents warm nearby coast. Cold ocean nearby coast. Cold ocean
currents cool nearby coast.currents cool nearby coast.
Ocean currents can produce fog.Ocean currents can produce fog.
TopographyTopography Leeward side of mountains Leeward side of mountains warmer than windward sidewarmer than windward side
Windward side of mountains are Windward side of mountains are wetter than leeward sidewetter than leeward side
Prevailing WindsPrevailing Winds Air masses delivered from hot or Air masses delivered from hot or cold regions determine cold regions determine
temperaturetemperature
Air masses delivered from wet or Air masses delivered from wet or dry regions determine dry regions determine
precipitationprecipitation
VegetationVegetation Vegetation affects rate at which Vegetation affects rate at which Earth heats/coolsEarth heats/cools
Vegetation releases water vaporVegetation releases water vapor
What are the major climate controls here in La Cañada?
Controls on Climate in La CañadaTemperatureTemperature PrecipitationPrecipitation
LatitudeLatitude Temperatures are moderateTemperatures are moderate Most precipitation occurs in Most precipitation occurs in winterwinter
ElevationElevation Cooler temperatures up Angeles Cooler temperatures up Angeles CrestCrest
More rain falls at higher More rain falls at higher elevations due to orographic elevations due to orographic
liftinglifting
Nearby WaterNearby Water Temperatures moderated by Temperatures moderated by nearby oceannearby ocean
Precipitation comes from Pacific Precipitation comes from Pacific OceanOcean
Ocean CurrentsOcean Currents Our cold California Current keeps Our cold California Current keeps temperatures moderate.temperatures moderate.
Cold ocean current can produce Cold ocean current can produce fog and low clouds.fog and low clouds.
TopographyTopography Cooler temperatures up Angeles Cooler temperatures up Angeles CrestCrest
More rain falls at higher More rain falls at higher elevations due to orographic elevations due to orographic
liftinglifting
Prevailing WindsPrevailing Winds Winds blow from Southwest off of Winds blow from Southwest off of ocean keeps LC cool. Northeast ocean keeps LC cool. Northeast Santa Ana winds keep LC warm.Santa Ana winds keep LC warm.
Southwest winds bring Southwest winds bring precipitation. Northeast winds precipitation. Northeast winds
bring clear, dry weather.bring clear, dry weather.
VegetationVegetation Chaparral in hills keeps LC cool Chaparral in hills keeps LC cool at night. Asphalt keeps us hot.at night. Asphalt keeps us hot.
Vegetation releases water vaporVegetation releases water vapor
What is El Niño?
Warm ocean water makes its way across the Pacific Ocean and reaches our coast around Christmas time. This produces more rainfall in La Cañada.
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
PolarPolar TundraTundra
IcecapIcecap
Always cold & dry with short, cool summersAlways cold & dry with short, cool summers
Freezing all yearFreezing all year
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
DryDry Desert: AridDesert: Arid
SemiaridSemiarid
Very Dry: Evaporation > PrecipitationVery Dry: Evaporation > Precipitation
Dry: Evaporation > PrecipitationDry: Evaporation > Precipitation
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
Humid TropicalHumid Tropical Tropical WetTropical Wet
Tropical Wet & DryTropical Wet & Dry
Hot & Rainy most of yearHot & Rainy most of year
Hot all year with wet & dry seasonsHot all year with wet & dry seasons
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
Moist mid-Moist mid-latitude with latitude with mild wintersmild winters
Humid SubtropicalHumid Subtropical
Marine West CoastMarine West Coast
MediterraneanMediterranean
Hot, humid summers & mild wintersHot, humid summers & mild winters
Mild and rainy all yearMild and rainy all year
Hot, dry summers. Mild, rainy wintersHot, dry summers. Mild, rainy winters
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
Moist mid-Moist mid-latitude with latitude with
severe winterssevere winters
Humid ContinentalHumid Continental
SubarcticSubarctic
Warm summers & cold, snowy wintersWarm summers & cold, snowy winters
Short summers & long, cold, snowy Short summers & long, cold, snowy winterswinters
Climate Zones around the World
Climate ZoneClimate Zone SubclimateSubclimate DescriptionDescription
HighlandHighland NoneNone Temperature & Precipitation vary Temperature & Precipitation vary greatly with latitude & elevationgreatly with latitude & elevation
Climate Change
Earth’s Climate Over the Past 400,000 years
Climate Change
How does Earth’s energy budget affect climate?
Causes of Climate Change
Earth’s Motions and Milankovitch Cycles: Eccentricity
The shape of Earth’s orbit changes with a period of 100,000 years.
Causes of Climate Change
Earth’s Motions and Milankovitch Cycles: Axial Tilt
The tilt of Earth’s axis goes between 22.1 and 24.5 every 41,000 years. The tilt right now is 23.5.
Causes of Climate Change
Earth’s Motions and Milankovitch Cycles: Precession (Wobble)
You can think of the Earth as a top that wobbles back and forth. Earth’s axis wobbles with a period of 23,000 years.
Causes of Climate Change
Plate Tectonics
Large landmasses near the poles cause temperature differences
between the poles and the equator to increase. This usually
contributes to global cooling because glaciers on land reflect
light. Global warming occurs when there are no large
landmasses near the poles.
Causes of Climate Change
Sunspot Cycles:
Sunspot cycles occur on 11 year cycles.
Causes of Climate Change
Sunspot Cycles:
More sunspots on the face of the sun means that the sun gives off more energy. This translates to global warming.
Fewer sunspots means that the sun gives off less energy. This translates to global cooling and the Maunder Minimum.
Causes of Climate Change
Sunspot Cycles:
Sunspot cycles occur on 11 year cycles.
Causes of Climate Change
Sunspot Cycles:
Sunspot number prediction through the year 2015.
Causes of Climate Change
Volcanic Eruptions:
Dust and sulfur dioxide gas are sent into the stratosphere when volcanoes erupt. Sulfur dioxide reacts with water to form sulfuric
acid droplets that remain suspended in the stratosphere for many years. This reflects sunlight and causes global cooling.
Causes of Climate Change
Volcanic Eruptions:
Very large volcanic eruptions can cause large amounts of carbon dioxide to be ejected into the atmosphere. Carbon dioxide, as you know, is a greenhouse gas. This can cause global warming. Go here for an LA Times story about volcanic eruptions that caused
warming.
Causes of Climate Change
Human Effects:
We spoke of these during our viewing of Inconvenient Truth.
Causes of Climate Change
Human Effects:
Mr. Gore spoke of the relationship between carbon dioxide emissions and global temperatures.
Causes of Climate Change
Human Effects:
Mr. Gore spoke of the effects of human-induced global warming, such as sea level rise.
Causes of Climate Change
Human Effects:
The effects of human-induced global warming, such as species extinction
Causes of Climate Change
Human Effects:
Mr. Gore spoke of the effects of human-induced global warming, such as storm intensities.
Methods for Measuring Climate Change
Sea floor Sediments:
Scientists can use the ratio of Heavy Oxygen 18 to Lighter Oxygen 16 to tell what climate was like in the past. More Oxygen 18 in sea floor sediments means that more glaciers existed when
the shells in the sediments formed.
Methods for Measuring Climate Change
Glacier Ice Core Samples:
Bubbles of ancient air in samples can be analyzed for carbon dioxide content. Snow that fell on a glacier during a warm period
has more heavy Oxygen 18.
Methods for Measuring Climate ChangeTree Growth Rings: Scientists can study a tree’s growth rings to
determine past climate. Thicker growth rings signify a wetter, cooler period. Thinner growth rings signify a dryer, warmer period.