Review: Meteorology

What is Weather?

What is Weather?

• The state of the atmosphere at a given time and place

• Constantly Changing

Composition of the Atmosphere

• 78% Nitrogen (N2)

• 21% Oxygen (O2)

• 1% Other gases

Composition of the Atmosphere

• 78% ________?

• 21% ________?

• 1% ________?

Other Components• Water Vapor– Most important gas for

atmospheric processes

– Source of all clouds and precipitation

• Carbon Dioxide (CO2)

– Absorbs energy given off by the Earth

• Ozone (O3)

– Absorbs harmful ultraviolet (UV) radiation from the sun

Layers of the Atmosphere

Layers of the Atmosphere

• Divided into layers based on temperature

• Rapidly thins as you travel away from Earth

• Layer 1: _________?–Bottom layer

–Temperature ________? as altitude increases

–________? occurs, we live in it

• Layer 1: Troposphere–Bottom layer

–Temperature decreases as altitude increases

–Weather occurs, we live in it

• Layer 2: _______?–Temperature remains

constant then slowly _____? with height

–Location of the _______? layer

• Layer 2: Stratosphere–Temperature remains

constant then slowly increases with height

–Location of the ozone layer

• Layer 3: _______?– Temperature ________?

with height

–Meteors occur here

• Layer 4: ________?– Temperature ________?

with height

– Thins out to space

– Auroras occur here

• Layer 3: Mesosphere– Temperature decreases

with height

–Meteors occur here

• Layer 4: Thermosphere– Temperature increases

with height

– Thins out to space

– Auroras occur here

Air Pressure & The Atmosphere

• Air Pressure–Force of the weight

of air above

• Increase in altitude will cause the air pressure to _______?

Air Pressure & The Atmosphere

• Air Pressure–Force of the weight

of air above

• Increase in altitude will cause the air pressure to decrease

What Happens to Solar Radiation?

• ________?– Radiation bounces off

the object

• _________?– Produces a large number

of rays that travel in many directions

• __________?– To take within the object

What Happens to Solar Radiation?

• Reflection– Radiation bounces off

the object

• Scattering– Produces a large number

of rays that travel in many directions

• Absorption– To take within the object

What percentage of Solar Radiation Reaches Earth’s

Surface?• ______% reaches

Earth’s surface

• _____% absorbed by clouds

• ____% reflected or scatters back to space

What percentage of Solar Radiation Reaches Earth’s

Surface?• 50% reaches

Earth’s surface

• 20% absorbed by clouds

• 30% reflected or scatters back to space

How can Heat transfer?

• _________?– Direct contact

(touching)

• _________?– By circulation (hot air

goes up, cold air goes down)

• _________?–Waves through space

How can Heat transfer?

• Conduction– Direct contact

(touching)

• Convection– By circulation (hot air

goes up, cold air goes down)

• Radiation–Waves through space

Why do Temperatures Vary?

Why do Temperatures Vary?

• Altitude

• Geographic Position

• Cloud Cover

• Ocean Currents

• Heating of Land

• Heating of Water

Heating of Land vs. Water

• Land heats up ________? than water

• Land cools down ________? than water

Heating of Land vs. Water

• Land heats up faster than water

• Land cools down faster than water

Albedo

• The fraction of total radiation that is reflected by any surface

• Daylight Cloud Cover– Temperatures ______? than

on a clear day

– Clouds reflect radiation back to space

• Nighttime Cloud Cover– Temperatures ______? than

on a clear night

– Clouds absorb radiation from Earth, and send it back down

Albedo

• The fraction of total radiation that is reflected by any surface

• Daylight Cloud Cover– Temperatures lower than on

a clear day

– Clouds reflect radiation back to space

• Nighttime Cloud Cover– Temperatures higher than on

a clear night

– Clouds absorb radiation from Earth, and send it back down

What Causes Wind?

What Causes Wind?

• Air pressure differences– Steep pressure

differences cause strong winds

– Gentle pressure differences cause light winds

• The sun fuels the pressure differences

How do Winds move?

• Flow from a _____? air pressure area to a _____? air pressure area

How do Winds move?

• Flow from a high air pressure area to a low air pressure area

Global Winds

• The atmosphere balances itself by acting as a giant heat-transfer system.

• Moves warm air towards ______ latitudes and cool air towards the _______

Global Winds

• The atmosphere balances itself by acting as a giant heat-transfer system.

• Moves warm air towards high latitudes and cool air towards the equator

What are the Global Winds?A. __________?– Two belts of winds that blow almost

constantly from East to West

B. __________?– Dominate west to east motion of the

atmosphere

– Jet stream occurs

C. _________?– Winds that blow east to west

D._________?

– Interaction of warm and cool air masses produces a storm belt

What are the Global Winds?A. Trade Winds– Two belts of winds that blow

almost constantly from East to West

B. Westerlies– Dominate west to east motion of

the atmosphere– Jet stream occurs

C. Polar Easterlies– Winds that blow east to west

D. Polar Front– Interaction of warm and cool air

masses produces a storm belt

How about Local Winds?

• Either–Land Breeze

–Sea Breeze

–Valley Breeze

–Mountain Breeze

States of Matter

States of Matter

• Solid

• Liquid

• Gas

• Plasma

• Solid, Liquid, and Gas are the most important with weather

Changing Between States

Changing Between States

1. Melting

2. Freezing

3. Condensation

4. Vaporization

5. Sublimation

6. Deposition

What is Humidity

• ________?

• Warm air contains ______? water vapor than cool air

What is Humidity

• Amount of water vapor in the air

• Warm air contains more water vapor than cool air

What is Relative Humidity?

• Is the ratio________?

• Increasing air temperature causes an _______? in relative humidity

What is Relative Humidity?

• Is the ratio of the actual water vapor content compared with the amount of water vapor air can hold

• Increasing air temperature causes an increase in relative humidity

What is Dew Point?

• The temperature to which air would need to be cooled to be________?

• Cool past this point, water will __________?

What is Dew Point?

• The temperature to which air would need to be cooled to be saturated

• Cool past this point, water will condense

What is a Cloud?

What is a Cloud?

• Forms when air cooled to its dew point

• Classified on the basis of their appearance and height

What is Precipitation?

What is Precipitation?

•Any form of water that falls from a cloud

Types of Precipitation• ________?– Drops of water that fall

• ________?– Light, fluffy, six-sided ice crystals

• _______?– Fall of clear to translucent ice

• ________?– Rain that turns to ice when they

impact objects

• _______?– Balls of ice produced in

cumulonimbus clouds

Types of Precipitation• Rain– Drops of water that fall

• Snow– Light, fluffy, six-sided ice crystals

• Sleet– Fall of clear to translucent ice

• Glaze– Rain that turns to ice when they

impact objects

• Hail– Balls of ice produced in

cumulonimbus clouds

What is an Air Mass?

What is an Air Mass?

• Large body of air that is characterized by similar temperatures and amount of moisture

Air Mass and Weather

• Fairly ________? weather in the area the air mass is in

• Carries _______ & _______ as it moves

• As an air mass moves south, it will start to warm but bring _______ temperatures

Air Mass and Weather

• Fairly constant weather in the area the air mass is in

• Carries moisture & temperature as it moves

• As an air mass moves south, it will start to warm but bring colder temperatures

Classifying Air Masses

• Based on–____?

–____?

Classifying Air Masses

• Based on–Temperature

–Surface area over which it forms

Classifications of Air Masses

By Temperature•Polar (P)– High Latitude (towards

the poles

– Cold Temperatures

•Tropical (T)– Low Latitude (near the

equator)

– Warm Temperatures

Surface Area•Continental (c)– Over Land

– Cold or warm depending on latitude

•Maritime (m)– Over Water

– Cold or warm depending on latitude

Classifications of Air Masses

By Temperature•________?– High Latitude (towards

the poles

– Cold Temperatures

•_______?– Low Latitude (near the

equator)

– Warm Temperatures

Surface Area•________?– Over Land

– Cold or warm depending on latitude

•________?– Over Water

– Cold or warm depending on latitude

Four Basic Types of Air Masses

cP = Continental Polar– Dry & Cool

– Cold & Dry in winter and summer

cT = Continental Tropical

– Dry & Warm

– Extremely hot, drought like conditions

mP = Maritime Polar–Wet & Cold

–Mild, humid, unstable cold air from Canada

mT = Maritime Tropical

–Wet & Warm

– Source of the precipitation in the U.S.

What is a Front?

• __________?

• Types of Fronts–Warm

–Cold

–Stationary

–Occluded

What is a Front?

• Boundary where two air masses meet

• Types of Fronts–Warm

–Cold

–Stationary

–Occluded

_______? Front

• Warm air pushes upward over cold air

• Light to __________?

• Temperatures rise in the areas

• Symbol– A line with red semi-

circles extending on one side in the direction of motion

Warm Front

• Warm air pushes upward over cold air

• Light to moderate rain

• Temperatures rise in the areas

• Symbol– A line with red semi-

circles extending on one side in the direction of motion

_______? Front

• When cold, dense air moves into a region occupied by warmer air

• __________?

• Temperatures drop

• Symbol– A line with blue triangles

extending on one side in direction of motion

Cold Front

• When cold, dense air moves into a region occupied by warmer air

• Thunderstorms

• Temperatures drop

• Symbol– A line with blue triangles

extending on one side in direction of motion

________? Front

• Does not move

• Gently to moderate ______?

• Could rain for days

• Symbol– Red semi-circles on

one side and blue triangles on the other

Stationary Front

• Does not move

• Gently to moderate rain

• Could rain for days

• Symbol– Red semi-circles on

one side and blue triangles on the other

_________? Front

• When a cold front overtakes a warm front

• When overtaking occurs, _________?occurs

• Symbol– Alternating purple

triangles and purple semi-circle

Occluded Front

• When a cold front overtakes a warm front

• When overtaking occurs, heavy rain occurs

• Symbol– Alternating purple

triangles and purple semi-circle

High Pressure Systems

• Clockwise Motion

• _____? Weather Conditions

• AKA: Anti-cyclones

• Symbol: blue “H”

High Pressure Systems

• Clockwise Motion

• Fair Weather Conditions

• AKA: Anti-cyclones

• Symbol: blue “H”

Low Pressure Systems

• Counterclockwise Motion

• Stormy Weather

• AKA: Cyclones

• Symbol: red “L”

Low Pressure Systems

• Counterclockwise Motion

• ________? Weather

• AKA: Cyclones

• Symbol: red “L”

What is Lightning?

What is Lightning?

• Result from the build-up and discharge of electric energy

• Connection between positive charges (ground) and negative charges (clouds)

What is Thunder?

What is Thunder?

• The sound of rapidly expanding air usually associated with lightning

• You see lightning before hearing thunder

What is a Tornado?

What is a Tornado?

• Violent low pressure windstorm that takes the form of a rotating column of air (vortex)

• Forms from cumulonimbus clouds

• Produces heavy rain and hail

Tornado Watch vs. Warnings

• Tornado _____?–Possibility of

development in an area

• Tornado ______?–Tornado has been

seen

– Indicated by radar

Tornado Watch vs. Warnings

• Tornado Watch–Possibility of

development in an area

• Tornado Warning–Tornado has been

seen

– Indicated by radar

What is a Hurricane?

What is a Hurricane?

• Whirling tropical cyclone– Low pressure system

• Winds at least 119 km/h or 73 mph

• Most powerful storm on Earth

What are Isobars?

• Lines connecting areas of equal pressure

• Closely spaced isobars– High winds

– Steep pressure gradient

• Widely spaced isobars– Light winds

–Weak pressure gradient

What are Isobars?

• Lines connecting areas of equal _________?

• Closely spaced isobars– _______? winds

– Steep ______? gradient

• Widely spaced isobars– _______? winds

–Weak _______ gradient

What are Isotherms?

• Lines connecting areas of same temperatures

How to read a weather map symbol?

What is Air Pollution?

What is Air Pollution?

• Airborne particles and gases that occur in concentrations large enough to endanger the health of organisms

What are Primary Pollutants?

• Emitted directly from identifiable sources

• Where do they come from?

What are Primary Pollutants?

• Emitted directly from identifiable sources

• Where do they come from?– Transportation vehicles

(half by weight)

– Industrial Processes

– Aerosols

– Burning Coal

What are Secondary Pollutions?

What are Secondary Pollutions?

• Not emitted directly into the air

• Form in the atmosphere through reactions

Pollutions effects on Human Health

Pollutions effects on Human Health

• Chronic Bronchitis

• Asthma

• Emphysema

• Lung Cancer

What is Acid Rain?

What is Acid Rain?

• Rain that is more acidic than normal

• Measured using the “pH” scale

• Normal rain is slightly acidic and has a pH of about 5.6

• As of 2000, most acid rain measures 4.3

How does Acid Rain Form

How does Acid Rain Form

• Gases react in the atmosphere with water, oxygen and other chemicals to form mild solutions of sulfuric acid and nitric acid

• Usually downwind from large cities and factories

Effects of Acid Rain?

Effects of Acid Rain

• Chemical Weathering of Structures

• pH levels of rivers become more acidic

• Kills fish and trees

• Mutation in aquatic organisms

How do we monitor Air Pollution?

How do we monitor Air Pollution

• Laws– 1955: Air Pollution

Control and Technical Assistance Act

– 1967: Air Quality Act

– 1970: Clean Air Act

– 1978: CFCs banned in the United States

– 1980: Acid Precipitation Act

• Others– Develop clean energy

sources

– Use electric and hybrid cars

– Set strict emission control standards

– Factories install and use pollution control devices

Climate

What is Climate?

What is Climate?

• Yearlong average of weather patterns over an area; determined by temperature and precipitation

Factors that Affect Climate?

Factors that Affect Climate

• Latitude

• Elevation

• Topography

• Water Bodies

• Global Winds

• Vegetation

Factor #1: Latitude

• As latitude increases, the intensity of solar energy ______?

• Three Zones–Tropical

–Temperate

–Polar

Factor #1: Latitude

• As latitude increases, the intensity of solar energy decreases

• Three Zones–Tropical

–Temperate

–Polar

Factor #2: Elevation

• Higher the elevation is, the _______? the climate

• Elevation determines amount of precipitation area receives

Factor #2: Elevation

• Higher the elevation is, the colder the climate

• Elevation determines amount of precipitation area receives

Factor #3: Topography

• Land features affect amount of precipitation that falls over an area

• Mountains cause a ____________?

-One side has cool, wet air

– One side has warm, dry air

Factor #3: Topography

• Land features affect amount of precipitation that falls over an area

• Mountains cause a rain shadow event– One side has cool, wet

air

– One side has warm, dry air

Factor #4: Water Bodies

• Large bodies of water (lakes & oceans) have an important effect on the temperature of an area.

• Temperature of the water body influences the temperature of the air above (land areas near warm water currents have ______? temperatures; ocean currents traveling away from equator are _______? water currents)

Factor #4: Water Bodies

• Large bodies of water (lakes & oceans) have an important effect on the temperature of an area.

• Temperature of the water body influences the temperature of the air above (land areas near warm water currents have warm temperatures; ocean currents traveling away from equator are warm water currents)

Factor #5: Global Winds

• Winds distribute heat and moisture around the Earth

• Warm air moves to the ______?

• Cold air moves to the ______?

Factor #5: Global Winds

• Winds distribute heat and moisture around the Earth

• Warm air moves to the poles)

• Cold air moves to the equator

Factor #6: Vegetation• Affects both temperature

and precipitation

• Temperature– Influence how much of the

sun’s energy is_________?and how quickly it is released

• Precipitation– When plants release water

vapor from its leaves into the air (called: ___________?)

Factor #6: Vegetation• Affects both temperature

and precipitation

• Temperature– Influence how much of the

sun’s energy is absorbed and how quickly it is released

• Precipitation– When plants release water

vapor from its leaves into the air (transpiration)

Köppen Climate Classification System

• Most commonly used system

• Uses mean monthly and annual values of temperature and precipitation

• Five Principal Groups– Humid Tropical

– Humid Mid-Latitude

– Dry

– Highland (___________?)

– Polar

Köppen Climate Classification System

• Most commonly used system

• Uses mean monthly and annual values of temperature and precipitation

• Five Principal Groups– Humid Tropical

– Humid Mid-Latitude

– Dry

– Highland (cooler and wetter)

– Polar

Natural Processes that Change Climate?

Natural Process that Change Climate

• Volcanic Eruption

• Ocean Circulation

• Solar Activity

• Earth’s Motions

Volcanic Eruption

Volcanic Eruption

• The presence of volcanic ash, dust and aerosols in the air increase the amount of solar radiation that is reflected back into space.

• Causes Earth’s lower atmosphere to cool

Ocean Circulation

• EL NINO

Ocean Circulation

• EL NINO– Causes parts of the eastern

tropical Pacific Ocean to become warmer than usual

– Arid places receive large amounts of rain

– Places that receive lots of rain may experience dry periods

– HERE? We have wet summers

• LA NINA

• LA NINA– Surface temperatures

in the Eastern Pacific are colder than average

– Hurricanes damage greater in La Nina times

– HERE? We have dry summers

Solar Activity

Solar Activity

• Formation of sunspots appear to correspond with warm periods in Europe and North America

• 11 year cycle

Earth’s Motion

• Orbit and Tilt

Earth’s Motion

• Orbit and Tilt– Earth’s tilt causes the

seasons

– Change in the degree of tilt or shape of orbit could cause global climate changes

Human Impact on Climate Change

• The Greenhouse Effect– Is a natural warming of

both Earth’s lower atmosphere and surface

– Makes life as we know it possible

– Major Gases: Water Vapor and Carbon Dioxide

– Humans have added more greenhouse gases to the atmosphere in the past 200 years by burning fossil fuels

Human Impact on Climate Change

• The Greenhouse Effect

Global Warming

Global Warming

• As a result of increases in Carbon Dioxide (CO2) as well as other greenhouse gases, global temperatures have increased

• Affects weather and climates

Temperatures Rising due to Global Warming

• Effects?

Temperatures Rising due to Global Warming

• Effects– Glaciers melting

– Greenland—If all of the ice melts, oceans will rise 23 feet

– Antarctic—major reduction in ice coverage

– Permafrost in Tundra is releasing CO2 that is stored under the ice

– Effect on living things sensitive to temp.