meteorology and climate change. een. 2.5.1 summarize the structure and composition of our atmosphere...

Meteorology and Climate Change

EEn. 2.5.1Summarize the structure and composition of our atmosphere

• ATMOSPHERE - layer of gases and tiny particles surrounding the earth

Composition of AtmosphereElements:

– NITROGEN (N2)– OXYGEN (O2) – ARGON (Ar)

• Compounds: – CARBON DIOXIDE (CO2)

– WATER (H2O)

– OZONE (O3)• absorbs harmful UV RAYS

(ultraviolet)

Atmospheric Layering is caused by TEMPERATURE differences.

Atmospheric Layers

(1) TROPOSPHERE • Closest to earth• Holds the most CO2 and

H2O vapor• All WEATHER changes

happen here• Temperature ↓ as altitude

increases.– Why? FARTHER FROM THE

HEAT ABSORBED BY EARTH

2) STRATOSPHERE• From tropopause to

50km in altitude• Includes the OZONE

LAYER (O3)

• Temperature ↑ as altitude increases.– Why? CLOSER TO O3

LAYER WHICH ABSORBS UV LIGHT & HEAT

3) MESOSPHERE• From stratopause to

80km in altitude• Coldest layer• Temperature ↓ as

altitude increases.– Why? FARTHER

FROM O3 LAYER

(4) THERMOSPHERE• From mesopause to

outer space• Temperature ↑as

altitude increases.– Why? OXYGEN AND

NITROGEN ABSORB SHORT-WAVE, HIGH-ENERGY SOLAR RADIATION

•Most common features on any weather map & weather generalizations can be made using pressure centers•Winds are influenced by temperature gradients, pressure gradients, and the Coriolis effect– Winds blow from high pressure to low pressure– The larger the pressure difference, the faster the

wind speed– Coriolis effect influences only the direction of wind

EEn. 2.5.2Explain the formation of typical air masses and the weather systems

that result from air mass interactions.

• What goes in, must come out!!!!• When there is a converging air mass at the

surface, it must be balanced by outflow • - a surface CONVERGENCE can be maintained if

a DIVERGENCE occurs above the low at the same rate as the inflow below and vice versa.

Air spreads out (diverges) above surface cyclones and comes together (converges) abovesurface anticyclones

AIR MASSES

• an immense body of air that is characterized by similar temperature and moisture

• can be 1,600 km or more across… take several days to move over an area

• When an air mass moves out of the region over which it formed, it carries its temp & moisture

• - The characteristics of an air mass change as it moves and so does the weather in that area

• - Air masses are classified according to the surface over which they form

Air Mass Temp and Moisture Location

Maritime Polar Cold, wet NW, NE coastlines

Maritime Tropical Warm, wet SW, SE coastlines, Gulf of Mexico

Continental Polar Cold, dry Canada, Upper Midwest

Continental Tropical Warm, dry SW U.S., Mexico

Fronts

• Front: narrow region separating 2 air masses of different densities____

• Air masses collide forming _fronts_.• Fronts can cause dramatic __changes__ in

weather.• In all fronts, warm air is forced upward• 4 Types: _cold , __warm__,

___stationary__, and __occluded___

Cold Front

• Cold, dense air displaces ___warm___ air, forcing the warm air _up__ along a steep front.

• Warm air _rises _, cools, and _condenses_• Forms __clouds__, __showers__, and sometimes

__thunderstorms_____• Fast temperature change: air gets colder.• Advance more ___rapidly___ than a warm front.

SYMBOL:

WARM FRONT

• Advancing _warm___ air displaces __cold___ air, and the warm air rises above the cold air.

• Extensive _cloudiness__ and ___precipitation____

• Slow temperature change: air gets warmer.

SYMBOL:

Stationary Front

• Warm and Cold air meet, but neither moves into the other’s territory, which __stalls__ the front.

• They stall because the ___temperature__ and __pressure___ gradients are small.

SYMBOL:

Occluded Front• A cold air mass moves so rapidly that it __overtakes a warm front____.

• The cold air masses collide, pushing the warm air ___upward____.

• Causes precipitation on both sides of the front_______.SYMBOL:

Occluded Front

EEn. 2.5.3Explain how cyclonic storms form based on the interaction of air masses

• Thunderstorms: Form when warm humid air rises in an unstable environment– generate lightning and

thunder and frequently produces gusty winds, heavy rain & hail

•Strong updrafts•Supply moist air•Cloud grows vertically

•Amount of precipitation is too great for updrafts to support•Heavy precipitation•Gust winds, lightning

•Downdrafts dominate through the cloud•Cooling effect of falling rain and the flowing of colder air from high above calms the storm

Tornadoes• Violent windstorms that take the form of a rotating

column of air called a vortex that extends downward from a cumulonimbus cloud.

Hurricanes

• Whirling tropical cyclones that produce winds of at least 119 Km/hr

• Cause high winds, huge waves, and extensive flooding hundreds of miles away

• Growing threat- >50% of the US population lives within 75 km of the coast.

• The north pacific has the greatest number of storms (~20 per year)

• In the Northwest Pacific - called a “typhoon” and “cyclones” occur in the South Pacific and Indian Ocean

Hurricane Development

• Late summer when temps are warm enough to provide heat and moisture the air

• Begins as a tropical disturbance- disorganized clouds & thunderstorms w/ low pressure

• Inward rush of warm moist air moves towards the center

• Air turns upwards and rises in a cumulonimbus cloud (eye wall)– eye wall has the greatest wind speeds & heaviest rain

• Rising air is carried away from the storm center- provides room for more inward flow

• At the very center of storm is the eye– zone where precipitation ceases and winds

subside.– air gradually descends in the eye and compressed-

warmest part of the storm

EEn. 2.5.4Predict the weather using available weather maps and data

• Humidity = AMOUNT OF WATER VAPOR IN AIR– SATURATED = air contains all of the water vapor it

can hold.– When saturated, WARM air can hold more water

vapor than COLD air.– Measuring Devices: HYGROMETER or

PSYCHROMETER• Differences in wet bulb and dry bulb thermometers

determine relative humidity

Calculating Relative Humidity

• Specific Humidity = ACTUAL amount of moisture in the air. (Grams H2O / kg air)

• Relative Humidity = percent mass of water vapor compared to mass water vapor at saturation.

Ex: At 200 C, air contains 14.3g H2O / m3 air. Saturation point: 17.1 g/m3

– Specific Humidity: 14.3 g/m3

– Relative Humidity: 14.3 g/m3 = 84% Relative Humidity 17.1 g/m3

• Dew Point = TEMPERATURE to which the air must be cooled to reach saturation.

• Depends on Relative Humidity.• When temp. is below Dew Point:

CONDENSATION (dew) or DEPOSITION (frost) occur

• Cloud Formation = from CONDENSATION of water vapor over a large area of air.

Types of Precipitation

• ***The type of precipitation that reaches Earth’s surface is determined by the temperatures in the lowest few kilometers of the atmosphere.

• Rain & Snow• Sleet = small particles of clear-to-translucent

ice.

• Glaze = A.K.A. “FREEZING RAIN” – rain is supercooled (below 0°C) & become ice when they impact frozen objects.

• Hail = small ice pellets grow as they impact supercooled water droplets as they fall through a cloud. UPDRAFTS push them back up, so they can gain new ice layers.

The Weather Station Model

©Steve Kluge 2007 Some images from the NYSED Earth Science Reference Tables

Get accompanying notes here

Draw a Station Model

EEn. 2.5.5Explain how human activities affect air quality

Acid Rain Formation• The main causes of acid rain

are process that release SO2 and oxides of nitrogen into the atmosphere. – burning of fossil fuels,

such as coal and gas, by power stations

– combustion in car engines.

Problems caused by acid rain include:• Damage to plant leaves, eventually killing the plants. Whole

forests of pine trees have been destroyed by acid rain• Acidification of lakes: as the water become more acidic, some

animals such as fish cannot survive and fish stocks are destroyed.• Increased risk of asthma attacks and bronchitis in humans.• Corrosion of stonework on buildings.• Release into soil of soluble aluminium ions that are toxic to fish

when washed into lakes.

Ozone DepletionOzone- molecule consisting of 3 oxygen atoms

Benefit to humans because it absorbs harmful UV radiation

OZONE DEPLETION• Hole in the ozone layer is caused

by CFCs, Halons, and Methyl Bromides– found in aerosols,

refrigerators/coolants, fire extinguishers, and certain pesticides

• CLIMATE CHANGE IS NOT THE SAME THING AS THE OZONE HOLE– GREENHOUSE GASES AND/OR

CARBON DIOXIDE HAVE NOTHING TO DO WITH THE HOLE IN THE OZONE LAYER!!!

How ozone is destroyed by CFCs

Effects of Ozone Depletion

• Humans– Increased incidences of skin cancer and cataracts

• Plants– Growth rate of plants can be slowed

• Marine Ecosystems– Changes in UV levels can affect the development

and growth of phytoplankton

Human Impact on Atmosphere• Burning of Fossil Fuels

– Combustion from industry and transportation add excess greenhouse gases into the atmosphere

• Deforestation– Clear-cutting forests for space and resources leads to less

carbon dioxide being absorbed from the atmosphere by trees• Over-farming

– Burning fossil fuels to produce fertilizers– Methane production from livestock– Burning fossils fuels in farming vehicles– Deforestation to make room for crop fields

EEn. 2.6.1Differentiate between weather and climate

• WEATHER - general atmospheric conditions at a particular time and place

• CLIMATE - general weather conditions over many years

Causes of Climate Change Description of what it is Explanation of how it impacts climate

(What SCIENTISTS say)

Volcanic eruptions

When volcanoes erupt, they release dissolved gases (like carbon dioxide, water

vapor and sulfur dioxide) into the atmosphere

Adds to the build-up of Greenhouse Gases

Sunspots More emitted radiation and increased temperatures are found around sunspots

More sunspots will increase the amount of heat that stays within the atmosphere.

Earth’s orbitThere is variation in Earth’s tilt which affects the amount of solar radiation

received.

Depending on the season, more or less energy is received from the sun.

Carbon Dioxide fluctuations

As heat is reflected back out into space, carbon dioxide (CO2) absorbs some of the

heat.

Heat is retained in the atmosphere (not radiated back into space) causing the global

temperature to rise.

EEn. 2.6.2Explain changes in global climate due to natural processes

EEn. 2.6.3Analyze the impacts the human activities have on global climate change

Climate Change

Heat Islands• The term "heat island"

describes built up areas that are hotter than nearby rural areas.

• The annual mean air temperature of a city with 1 million people or more can be 1.8–5.4°F (1–3°C) warmer than its surroundings.

• In the evening, the difference can be as high as 22°F (12°C).

• Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.

EEn. 2.6.4Attribute changes to Earth’s systems to global climate change

• Analyze how changes in global temperatures affect the biosphere (ex. agriculture, species diversity, ecosystem balance).

• Explain how changes in atmospheric composition contribute to ocean acidification. Analyze its effect on ocean life and its connection to global climate change.

• Explain how changes in global temperature have and will impact sea level.

• Analyze how sea level has been affected by other earth processes such as glaciations and tectonic movements. Consider long- and short-term changes.

Effects of Climate Change1. HIGHER

TEMPERATURES

Link: The Nature Conservancy

The five hottest years on record have all occurred since 1997.

2. CHANGING LANDSCAPES

Changing patterns of rain and snow are forcing trees and plants around the world

to move toward polar regions and up mountain slopes

Effects of Climate Change3. WILDLIFE AT RISK

Rising temperatures are changing weather and vegetative patterns across

the globe, forcing animal species to migrate to new, cooler areas in order to

survive. Experts predict that 1/4 of

Earth’s species will be headed

for extinction by 2050

4. RISING SEAS

Sea level rise from climate change could displace tens

of millions of people.Sea levels could continue to rise between 4 inches

and 36 inches over the next 100 years.

Effects of Climate Change5. INCREASED RISK OF DROUGHT,

FIRE & FLOODSMassive land erosion is one result of

overgrazing & drought in Kenya

6. STRONGER STORMS & HURRICANES

Hurricanes and tropical storms to become more intense — lasting longer,

unleashing stronger winds, and causing more damage to

coastal ecosystems

Effects of Climate Change7. MORE HEAT RELATED ILLNESS & DISEASE

As temperatures rise, so do the risks of heat-related illness and even death for the most vulnerable human populations. Increase the spread of infectious diseases.

8. ECONOMIC LOSSES

Climate change could cost between 5 and 20 percent of the annual global gross domestic

product. Declining crop yields could put hundreds of thousands of people at risk for

starvation.

Effects of Climate Change9. OCEAN ACIDIFICATION

As temperatures rise, so does the amount of carbon dioxide in the ocean causing

acidic water.

10. EL NINO & LA NINA

Weather patterns in the Pacific Ocean change causing an increased frequency of bad weather events to occur around the world.

Normal Ocean WaterNORMAL

• Strong Trade winds towards the

western pacific

• Warm water off Australia

• Cool waters off the coast of South

America.

• UPWELLING

El Nino

• Weaker trade winds in the pacific ocean• Warm water off Australia moves towards South

America• Cool waters off the

coast of South America begin to

warm.•More evaporation off

of S.A. leading to more precipitation

floods• Reduced upwelling

EL NINO

La Nina

• STRONG trade winds in the

pacific ocean force warm water back

to Australia

• COLD waters off the coast of South America return.

• STRONG upwelling

LA NINA