Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

The Atmosphere

No description
by

Dean Chigounis

on 29 September 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of The Atmosphere

The Atmosphere
Created by D. Chigounis, 2013
Based on Barron's AP ES 5th Edition & Princeton Review

Composition
Earth is composed of seven primary compounds:

Nitrogen (N2) 78%
Oxygen (O2) 21%
Water Vapor (H20) 0-4%
Carbon Dioxide (CO2) <1%
Methane (CH4) <1%
Nitrous Oxide (N20) <1%

Composition
Earth is composed of seven primary compounds:

-
Nitrogen (N2)
78%
nutrient for living organisms, component of DNA,
deposits via fixation, lightning, precipitation (HNO3) / returns to atmosphere via combustion & denitrification
-
Oxygen (O2)
21%
produced via photosynthesis & used in CR
-
Water Vapor (H20)
0-4%
Largest amt. near equator, over oceans, and in
tropics. Lower amts. in polar and desert regions
-
Carbon Dioxide (CO2
) <1%
increase 25% in past 300 years due to combustion
and deforestation. Produced via CR & decomposition /
reactant in photosynthesis. Major GH gas
-
Methane (CH4)
<1%
GH gas produced via combustion & anaerobic decomposition.
-
Nitrous Oxide (N20)
<1%
sources include combustion, fertilizers, deforestation & conversion to agricultural land.
-
Ozone (O3
) <1%
majority found in stratosphere (Ozone Layer), produced in the produciton of photochemical smog. CFC’s break down ozone layer.

Structure
The Atmosphere consists of several different layers:

LAYERS:

Troposphere
: (0-7 miles) above surface, 75% of atmosphere’s mass, weather occurs in this layer, GHG’s found here, temps decrease with altitude, reaching -76’F (-60C) at Tropopause (boundary layer)

Stratosphere
: temps increase with altitude due to absorption of heat by ozone layer

Mesosphere
: temps decrease with altitude, coldest layer, ice clouds occur here, meteors “shooting stars” incinerate in this layer.

Thermosphere
(Ionosphere): temps increase with height due to gamma rays, X-rays, and UV rays. Aurora borealis occurs here.

Exosphere
: outer space! Found 400km or 250 miles above our planet’s surface. That’s the driving distance from Great Mills High School to Manhattan. Think about that for a moment!

Weather & Climate
Weather
: is a short-term condition caused by movement & transfer of heat energy (initially from the sun), which influences:
- temperature
- air pressure
- humidity
- precipitation
- available sunlight
- wind speed & direction

Climate
: describes the avg. weather in a given place.

Energy
: can be transferred where temp. differences occur between two objects via: radiation, conduction, & convection.

Weather and Climate
Radiation
: the flow of electromagnetic radiation – the method by which Earth receives solar energy.

Conduction
: is the transfer of heat through a solid, liquid, or gas by DIRECT contact.

Convection
: is the transfer of heat from one place to another by the movement of molecules (often fluids). - Primary determinant in weather patterns. Occurs horizontally and vertically.
Ex) when air near ground becomes warm and less dense, it rises. Pressure differences equate to wind or “horizontal convection”.

Weather and Climate
Facts:

Equatorial regions receive more solar energy than that of the poles.

The latitudinal differences (bands going horizontal from pole to pole) of air temps create global-scale flows of energy within atmosphere, creating global weather patterns.

Without convection and the transfer of energy, the equator would be 27 degrees warmer and the Arctic would be 45 degrees colder!

Factors that Influence Climate
Evidence of Climate Change:
written accounts (subjective)
tree rings
fossilized plants
insect and pollen samples
gas bubbles trapped in glaciers
deep ice core samples
lake sediments
stalactites & stalagmites
marine fossils

Conclusion: Earth’s climate HAS endured many cycles of warming and cooling trends!

Factors that Influence Climate
Air Mass
Air Pressure
Albedo
Altitude
Angle of Sunlight
Clouds
Proximity to Oceans
Fronts
Heat
Land Alterations
Latitude
Location
Humidity
Mountain Ranges
Pollution
Rotation
Wind P
atterns

Air Mass
: a large body of air that has similar temps and moisture content.
Categorized as:
- equatorial, tropical, polar, arctic, continental, or maritime

Air Pressure
: most of total mass of atmosphere is within 20 miles of Earth’s surface, measured in millibars, inches of mercury, or hectopascals. Air pressure decreases with altitude.

L
ow Pressure
: cloudy and stormy weather
High Pressure
: cool, dense air, fair weather

Albedo
Albedo
IS reflectivity!

Low Albedo
: ocean water (absorbs radiation)

Medium Albedo
: land masses (some reflectivity)
High Albedo
: snow, ice, (lots of reflectivity)

Positive Feedback Mechanisms
:

1) Polar ice reflects solar energy back towards space, creating cooling period.

2) Dust in atmosphere reflects solar energy back towards space, creating cooling period. (where have you heard this before?)

Altitude
Facts:

For every 1,000 ft (300m) rise in elevation, there is a 3F (1.5C) drop in temperature.

A 300 ft (90m) rise in elevation is equivalent to a shift of 62 miles (100km) north in latitude and biome similarity.

Angle of Sunlight
In the Northern Hemisphere winter, Earth is closest to the sun. The angle of sunlight reaching Earth affects the climate. Areas closest to equator receive most sunlight, hence, have higher temps.

Carbon Cycle
-Consumption of CO2 results in cooling.

Two processes consume (fix) carbon dioxide:
carbonate rock formation
silicate rock formation

Production of CO2 results in warming

Clouds
Clouds
: collections of water droplets or ice crystals suspended in atmosphere.

Formation
: (Condensation) warm moist air rises and cools in atmosphere, condensing and forming droplets (
alto
– midlevel,
strato
– low level, or high (
cirr
)

Proximity to Oceans
Facts:

Oceans more thermally stable than landmasses.
Specific heat (heat-holding capacity) of oceans is 5x greater than air.
Therefore, changes in temp in middle of continent more extreme than along the coast.

Proximity to Oceans
Cold water currents, sea breezes, and arid climates.

Fronts
General Info:

Fronts occur where two different air masses collide.
Can vary in temp, moisture, and wind direction.

Warm-front: the boundary between advancing warm air mass and cooler one that it’s replacing.
Since warm air less dense, it rises and cools (condensation), resulting in rain.

Cold-fronts: is the leading edge of an advancing mass of cold air.
Associated with thunderhead clouds, high surface winds, and thunderstorms.
After cold front passes, weather usually cool with clear skies.

Greenhouse Effect
Most significant GHG include:
- water vapor (H2O)
- carbon dioxide (CO2)
- methane (CH4)
- ozone (O3)

Without these GHG’s Earth would be cold and inhospitable.
Conversely, other extreme is global warming
Heat (Convection)
Climate is influenced by how heat is exchanged between air over the ocean and land.

Land Alteration

Climate is influenced by urbanization and deforestation. ex) salt ponds impact on South Caicos Island, BWI

Latitude
The higher the latitudes, the less solar radiation (further from equator).

Humidity

Humidity determines plant growth and distribution (i.e. biome type).
Water vapor = GHG
Dew point = temp at which condensation takes place

Mountain Ranges
Presence impacts climate.
Windward side = side facing ocean
Leeward side = side opposite ocean
Temp decreases with altitude
Orographic lifting: occurs when air mass is forced from a low elevation to a higher elevation as it moves over terrain.
As mass moves upward, it cools (condensation), leading to rain.
This is the RAIN SHADOW EFFECT!
This phenomenon also contributes to deserts!

Plate Tectonics & Volcanoes
Volcanoes produce SO2, and GHG’s (CH4 & CO2) but also increase Albedo Effect!

Pollution

GHG emitted from both natural (volcanoes) and anthropogenic (human) sources (industry, transportation, etc.)

Precession
Wobble of Earth on its axis changes amount of energy received from sun.
Changes in orientation in space (tilt & obliquity) also impact climate.

Rotation

Daily temp cycles influenced by Earth’s rotation (once every 24hrs)
At night, heat escapes from surface.

Volcanoes
Sulfur-rich eruptions eject material into stratosphere, causing tropospheric cooling and stratospheric warming.

Volcanic ash deposit in oceans can:

Increase iron content in seawater
Iron promotes biotic activity
This lowers CO2 levels in oceans & atmosphere.
Results in global cooling

Wind Patterns
Wind patterns influenced by:
temperature
pressure gradients
Coriolis effect

Global air circulation is caused / affected by:
uneven heating of Earth’s surface
seasons
Coriolis Effect
amt. of solar radiation reaching Earth
convection cells in warm oceans

During calm, sunny days:
Land warms up faster than sea.
Air above land becomes less dense, resulting in sea breeze (on-shore thermal).

(Conversely)

During night:
Land cools down faster than sea:
Air above land becomes denser than air above sea.
Results in air moving from land towards sea.

Coriolis Effect
Deflection of air is called “Coriolis force”

Coriolis force results from Earth’s rotation

As air moves from high to low pressure in N. Hemisphere, it’s deflected to the right.

As air moves from high to low pressure in the S. Hemisphere, it’s deflected to the left.

Stronger winds at poles are deflected more so than weaker winds closer to equator.

Coriolis force is ZERO at the equator.

Human Activity
Climate can be influenced by:
Deforestation
Urbanization
Heat Island Effect
GHG’s
Combustion
Acid Rain

Atmospheric Circulation & Coriolis Effect
Trade Winds:
Easterly surface winds found in tropics (equator)
Occur within lower portion of troposphere
Blow from Northeast in N. Hemisphere
Blow from Southeast in S. Hemisphere
Strengthen during Winter
Steer tropical storms over world’s oceans

Horizontonal Winds:
Move from areas of high pressure to low pressure
Wind speed determined by pressure differences in air masses – greater the pressure, stronger the wind.
Wind direction defined from where wind is coming
Anemometer used to measure wind speed & direction

Atmospheric Circulation & Coriolis Effect
Coriolis Effect causes winds to spiral clockwise in N. Hemisphere and spiral counter-clockwise in S. Hemisphere.

Atmospheric Circulation & Coriolis Effect
Worldwide system of winds transports warm air from equator towards cooler higher latitudes, creating Earth’s Climatic Zones.

Three types of air circulation cells associated with latitude:
Hadley
Ferrel
Polar

Atmospheric Circulation & Coriolis Effect
Hadley Air Circulation Cells
:

Tropical, 29° and 49°N: characterized by by high humidity, high clouds, and heavy rains.

Subtropical Hadley Cells: low relative humidity, few clouds, high ocean evaporation, often occurs in deserts & savanna.

Atmospheric Circulation & Coriolis Effect
Ferrel Air Circulation Cells
:

Occur between 30° and 60° north and south latitudes.

Midlatitude can have severe winters and cool summers due to cyclone pattern.

Pacific Coast of US is drier in summer than eastern US due to ocean high pressure bringing cool, dry air from north. Cold ocean current also absorbs moisture.

Defined seasons are the rule. Seasonal fluctuations in temperature are greater than those occurring in 24hr cycle.

Areas with Ferrel Cells contain broadleaf deciduous and coniferous evergreen forests
Atmospheric Circulation & Coriolis Effect
Polar Air Circulation Cells
:

Originate as icy-cold, dry, dense air that descends from the troposphere to ground.
Air meets warm tropical air from mid-latitudes.
Air then returns to poles, cooling and sinking.
Sinking air suppresses precipitation (polar regions become deserts (deserts defined by moisture, not temp)
Very little liquid water exists because it’s mostly frozen.
Climes characterized by low temps, severe winters, little precipitation, short & colder summers
Two major biomes here: tundra & taiga!

Atmospheric Circulation & Coriolis Effect
Recap:
Horse Latitudes, Doldrums, Jet Stream & Trade Winds
Horse Latitudes
:
Around 30°N (FL)
Region of sinking, dry air

Doldrums:
Located near equator
Very little winds
Made passage across equator difficult for sailors

Jet Stream (Prevailing Westerly):

Narrow band of very strong, westerly winds.
Encircles the globe several miles above earth.
Typically two or three jet streams in each hemisphere (see illustration).

Trade Winds:

Easterly surface winds (troposphere) found in tropics
Blow from northeast, sailors used to move merchandise


Hurricanes, Cyclones, and Tornadoes
Hurricanes:
“Hurricanes” for Atlantic / “Typhoon” for Pacific.
Most severe weather phenomenon on planet.
Katrina responsible for $81 billion in damages / 1,830 deaths.
Hurricanes form over warm ocean in areas where trade winds converge. Warm water fuels hurricane.
Subtropical high-pressure zone creates high daytime temps with low humidity = high evaporation.
Coriolis effect initiates cyclonic flow!
In center of hurricane is the “eye” (descending air & low pressure).
Hurricanes dissipate over cooler land masses.
Major damage caused by storm surge, heavy winds, flooding.

Hurricanes (Cyclones) and Tornadoes
Tornadoes:
Swirling masses of air with speeds up to 300 mph
Like hurricanes, center contains low pressure
Produced from single convective storm such as thunderstorm.
Typically short-lived (< hr.) compared to cyclones (days).
Season occurs from April – July
Mostly occur in center of continent (Tornado Alley)
Weather forecasting models had decreased casualties

El Nino – the “warm” phase of ENSO
Caused by air pressure patterns in S. Pacific reversing direction and trade winds decreasing & reversing direction.
Normal flow of water away from S. America decreases.
Water piles up off pacific coast of S. America:
pushing thermocline deeper
decreases upwelling of nutrients
sea surface temp. increase
with less nutrients, fish kills occur
shift in rain pattern towards Central Pacific

El Nino (ENSO)
Normal Conditions:

El Nino (ENSO)
El Nino Southern Oscillation:
La Nina – the “cool” phase of ENSO
Occurs when trade winds blowing across tropical Pacific increase in strength.
Increases upwelling off S. America
Cooler than normal sea surface temps
Rain pattern shifts further west
Winds pile up warm surface water in W. Pacific

La Nina’s impact on US (know these!):
wetter than normal conditions across Pacific Northwest
milder winter temps in SE US & cooler temps in NW.
increase in Hurricanes in Atlantic

El Nino vs. La Nina
Quick Review Checklist
Atmosphere Composition:
Nitrogen, oxygen, water vapor, carbon dioxide, methane, nitrous oxide, ozone
Structure of Atmosphere:
Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere
Weather & Climate:
Differences between weather and climate
Factors that affect climate: air mass, air pressure, albedo, altitude, angle of sunlight, clouds, distance to oceans, fronts, heat, land changes, latitude, location, humidity, mountain ranges, pollution, rotation, wind patterns
Human activity and influence on climate.
Atmospheric Circulation:
Coriolis effect
Types of winds (breezes): sea breeze, land breeze
Hadley, Ferrel, and Polar cells
Doldrums, Westerly (Jet Steam), Trade Winds, Horse Latitudes
Hurricanes and Tornadoes: what causes them, mitigation, case studies (Katrina)
El Nino and La Nina:
How they develop
Environmental impacts


A Journey Through the Atmosphere
Heat Island Effect
ENSO Recap
Full transcript