Transcript The Atmosphere - This is Worley Science

The Sun....
provides the energy that drives
convection within the
atmosphere and oceans,
producing winds and ocean
currents.
Ocean Currents
• Stream-like movements of water in oceans
• Heat is transferred around the world by ocean
currents through convection.
– Over ½ the heat that reaches the Earth from
the sun is absorbed by the oceans surface.
• This heat affects the Earth’s weather and climate.
Surface Currents
• Currents at or near the surface of the ocean
• Affect weather and climate for coastal regions
around the world.
– Warm currents originate at the Equator and
warm coastal areas
– Cold currents originate at the Poles and cool
coastal areas
Surface Currents
• Controlled by 3 factors:
– Global winds - Winds are named by the direction from
which they blow. The globe is encircled by six
major wind belts, three in each hemisphere. From pole to
equator, they are the polar easterlies, the westerlies, and
the tradewinds.
– Coriolis effect - curving of moving objects from a straight
path due to the rotation of the Earth.
• Currents in the Northern Hemisphere turn clockwise.
• Currents in the Southern Hemisphere turn counter clockwise.
– Continental deflections - When surface currents meet
continents, they deflect, or change direction.
Specific Heat Capacity
of Our Oceans
– Ocean water has a high specific heat
capacity
• amount of energy needed to change it’s
temperature
– It takes far more energy to change the
temperature of water than land or air
• Water cools down and warms up much slower
– This keeps coastal areas cooler in the
summer and warmer in the winter.
Coriolis Effect
Currents Trade Places
• Water from deep currents get warmer as they
reach the equator and starts to rise.
• Water from surface currents get colder as they
reach the poles and starts to sink
• Heat is transferred by convection currents,
continually moving from deep currents to surface
currents
Changes in Ocean Currents
– El Nino – the warming of water
Ocean
in the Pacific
– La Nina – the cooling of water in the Pacific
Ocean
The Wind
Winds are the result of uneven heating of
the Earth’s surface
This uneven heating
causes differences
in air pressure
to develop
Molecules always
move from areas of
high pressure to
areas of low
pressure
Convection of Air
Our Earth’s Weather and Climate
Weather and Climate
• Complex interactions between the sun (energy) and the
oceans, the land, and the atmosphere (matter)
• Weather
– The condition of the atmosphere at a certain time and place.
– Continually changes dynamically (daily)
• Climate
– The overall weather patterns of an area during periods of seasons
or years.
– Changes occur over long periods of geologic time (last ice age
ended about 10,000 years ago).
Causes of Weather and Climate
Changes
• Amount of Solar energy from the sun.
• Natural events from Volcanoes and Fires
• Human impacts contributing to global warming
• Temperature of Ocean Waters
Weather Vocabulary
• Water cycle – circulation of water
• Air Pressure –Weight of the air in the atmosphere
• Air Masses – Large bodies of air that have the same
temperature and moisture.
• Fronts – Areas where two different air masses meet.
• Global winds – Wind caused by global circulation
patterns.
• Heat – Transfer of Thermal energy by infrared radiation
from the sun.
• Temperature – Kinetic energy of molecules in the
atmosphere.
• Humidity – Amount of water vapor in the air.
Evaporation
• Occurs when the sun heats up water and
turns it into water vapor (a gas) or steam
which travels into the air.
Condensation
Water vapor in the air gets cold and
changes back into liquid, forming clouds.
Precipitation
• Occurs when so much
water has condensed,
turned back into liquid,
that the air cannot hold it
anymore. The clouds get
heavy and water falls back
to the earth in the form of
rain, hail, sleet or snow.
Transpiration
• The process by which
moisture is carried
through plants and
released to the
atmosphere. Its the
evaporation of water
from plants.
Clouds
• Millions of tiny water drops or ice crystals
• Form as warm air rises and cools
• Water vapor condenses (changes to a liquid
or a solid depending on the air temp.) and
forms clouds.
Air Masses
• Large bodies of air that have the same
temperature and moisture throughout
• Causes changes in weather.
– Types of air masses
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Continental - formed over land; dry
Maritime - formed over water; wet
Tropical - originated in a tropical region; warm
Polar - originated in a polar region; cold
Fronts
• The area where two different air masses
meet.
– 4 types of fronts
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Cold
Warm
Occluded
Stationary
Fronts – Where air masses meet
Earth’s Energy Source
The Sun – Solar Energy
• Energy from the sun is electromagnetic radiation
(Waves).
– Electromagnetic Spectrum
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Radio waves
Microwaves
Infrared waves
Visible light
Ultraviolet light
X-rays
Gamma Rays
Cosmic Radiation
Earth’s Matter
• Atmosphere – Mixture of Nitrogen (N2), Oxygen
(O2) and small amounts of other gases including
Carbon Dioxide (CO2) and water vapor (H2O).
• Hydrosphere – All liquid and solid form of water
(H2O).
• Lithosphere – The Earth (all rocks and minerals)
• Biosphere – Living matter made of cells
(prokaryotic and eukaryotic cells)
The Atmosphere
A 500 mile thick sphere of
gases that separate the Earth
from the inhospitable climate
of Space
Earth’s Atmosphere
• Primarily made of nitrogen
and oxygen
• Also made of Carbon
dioxide, ozone and small
amounts of other gases.
• These gases keep our
planet warm and protect
us from the direct effects
of the Sun’s radiation (xrays and gamma rays).
Layers of the Atmosphere
Determined by:
- Temperature
- Chemical composition
- Movement
- Density
Layers:
1.
2.
3.
4.
5.
Troposphere
Stratosphere
Mesosphere
Ionosphere
Exosphere
Layers of our Atmosphere
Troposphere
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Lower atmosphere
8-14.5 Km High (5-9 miles)
Where all weather occurs
Most dense
As you climb higher, temperatures drop
from about 17 to -52 degrees Celsius
Stratosphere
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2nd layer
50 Km (31 miles) high.
Dry and less dense
Temperature increases due to ultraviolet
radiation from the sun.
• Contains the Ozone Layer, which absorbs
most ultraviolet radiation
Mesosphere
• Extends 85 Km (53 miles) above the
stratosphere.
• Temperatures fall as low as -93 degrees
Celsius.
• Known as the Middle atmosphere
Ionosphere
• Starts about 70-80 Km high (43-50 miles)
and continues for hundreds of Km (about
640 Km = 400 miles)
• Contains ions and free electrons (plasma).
• Ions are created when sunlight hits atoms
and tears off electrons
• Auroras occur here.
Exosphere
• Outermost layer of the atmosphere
• From about 640 Km (400 miles) to 1,280 Km (800
miles) high.
• Atmospheric pressure, density and temperature is
very low.
• Mostly hydrogen and helium
• Reaches out to space
Formation of our Atmosphere
• Formed by planetary degassing, a process in
which gases like carbon dioxide, water vapor,
sulfur dioxide and nitrogen were released from
the Earth’s interior by volcanoes and other
processes.
• Life forms on Earth have modified the
composition of the atmosphere since their
evolution.