Zusammenfassung der Ressource
The Atmosphere
- Section 1: The
Air Around You
Anmerkungen:
- Weather: the condition of Earth's atmosphere at a particular time and place
Atmosphere: the envelope of gases that surrounds the planet
- Composition of
the atmosphere
Anmerkungen:
- Earth's atmosphere is made up of nitrogen, oxygen, carbon dioxide, water vapor, and many other gases, as well as particles of liquids and solids.
- Nitrogen
Anmerkungen:
- Nitrogen is the most common gas in the atmosphere, and it makes up three fourths of the air we breathe.
- Oxygen
Anmerkungen:
- Like nitrogen, oxygen in the air moves through a natural cycle involving living things. Oxygen is used slowly in any processes .
- Carbon
Dioxide
Anmerkungen:
- Carbon dioxide is essential to life because plants take in carbon dioxide from the air to make food. When plant and animal cells break down food to produce energy, they give of carbon dioxide as a waste product.
- Water
Vapor
Anmerkungen:
- Water Vapor: water in the form of a gas. Water vapor plays an important role in the weather. Clouds form when water vapor condenses out of the air to form tiny droplets of liquid water or crystals of ice.
- Other Gases
Anmerkungen:
- Oxygen and nitrogen together make up 99 percent of dry air. Argon and carbon dioxide make upmost of the other one percent. The remaining gases are called trace gases because only small amounts of them are present.
- Particles
Anmerkungen:
- Pure air consists of only gases, but it only exists in laboratories. The air we breathe also contains tiny solid and liquid particles of dust, smoke, salt, and other chemicals.
- Importance of
the Atmosphere
Anmerkungen:
- Earth's atmosphere makes conditions on Earth suitable for living things.
- Air Quality
Anmerkungen:
- Pollutants: harmful substances in the air, water, or soil.
- Sources of Pollution
Anmerkungen:
- Most air pollution is the result of burning fossil fuels, such as coal, oil, gasoline, and diesel fuel.
- Smog and
Acid Rain
Anmerkungen:
- Photochemical smog: the brown haze that develops in sunny cities.
Acid rain: rain that contains more acid than normal.
- Improving
Air quality
Anmerkungen:
- Even though the air quality int he country has decreased over the past 30 year, there are still American cities that are polluted.
- Section 2:
Air Pressure
- Properties
of Air
Anmerkungen:
- Because air has mass, it also has other properties, including density and pressure.
- Density
Anmerkungen:
- Density: The amount of mass in a given volume of air.
- Pressure
Anmerkungen:
- Pressure: The force pushing on an area or surface.
Air pressure: the result of the weight of a column of air pushing down on an area.
Air pressure can change from day to day.
- Measuring
Air Pressure
Anmerkungen:
- Barometer: an instrument that is used to measure air pressure.
Two kinds of barometers are mercury barometers and aneroid barometers.
- Mercury
Barometers
Anmerkungen:
- Mercury Barometer: consists of a glass tube open at the bottom end and partially filled with mercury.
- Aneroid
Barometers
Anmerkungen:
- Aneroid Barometer: has an airtight metal chamber.
- Units of Air
Pressure
Anmerkungen:
- Weather reports use several different units for air pressure. It is ,measured by inches of mercury, or millibars.
- Altitude and the
Properties of Air
Anmerkungen:
- Altitude: elevation, is the distance above sea level of the surface of the oceans.
- Altitude Affects
Air Pressure
Anmerkungen:
- Air pressure is greater at sea level. Air near the top of the atmosphere has lower air pressure.
- Altitude Also
Affects Density
Anmerkungen:
- As you go up through the atmosphere, the density of the air decreases. The gas molecules that make up the atmosphere are farther apart at high altitudes than they are at sea level.
- Section 4: Energy
in Earth's
Atmosphere
Anmerkungen:
- The movement of heat in the atmosphere causes temperatures to change, winds to blow, and rain to fall.
- Energy From
the Sun
Anmerkungen:
- Electromagnetic Waves: a form of energy that can move through the vacuum of space.
Radiation: the direct transfer of energy by electromagnetic waves.
Most of the energy from the sun travels to earth in the form of visible light.
- Visible Light
Anmerkungen:
- Visible light includes all the colors you see in a rainbow, and the different colors are the result of different wavelengths.
- Non-Visible
Radiation
Anmerkungen:
- Infrared Radiation: a form of electromagnetic energy that has wavelengths that are longer than red light.
Ultra-violet Radiation: an invisible form of energy with wavelengths that are shorter than violet light.
- Energy in the
Atmosphere
Anmerkungen:
- Scattering: a process in which dust particles and gases in the atmosphere reflect light in all directions.
Some sunlight is absorbed or reflected by the atmosphere before it can reach the surface. The rest passes through the atmosphere to the surface.
- Energy at
Earth's Surface
Anmerkungen:
- When Earth's surface is heated, it radiates most of the energy back into the atmosphere as infrared radiation.
Greenhouse Effect: the process by which gases hold heat in the air.
- Section 3: Layers
of the Atmosphere
Anmerkungen:
- Scientists divide Earth's atmosphere into four main layers classified according to changes in temperature. These layers are the troposphere, stratosphere, mesosphere, and the thermosphere.
- The
Troposphere
Anmerkungen:
- Troposphere: the inner, or lowest layer of Earth's atmosphere.
The troposphere is the layer of the atmosphere in which Earth's weather occurs.
- The
Stratosphere
Anmerkungen:
- Stratosphere: the layer of the atmosphere that extends from the top of the troposphere to about 50 kilometers above Earth's surface.
The stratosphere is the second layer of the atmosphere and contains the ozone layer.
- The
Mesosphere
Anmerkungen:
- Mesosphere: the layer above the stratosphere, where there is a drop in temperature.
The mesosphere is the layer of the atmosphere that protects the Earth's surface from being hit by most meteoroids.
- The
Thermosphere
Anmerkungen:
- Thermosphere: the layer that extends from 80 kilometers above the Earth's surface outward into space.
The thermosphere is the outermost layer of Earth's atmosphere .
Temperature: the average amount of energy of motion of each molecule o fa substance.
Ionosphere: The lower layer of the thermosphere which begins about 80 kilometers above the surface, and extends to about 400 kilometers.
Exosphere: the out portion of the thermosphere which extends from 400 kilometers outward for thousands and thousands of kilometers.
- Section 5: Heat
Transfer In the
Atmosphere
Anmerkungen:
- Heat transfer in the troposphere plays an important role in influencing Earth's weather.
- Thermal Energy
and Temperature
Anmerkungen:
- Thermal Energy: the total energy of motion in the particles of a substance
The faster the particles are moving, the more energy they have. Energy is the average amount of energy of motion of each particle of a substance.
- Measuring
Temperature
Anmerkungen:
- Thermometer: a thin glass tube with a bulb on one end that contains a liquid, usually colored alcohol.
Air temperature is usually measured with a thermometer.
- Temperature
Scales
Anmerkungen:
- Temperature is measured in degrees, either Fahrenheit or Celsius. The boiling point of pure water is 100 degrees Celsius, and the freezing point is 0 degrees Celsius.
- How Heat is
Transferred
Anmerkungen:
- Heat: the transfer of thermal energy from a hotter object to a cooler one.
Heat is transferred in three different ways within the atmosphere: radiation, conduction, and convection.
- Radiation
Anmerkungen:
- Radiation is the direct transfer of energy by electromagnetic waves.
- Conduction
Anmerkungen:
- Conduction: the direct transfer of heat from one substance to another substance that is touching.
The closer together the particles in a substance are, the more effectively they can conduct heat.
Air and water do not conduct heat very well.
- Convection
Anmerkungen:
- Convection: the transfer of heat by the movement of a fluid.
- Heating the
Troposphere
Anmerkungen:
- Convection Currents: The upward movement of warm air and the downward movement of cold air.
Within the troposphere, heat is transferred by mostly by convection.
- Section 6:
Winds
- Global Wind Belts
Anmerkungen:
- The major global wind belts are the trade winds, the polar easterlies, and the prevailing westerlies.
- Doldrums
Anmerkungen:
- Regions near the equator with little or no wind are called the doldrums. Cool air moves into the equator, but is warmed rapidly and rises before it moves very far, which is why there is very little horizontal movement, so the the winds near the equator are very weak.
- Horse Latitudes
Anmerkungen:
- Latitude: the distance from the equator, measured in degrees. At about 30 degrees north and south latitudes, the air stops moving toward the poles and sinks. In each of these regions, another belt of calm air forms. The latitudes 30 degrees north and south of the equator came to be called the horse latitudes.
- Trade Winds
Anmerkungen:
- When cold air over the horse latitudes sinks, it produces a region of high pressure which caused surface winds to blow both toward the equator and away from it. The winds that blow toward the equator are turned west by the Coriolis effect. As a result, these steady easterly winds are called the trade winds.
- Prevailing Westerlies
Anmerkungen:
- In the mid-latitudes, between 30 degrees and 60 degrees north and south, winds that blow toward the poles are turned toward the east by the Coriolis effect, and are called the prevailing westerlies because they blow from west to east. They play an important role in Earth's weather.
- Polar Easteries
Anmerkungen:
- Cold air near the poles sinks and flows back toward lower latitudes and gets shifted west by the Coriolis effect, producing polar easterlies.The polar easterlies meet the prevailing westerlies along a region called the polar front. The mixing of warm and cold air along the polar front has a major effect on weather in the United States.
- Jet Streams
Anmerkungen:
- Jet Streams: bands of high-speed winds above Earth's surface. they generally blow from west to east at speeds of 200 to 400 kilometers per hour. As jet streams travel around Earth, they wander north and south along a wavy path.
- Global Winds
Anmerkungen:
- Global Winds: winds that blow steadily from specific directions over long distances.
Global winds are created by the unequal heating of Earth's surface. But unlike the local winds, global winds occur over a large area.
- The Coriolis
Effect
Anmerkungen:
- Coriolis effect: the way Earth's rotation makes wind curve. If earth did not rotate, global winds would blow in a straight line from the poles to the equator.
- Global Convection
Currents
Anmerkungen:
- Temperature differences between the equator and the poles produce giant convection currents in the atmosphere. Higher in the atmosphere, the air flows away from the equator toward the poles. Those air movements produce global winds.
- Local Winds
Anmerkungen:
- Local Winds: winds that blow over short distances.
Local winds are caused by the unequal heating of the Earth' s surface within a small area.
- Sea Breeze
Anmerkungen:
- Sea Breeze: a local wind that blows from an ocean or lake(during the day).
As the sun heats the Earth's surface during the day, the land warms up faster than the water.
- Land Breeze
Anmerkungen:
- Land Breeze: the flow of air from land to a body of water is called a land breeze( at night).
At night, the land cools faster than the water, so the air over the land becomes cooler than the air over than the air over the water.
- What is Wind
Anmerkungen:
- Wind: the horizontal movement of air from an area of high pressure to an area of lower pressure.
Winds are caused by differences in air pressure. most different air pressures are caused by the unequal heating of the atmosphere.
- Measuring Winds
Anmerkungen:
- Anemometer: an instrument that measures wind speed.
Wind direction is measured by a wind vane. The name of a wind tells you where it's coming from.
- Wind-Chill Factor
Anmerkungen:
- Wind-Chill Factor: the increasing cooling a wind can cause.The wind blowing over your skin removes body heat. The stronger the wind, the colder you feel.