table of contents the air around you air pressure layers of the atmosphere energy in earth’s...

Table of Contents

The Air Around You

Air Pressure

Layers of the Atmosphere

Energy in Earth’s Atmosphere

Heat Transfer

Winds

The Atmosphere

The Air Around You

Weather: the condition of the Earth’s atmosphere at a particular time and place.

Atmosphere is the envelope of gases that surrounds the planet. The atmosphere consists of nitrogen, oxygen, carbon dioxide, water vapor, and other trace gases as well as particles of solid such as dust.

Water vapor is water (H20) in the form of a gas. The amount of water vapor in the air varies from place to place. Clouds form when water vapor condenses out of the air to form tiny droplets of liquid water or crystals of ice.

The Air Around You

Energy from the sun, wind, water, currents, etc. affect the weather in all areas of the Earth. Events in one part of the atmosphere also affect other parts of the atmosphere.

Air Pressure

Because air has mass, it also has other properties including density and pressure.

Density: the amount of mass in a given volume of air.

Air Pressure: the result of the weight of a column of air pushing on an object. Denser air exerts more pressure, which are measured by barometers.

Altitude, or elevation, is the distance above sea level. As altitude increases, air pressure and air density decreases.

Effect of Altitude on Pressure and DensityHow densely packed would the molecules be at the different altitudes?

Air Pressure

Layers of the Atmosphere

Troposphere: the lowest layer of Earth’s atmosphere. “Tropo” means turing or changing because this is where Earth’s weather is and the conditions are more variable than other layers.

Stratosphere: extends from the troposphere upward to about 50 km above Earth’s surface. It is the second layer and contains the ozone layer (O3) molecules that protect the Earth from ultraviolet radiation from the sun.

Scientists divide Earth’s atmosphere into four main layers classified according to changes in temperature.

Layers of the Atmosphere

Mesosphere: (“meso” meaning middle) and is between 50 to 80 km above the Earth’s surface. This layer protects Earth’s surface from being hit by most meteoroids.

Thermosphere: is the outermost layer of Earth’s atmosphere is the thermosphere. It has no definite outer limit. It is extremely hot in this layer, even though there are little air molecules.

Radiation From the SunEnergy travels to Earth as electromagnetic waves. What are the types of electromagnetic radiation in the diagram?

Energy in Earth’s Atmosphere

Infrared radiation: not seen by humans but can be felt as heat

Visible Light: includes all of the colors that you see in a rainbow.

Ultraviolet radiation: invisible for of energy that can cause sunburns

Energy in Earth’s Atmosphere

Energy in the AtmosphereSome wavelengths reach Earth’s surface. Other wavelengths are completely or partially absorbed in the atmosphere. The rest pass through the atmosphere to the surface.

Clouds act as mirrors to reflect sunlight back into space. Dust sized particles and gases also disperse light in all directions in a process called scattering.

Materials at Earth's surface reflect different amounts of energy. How would you use the higher percentages below to show a bar graph?

Energy in Earth’s Atmosphere

Energy at Earth’s SurfaceComplete each sentence with a word from the Word Bank to learn what is happening to the energy at Earth's surface and in the lower atmosphere.

Energy in Earth’s Atmosphere

Greenhouse EffectThe greenhouse effect is a natural heat-trapping process. The energy from absorbed radiation heats carbon dioxide, water vapor, methane, and other gases in the air. In turn, these gases hold heat.

What is the sequence of events that causes it to occur?

Energy in Earth’s Atmosphere

Heat Transfer

Thermal energy is the measure of the total energy of motion in the particles of a substance. Air temperature is usually measured with a thermometer.

Thermal energy is transferred through conduction (in direct contact with each other), convection (movement of a fluid), and radiation (transfer through electromagnetic waves).

Heat is transferred mostly by convection currents within the troposphere.

Heat Transfer

Measuring TemperatureDoes the tea in the pot have more or less thermal energy than the tea in the cup? If you know the degrees of Farenheit, how do you find the degrees of Celsius?

Winds

Differences in air pressure cause the air to move. Wind is the movement of air parallel to Earth’s surface and move from areas of high pressure to low pressure. Most differences in air pressure are caused by the unequal heating of the atmosphere.

Wind speed is measured with an anemometer.

WindsGlobal winds are winds that blow steadily from specific directions over long distances and large areas. These are due to the uneven heating of Earth’s Surface.

The angle of the sun's rays causes temperature differences at Earth's surface.

Which area on Earth receives the most direct light from the sun, and which areas receive the least?

Winds

Local winds are caused by the unequal heating of Earth’s surface within a small area. Two types of local breezes are sea Breezes (a local wind that blows from an ocean or lake during the day) and land breezes (local winds that flow from the land to the body of water at night).

The Coriolis EffectThe Coriolis effect determines the direction of global winds. Global winds in the Northern hemisphere gradually turn toward the right and in the southern hemisphere toward the left.

Winds

WindsGlobal Wind BeltsThe Coriolis effect and other factors combine to produce a pattern of wind belts and calm areas around Earth. Match the descriptions of the global winds with their location on the globe.