Solar Energy and the Atmosphere California Standards: 4b, c, d; 5a, b, c.

Radiation & the Electromagnetic Spectrum Energy or radiation is transmitted through space from the sun or other stars in the form of electromagnetic radiation. This energy travels at the speed of light. This energy can be in the form of x-rays, radio waves or visible light.

Electromagnetic Spectrum

Atmospheric Energy Balance

Reflected or scattered Earth’s Albedo is 30% Reflected or scattered

The Greenhouse Effect The greenhouse effect is a process whereby heat from the sun is reradiated, or bounced back, into the atmosphere and then prevented from escaping the Earth’s atmosphere due to certain gases in the atmosphere. These gases are primarily CO2.

Energy or Heat and the Atmosphere Some of this electromagnetic spectrum can be trapped as heat in our atmosphere. Some of the gases in the troposphere can trap radiation. These gases can be water vapor, methane and carbon dioxide. Some of the radiation escapes our atmosphere.

Energy and Latitude Because the Earth is round not all parts of the Earth receive the same amount of radiation. This curved surface of the Earth therefore causes the Earth to be warmer near the equator and cooler near the poles.

Earth’s Tilt and Radiation

Solar Radiation and Latitude

With less energy to heat the poles, than the equator, the temperature is lower at the poles. More solar radiation at the equator than at the poles converts into higher temperatures at the equator.

Tropical Energy

Polar Energy

Thus, more solar radiation at the equator means: 1. Air above the equator is hotter. 2. The air is less dense. 3. Therefore, the air moves upward. 4. As this air moves up it is replaced by cooler air. 5. Thus you have convection currents.

Convection Currents

The Four Seasons The reason there are seasons on Earth is because of the tilt of the Earth. This tilt is 23 ½ degrees. When the northern hemisphere is tilted away from the sun you have the winter and when it is tilted towards the sun you have summer.

N hemisphere away from sun Winter S hemisphere towards the sun

N hemisphere towards the sun, summer S hemisphere away from the sun, winter

So… the reason there are seasons is because of the tilt of the Earth So… the reason there are seasons is because of the tilt of the Earth. This is a quiz, benchmark and district final question. Now you know the answer.

Transfer of Energy Energy can be transferred by three methods: Conduction is transfer of energy by direct contact Convection is the transfer of energy by mass flow of a liquid or gas. Radiation is the transfer of energy by electromagnetic waves or energy.

Conduction: energy transfer by direct contact

Convection Currents

Convection: mass flow of water, gas or molten lava

Energy Transfer

The Coriolis Effect 1. The coriolis effect causes air and water to move to the right in the northern hemisphere and 2. to move to the left in the southern hemisphere. 3. This effect causes distinct water and wind patterns.

The Coriolis Effect In a nutshell, the Coriolis effect is the movement of atmospheric air and ocean waters due to the rotation of the Earth on it’s axis.

What causes the wind deflection from the north and the south poles? A. The Coriolis effect.

The Surface Winds 1. Between 0 and 30 degrees N and S latitude are the trade winds, while 2. between 30 and 60 degrees N and S latitude are the westerlies.

Global Winds Westerlies NE Trade Winds SE Trade Winds Westerlies

Trade Winds and Westerlies

High Altitude Winds 1. High altitude winds or jet streams are narrow belts of wind that can blow from 97 to 185 km/hr. 2. Airplane pilots use these winds to move around the world. 3. Change from day to day and season to season.

Jet stream in the upper troposphere and lower stratosphere.

Jet Stream, January 12, 2007 Can you say Cold?

Daily and Seasonal Winds 1. A convection current is when a large body of water meets a large land mass which can result in convection currents. 2. Solar radiation warms the land faster than the water so the air over the land moves upward being replaced by the air over the water.

Sea and Land Breezes 1. When the air moves from the land to the sea it is called a land breeze. 2. When the air moves from the sea to the land it is called a sea breeze.

Sea Breezes

Land Breezes

Which of the figures represents a sea breeze? Letter D, air moving from the sea to the land. Which of the figures represents a land breeze? Letter C, air moving from the land to the sea.

The End

Quick Quiz 1. The __________ are responsible for the movement of much of the weather across the United States. a. prevailing westerlies b. polar easterlies c. trade winds d. doldrums

2. The deflection of wind, or Coriolis effect, from the north and south poles is due to a. Rotation of the Earth b. The shape of the Earth c. The tilt of the Earth on it’s axis d. The total land mass in North America.

3. Temperature differences on Earth are caused by ___________. a. the rotation of the sun b. the closeness of the sun to the Earth c. the tilt of the Earth on it’s axis d. the distance to the sun during the summer.

4. Air above the equator is heated more than at other places on Earth because the sun’s rays strike Earth _________ at the equator. a. at a low angle b. at a tilt c. directly d. at a 45 degree angle

5. When the land is heated faster than the ocean the result is a a. land breeze b. sea breeze c. directional breeze d. none of the above

6. What type of wind is located at letter C? 1. Trade winds 2. Westerlie winds 3. Easterly winds 4. Polar trade winds

7. The land heats faster than the ocean. Which way will the wind blow? 1. From the land to the sea 2. From the sea to the land 3. From the ocean to the atmosphere 4. From the atmosphere to the land

1. It rises 2. It sinks 3. It stagnates 4. It contracts 8. What happens to the air around A as the air warms and decreases in density? 1. It rises 2. It sinks 3. It stagnates 4. It contracts

Well… how’d you do?