Table of Contents • Energy in Earth’s Atmosphere • Heat Transfer • Winds • Water in the Atmosphere • Precipitation
- Energy in Earth’s Atmosphere Energy From the Sun • Most of the energy from the sun travels to Earth in the form of visible light and infrared radiation. A small amount arrives as ultraviolet radiation.
- Energy in Earth’s Atmosphere Energy in the Atmosphere • Some sunlight is absorbed or reflected by the atmosphere. The rest passes through to the surface.
- Energy in Earth’s Atmosphere Greenhouse Effect • When Earth’s surface is heated, it radiates most of the energy back into the atmosphere as infrared radiation. Much of this energy is held by the atmosphere, warming it.
- Energy in Earth’s Atmosphere Sequencing • As you read, make a flowchart that shows how the sun’s energy reaches Earth’s surface. How Earth’s Atmosphere Gets Energy Sun gives off energy. Energy travels to Earth as electromagnetic radiation. Some of the sun’s energy is reflected back into space or absorbed by gases or particles in the air. The remaining energy is absorbed or reflected by the surface. Much of the energy absorbed by the surface is radiated back into the atmosphere.
- Heat Transfer Temperature and theMovement of Molecules • The iced tea is cold, so its molecules move slowly. The herbal tea is hot, so its molecules move faster than the molecules in the iced tea.
Temperatures in weather reports are usually given in Fahrenheit scale, but scientists use the Celsius scale. Temperature readings can be converted from the Fahrenheit scale to the Celsius scale using the following equation: If the temperature is 68ºF, what is the temperature in degrees Celsius? ºC = 20ºC - Heat Transfer Converting Units
Practice Problem Use the equation to convert the following temperature from Fahrenheit to Celsius. 35.0ºF 1.67ºC - Heat Transfer Converting Units
Practice Problem Use the equation to convert the following temperature from Fahrenheit to Celsius. 60.0ºF 15.6ºC - Heat Transfer Converting Units
Practice Problem Use the equation to convert the following temperature from Fahrenheit to Celsius. 72.0ºF 22.2ºC - Heat Transfer Converting Units
- Heat Transfer How Heat Is Transferred • Heat is transferred in three ways: radiation, conduction, and convection.
- Heat Transfer Outlining • As you read, make an outline about how heat is transferred. Use the red headings for the main topics and the blue headings for the subtopics. Heat Transfer • Thermal Energy and Temperature • Measuring Temperature • Temperature Scales • How Heat Is Transferred • Radiation • Conduction • Convection • Heating the Troposphere
- Winds Angle of the Sun’s Rays • Energy from the sun strikes Earth most directly near the equator. Near the poles, the same amount of energy is spread out over a larger area.
- Winds Coriolis Effect • As Earth rotates, the Coriolis effect turns winds in the Northern Hemisphere toward the right.
- Winds Global Wind Belts • A series of wind belts circles Earth. Between the wind belts are calm areas where air is rising or falling.
- Winds Jet Streams • The jet streams are high-speed bands of winds occurring at the top of the troposphere.
- Winds Relating Cause and Effect • As you read, identify how the unequal heating of the atmosphere causes the air to move. Write the information in a graphic organizer like the one below. Effects Warm air expands, becomes less dense, and rises. Cause Cold, more dense air sinks. Unequal heating of the atmosphere Dense cold air has a higher pressure than less dense warm air. Wind blows from areas of higher pressure to areas of lower pressure.
- Water in the Atmosphere Determining Relative Humidity • Relative humidity is affected by temperature. Use the data table to answer the following questions. First, find the dry-bulb temperature in the left column of the table. Then find the difference between the wet- and dry-bulb temperatures across the top of the table. The number in the table where these two readings intersect indicates the relative humidity in percent.
64% Interpreting Data: At noon, the reading on a sling psychrometer are 18ºC for the dry-bulb thermometer and 14ºC for the wet-bulb thermometer. What is the relative humidity? - Water in the Atmosphere Determining Relative Humidity
88% Interpreting Data: At 5 p.m., the psychrometer is used again. The reading on the dry-bulb thermometer is 12ºC and the reading on the wet-bulb thermometer is 11ºC. Determine the new relative humidity. - Water in the Atmosphere Determining Relative Humidity
It decreased from 18 degrees to 12 degrees. Interpreting Data: How did the temperature change between noon and5 P.M.? - Water in the Atmosphere Determining Relative Humidity
It increased. Interpreting Data: How did the relative humidity change during the course of the day? - Water in the Atmosphere Determining Relative Humidity
For the same amount of water in the air, as the temperature decreases, the relative humidity increases. Warm air can hold more moisture than cool air can. Drawing Conclusions: How was the relative humidity affected by air temperature? Explain your answer. - Water in the Atmosphere Determining Relative Humidity
- Water in the Atmosphere How Clouds Form • Clouds form when warm, moist air rises and cools. Water vapor condenses on tiny particles to form liquid water or ice crystals.
- Water in the Atmosphere Types of Clouds • Scientists classify clouds into three main types based on their shape: cirrus, cumulus, and stratus. Clouds are further classified by their altitude.
- Water in the Atmosphere Asking Questions • Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions. Question Answer How does the water cycle work? Water evaporates from the surface, condenses to form clouds, and falls to Earth as rain or snow. What is relative humidity? The percentage of water vapor in the air compared to the maximum amount air can hold at that temperature How do clouds form? Water in the air condenses on tiny particles in the air to form liquid water or crystals. Can you determine weather conditions by looking at clouds? Yes; each type of cloud is associated with a particular type of weather.
- Precipitation Water Droplets • Droplets come in many sizes. A raindrop has about one million times as much water in it as a cloud droplet.
- Precipitation How Hail Forms • Hailstones start as small pellets of ice in cumulonimbus clouds. They grow larger as they are repeatedly tossed up and down until they become so heavy they fall to the ground.
- Precipitation Measuring Precipitation • Scientists measure precipitation with various instruments, including rain gauges.
- Precipitation Using Prior Knowledge • Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about precipitation in a graphic organizer like the one below. As you read, write what you learn. What You Know Precipitation can be rain or snow. Precipitation comes from clouds. What You Learned Sleet, freezing rain, and hail are forms of precipitation. Droplets or ice crystals in clouds must grow heavy enough to fall through the air before precipitation occurs.
Earth’s winds include include Local winds two types three types Trade winds Graphic Organizer Global winds Prevailing westerlies Polar easterlies Sea breeze Land breeze