Chapter 1: The Atmosphere Weather Chapter 1: The Atmosphere

Earth’s Atmosphere Supports Life Read p. A9-A11 to distinguish the two truths from the lie. Air gets thinner the higher you go up a mountain. Air is mostly oxygen. Here is an analogy: earth:atmosphere::peach:fuzz

Characteristics of the Atmosphere As you increase your height above sea level (ALTITUDE), the air has less oxygen and is called “thinner.” The thickness of the air is determined by looking at its density, or the amount of material that is contained within a space. Think about a brick and a wooden block the same size. The brick has a greater density because there is more mass in the same size block.

Materials in the Atmosphere Most of the atmosphere is composed of gases but there are some other solid and liquid particles, like dust and smoke. Air is . . . 78% nitrogen 21% oxygen 1% combined argon, carbon dioxide, and other gases The amount of water vapor varies a lot depending on humidity.

Ongoing Processes in the Atmosphere Carbon Cycle Nitrogen Cycle Water Cycle Animals breathe in oxygen and release carbon dioxide. Plants do the opposite. This is a symbiotic relationship. We help one another. Microorganisms remove nitrogen from the air and change it into other chemicals, which are released into the soil. Living things then use this nitrogen. When they die, the nitrogen returns to the soil. Nitrogen from the soil is gradually released into the air. Precipitation Run off Evaporation Condensation

Sudden Atmospheric Changes Volcanic eruptions, forest fires, and dust storms disrupt the normal atmospheric cycles and release substances and gases into the atmosphere.

Moving Energy – What’s the Difference? Convection Conduction Radiation Energy moving by heated gases and liquids Hot air rising and cool air sinking Energy that travels from one substance to another by direct contact Walking barefoot on hot sand Energy that travels in waves Sunlight warming the Earth

Layers of the Atmosphere Posters

Gases in the Atmosphere Absorb Radiation The atmosphere can . . . Absorb light – take it in Reflect light – bounce it back off Let light pass through Give off light

Types of Radiation Lots of energy “Ultra violent” Causes sunburn Ultraviolet Radiation Infrared Radiation Lots of energy “Ultra violent” Causes sunburn Low energy Night vision goggles

Ozone Made of three oxygen molecules stuck together The stratosphere has a collection of ozone called the OZONE LAYER. The ozone layer protects the Earth by absorbing bad UV radiation.

The Greenhouse Effect Gases in the atmosphere keep energy close to the Earth’s surface. The term GREENHOUSE EFFECT came from the way our atmosphere holds gases inside, much like the way a greenhouse maintains heat for its plants. Greenhouse Gases . . . Carbon dioxide Methane Water vapor Nitrous Oxide Others Most greenhouse gases are in the atmospheric layer closest to Earth, the troposphere. Greenhouse gases enable life to thrive on Earth. Without them, Earth would be too cold for life. Over time, energy escapes into outer space. Otherwise, Earth’s temperature would rise higher and higher until life could not survive.

Human Activity Cause Air Pollution Air pollution refers to smoke and other harmful particles that are added to otherwise healthy air. Winds spread air pollution. Gas pollutants … Methane Carbon monoxide Ozone Some are naturally occurring, like the methane produced by cows. Pollutants refer to when these particles cause harm. Ozone in the troposphere is good but breathing it in is bad. PARTICULATES are the tiny particles or droplets that are carried in the air, like smoke, dust, pollen, salt, etc. Burning FOSSIL FUELS like coal and oil produce pollution. SMOG = smoke + fog Smog comes from both factories and cars.

Irritates eyes, nose, throat, lungs Smells bad Difficulty breathing Effects of Pollution Controlling Pollution Ozone alerts on the news warn people of unhealthy days. The Clean Air Act limits the amount of pollution factories are allowed to introduce into the air. Car inspection stickers Environmental Protection Agency (EPA) keeps track of pollution and enforces laws – big $$$ fines for breaking laws Irritates eyes, nose, throat, lungs Smells bad Difficulty breathing Darkens skies

Global Warming Earth can handle some greenhouse gases on its own. Nature contributes some of these gases. The problem occurs when Earth can’t keep up with the added demands that humans place on it. Due to the increase of greenhouse gases, Earth is slowly becoming warmer and warmer. This is called GLOBAL WARMING. CFCs (chlorofluorocarbons) in air conditioners, refrigerators, spray cans, and packaging materials increase bad chemicals in the air. Ozone levels vary across the globe. The South Pole has suffered greatly. Montreal Protocol was created in 1987 and includes 180 nations. The MP asks companies to stop making and using chemicals that destroy the ozone layer.