Chapter 1: The Atmosphere Weather Chapter 1: The Atmosphere

Earth’s Atmosphere Supports Life 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

What is the Atmosphere? Atmosphere is the envelope of essential gases that surround Earth In addition to these gases, particles of liquids, solids and water vapor can also be found in Earth’s atmosphere Our atmosphere makes conditions on Earth suitable for living organisms

Characteristics of the Atmosphere As you increase your height above sea level (ALTITUDE), the air has less oxygen and is called “thinner.” Altitude is the distance above sea level. The higher the altitude the less dense the air. 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. Think about football and specifically, the Denver Broncos. They play at “Mile High Stadium” which means it is one mile above sea level. Watch what the players from the opposing teams do when they come off of the field. Some of them will take oxygen (put on a mask) on the side line. This is because you need oxygen for your muscles to continue to work. Since there is less oxygen, muscles could cramp more or they would get tired faster.

Scientists divide Earth’s atmosphere into five main layers classified according to changes in temperature Troposphere Stratosphere Mesosphere Thermosphere Exosphere Layers of Atmosphere

Troposphere inner or lowest layer of Earth’s atmosphere the layer in which we live and our weather occurs as altitude increases, temperature decreases goes from Earth’s surface to approximately 10km above the surface

Stratosphere extends from the top of the troposphere (10km) to about 50km above Earth’s surface The ozone layer protects us from the sun’s harmful ultraviolet (UV) rays. as altitude increases, temperature increases

Mesosphere begins 50km from Earth’s surface and extends to 80km considered to be the “middle” of the layers protects Earth from meteoroids as altitude increase, temperature decreases

Thermosphere the outermost layer of Earth’s atmosphere extends from 80km into outer space ‘thermo’ means hot as altitude increases, temperature increases Includes the exosphere which is the outermost edge of the atmosphere This is the highest region in the atmosphere

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. So mathematically speaking, the air is only about 1/5 oxygen. We can not live on 100% oxygen. It would be toxic to us. People that use things like oxygen masks have to have a higher percentage of oxygen in their air because they have damage to their lung tissue which makes them not work as effectively.

Ongoing Processes in the Atmosphere Carbon Cycle Nitrogen Cycle Water Cycle Animals breathe in oxygen and release carbon dioxide. Plants breathe in carbon dioxide and release oxygen. 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

Carbon/Oxygen Cycle

Nitrogen Cycle

Water Cycle

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 that travels from one substance to another by direct contact Walking barefoot on hot sand Energy that travels in waves Sunlight warming the Earth Energy moving by heated gases and liquids Hot air rising and cool air sinking

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. Because of the composition of ozone, it can chemically combine with gasses that we give off from our cars and burning fuels. Ozone is a very crowded molecule, if one of the oxygen molecules can leave, it will. That’s why Carbon Monoxide is so bad. It will go up, take an oxygen molecule and make carbon dioxide. What was left of the ozone molecule is now O2 which is the oxygen that we breathe. You wouldn’t think that was bad, but we need to have the ozone layer to survive. Ozone can mend itself, but that means that we need to focus on not destroying it.

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. Sometimes you hear the word Greenhouse Effect and automatically think bad thoughts. We need some of these gasses to keep our heat in. However, too much could cause a negative effect.

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 stratosphere 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. So remember Ozone Stratosphere good, Ozone Troposphere bad!!!

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 theory 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 18+ nations. The MP asks companies to stop making and using chemicals that destroy the ozone layer. I am not going to tell you my stance on Global Warming. We all know this is a hot button topic. What I would like for you to do is to read both sides of the stance and then decide on your own what you think.