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Earth: The Biography-Atmosphere-The atmosphere creates our climate. It also creates oxygen to fuel our bodies. -The atmosphere also protects us. Without atmosphere, the planet would be uninhabitable (no one could live here)-Humans can live at ground level because it has the right mix of gasses, the correct temperature, and the right pressure. If we lived higher in the atmosphere we would not be able to survive. -The atmosphere is made of 4 levels:1. Troposphere -more than 6 miles thick-oxygen rich air-unstable but life depends on it2. Stratosphere-very different from troposphere-air is stable and very dry so almost no weather-ozone layer is located here-80% of gases that make up atmosphere are below 50,000 feet (ft)3. mesosphere-30 miles beyond the stratosphere-this protects us from meteors-when you see a shooting start it’s actually a meteor burning up in the atmosphere-noctilucent clouds are found here4. thermosphere-50 miles high. Beyond 50 miles we approach the beginnings of space-This is where nitrogen and oxygen interact with the sun’s lethal win-This interaction creates the auroras-In the 1960s Kittenger took a trip up into the stratosphere in a balloon. -Kittenger jumped from the balloon to Earth and reached a speed of 623 miles per hour-Kittenger couldn’t feel this speed though-he felt like he was suspended in space-His jump remains the longest free fall in history. -15 minutes after he jumped, he was back on the ground-He fell through 99% of the atmosphere’s mass-It’s weight is equal to water 34 feet deep-The atmosphere is not just gases. It’s a balance-It’s like we live in a sea of atmosphere-Tornados are like giant whirlpools-The atmosphere has “waves”-they can reach to over a mile high-they combine with humidity to form a visible cloud-as the air cools it condenses to form a cloud that moves 25 miles an hour-The atmosphere has a weight (14 pounds per square inch) that pushes down on us-we don’t get crushed because of the gases in our body-Air is fluid, like an ocean-The Earth’s atmosphere can shape the planet. It can cut through solid rock. -There is a rock formation in Arizona that was shaped by the atmosphere. -It is called “The Wave”-it looks like it’s been carved by water but it was actually carved out by the wind-the wind picks up grains of sand and scratches out the lines in the rock formation which is why it looks like waves. -it is formed over hundreds of thousands of years (seems like a long time but in geological terms that is a short time). -This shows how powerful the air is. It’s constantly shaping the land/the Earth’s surface-The wind can carve giant ridges. This has happened in Iran and China.-This is only the first process of shaping the Earth’s surface. -When the wind starts to blow in the Sahara desert then the sand is blown across the Atlantic Ocean. Much of it falls into the ocean but some continues on to the Amazon Rain Forest in South America. -40 million tons of dust is transported from the Sahara to the Amazon every year. The rain in the Amazon washes it out of the atmosphere and into the soil below. This helps keep the rainforest health. -Example of the cycle of life on earth. It creates the weather. -The heart of all weather is heat. -Clouds are generated by moisture from ocean and land. -Weather is different because of the way the atmosphere interacts with land, sea, and ice. -There are two opposing air masses in Argentina-Both are powerful and very different from each other-The Amazon basin is in the north and creates warm sticky air-The Antarctic circle is to the south and creates cold air-Storms happen here a lot and are very strong-The Andes Mountains trap the warm and cold air in the same place-when these airs mix it is a clash (fight) between the two-The Andes Mountain region in Argentina is famous for lightning-lightning is a byproduct of the extreme air movement in the clouds-ice collides and builds electricity-the electricity builds up and becomes so strong that it reaches for earth below (lightning)-Higher in the atmosphere is a different form of lightning-These are called “sprites”-type of lightning that strikes up toward the mesosphere instead of going down toward earth-30 to 50 miles high-The planet’s atmosphere was created 4 ? billion years ago-Early earth had many volcanos and for millions of years the volcanos gave off a lot of gases. -These gases created the atmosphere but this atmosphere was different than today-a lot of methane, carbon dioxide and NO oxygen-this lasted for 2 billion years until primitive life began to transform (change) the atmosphere-Stromatilytes are the earliest form of life on Earth. They live in the ocean. They are just big rocks of bacteria. They create a slime that builds up layer upon layer. They are the most successful form of life of the planet because they’ve been around for 3 ? billion years. -The stromatolites absorbed solar energy and began releasing oxygen. The bacteria forming the stromatolites were the first life to go through photosynthesis and release oxygen into our atmosphere. -Back then the seas were rich in nitrogen. When the oxygen from the stromatolites met the nitrogen it bonded and formed rust so the oxygen didn’t leave the sea. -The layers of rust were laid down across the earth and turned into iron ore. -Oxygen gave the planet a protective shield called the “Ozone Layer”-protects the planet from UV rays from the sun-this allowed complex life to live on our planet-The hole in the Ozone Layer is above Antarctica -Oxygen is highly reactive and can support much more energetic life than bacteria-Some cities in the Andes Mountains are very high (10,000 miles high)-people here couldn’t have children when they first arrived because there was a lack of oxygen-The Spanish were used to breathing air at sea level (21% oxygen) but the oxygen levels in the Andes is about half of that. The Andes people were used to it, but the Spanish were not. -Greenhouse gases (like carbon dioxide) are also very important for our atmosphere. -without these gases our average temperature would be -27 degrees-now we are releasing extra carbon dioxide into the atmosphere when we burn fossil fuels. -this causes the temperature of the planet to change -methane is a much more powerful greenhouse gas than carbon dioxide. -if methane is released into our atmosphere then global warming will increase. -methane is trapped in the ice in Siberia. If the ice melts the methane will be released into the atmosphere. -We are the first species ever to be knowingly warming the atmosphere. ................
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