lesson 13.1 atmosphere

• Nitrogen — 78 %

  Oxygen — 21 %

  Argon — 0.9 %

  Carbon dioxide — 0.03%
• Atmosphere - refers to the layer of gasses that surrounds the earth. It consists mainly of nitrogen and oxygen, along with small amounts of other gasses. The atmosphere provides protection, regulates temperature, and supports weather and climate systems.
• Troposphere - lowest layer of the earth’s atmosphere, extending from the earth’s surface up to an average altitude of about 12 km. It is the layer where weather occurs, and it is where we live and breathe. This is where hot air balloons and airplanes fly because it’s much safer and faster.
• Stratosphere - is the layer located above the troposphere. It extends roughly from an altitude of about 12 km to 50 km above the earth’s surface. It is also home to the ozone layer, which shields the earth from harmful UV radiation.
• 1. The mesosphere - is the third layer of the Earth’s atmosphere. It extends approximately from an altitude of about 50 km to 85 km above the earth’s surface.  It is characterized by thin air and low atmospheric pressure. It is also where the meteors burn.
• Thermosphere- is the fourth layer of the earth’s atmosphere. It begins approximately at an altitude of 85 km and has no clearly defined upper boundary. It is primarily composed of individual gas molecules, such as oxygen and nitrogen, rather than molecular combinations. It is where auroras and northern light occur.
• Exosphere - is the outermost layer of the earth’s atmosphere, located above the thermosphere. It is the uppermost region of the atmosphere and gradually transitions into the vacuum of space. It is where satellites and the human-made objects in Earth’s orbit are found, Satellites are strategically placed in orbit within the exosphere to perform their various functions.