10B READING/NOTES
Movement of Air in Earth's Atmosphere:
Wind and Air Pressures:
- The atmosphere has different layers made up of nitrogen, oxygen, carbon dioxide, water vapor, and other gases.
- The troposphere is the closest layer to the surface of the Earth.
- It is the location where weather occurs.
- The temperature decreases the higher you go through the layers.
Wind and Air Pressures:
- Air expands and takes up more space when heated.
- The density of the heated air decreases, because it's more spread out and less compacted.
- As this air rises, it leaves behind less pressure, which causes a low pressure on the surface of the Earth.
- An example of this process would be hot air balloon.
- Wind is the air moving from an area of high pressure to an area of low pressure.
- When the difference between the high and low pressures is greater, the wind moves faster.
- If the whole Earth had the same pressure, there would be no wind.
- The sun does heat some parts of the Earth more than others, which causes the surface to have uneven temperatures.
- With this, we can tell that wind is driven by solar energy.
Sea Breeze/Land Breeze:
How do these diagrams relate to density?
How do these diagrams relate to density?
SEA BREEZE: While the less denser warm air is rising, the denser colder air is moving through. The cold breeze meeting the warm one will cause a sea breeze. This happens during the day. Also, this is a horizontal movement of air.
LAND BREEZE: At night, the breezes flip, which makes the cooler air go out towards the warmer air, which is out on the sea now.
Jet Streams:
Jet Streams:
- A jet stream is a fast-moving current of air locates int the upper part of the troposphere.
- This air forms at the boundaries of air masses that have different temperatures.
- In the United States, the weather systems are mostly propelled from west to east by the Jet Streams.
- Jet Streams can help Texas by brining in cold air from Canada throughout winter.
High and Low Pressure:
- Air pressure is the weight of air pressing against us., which is all around us.
- When the density of air changes, the air pressure changes as well.
- When the cool air becomes more dense, it sinks into the air that has a higher pressure.
- As it sinks, it leaves more pressure, causing an area of high pressure on the Earth's surface.
- The air then moves from the high pressure to the low pressure, causing wind.
Weather Associated with highs and lows:
- Air masses are a very large section of the troposphere.
- These large masses of high and low pressure air systems move across the Earth's surface, which makes them responsible for the weather that occurs.
- Storms are usually occurring in the low pressure.
- Isobars are lines on a weather map that indicate areas with the same air pressure.
- Isobars also help predict the areas of high and low pressures, and relative wind speeds.
- Cool, sinking air causes dry, clear weather.