10b Reading/Notes
Notes:
- the troposphere is where weather occurs
- in the atmosphere there are multiple layers of gas such as oxygen, water vapor, carbon dioxide, and nitrogen
- air expands when it gets heated which makes it less compact, therefore making the air rise
- when the heated air rises, it creates low pressure below it
- wind is when air moves from a high pressure area to a low pressure area
- the bigger difference between the pressure of the winds, the faster the wind moves
- pressure differences are caused by the Sun heating the Earth's surface unevenly
Land and Sea Breezes:
- During the day, the cooler air blows towards the land
- During the night, the cooler air blows towards the ocean
- The warmer air is less dense than the cooler air
- The cooler air blows to the land because the land is the warmer than the ocean during the day due to the Sun
- The cooler air blows towards the ocean at night because the ocean is warmer than the land because it holds heat longer than the land
- land heats up quickly and cools down quickly
- the Ocean
- Due to the different levels of density, the warm air rises and the cooler air stays below the warmer air
Jet stream:
- it is a fast moving air current that is located in the upper part of the Troposphere
- mostly move west to east because of the Earth's rotation
- during the winter, the polar jet stream blows cold wind from Canada to Texas
- it cools down Texas in the winter
High and Low Pressure:
- air pressure is the weight of air pressing against us
- when the density of air changes, so does the air pressure
- cooler air is more dense than warmer air because cooler air contracts and takes up less space
- when cooler air sinks, it puts more pressure on the Earth's surface
- it makes a high pressure area
- when wind moves out from the high pressure area, it creates wind
Winds and Air Pressure:
- air masses are large sections of high and low air pressure in the troposphere
- they move across the Earth's surface and are responsible for the weather in the area that they were covering
- Isobars are lines on a weather map that shows that the air pressure is the same
- they help predict the air pressure and wind speed
- cooler, sinking air generally brings dry, clear weather
- in low pressure areas, there are usually cloud cover and rain