weathering

the atmosphere

  • the atmosphere is a thin layer of gasses that surrounds the earth

  • what gasses make up our atmosphere - 78% nitrogen, 21% is oxygen and less than 1% is carbon dioxide and argon

PS The atmosphere insulates the Earth from extreme temperatures

layers within the atmosphere

  • the atmosphere is about 480km thick but most are within 16km of the earth’s surface the atmosphere doesn’t end it gets so thin it merges with space

  • there are several layers within the atmosphere

Troposphere

  • lowest level in the earth’s atmosphere

  • it reaches from ground to water level up to about 17km

  • weather and clouds occur here

  • the temp generally decreases as altitude increases

stratosphere

  • it extends from 17km to 50km from the earth’s surface

  • the ozone layer is located here

  • some of the highest clouds can be found in the lower stratosphere

The Sun

  • solar energy is the energy from the

  • energy that travels through space. Called solar radiation

  • the amount of heat kept in the atmosphere depends on the amount of greenhouse gasses

the uneven heating of the earth

  • solar energy is distributed unevenly both over the earth and within the atmosphere its strength depends on latitude and the tilt of the earth on its axis

  • the earth is split into the northern and southern hemispheres the imaginary line in the middle is called the equator it is used as a starting point for measurement, and is at 0°

  • the lines around the earth that measure the distance from the equator are called lines on latitude and they extend to the poles

  • the south pole is 90 degrees south of the equator while the North pole id 90 degrees north of the equator

How Winds Are Formed

  • The sun heats the Earth, but it doesn't heat everything evenly. Some places, like the equator, get more sun than others, like the poles. This uneven heating creates areas of high and low pressure in the atmosphere.

  • Air always moves from areas of high pressure to areas of low pressure. This movement of air is what we call wind.

  • The Earth's rotation also affects wind patterns. This is called the Coriolis effect. It makes winds curve to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

  • So, winds are formed by the uneven heating of the Earth and the Earth's rotation.

  • Trade winds: These blow steadily from east to west near the equator. Sailors used them to travel across the oceans.

  • Doldrums: This is a calm area near the equator where the trade winds meet. It can be hard to sail through here because there's not much wind.

  • Prevailing westerlies: These blow from west to east in the middle latitudes. They're responsible for much of the weather in Europe and North America.

  • Horse latitudes: These are calm areas of high pressure around 30 degrees north and south of the equator. They got their name because sailors would sometimes have to throw their horses overboard to save water during long, calm periods in these areas.

  • Polar easterlies: These blow from east to west near the poles. They're cold and dry winds.