W.O.R.M. in Class on Monday March 27
Chapter 2 Test on WINDS Wednesday March 29
Earth’s Atmosphere Unit Exam Thursday April 6
Below is a lesson on GLOBAL WINDS, presented by a friend who is also a science teacher, Mr. Sean Mussleman.
Here is one of the Venn Word Banks we are doing in class this week. use this as a study guide – know the meanings and explanations of all the terms!
Describe the relationship between Heat, Pressure and Wind
How does this relationship affect the formation of winds? You can describe either local winds or global winds.
Be complete in your descriptions and your naming of the winds.
The Sun heats and cools the land faster than water. We call this UNEQUAL HEATING.
This UNEQUAL HEATING causes differences in pressure.
Differences in pressure cause winds to blow because AIR moves from HIGH PRESSURE to LOW PRESSURE.
Extra Credit – Develop an experiment to do this, and report on your findings. Use science facts and ideas to explain what you did.
Fun Facts about Wind: Click Here
We have been studying the effects of unequal heating of the Earth’s surface, and the resulting wind patterns these cause. Land that is heated more directly absorbs more of the sun’s heat through radiation. The ground touches the air, and through conduction, heats the air – the air becomes less dense which causes it to rise. This creates an area of lower pressure in the atmosphere. As the air rises, it cools, becomes more dense, and then falls back to the earth, creating an area of higher pressure. The movement of the air creates a convection current.
AIR ALWAYS MOVES FROM AREAS OF HIGH PRESSURE TO AREAS OF LOW PRESSURE.
Moving air is called WIND.
The spinning of the Earth causes the winds to bend to the right as they move across the globe. We call this effect the Coriolis Effect. Global Winds are winds that move across large areas around the globe. There are three major Global Wind Belts – the Trade Winds, the Westerlies and the Easterlies. These wind belts are found in both the Northern and the Southern Hemispheres. There are also areas of calm winds, called the doldrums near the equator, and the Horse Latitudes nearthe 30 degrees latitudes. See the diagrams below.
The same convection currents that cause the Global Winds also affect the atmosphere at the local level, especially at the seacoast. Here on Cape Cod we experience these local winds during the summer. Cape Cod is kept cool, sort of a natural air-conditioning, by the local sea and land breezes. The hot summer sun heats the land on Cape, causing the air to rise (low pressure). Cooler descending air from the water (higher pressure) rushes in to take the place of the rising warm air on land, forming a cooling Sea Breeze. This keeps the Cape comfortable on most summer days. At night, the land cools down much faster, the warmer ocean water heats the air, causing the air over the water to rise. Cooler air from the land moves in to take the place of the rising are, creating a Land Breeze.
Study the diagram below, and then CLICK on it to see the animation!.
Both Global Winds and Local Winds are caused by the unequal heating of the Earth’s surface, creating differences in air temperatures and air pressures.