What do we mean, air masses? Isn't air just a mass of gases anyway? Actually air masses have characteristics...Air masses cover many hundreds or thousands of square miles, and adapt to the characteristics of the surface below them. Air masses move from high pressure to low pressure. Since stronger high-pressure systems contain cooler or drier air, the air mass is more dense and flows towards areas that are warm or moist, which are in the area of low pressure systems. Why do air masses move from high pressure to low pressure? Simply the air masses are carried across the world by wind. Many times the winds and air masses run into areas of high pressure and low pressure. When this happens the air mass begins to change. This example shows how air masses will swirl around, warm air masses meeting cooler air masses and weather is born! Air masses move with the global pattern of winds. In most of the United States, air masses generally move from west to east. They may move along with the jet stream in more complex and changing patterns. When an air mass moves to a new region, it carries along its characteristic moisture and temperature. High pressure air masses are cool and dry, their particles tend to sink. A low pressure air mass is warm and moist, remember, these are the air masses that rise up and create clouds as the moisture condenses. A warm air mass can be blown by the wind across the continents and take that moisture with it. Or a high pressure air mass can be blown to a place taking its cool and dry air with it. As these two air masses meet together some pretty interesting weather is formed. Tornadoes, hurricanes, ice storms and lightning are just a few of the consequences when high pressure air masses meet low pressure masses. Yep, I think this next unit is going to be pretty fun. I love weather...especially stormy weather!
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |