Science: Air mass and fronts Flashcards
Study for quiz
What is a front?
A front is where different air masses meet, with different levels of temperature and humidity. The interactions between them cause the weather to change.
How big is a front
Can be from several hundred kilometers wide and thousands of kilometers long.
What is an air mass?
An air mass is a large mass of air of generally uniform temperature and humidity.
How are air masses formed?
Air masses are formed when the air remains over large areas of uniform temperature and humidity for long periods of time (these are known as source regions).
What are the characteristics of the source region?
heat and cold
What happens when 2 different air masses collide?
When 2 air masses meet they don’t mix but they push up against one another along a line called the front.
What happenes when a warm air mass meets a cold air mass?
When a warm air mass meets the cold air mass the warm air will rise because the warm air is lighter and the water vapour it contains condenses at higher altitudes.
What usually comes with a front?
fronts will generally bring precipitation
What happens to the front when the air is cold and dense?
When the air is cold and dense it takes the place of warmer air along the front.
How are clouds formed?
When the warm (moist) air rises, it will cool the water vapour it contains condesenses to form clouds.
what does condensed water vapour do?
falls back as precipitation
What is water vapour (Not on notes)
Water vapor is the gaseous form of water. It is created when liquid water evaporates (changes from a liquid to a gas) or sublimates (changes directly from a solid to a gas, as with ice turning to water vapor in very cold conditions).
What is a cold front?
A cold front is a boundary that forms when a cold air mass moves into and displaces a warmer air mass. Since cold air is denser than warm air, the cold air pushes under the warm air, forcing the warm air to rise rapidly.
What is a warm front?
A warm front is a boundary that forms when a warm air mass moves into and gradually replaces a colder air mass. Unlike a cold front, where the cold air pushes under the warm air, in a warm front, the warm air gently slides over the colder air because it is lighter and less dense.
What is a stationary front?
A stationary front occurs when neither a cold air mass nor a warm air mass is strong enough to fully push the other out of the way. This can lead to extended periods of weather that can last for several days.
What is the front occlus?
A front occlus is when warm air moves slower than the cold air (so the cold air essentially takes over) This pushes the warm air higher into the atmosphere causing more condensation and precipitation.
What symbol is the cold front?
A line with triangles along the top.
What front is the symbol with just the triangles
A cold front.
What symbol is the warm front?
A line with semi circles along the top.
What front symbol is with the just semi circles?
Warm front
What is the symbol for the front occlus?
A line with both triangles and semi circles along the top line.
What front symbol has the triangles and semi circles on one side of the line?
The front occlus.
What symbol is the front stationary?
A line with triangles and semi circles along the top and bottom of the line.
What front symbol has the semi circles on the top and the triangles on the bottom?
A stationary front.
