When two different air masses come into contact, they don’t mix. They push against each other along a line called a front. When a warm air mass meets a cold air mass, the warm air rises since it is lighter. As air masses move, pushed by winds, they directly influence the weather in the regions over which they pass.

1. Most Maritime polar air masses that affect the United States are formed in the north Pacific Ocean. Occasionally, however, maritime polar air forms in the North Atlantic Ocean, and moves into the New England states. 2.

Terms in this set (18) Maritime polar air masses form over the northern Atlantic and the northern Pacific oceans.

Tropical, or warm air masses form in the tropics and have low air pressure. Maritime air masses form over oceans and are humid. Warm, humid air masses form over oceans near the tropics. Maritime tropical air masses that form over the gulf of Mexico and the Atlantic Ocean move first into the southeastern United States.

Maritime tropical air masses

Five air masses affect the United States during the course of a typical year: continental polar, continental arctic, continental tropical, maritime polar, and maritime tropical. Continental air masses are characterized by dry air near the surface while maritime air masses are moist.

Maritime polar air masses, abbreviated mP on weather maps, tend to dominate the Pacific coast region. These air masses form over a cold ocean current in the northern Pacific Ocean. Although mP air masses originate at northerly latitudes, they do not feature as cold of air as continental polar air masses.

Answer. Continental Polar and Maritime Tropical air masses have the greatest effect on weather conditions in much of the United States.

What type of air mass originates in the northern reaches of the North Atlantic Ocean? What type of air mass originates mainly in northern Canada? Which two air masses appear to have the greatest impact on the midlatitudes east of the Rocky Mountains? Warm air advancing/occupying territory by cooler air.

An air mass forms whenever the atmosphere remains in contact with a large, relatively uniform land or sea surface for a time sufficiently long to acquire the temperature and moisture properties of that surface. The Earth’s major air masses originate in polar or subtropical latitudes.

Air masses are characterized by their temperature and humidity properties. The properties of air masses are determined by the the underlying surface properties where they originate. Upon movement, air masses displace residual air over locations thus changing temperature and humidity characteristics.

Winds and air currents cause air masses to move. Moving air masses cause changes in the weather. A front forms at the boundary between two air masses. Types of fronts include cold, warm, occluded, and stationary fronts.

Tropical (T): Tropical air is warm to hot. It forms at low latitudes, generally within 25 degrees of the equator.

With two terms for the humidity and four terms for the temperature, eight names are possible. These are: mE, mT, mP, mA, cE, cT, cP, cA (maritime equatorial, maritime tropical, maritime polar, maritime arctic, continental equatorial, continental tropical, continental polar, continental arctic).

Air masses do not usually mix. So, when two different air masses meet, a boundary is formed. The boundary between two air masses is called a front. Weather at a front is usually cloudy and stormy. There are four different fronts- Cold, Warm, Stationary, and Occluded.

What happens when two air masses meet? When two air masses meet, they form a front, which is a boundary that separates two air masses of different properties. How is a warm front produced? A warm front forms when warm air moves into an area formerly covered by cooler air.

Fronts

Cold air is always heavier than an equal volume of hot air. “Air” is actually a mixture of several gases. By volume, dry air contains 78.09 percent nitrogen, 20.95 percent oxygen, 0.93 percent argon, 0.039 percent carbon dioxide and small amounts of other gases.

This means that when a given volume of air is made more moist by adding water molecules, heavier molecules are replaced with lighter molecules. Therefore, moist air is lighter than dry air if both are at the same temperature and pressure.

Cold air sinks. Sinking air compresses and heats. As air sinks, air pressure at the surface is raised. Cold air holds less moisture than warm.

warm air

Hot air is lighter than cold air. The reason fr this is when air gets heated up it expands and becomes less dense than the air surrounding it also the distance between the molecules increases. So the less dense air floats in the much denser air just like ice floats on water as ice is less dense than water.

The air density depends on temperature, pressure and humidity. The reason that air density is lower in the summer is that temperatures are higher: warm air expands. Monthly mean atmospheric pressure is pretty much the same all year round. Humidity tends to be higher in the winter.

Oxygen

The most abundant gas in the atmosphere is nitrogen, with oxygen second.

The difference between air and oxygen is that oxygen is a pure chemical element, while air is a mixture, not an element.

Hydrogen