CHAPTER 8

Describe a Cold front

-Cold air moves in and forces the warm air to move up quickly -this forms cumulus clouds and heavy precipitation -cold fronts bring cold weather

Describe a stationary front

-the air doesn't move very much or it moves back and forth over the same area

Describe a warm front

-warm air moves against the cooler air, the warm air gradually rises above the cooler air -the clouds of a warm front often move slowly and cause longer periods of precipitation than cold fronts -warm fronts bring warmer weather

Name the three main kinds of fronts

1. Cold 2. Warm 3. Stationary

Identify each of the indicated principal North American air masses by selecting the correct response: 17.1 cA 17.2 mP (North-Western Atlantic) 17.3 mT (Pacific) 17.4 cP 17.5 mT (Gulf-Carribean-Atlantic) 17.6 mP (North Pacific) 17.7 cT

17.1 E- Continental Arctic 17.2 A- Maritime Polar 17.3 B- Maritime Tropical 17.4 G- Continental Polar 17.5 F- Maritime Tropical 17.6 D- Maritime Polar 17.7 C- Continental Tropical

Match the code with the proper description: 9.1 cP 9.2 mT 9.3 cA 9.4 mP 9.5 cT

9.1 Continental Polar 9.2 Maritime Tropical 9.3 Continental Arctic 9.4 Maritime Polar 9.5 Continental Tropical

What is a front?

A boundary between two air masses

An immense body of air, characterized by homogeneous physical properties is called a(n)_______.

Air mass

An air mass source region must be associated with a generally stagnant area such that ___________________________.

Air will stay over it long enough to come to some measure of equilibrium.

What is an air mass

An air mass is a large body of air with consistent temperature and amount of water vapor

The classification of an air mass depends upon _____.

Both latitude and surface of origin.

Describe a Continental Polar air mass?

Cold and dry air

Describe a Maritime Polar air mass?

Cold and moist air

What kind of front has heavy precipitation (rain or snow)

Cold front

Identify the air mass. The air mass over this area of land is cold and fairly dry.

Continental Polar Air

Identify the air mass. The air mass over this area of land is warm and fairly dry.

Continental Tropical Air

Areas in which air masses originate are called development regions.

False

Continental arctic (cA) air is distinguished from cP air by its generally warmer temperatures.

False

In the middle latitudes, relatively few weather events are associated with the movements of air masses.

False

Lifting over a mountain barrier will probably not produce any appreciable modification to an air mass.

False

The moisture content of an air mass is directly related to its air pressure.

False

How do fronts move in most of the US?

Fronts move from west to east and bring cloudy weather

An air mass source region must be characterized by a ___________________________ of atmospheric circulation.

General stagnation

If an air mass is colder than the surface over which it is moving, the _____.

It receives the designation, k.

Identify the air mass. The air mass over the ocean is cold and moist.

Maritime Polar Air

Identify the air mass. The air mass over the ocean is warm and very humid.

Maritime Tropical Air

Air is mostly composed of this gas

Nitrogen

Why does it rain at fronts?

Rising air at fronts causes rain (or snow)

How many types of air masses are there?

There are 4 basic kinds of air masses 1. continental tropical 2. Continental Polar 3. Maritime tropical 4. Maritime Polar

What happens in areas of high pressure away from fronts?

There are clear skies

Changes to an air mass can result from vertical movements induced by ______.

Topographic differences, cyclones, and anticyclones.

In the middle latitudes, most atmospheric disturbances occur along the boundaries separating air masses.

True

Fronts are always in areas of Low pressure (True or False)

True-Fronts occur in areas of low pressure

Air masses are identified by _________.

Two-letter codes: first is lowercase and second is uppercase.

Describe a Continental tropical air mass?

Warm and fairly dry air

Describe a Maritime Tropical air mass?

Warm and very humid air

What kind of front has more longer periods of precipitation

Warm front

How do air masses move?

Winds move air masses from place to place

A large body of air with similar properties all through it is called an ___________ .

air mass

This air mass is most associated with lake-effect snow.

cP

A cold front brings __________ air into an area.

colder

Warm air rising and cold air sinking creates a conveyor belt of air known as a _________ .

convection current

Air pressure (increases, decreases) as you go up through the atmosphere.

decreases

Most air masses move in what direction over the United States?

from west to east

A boundary between two air masses is called a _________ .

front

When a cold front moves into an area, it will cause (light, heavy) precipitation.

heavy

When a warm front moves into an area, it will cause (shorter, longer) periods of precipitation.

longer

An __________ air mass may produce an occasional nor'easter during the winter, but summertime incursions of this air often bring pleasant weather.

mP

The air mass most likely to produce a thunderstorm would be a ____ air mass.

mT

Land gets warmer (quicker, slower) in sunlight than water does.

quicker

When cooler air moves in, it forces warmer air to move up (quickly, slowly).

quickly

When warmer air moves in, it (quickly, slowly) rises above the cooler air.

slowly

A front that does not move very much is called a ___________ front.

stationary

A warm front brings _____________ air into an area.

warmer

Air masses move because of ____________ .

winds