Air Masses

Question 1

When do air masses happen?

Answer 1

When parcels of air stay over a particular location for a while

Question 2

What is the definition of an air mass?

Answer 2

A large body of air around 1000 miles or more across that has similar properties of temperature and moisture in the horizontal

Question 3

Air masses are usually ____ pressure

Answer 3

High pressure with little to no wind and movement

Question 4

An air mass can be one of three temperatures. What are they?

Answer 4

Warm (Tropical)
Cool (Polar)
Cold (Arctic)

Depends on the regions over which the mass gets stuck

Question 5

Depending on if an air mass is hanging out over the water or land, what is it called?

Answer 5

Continental or Maritime

Question 6

What are all the combinations or air mass names an air mass could have based on its temperature and whether its over water or land?

Answer 6

Continental Arctic/Polar/Tropical
Maritime Arctic/Polar/Tropical

Abbriviated as cA / cP / cT etc

Question 7

What are the main air masses that affect Canada?

Answer 7

1. mA
2. mP
3. cA
4. mT
5. cT

Question 8

The Source Region of an air mass will always occur in an area of ____ pressure

Answer 8

High pressure

Question 9

What kind of weather is associated with an air mass?

Answer 9

Even tho the moisture and temp are uniform does not mean it will be devoid of weather.

The weather in a mass will depend on:
* Its moisture content
* Stability
* Any cooling or heating processes present or introduced

Question 10

The weather happening in an air mass has nothing to do with the properties of an air mass.

Answer 10

The properties are that it is uniform in pressure and temperature in the horizontal.

The weather happening within the mass is dependant on a bunch of factors

Question 11

From north to south, what are the most common types or air masses in Canada?

Answer 11

cA, mA, mP, mT

Question 12

Properties of Continental Arctic air mass

Answer 12

• Cold and dry
• Rarely form in summer due to 24 hour daylight warming

Question 13

Properties of maritime arctic (mA) air mass

Answer 13

• Cold and wet
• Dominate in winter
• Can actually form over land in the north in the summer because there are so many gd lakes that it might as well be the ocean

Question 14

What are the charateristics of a stable air mass?

Answer 14

• Poor vis
• Layer clouds
• Steady precip
• Steady winds that can change a lot with height
• Smooth flying

Question 15

Characteristics of unstable air mass

Answer 15

• Good vis
• Convective clouds
• Showery precip
• Gusty winds
• Turbulence

Question 16

As an air mass moves from one source region to another, it will be modified through…

Answer 16

Either heating (causing instability) or cooling (causing stability) from below.

Question 17

An air mass that is warmed from below will always become more _______

Answer 17

Unstable.

Question 18

How will weather charts depict an air mass that is being warmed from below?

Answer 18

An additional script of k (cAk)

Question 19

How do weather maps depict an air mass being cooled from below?

Answer 19

With w. (mAw)

Question 20

When two different air masses colide, the boundary between them is known as a ____

Answer 20

Front

Question 21

A common exam question is for them to ask when kind of air mass will replace another as it moves north or south. For this, what do you need to remember?

Answer 21

Remember the order of air masses that are most common from north to south and use this map.

Question 22

An air mass is always topped by the ___________

Answer 22

Troposphere

Question 23

The warmer an air mass the ____ it will…

Answer 23

The higher it will cause the level of the tropopause to be

This also means that the temp at the tropopause will be colder over warmer air masses (because the tropopause will be hgiher)

Question 24

On a 250 millibar weather map what is important to remember about the L and Hs on it?

Answer 24

They’re not depecting high and low pressure but high and low collumns of air

Question 25

The air mass that is responsible for bringing Canada cool, damp weather is….

Answer 25

Maritime Polar

Question 26

The air mass that brings clear and nice wx to the praries is….

Answer 26

Maritime Arctic.

Moist air comes off the pacific and then looses moisture as the air mass moves over the rockies, then brings the dry air into the praries