Exam 3 Review - EVSC 3300

What occurs when a warm air mass is over a cold air mass?

An unstable air mass.

What is the result of a cold air mass over a warm air mass?

A stable air mass.

What type of air mass is associated with very cold, dry stable conditions and ice & snow?

Arctic air mass.

What are the characteristics of a Polar air mass?

Cold, dry, and stable.

Describe the Tropical air mass and its stability.

Hot, dry, stable aloft, but unstable at the surface.

What defines a Maritime Polar air mass?

Cool, moist, and unstable.

What is a Maritime Tropical air mass characterized by?

Warm, moist, and unusually stable.

In a warm front, what happens to the air?

Warm air overrides cold air, leading to gentle precipitation.

What describes a cold front?

Cold, dense air wedges under warm air, causing warm air to rise.

What is a stationary front?

A motionless front where winds blow parallel.

What is a dryline in meteorology?

A front defined by differences in dew point.

What force drives air from high to low pressure?

Pressure Gradient Force (PGF).

How does thickness relate to air temperature?

Warm air is thicker than cold air.

What happens to pressure with height in cold air?

Pressure decreases faster.

What describes thermally direct circulation?

Air flows away from warm areas causing a decrease in pressure and into cold areas causing an increase in pressure.

What is the wind direction during land and sea breezes?

Clockwise for land breezes and counterclockwise for sea breezes.

What balances the forces in the atmosphere at hydrostatic condition?

Gravity plus pressure gradient force (PGF).

What is the geostrophic balance?

Pressure gradient force (PGF) plus Coriolis force.

What distinguishes wind direction around high and low pressures in the Northern Hemisphere?

Counterclockwise and convergent around low pressure; clockwise and divergent around high pressure.

How does the Southern Hemisphere differ in wind direction around pressure systems?

Clockwise and convergent around low pressure; counterclockwise and divergent around high pressure.

What indicators suggest strong winds on a weather map?

Isobar lines close together.

What do isobar lines that are far apart indicate?

Even air pressure, calm air, or light breezes.

What happens when cold and warm fronts meet?

It creates a low pressure system.

What does a tight isobar interaction between high and low pressure indicate?

Strong winds.