Chapter 8 Flashcards
What is an air mass?
A vast pool of air having similar temperature and moisture characteristics over its horizontal extent.
What is an air mass source region?
Where air masses are born; where they take on their characteristic temperature and moisture content.
What does cP air mass stand for and what are its characteristics?
Continental polar (cP) air is considered a cold and dry air mass that is warmer than the arctic air mass.
What is the main characteristic of mP air mass?
Maritime polar (mP) air is cool and moist, bringing mild weather to coastal locations.
What is cA air mass and its characteristics?
Continental arctic air (cA) is typically described as extremely cold and dry.
What does cAA air mass refer to?
An exceedingly cold air mass that is drier than its arctic counterpart.
What is a cT air mass?
An air mass found over subtropical and tropical continents that is hot and dry.
What happens during air mass modification?
As air masses move out of their source region, the temperature and moisture content of air masses are modified.
What is a front in meteorology?
Boundaries between contrasting masses of air.
What occurs at a cold front?
Cold air replaces warm air.
What occurs at a warm front?
Warm air replaces cold air.
What is an occluded front?
Forms when a cold front catches up with a warm front.
What is a stationary front?
Where no change in air masses or movement of the front occurs.
What is a quasi-stationary front?
Found migrating within a particular latitudinal zone throughout most of the year.
What defines the polar front?
The boundary between polar-type air and tropical-type air.
What is the arctic front?
The boundary between cold arctic air mass and the warmer air of the polar cell.
What type of weather is associated with warm fronts?
Increase in humidity; ‘fair weather’ clouds often created by convection.
What is cyclogenesis?
The development and intensification of a cyclone.
What happens in the initial stage of cyclogenesis?
Opposing streams of air meet and create a cyclone shear.
What characterizes the wave stage of cyclogenesis?
Warm air from the south invades where cold air was once located north of the polar front.
What occurs during the occluded stage of cyclogenesis?
The cold front catches up with the warm front, leading to occlusion.
What happens during the dissolving stage of cyclogenesis?
The system dissipates as the lifting mechanism is cut off.
What is the cumulus stage of a thunderstorm?
The initial stage where warm, moist air is lifted and condenses into a cumulus cloud.
What occurs during the mature stage of a thunderstorm?
Warm, moist updrafts feed the storm while cold downdrafts begin to form.
What characterizes the dissipating stage of a thunderstorm?
The thunderstorm dissolves as warm updrafts cease and only cool downdrafts are present.
What is lightning?
A massive discharge of electricity in response to a charge differential.
What causes thunder?
A shockwave through the atmosphere caused by lightning.
What defines a tornado?
An intense system of low pressure with violent updrafts and converging winds.
What is a hurricane?
A large rotating cyclonic system born in the tropics.
What is a storm surge?
The high water level that accompanies a hurricane as it comes ashore.
