Unformatted text preview:

1Chapter 8: Air Masses Regional FormationMovement: North AmericaInfluence on WeatherAir Mass: -immense body of air (1600km across, several km thick)-homogeneous physical propertiestemperaturemoisture content-migration & influence2Air Mass Weather: -migration and regional influence-conditions may exist for several days, consistent weather-many disturbances, originate along air mass boundariesSource Region: areas in which air mass originateshomogeneous surfaceextensive geographic regionstagnant atmospheric circulationattain equilibrium with the surfaceslow moving anticyclonesLow pressure systems are not good because surface convergence brings several unlike air masses together (mixing)3Source Regions for North American Air MassesmT, cT : warmmP, cP, cA: coldmid latitudes are zones of classing air masses = stormyClassifying Air Masses: influenced by latitude and surfaceTemperatureHigh latitude = cold, low latitude = warmP-PolarA -Arctic :similar to polar just colderT-TropicalHumiditym -Maritime -wetc -Continental -dry4Air Mass Modification:Ex. cA, cP: travel over oceanextract moisture, heated from below, overturnquickly change to mPk-denotes air mass cooler than surrounding surfacew-denotes air mass warmer than surrounding surfaceindicates stability (cPk, mTw)Properties of North American Air MassesIntense radiation coolingEnters between the Great Lakes and the Rocky Mnts.5cPLake Effect Snow:Intense snow storms associated with a lakeInfluence extends 80-100 km downwind of the lakeextract moisture and heat, convective overturning, Bergeron Process6Snow Belts:Properties of North American Air Massescool, humid air massesformed at high latitudes over the ocean7mP North Pacificbegins as cP air over Siberiamoves over Pacific, warmed, extract waterrelatively unstable, low clouds, showersOrographic effectmP Western North Atlanticbegins as cP airmoves over Atlantic, warmed, extract waterdrawn back over east coast during the passage of a low pressure system, nor’eastersurface convergence, rising, precipitation8Properties of North American Air Masseswarm-hot, humid export heat, moistureGulf, Caribbean, Atlanticinfluence weather east of RockiesWinter: invasion mTw, advective fogs, light precipitation, absorbed into traveling cyclonesSummer: monsoonal effect, hazy, hot and humidheating of surface sets up convective thunder storms9mT Gulf, Caribbean, Atlanticprovides most of the moisture for eastern 2/3 of USmT Pacific orographic moisture lossmT PacificWinter: stable, precipitation associated with orographic upliftSummer: associated with monsoonal effect in Mexico and southwest US10Properties of North American Air Massesprimarily influence source


View Full Document

CUNY PGEOG 130 - Air Masses

Download Air Masses
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Air Masses and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Air Masses 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?