what are the characteristicts that define air masses?
361485
In meteorology, an airmass or air mass is a large volume of air having fairly uniform characteristics of temperature, atmospheric pressure, and water vapor content. Air masses cover many hundreds or thousands of square miles, and slowly change in accordance with the terrain they are over.
367999
It weighs the amount that the air inside it weighs.
26504
The mass is a property of an object, a fundamental measure of the amount of matter in the object. The usual symbol for mass is m and its SI unit is the kilogram.\n\nThe weight of an object is the force of gravity on the object and may be defined as the mass times the acceleration of gravity, w = mg. Since the weight is a force, its SI unit is the newton.
527581
Expansion coefficients for air can be determined using the attached link.\n\nBest wishes !
329787
Wind is the roughly horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earth's surface. It occurs at all scales, from local breezes generated by heating of land surfaces and lasting tens of minutes to global winds resulting from solar heating of the Earth. The two major influences on the atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect).\n\nGiven a difference in barometric pressure between two air masses, a wind will arise between the two which tends to flow from the area of high pressure to the area of low pressure until the two air masses are at the same pressure, although these flows will be modified by the Coriolis effect in the extratropics.\n\nWinds can be classified either by their scale, the kinds of forces which cause them (according to the atmospheric equations of motion), or the geographic regions in which they exist. There are global winds, such as the wind belts which exist between the atmospheric circulation cells. There are upper-level winds, such as the jet streams. There are synoptic-scale winds that result from pressure differences in surface air masses in the middle latitudes, and there are winds that come about as a consequence of geographic features such as the sea breeze. Mesoscale winds are those which act on a local scale, such as gust fronts. At the smallest scale are the microscale winds which blow on a scale of only tens to hundreds of metres and are essentially unpredictable, such as dust devils and microbursts.
581432
atmospheric pressure, winds, light
293050
Are you refering to Physical Responses, or Interation of mass structure?Nuclear reaction,chemical reaction...etc..
432484
Atmospheric pressure is a direct result of the weight of the air. This means that air pressure varies with location and time, because the amount (and weight) of air above the earth varies with location and time. Atmospheric pressure drops by ~50% at an altitude of about 5 km (equivalently, about 50% of the total atmospheric mass is within the lowest 5 km). The average atmospheric pressure, at sea level, is about 101.3 kilopascals (about 14.7 pounds per square inch).
26899
go to encarta.msn.com and search for keys mass/solid structure, surface Structure
987167
Atmospheric pressure and physics
586003
Air Pressure.  The humidity and such in the air is higher and therefore holds more warmth.\n\nAt higher altitudes, where the air is less dense, there is greater distance between particulates and heat is lost faster.
36446
A cloud is a visible body of very fine water droplets or ice particles suspended in the atmosphere at altitudes ranging up to several miles above sea level.
130644
Air masses generally form where turbulence is minimal, and over fairly flat and continous surfaces. So, any area on the earth, with prutrusions as mountain[eg. the andes mt] or areas with turbulence will not allow the formation of airmasses.
823430
the buoyancy of the object and its volume.
590952
A front forms.\n\nIf the two air masses come from completely different source regions then you may be in for some stormy weather. Just depends on where they originate as to what type of front forms. Let me explain...\n\nIf an air mass originates over land it will be dry. It is said to be a continental air mass.\n\nIf it originates over water it will be moist & is said to be a maritime air mass.\n\nIf it originates over a tropical area...yes you guessed it... a tropical air mass & will be warm.\n\nIf it originates over a polar area it is said to be polar & will be cold.\n\nThere are different combinations of the above. You can have cP, cT, mP, & mT.\n\nIf a cP air mass from Canada rides south and meets up with a mT air mass from the south you are more than likely looking at some stormy weather...thunderstorms, hail, lightning, tornadoes.\n\nWhen two air masses that are completely different come together watch out for the skies!
382921
Meteorology and physiology.
604591
Fronts are defined as the local areas of lowest pressure.  Air flows towards low pressure, so winds are northeasterly north of a warm front and more southerly to the south of it (in the typical northern hemisphere setup).\n\n---\nYou use the term veering (wind changing clockwise with time) like you are looking for a more indepth meteorological answer... but I'm not sure exactly what you are asking when you bring up the air mass and the jet stream.  If you have taken some meteorology classes and are having trouble relating some of the concepts, like Thermal Wind and Quasigeostrophic Theory, let me know by email, and I'll try to help you more.\n\nHope I helped,\nGod bless,\nShane