why does the amount of water vapour decrease rapidly with altitude?
819238
Yes it does decrease because cold air can hold less water vapour than warm air. So at altitude water vapour gets "squeezed out" and forms droplets which make clouds and fall as rain.
636659
Mountains are higher in altitude than the plains.\n\nThe higher you go, the less atmospheric gases there are. This is due to the fact that gravity holds these gases close to the surface.\n\nAir holds heat. If you have less air then there will be less heat.\n\n:)
620707
As air gets warmer it's able to contain more water vapor.  An easy way to illustrate this is in a steamy kitchen or bathroom where you'll see that condensation forms on the coldest surfaces such as windows, mirrors, tiles etc.\n\nWhen the amount of water vapor in the air reaches it's maximum point the air is described as being saturated (saturation vapor pressure or SVP for short).  SVP is therefore reached more quickly when the air is cooler.\n\nWhen air reaches SVP it has to deposit the excess moisture which it does as dew or condensation and the point at which this occurs is called the dew point.  The colder the temperature the lower the dew point which helps explains the cool mornings when there's dew on the grass.\n\nHumidity is a measure of the amount of water vapor that's present in the air and is measured as a percentage of the maximum possible.  So a Relative Humidity (or RH) or say 60%, means that the air contains 60% of the maximum possible water vapor.  As mentioned, the amount of water vapor possible increases with temperature and so RH is affected by temperature.  An RH of 80% in a hot tropical climate is going to feel much damper and humid than an RH of 80% in a cooler climate.
634175
It´s not quite clear to me what you are looking for, but here goes....\n\nThe air pressure goes down with the height in the atmosphere. In a gas mixture the molecules are free to roam where they can but under the influence of gravity they stick mainly close to the earth. The pressure drops by about 10% over the first kilometer and is about a third of that at groundlevel at the top of the Mount Everest. The decrease is exponential and the gradient depends on the average velocity of the molecules (a few hundred meters per second).\n\nIn the ocean pressure increases linearly with depth approx. 1 atmosphere each 10 meters. The reason is that the weight of the upper layers presses on the lower layers of a liquid.   \n\nJess knows somewhat more.
677782
It's the change in air pressure which causes it.
1182741
This is due to two reasons:\n\nAt high altitude, the atmospheric pressure is much less than sea level, because gravity causes most of the atmosphere to settle towards the Earth.  In fact, over 50% of the atmosphere resides under the five mile mark above the Earth.  As a result, the air is less dense the higher you go.  \n\nNow it is true that the sun heats this air, but since there is less pressure, it expands as it rises much more easily than the air does near the Earth.  As a result of this expansion, the air cools.
1115854
The weight of the air pressing down on the Earth, the ocean and on the air below causes air pressure. Earth's gravity, of course, causes the downward force that we know as "weight." Since the pressure depends upon the amount of air above the point where you're measuring the pressure, the pressure decreases as you go higher.\n\nso im guessing he talked about how in mountains, atmospheric pressure is low and high in deserts with regards to elevation. as air goes down/descends, it warms and cools as it goes up. \n\nhttp://www.usatoday.com/weather/tg/whighlow/whighlow.htm\n\nyes. froggie is right. the phenomenon is called rainshadow effect. \n\nnow i dont really know what your question is, but just a trivia. notice that on one side of tall mountain, it is high in plant life while the other is mainly desert? this is because the mountain blocks the moving air and forces it to precipitate thus causing rain which in turn supports lots of plants which support the animals.  now since the water molecules in the air was already precipitated/ let go on the one side, there is nothing left for the other side of the mountain thus the formation of deserts. so instead of formation of rain, the air starts to gather water molecules from its surroundings, depriving the plants of necessary moisture thus no plant life can be observed in most deserts. \n\nhope that helps.
233535
i always thought it was because there was no humidity in the air...probably wrong, anyway. or maybe its because the warm climate doesnt allow the moisture to turn back into water. who knows? prob a weatherman.
577442
The water vapor which is released through the combustion of the gases becomes like fog and converts to water droplets when cooled in the air. This is just like the clouds
937278
Geographic location and altitude of the air mass, also the proximity of large bodies of water. Water tends to have a moderating effect on temperature. Moisture content changes at altitude and lower temperatures as moisture is lost in the form of precipitation.\n\nFor example you have on a mountain peak several zones one of which is the zone of precipitation, the altitude at which precipitation is likely to occur. The second is the zone of accumulation which is the altitude at which accumulation of precipitated materials is likely to occur (snow line).
193750
This is due to the seawater having a greater heat capacity than the land, thus they heat and cool off at different rates, causing pressure differentials in the air above them. See the source for details.
538503
Because the air is less dense the higher the altitude, there are less molecules available to retain heat. Therefore the heat of the sun dissipates more readily.
438791
altitude.....higher altitude means lower air pressure.  Liquids, water included, vaporizes at lower temp when pressure lowers.  (a glass of water will boil at room temp in a vaccumn)
553562
When a Liquid evaporates it takes the heat of the surroundings to reach its Vapourisation State ... Thus making you fell cooler
358112
about 50 degrees celsius less (about -10 degrees celsius for every kilometer increase in altitude), that is assuming the air parcel is unsaturated.
833749
Clouds are water vapor. Think of it like a pocket of fog in the sky.
591984
It gets colder as you go up through the troposphere because the air is "thinner".\n\nThere is less atmosphere here due to less gravity.\n\nB/c there is less air, there will be less heat. Air is an insulator that holds heat. Less air = less heat.\n\n:)