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When is air saturated? What is dew point? What is wet - dry bulb temperature?


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  • Location: Toronto, Ontario, Canada, Altitude: 189 m, Density Altitude: 6 m
  • Weather Preferences: Tropical Cyclone, Blizzard, Thunderstorm, Freezing Cold Day and Heat Wave.
  • Location: Toronto, Ontario, Canada, Altitude: 189 m, Density Altitude: 6 m

    Here: http://www.crh.noaa....cu/humidity.php

    I read this:

    The dewpoint temperature, which provides a measure of the actual amount of water vapor in the air, is the temperature to which the air must be cooled in order for that air to be saturated.

    I cannot understand what is the meaning of the phrase "Air is saturated". Can you explain to me?

    Also, it says: Meteorologists routinely consider the "dewpoint" temperature (instead of, but analogous to absolute humidity) to evaluate moisture, especially in the spring and summer.

    What is the relation between dewpoint and absolute humidity? The unit of absolute humidity is grams of water vapor per cubic meter volume of air, and the unit of dewpoint temperature is the degrees C or degrees F? I am right? The unit of dewpoint?

    How dew point influences in our body's feelings?

    And finally tell me about wet bulb temperature and dry bulb temperature.

    Thank you.

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  • Location: Kingdom of Fife: 56.2º N, 3.2º W
  • Location: Kingdom of Fife: 56.2º N, 3.2º W

    Look at it this way, when a sponge is saturated it cannot take in any more water. When air (a mixture of gasses) is saturated it cannot take in any more water vapour and water vapour will condense out as liquid water. This is termed the saturation point.

    Air is classed usually as a percentage of saturation, dry air being 0% and saturated 100%

    However, unlike the sponge ananalogy, 1kg of air will have a different capacity for water vapour depending on its temperature (and pressure). Charts (Psycrometric Charts) are available that allow the degree of saturation to be calculated, usually by determining the dew point (temperature at which 100% saturation occurs) by using a wet bulb thermometer and comparing it with the normal dry bulb temperature.

    Far better and deeper explanation on Wiki

    http://en.wikipedia..../Psychrometrics

    With regard to how we feel, dryer air contains less moisture so that for the same temperature rise it takes correspondingly less energy to raise its temperature than more saturated air so that we normally feel warmer in dry air than we do in saturated air at the same temperature. It's a complex subject and deals with psycological as well as physical factors but there are standard models that can be used.

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  • Location: Toronto, Ontario, Canada, Altitude: 189 m, Density Altitude: 6 m
  • Weather Preferences: Tropical Cyclone, Blizzard, Thunderstorm, Freezing Cold Day and Heat Wave.
  • Location: Toronto, Ontario, Canada, Altitude: 189 m, Density Altitude: 6 m

    I am trying to understand better, what is water vapor - moisture and what exactly is the saturation. When we have a sponge under the water, for example under the sea level, "it is saturated"?

    Water vapor is the gas version of water? If we heat the ice (solid), we take water (liquid), and if we heat water (liquid), we take water vapor (gas)? I have understood well?

    Why the air cannot take in more water vapor? What is the reason and what is the limit?

    If we have two similar closed boxes, what is the difference if the one has 100% saturated air and the other has 100% water from sea?

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