Concept of Humidity

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Concept of Humidity
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What is the relationship between water vapor
holding and temperature?
Air hold more water vapour at higher temperature.
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Humidity

• The amount of water vapour in the air

(Holding) Capacity of air

• The maximum amount of water vapour in the air

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Conditions of Saturated Unsaturated

• Saturated an air mass holding maximum amount of
  water vapour
• Unsaturated an air mass holding less than the
  saturated amount
• Supersaturated an air holding more than the
  maximum amount

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Humidity Indicator (1)Absolute Humidity (Water
Vapour Density)

• Mass of water vapour / Volume of air
• meaning of mass weight

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Why do we seldom use the indicator of absolute
humidity?

• Because the humidity concentration depends on
  temperature
• BUT
• absolute humidity does not consider such change

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Humidity Indicator (2)Relative Humidity

• Water vapour content / water vapour capacity

• Vapour pressure / saturated vapour pressure

• Different formula, but same thing

mg/cubic m
hPa
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Spatial Distribution of RH globally