Class 4a: Atmospheric moisture

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Class 4a Atmospheric moisture
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Introduction to water

• Earths temperature ? special properties of water

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Introduction to water

• Energy needed to change state

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Evaporation

• How does water evaporate?

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Evaporation

• Water vapor stores latent heat
• Vapor pressure pressure exerted by water vapor

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Vapor pressure
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Evaporation

• How quickly does water evaporate?

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Humidity

• Absolute humidity ratio of water vapor to a
  given volume of air
• Specific humidity ratio of water vapor to a
  given mass of air

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Humidity

• Relative humidity ratio of water vapor to
  maximum water vapor capacity

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Dew point

• When air cools, water vapor capacity _____ and
  relative humidity _____

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Condensation

• Condensation water vapor becomes liquid,
  releases latent heat

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Lapse rates

• Normal lapse rate 3.5F/1000 feet

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Adiabatic processes

• Air changes temperature by convection, not
  conduction

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Adiabatic processes

• If a rising parcel of air cools to its dewpoint,
  then ______ occurs

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Adiabatic processes
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Stability of air

• Buoyancy tendency of an object to rise

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Stability of air
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Stability of air

• Stability normal lapse rate of surrounding air
  is less than DALR

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Stability of air

• Unstable air normal lapse rate of surrounding
  air is greater than DALR

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Stability of air

• Conditionally unstable air stable up to a point

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Stability of air