Intro To Earth System Studies
Atmospheric Water and Weather
Earth System Sciences
Atmospheric Water and Weather
Water in all forms compromises Earth's hydrosphere. Most of Earth’s water is located within the ocean.
Water On Earth
● For water to change into different phases, heat pressure has to be either released or
added. Just like matter, there are three phases of water: solid, liquid, and gas.
○ Evaporation (liquid —> gas)
○ Condensation (gas—> liquid)
○ Freezing (liquid—> solid)
○ Melting (solid—> liquid)
○ Sublimation (gas —> solid OR solid—> gas)
Humidity
● Relative Humidity (expressed as RH) is a massive comparison between the content of
water vapor in the air and the amount it can hold at a particular temperature.
○ RH is measured using a sling psychrometer.
● Air saturated with 100% RH is at its dew point.
● There is an inverse relationship between temperature and RH, meaning that the higher
the temperature, the lower the RH.
Atmospheric Stability
● Adiabatic processes are warming and cooling by either expansion or compression.
● Ascending air is cooled by expansion whilst descending air is cooled by compression.
● Rising and falling parceling of air (water vapor) are cooled or warm because of the lapse
rate. Atmospheric stability is related to parcels of air that stay in place, rise, or fall.
Clouds and Fog
Atmospheric Water and Weather
Earth System Sciences
Atmospheric Water and Weather
Water in all forms compromises Earth's hydrosphere. Most of Earth’s water is located within the ocean.
Water On Earth
● For water to change into different phases, heat pressure has to be either released or
added. Just like matter, there are three phases of water: solid, liquid, and gas.
○ Evaporation (liquid —> gas)
○ Condensation (gas—> liquid)
○ Freezing (liquid—> solid)
○ Melting (solid—> liquid)
○ Sublimation (gas —> solid OR solid—> gas)
Humidity
● Relative Humidity (expressed as RH) is a massive comparison between the content of
water vapor in the air and the amount it can hold at a particular temperature.
○ RH is measured using a sling psychrometer.
● Air saturated with 100% RH is at its dew point.
● There is an inverse relationship between temperature and RH, meaning that the higher
the temperature, the lower the RH.
Atmospheric Stability
● Adiabatic processes are warming and cooling by either expansion or compression.
● Ascending air is cooled by expansion whilst descending air is cooled by compression.
● Rising and falling parceling of air (water vapor) are cooled or warm because of the lapse
rate. Atmospheric stability is related to parcels of air that stay in place, rise, or fall.
Clouds and Fog
