ATM S 103 UW Midterm 1 Study Guide
What are the three ingredients needed for cloud formation? - correct answer ✔✔-Water vapor
-Cooling (the air has to cool to saturation in order for condensation to occur)
-Cloud condensation nuclei (CCN)
What are the three states of water and the bonds associated with them? - correct answer ✔✔-Gas
(vapor): All bonds are broken and it is invisible
-Liquid (droplets): Some bonds are broken
-Solid (ice): No bonds are broken
What two states of water make up clouds? - correct answer ✔✔Solid (ice crystals) and liquid (water
droplets)
What is latent heat? - correct answer ✔✔The energy (heat) required to break molecular bonds and only
happens when the state changes
What is evaporation? - correct answer ✔✔Liquid droplets to water vapor
Ex: Sweat; latent heat is needed for cooling
What is condensation? - correct answer ✔✔Water vapor to liquid droplets (occurs when the air parcel is
saturated)
Ex: Formation of cloud droplets; latent heat is released warming the air
When is an air parcel saturated? - correct answer ✔✔-When its vapor vapor pressure exceeds its
saturation vapor pressure
-When its relative humidity becomes greater than 100%
-When its temperature reaches dew point
What are the two measures of humidity? - correct answer ✔✔-Relative humidity (%)
, -Dew point (in C or F)
What is relative humidity? - correct answer ✔✔The ratio of actual vapor pressure to saturation vapor
pressure (the ratio of water vapor content to water vapor capacity).
What is vapor pressure? - correct answer ✔✔The net force per unit area exerted by molecules of water
vapor in a parcel of air
What does relative humidity tell you? - correct answer ✔✔How close the air is to saturation
What does relative humidity depend on? - correct answer ✔✔Temperature and the amount of water
vapor
What is saturation vapor pressure? - correct answer ✔✔The pressure exerted by water vapor when the
air is saturated and increases with temperature though it does not tell you the amount of actual water
vapor
What does saturation vapor pressure depend on? - correct answer ✔✔Temperature only
For an air parcel, as temperature decreases, saturation vapor pressure decreases, relative humidity
increases. What does this tell you? - correct answer ✔✔Warm saturated air contains more water vapor
than cold saturated air
What is dew point? - correct answer ✔✔The temperature to which air has to cool down to for
condensation to occur
What does the dew point depend on? - correct answer ✔✔Only on the amount of actual water vapor
content
What does the dew point tell you? - correct answer ✔✔How much water vapor molecules the air holds
at present temperature
What are the three ingredients needed for cloud formation? - correct answer ✔✔-Water vapor
-Cooling (the air has to cool to saturation in order for condensation to occur)
-Cloud condensation nuclei (CCN)
What are the three states of water and the bonds associated with them? - correct answer ✔✔-Gas
(vapor): All bonds are broken and it is invisible
-Liquid (droplets): Some bonds are broken
-Solid (ice): No bonds are broken
What two states of water make up clouds? - correct answer ✔✔Solid (ice crystals) and liquid (water
droplets)
What is latent heat? - correct answer ✔✔The energy (heat) required to break molecular bonds and only
happens when the state changes
What is evaporation? - correct answer ✔✔Liquid droplets to water vapor
Ex: Sweat; latent heat is needed for cooling
What is condensation? - correct answer ✔✔Water vapor to liquid droplets (occurs when the air parcel is
saturated)
Ex: Formation of cloud droplets; latent heat is released warming the air
When is an air parcel saturated? - correct answer ✔✔-When its vapor vapor pressure exceeds its
saturation vapor pressure
-When its relative humidity becomes greater than 100%
-When its temperature reaches dew point
What are the two measures of humidity? - correct answer ✔✔-Relative humidity (%)
, -Dew point (in C or F)
What is relative humidity? - correct answer ✔✔The ratio of actual vapor pressure to saturation vapor
pressure (the ratio of water vapor content to water vapor capacity).
What is vapor pressure? - correct answer ✔✔The net force per unit area exerted by molecules of water
vapor in a parcel of air
What does relative humidity tell you? - correct answer ✔✔How close the air is to saturation
What does relative humidity depend on? - correct answer ✔✔Temperature and the amount of water
vapor
What is saturation vapor pressure? - correct answer ✔✔The pressure exerted by water vapor when the
air is saturated and increases with temperature though it does not tell you the amount of actual water
vapor
What does saturation vapor pressure depend on? - correct answer ✔✔Temperature only
For an air parcel, as temperature decreases, saturation vapor pressure decreases, relative humidity
increases. What does this tell you? - correct answer ✔✔Warm saturated air contains more water vapor
than cold saturated air
What is dew point? - correct answer ✔✔The temperature to which air has to cool down to for
condensation to occur
What does the dew point depend on? - correct answer ✔✔Only on the amount of actual water vapor
content
What does the dew point tell you? - correct answer ✔✔How much water vapor molecules the air holds
at present temperature
