Quiz 1 Flashcards
Vapor Pressure
- the portion of the total atm pressure that is contributed by water vapor
- what is in the air regardless of temp
Saturation vapor pressure
- how much water vapor pressure that is necessary to make the air saturated at any give temp
- what it would take to saturate the air
Vapor pressure and dew point:
-express what is in the air regardless of temp
Relative humiditiy
-evaporative capacity of the air
Dew point depression
-the difference between the air temp and the dew point
How does fog form
- Cooling: air is cooled before its saturation point
- evaporation and mixing
What makes clouds
- rising air
- rising air cools to its dew point and saturates the air
What gets rid of clouds
- sinking air
- sinking air compresses and heats the the air
Atmospheric stability
-how fast the environment temp decreases with altitude
lifting condensatioin level
- point at which clouds form
- when dew point = temp
Unstable env
-cold above, warm below
How to make the env stable
- warm advection aloft to stabilize the air
- or cold advection below
- or both
Stable env
-an env lapse rate that is less that 6 degrees C/km
Conditionally unstable env
-env lapse rate greater than 6 but less than 10 degrees C/km
Absolutely unstable env
-last rate of en greater than 10 degrees C
Precip growth processes
- collision and coalescence
- ice-crystal process (bergeron process)
Collision and coalescence
- large droplets overtake and collide with smaller drops in their path
- not common, only deep in tropics (warm cloud env)
Ice-crystal process
- both ice crystals and liquid cloud droplets are present in the clouds at freezing temp
- supercooled water in motion with no nucleus to adhere to
When do dendrites form
-12 to -18 degrees C
Accretion
-ice crystals growing at the expense of nearby water droplets
Adiabatic
-no gain or loss of heat within a system
Non-adiabatic
-when condensation is present
