1) collision-coalescence - warmer clouds, liquid water...
TRANSCRIPT
Cloud Droplet Growth Processes: 1) Collision-Coalescence
- warmer clouds, liquid water only - different size drops fall at different speeds
2) Ice-Crystal Process
- colder clouds with both liquid water and ice
Clicker Question
The collision-coalescence process is most efficient when: (A) all the cloud droplets are small (B) all the cloud droplets are large (C) there is a mix of small and large cloud droplets
Set Frequency to "BB"
Collision - Coalescence Process (Warm process)
Cloud Droplet Growth Processes: 1) Collision-Coalescence
- warmer clouds, liquid water only - different size drops fall at different speeds
2) Ice-Crystal Process
- colder clouds with both liquid water and ice
T=0°C (Freezing level)
Liquid Only
Surface
Tall Cumulonimbus Cloud
T=0°C (Freezing level)
T=-40°C
Liquid Only
Supercooled Liquid and Ice
Ice Only
Surface
Tall Cumulonimbus Cloud
This region is where Ice-Crystal Process occurs
Question: How can liquid water exist below freezing point? - need freezing nuclei for liquid water to freeze into ice crystal if temperature is between 0 and -40°C. - similar idea as cloud condensation nuclei, except the structure of freezing nuclei must be similar to structure of ice crystal ==> As a result, much fewer freezing nuclei in atmosphere compared to number of cloud condensation nuclei
In Equilibrium: Condensation = Evaporation
Liquid Drop and Water Vapor
Ice Crystal and Water Vapor
water vapor liquid water ice crystal
In Equilibrium: Condensation = Evaporation
Liquid Drop and Water Vapor
Ice Crystal and Water Vapor
More Water Vapor Around Liquid Drop
Less Water Vapor Around Ice Crystal
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
Liquid Drop and Water Vapor
Ice Crystal and Water Vapor
More Water Vapor Around Liquid Drop
Less Water Vapor Around Ice Crystal
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
Now more water vapor around Ice Crystal => Vapor condenses on Ice
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
Now more water vapor around Ice Crystal => Vapor condenses on Ice
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
Now more water vapor around Ice Crystal => Vapor condenses on Ice As water vapor decreases => Liquid water evaporates from drops
water vapor liquid water ice crystal
Now, put Liquid Drop and Ice Crystal Together
water vapor liquid water ice crystal
Now more water vapor around Ice Crystal => Vapor condenses on Ice As water vapor decreases => Liquid water evaporates from drops
=> Ice Crystal Grows => Liquid Drop Shrinks
Ice Crystal Process (also referred to as Bergeron Process)
Sleet - rain refreezes before hitting surface - deeper cold layer near surface
Sleet
Freezing Rain - rain refreezes on contact with surface - shallow cold layer near surface
Sleet - rain refreezes before hitting surface - deeper cold layer near surface
Freezing Rain
Freezing Rain
Freezing Salt Water Spray?
Rime: Fog droplets freeze on contact
Clicker Question
Red line = Temperature Green line = Dew Point Temperature
Set Frequency to "BB"
Clicker Question
Red line = Temperature Green line = Dew Point Temperature At what altitude would you expect clouds? (A) 2-4 km (B) 4-6 km (C) 6-8 km (D) 8-10 km
Set Frequency to "BB"
Clicker Question
Red line = Temperature Green line = Dew Point Temperature At what altitude would you expect clouds? (A) 2-4 km (B) 4-6 km (C) 6-8 km (D) 8-10 km
Set Frequency to "BB"
cloud
Clicker Question
Red line = Temperature Green line = Dew Point Temperature What would the cloud consist of? (A) liquid drops only (B) ice crystals only (C) both liquid drops and ice crystals
Set Frequency to "BB"
cloud
Clicker Question
Red line = Temperature Green line = Dew Point Temperature What would the cloud consist of? (A) liquid drops only (B) ice crystals only (C) both liquid drops and ice crystals
Set Frequency to "BB"
cloud
Clicker Question
Red line = Temperature Green line = Dew Point Temperature Precipitation reaching the surface would be: (A) rain (liquid only) (B) freezing rain (C) sleet (D) snow
Set Frequency to "BB"
cloud
Clicker Question
Red line = Temperature Green line = Dew Point Temperature Precipitation reaching the surface would be: (A) rain (liquid only) (B) freezing rain (C) sleet (D) snow
Set Frequency to "BB"
cloud