Flashcards in Lesson 301 Evolution Of Clouds Deck (15):
The nucleation process can be defined as:
The action leading to the formation of the first new specks as a material begins to undergo a change of state at the boundary between two phases.
The process of _______ ________ is one by which molecules of water vapour are brought together in sufficient numbers to form ________ water.
Relative humidity in the atmosphere rarely exceeds _____%.
Nuclei that become impregnated with water before saturation of the air occurs are called:
Particles that require a level of supersaturation to form droplets are called:
Hygroscopic nuclei are composed of _______ _______ substances.
Name the 3 types of nuclei and their dimensions.
Aitken nuclei: radius less than a tenth of a micrometer
Large nuclei: 0.1 - 1 micrometer
Giant nuclei: 1 micrometer or more
* large are the most active
At a temperature of less than ______ all water droplets freeze.
The evolution and type of cloud depends on what four factors?
Amount of water vapour available
Abundance of condensation or freezing nuclei
Stability of the air
Amount of lift
For each _____ C increase in temperature, the saturation mixing ratio approximately __________.
Most clouds form when moist air is subjected to some type of upward (vertical) motion and cools to the saturation point called the Lifted Condensation Level (LCL). The various types of lifting that lend to the formation of clouds are: LCOM
Large scale lift
What are the two main processes that initiate convection in the atmosphere?
Day time heating
Cold air advection
Convective lift (in contrast to large-scale dynamic lift) is a small scale thermal process, its domain being in the order of ________ km whereas large-scale dynamic lift is ___________ km.
With mechanical turbulence cloud formation, there will always be an ___________ at the top of the mixed layer.
The cloud formed will frequently be __________.