ATMO 9/30 Clouds

Changes in Air Parcel with Altitude:

Altitude, Temp, Dew Point, Saturated?
- 7000, -20C, -20C, Yes
- 6000, -14C, -14C, Yes
- 5000, -8C, -8C, Yes
- 4000, -2C, -2C, Yes
- 3000, 4C, 4C, Yes
- 2000, 10C, 10C, Yes
- 1000, 20C, 10C, No
- 0000, 30C, 10C, No

Clouds:
- Where air temperature in a cloud is between 0C and -40C, there exists a mixture of super cooled liquid droplets and ice crystals
- Where T > 0C, all liquid
- Where T < -40C, all ice

Cloud Seeding Experiments:
- Try to get non-precipitating clouds to precipitate
- Very little success until recent years

Types of Precipitation:
- Snow
- Rain
- Freezing Rain (Ice Storms): snow falls, melts, then freezes on contact with surfaces below freezing
- Sleet: snow falls, partially melts, and re-freezes

Stability of the Atmosphere:
- Stable: thunderstorms will not form (still may have clouds and rain)
- Unstable: Thunderstorms may form

Two General Cloud Types:
- Stratiform Type Cloud: vertically thin layers that cover large horizontal areas, tend to form in stable conditions
- Cumuliform Type Cloud: vertically tall, but horizontally small, often clear sky between cloud elements and tend to form in unstable conditions

Atmospheric Instability:
- Heated air expands and it's density is lower, forcing it to rise
- Cloud formation and the addition of latent heat cause atmospheric Instability