Exam 6: Precipitation Extremes
Explain why it is possible for an ice crystal to grow in a cold cloud even though the supercooled water droplets surrounding the ice crystal do not.
Ice crystals can grow in a cold cloud even though the supercooled water droplets surrounding them do not because of a process called nucleation. In a cold cloud, the air is saturated with water vapor, but the water droplets remain in a supercooled state, meaning they are below the freezing point but have not yet turned into ice crystals. When an ice crystal is introduced into the supercooled environment, it serves as a nucleation site, meaning it provides a surface for the water molecules to gather and form into an ice crystal. This process is known as heterogeneous nucleation.
Once the ice crystal forms, it can continue to grow as water vapor molecules in the cloud freeze onto its surface, adding to its size. Meanwhile, the supercooled water droplets surrounding the ice crystal remain in a liquid state because they lack a nucleation site to start the ice formation process. This is why ice crystals can grow in a cold cloud even when the surrounding supercooled water droplets do not.
If you observe large raindrops hitting the ground,you could probably say that the cloud overhead was __________ and had __________ updrafts.
B
Which cloud type below will only produce precipitation by the collision-coalescence process?
B
In the midlatitudes,most rain results from melted snow that formed from the ice crystal process.
Radar gathers information about precipitation in clouds by measuring the:
The collision-coalescence process is most effective when clouds are made entirely of ice crystals.
The difference in saturation vapor pressure between supercooled water and ice reaches a maximum at about -12oC.This means that the ice crystal process will be most effective in producing precipitation when cloud temperatures are:
Explain why it is much more difficult to measure snowfall amount than rainfall amount.
Which of the following is not an important factor in the production of rain by the collision-coalescence process?
The growth of a precipitation particle by the collision of an ice crystal (or snowflake)with a supercooled liquid droplet is called deposition.
At the same sub-freezing temperature,the saturation vapor pressure just above a liquid water surface is __________ the saturation vapor pressure above an ice surface.
The main difference between a cloud drop and a raindrop is its:
Cloud seeding using silver iodide works well in warm clouds composed entirely of water droplets.
What is the main difference between a raindrop and a cloud droplet?
Thunderstorm cloud bases are generally higher above the ground in Arizona than in Florida.Why?
Briefly describe the differences in the atmospheric temperature profiles necessary to produce snow,freezing rain,sleet,and hail.
Filters
- Essay(0)
- Multiple Choice(0)
- Short Answer(0)
- True False(0)
- Matching(0)