Condensation and Precipitation

Question 1

Do most processes that result in condensation involve a cooling or warming of an airmass?

Answer 1

cooling

Question 2

If we have an unsaturated air mass what can cause condensation?

Answer 2

1- Add water vapour into air until it reaches saturation
2- Cool air down till the saturation vapour pressure meets the actual vapour pressure and condensation occurs

Question 3

Give real examples of the scenarios that can cause condensation is air is not already saturated?

Answer 3

1- have warm dry air mass come across open water
2- have air cool down to dew point temp (where sat vap pressure = actual vap pressure)

Question 4

How is dew formed?

Answer 4

When the ground cools via radiation at night and becomes below the dew point temp the water will start to condense on the grass

Question 5

How is frost formed?

Answer 5

same as dew but now dew point temp below 0 so water vapour gets depositied as ice

Question 6

What are clouds? What are the three ways they’re formed?

Answer 6

Clouds are features where condensations happens above the surface
Rising air drives the cooling of air, as you lift a parcel of air moving up a surface it’ll expand due to loosing pressure, this well then cool, when it cools beyond the dew point temp you get condensation and therefore a cloud.
3 diff mechanism by what we might cause air to rise, on warm summer day we get a lot of heating at the surface. The air parcel begins to rise through convection- if it rises high enough and cools then you will begin to form a cloud. Convection is a common process that creates clouds on a warm summer day.
Orographic lift- is when air blows up against mountain or another large obstacle and that forces the air up cooling the air and getting clouds forming.
Convergence- Have two air masses blowing at the surface, they converge (happens at tropics), this creates uplift. This happens over large scales. Play a big role in cloud formation at global scale.

Question 7

What is a frontal system?

Answer 7

When warm air runs into and over cold air, this creates clouds and ppt

Question 8

What is divergence?

Answer 8

Is when air diverges aloft, happens in the jet stream and creates updrafts.

Question 9

What does the prefix cirr mean?

Answer 9

It’s a high cloud

Question 10

What does the prefix alto mean?

Answer 10

it’s a medium height cloud

Question 11

What does no prefix mean?

Answer 11

It’s a low cloud

Question 12

If the cloud has the term cumulus in it, what does that mean?

Answer 12

it’s a puffy cloud

Question 13

If a cloud has the term stratus in it, what does that mean?

Answer 13

it’s layered

Question 14

If a cloud has the term nimbus what does that mean?

Answer 14

it’s a raining cloud

Question 15

What are cirrus clouds associated with?

Answer 15

good weather, are thin and wispy

Question 16

What do stratus clouds look like?

Answer 16

are layered and very low and foggish looking

Question 17

What is the classic thunder cloud?

Answer 17

cumulonimbus

Question 18

Why don’t cloud droplets fall?

Answer 18

Because they’re updraft exceeds their terminal velocity, the cloud droplet will only fall if they become super duper big in size

Question 19

How much does a cloud droplet need to grow to become a rain droplet and fall?

Answer 19

A typical cloud droplet needs to INCREASE its diameter by about 100 time and increase in volume about 1 mill times

Question 20

What are the two ways we can grow rain droplets that will fall?

Answer 20

collision and coalescence
the burgeon feindesen process

Question 21

How does growth by collision and coalescence work?

Answer 21

the cloud droplets bump into eachother through updraft, gets big enough to fall and continues to grow as it falls smashing into other droplets, then it exceeds updraft and falls out of cloud

Question 22

How does the bergeron-findesisen process work?

Answer 22

in the middle part of clouds around -20 degrees where it’s mixed ice and water the vapour pressure over ice will be much lower than water, therefore water vapour will move to the area of lower vapour pressure and condense over ice creating droplets big enough to fall.

Question 23

Once the bergeron-fiendesen process occurs and the droplet falls what three things can happen?

Answer 23

They can smash into other water droplets, freezing to them and growing. (pic 1)
They can break apart, seeding other ice crystals to start growing via the same processes. (pic 2- can start process of water droplets wate rvapour hitting them too)
They can crash into other ice crystals, which stick to them, and form pretty snowflakes

Question 24

What process of precipitation dominates calagry? Why doesn’t all our ppt come down as snow?

Answer 24

the bergeron-findeisen process, not all snow as the snow melts coming down due to warm temps

Question 25

When do you get ice pellets as precipitation? How about freezing rain?

Answer 25

when you have a deep freezing layer, when you have a shallow freezing layer