Clouds and Precipitation

Question 1

What is a Condensation Nuclei?

Answer 1

Tiny particles upon whose surfaces condensation of water vapor begins in the atmosphere

Question 2

What is condensation nuclei made out of?

Answer 2

dust, sand, pollutants, etc.

Question 3

What is an Hygroscopic Condensation Nuclei?

Answer 3

water-attracting nuclei (e.g. salts); water vapor condenses upon these surfaces when RH is lower than 100%

Question 4

What is an Hydroscopic Condensation Nuclei?

Answer 4

water-repelling nuclei (e.g. waxes); resist condensation when RH is above 100%

Question 5

What are the two ways clouds form?

Answer 5

mixing and cooling

Question 6

How do clouds form when mixing?

Answer 6

adding enough moisture to unsaturated air to raise to 100% (saturate it)

Question 7

How do clouds form when cooling?

Answer 7

cool unsaturated air until it becomes saturated (RH=100%)

Question 8

What happens during the mixing cloud formation?

Answer 8

air is unsaturated
RH is high
temperature and humidity decline with height

Question 9

What happens when the dew point and the environmental lapse rate mix at the moist layer of air near the surface?

Answer 9

the produce a deck of stratocumulus clouds

Question 10

What happens to rising parcels?

Answer 10

pressure declines
volume increases
air cools

Question 11

What happens to sinking parcels?

Answer 11

pressure increases
volume decreases
air warms

Question 12

What is rising and cooling air?

Answer 12

the primary method of cloud formation

Question 13

What are the primary ways clouds form?

Answer 13

surface heating and convection
orographic lifting
cyclone
air fronts

Question 14

What is an orographic uplift?

Answer 14

lifting of air over a topographic barrier (i.e., mountains

Question 15

What happens on the windward side of mountain during the orographic lifting?

Answer 15

temperature drops to dew point forming clouds

Question 16

What happens on the leeward side of mountain during the orographic lifting?

Answer 16

air sinks making the air drier
moisture was removed in the form of clouds and precipitation resulting in a rain shadow
dew point temperature is lower while the temperature is higher producing a low RH

Question 17

What happens during the convective cloud formation?

Answer 17

-thermal forms (air is warmer than it surrounding)
-air rises, expands and cools (air is cooler than its surrounding)
-condensation, visible cumulus cloud froms
-forms a cumulus humilis, then cumulus congests, and finally a cumulonimbus

Question 18

How are stratiform clouds formed?

Answer 18

large-scale lifting of stable air; no vertical development

Question 19

How are cumuliform clouds formed?

Answer 19

vertical development caused by convection; flat cloud base; form in unstable air

Question 20

What are stratiform clouds (high clouds)?

Answer 20

-“cirro-“
-composed of ice -crystals only
-no shadow cast
-cirrus clouds
-cirrostratus (stratus=sheetlike)
-cirrocumulus (cumulus=puffy)

Question 21

What are stratiform clouds (middle clouds)?

Answer 21

-“alto-“
-water only or water/ice mix, clouds block direct sunlight, shadow at base
-altostratus
-altocumulus

Question 22

What are stratiform clouds (low clouds)?

Answer 22

-“strato-“
-composed of liquid water only
-stratus
-stratocumulus
-nimbostratus (nimbo-rain)

Question 23

What are cumuliform clouds?

Answer 23

-flat cloud base, caused by convection, form in unstable air
-cumulus humilis
-cumulus congestus
-cumulonimbus

Question 24

What are cirrus clouds?

Answer 24

high cloud composed of ice crystals in the form of thin, white, featherlike clouds in patches

Question 25

What are cirrocumulus clouds?

Answer 25

high cloud that appears as a white patch of clouds; consists of very small elements in the form of grains or ripple

Question 26

What are cirrostratus?

Answer 26

High, thin, sheetlike clouds, composed of ice crystals. They frequently cover the entire sky and often produce a halo.

Question 27

What are altocumulus clouds?

Answer 27

middle cloud, usually white or gray. Often occurs in layers or patches with wavy, rounded masses or rolls.

Question 28

What are altostratus?

Answer 28

middle cloud composed of gray or bluish sheets or layers of uniform appearance. In the thinner regions, the sun or moon usually appears dimly visible.

Question 29

What are nimbostratus?

Answer 29

a dark, gray cloud characterized by more or less continuously falling precipitation. It is rarely accompanied by lightning, thunder, or hail.

Question 30

What are stratocumulus clouds?

Answer 30

a low cloud, predominantly stratiform, with low, lumpy, rounded masses, often with blue sky between them.

Question 31

What are stratus clouds?

Answer 31

A low, gray cloud layer with a rather uniform base whose precipitation is most commonly drizzle.

Question 32

What are cumulus clouds?

Answer 32

a cloud in the form of individual, detached domes or towers that are usually dense and well defined.

Question 33

What are cumulonimbus clouds?

Answer 33

exceptionally dense and vertically developed cloud, often with a top in the shape of an anvil. The cloud is frequently accompanied by heavy showers,