Earth Science Chapter 19C Study Guide

True

(True or False) Dew is NOT a form of precipitation.

False. If the relative humidity is only 84%, it is impossible for dew to form. Dew can form when the relative humidity is 100%.

(True or False) Dew will form when nighttime temperature drops to 5 degrees C, at which temperature the relative humidity is 84%.

False

(True or False) The only type of solid precipitation is snow.

High humidity causes cloud droplets to form around condensation nuclei. Through coalescense, many smaller droplets join to form larger droplets. As these droplets fall under the influence of gravity, coalescence continues to increase the size of the droplet until it becomes a raindrop.

Explain how raindrops form.

Meteorologists use the prefixes strato- for low clouds, alto- for mid-height clouds, and cirro- for high-altitude clouds. Puffy or vertically developed clouds that can occupy two or more altitude zones have the prefix cumulo-

Give the prefixes or names for the four cloud height categories.

The basic shapes of clouds are stratus (flat layers), cumulus (clumps or piles), and cirrus (wispy curls).

Name and briefly describe the three categories of cloud shapes.

altostratus clouds

Name the kind of cloud that forms a broad flat layer around 4 km above the ground.

1. Rising air cools as it expands. 2. Cloud droplets form as they condense on airborne particles. 3. Larger and more numerous cloud droplets form. 4. A cloud droplet coalesces until it grows too large to be held up. 5. Cloud droplets fall and coalesce into raindrops.

Order the events chronologically.

Water can exist as a gas (water vapor), a liquid (clouds, rain), and a solid (clouds, snow, hail). Water vapor is invisible but we can sense it when relative humidity is high. We can see and feel the various forms of liquid and solid water as clouds or precipitation.

What are the physical states in which water can exist in the atmosphere? Give an example of how we can sense each state.

Under these conditions, water vapor can undergo deposition, forming ice crystals (snow or frost).

What can happen to water vapor in saturated air of the temperature drops to the dew points of -7 degrees C and there are dust particles present?

condensation, freezing, or deposition

What changes of state can happen to water in the atmosphere to form precipitation?`

Water that condenses on a cool object forms dew. Water that undergoes deposition on a colder (below freezing) object forms frost.

What forms when water vapor condenses on an object? What forms when water vapor deposits on a colder object?

supercooled water

What is liquid water colder than 0 degrees C called?

The dew point is the temperature at which the relative humidity is 100%. It is also called the saturation point.

What term refers to the temperature at which the relative humidity is 100%?