Water Cycle and Clouds Objectives Explain how water

Water Cycle and Clouds

Objectives • Explain how water moves through the water cycle. • Describe how relative humidity is affected by temperature and levels of water vapor. • Describe the relationship between dew point and condensation.

The Water Cycle • The condition of the atmosphere is affected by the amount of water in the air. Water in liquid, solid, and gaseous states is constantly being recycled through the water cycle. • The water cycle is the continuous movement of water from sources on Earth’s surface into the air, onto and over land, into the ground, and back to the surface.

Steps of the Water Cycle • Transpiration - the process in which some water within plants evaporates into the atmosphere. Water is first absorbed by the plant's roots, then later exits by evaporating through pores in the plant. • Evaporation - the process in which liquid water becomes water vapor (a gas). Water vaporizes from the surfaces of oceans and lakes, from the surface of the land, and from melts in snow fields.

• Condensation is the process by which a gas, such as water vapor, becomes a liquid. Forms clouds or water droplets. • Dew Point The dew point is the temperature at which a gas condenses into a liquid. • Relative Humidity is the amount of water vapor in the air compared to the maximum amount of water vapor that the air can hold at a certain temperature.

Humidity • Humidity is the amount of water vapor in the air. • The air’s ability to hold water vapor changes as the temperature of the air changes.

• Precipitation - the process in which water (in the form of rain, snow, sleet, or hail) falls from clouds in the sky. • Run-Off - rain, snow melt, or other water that flows in on or underground streams, drains, or sewers.

• Accumulation - the process in which water pools in large bodies (like oceans, seas and lakes).

Review

Bellringer Answer • Precipitation • Rain is the most common form of precipitation. • Sleet and Snow • Sleet forms when rain falls through a layer of freezing air. • Snow forms when temperatures are so cold that water vapor changes directly to a solid. • Hail are balls or lumps of ice that fall from clouds.

Objectives • List three types of cloud forms. • Identify four kinds of precipitation.

Clouds • A Cloud is a collection of small water droplets or ice crystals suspended in the air, which forms when the air is cooled and condensation occurs. • Clouds are classified by form, and by a altitude.

• Cumulus Clouds are puffy, white clouds that tend to have flat bottoms. • Stratus Clouds are clouds that form in layers. • Cirrus Clouds are thin, feathery, white clouds found at high altitudes.

Prefixes and Suffixes Used to Describe Clouds • Clouds are defined by both the way they look and how high they are in the atmosphere. • Cirro (meaning "wisp of hair") is a prefix given to • high-altitude clouds (above 20, 000 feet). Alto (meaning "high") is a prefix given to midaltitude clouds (between 6, 000 and 20, 000 feet). There is no prefix for low-altitude clouds. When clouds are by the ground we call them fog.

• Nimbo (meaning "rain") as a prefix, or nimbus • • added as a suffix, in a cloud name indicates that the cloud can produce precipitation (rain, snow, or other forms of falling water). Cumulo (meaning "heap") refers to piled-up clouds. Strato (meaning "layer") refers to flat, wide, layered clouds

Type of Cloud (Genus) Abbreviation Appearance Composition Cumulo-nimbus =Thunderheads Sb Can cause lightning, thunder, hail, strong rains, strong winds, and tornadoes Near ground up to 75, 000 feet (Vertical clouds) Cirro-stratus Cs Thin, wispy, appears in sheets. Located above thunderheads Above 18, 000 feet (High-altitude clouds) Cirrus Ci Thin, wispy, filamentous, or curly Cirro-cumulus Cc Small, puffy, patchy and/or with a wavelike appearance Above 18, 000 feet (High-altitude clouds) Alto-cumulus Ac Medium-sized puffy, patchy, scattered clouds - often in linear bands 6, 500 - 20, 000 feet (Middle-altitude clouds) Alto-stratus As Thin, uniform 6, 500 - 20, 000 feet (Middle-Alttude clouds) Strato-cumulus Sc Broad and flat on the bottom, puffy on top, Below 6, 500 feet (Low-altitude clouds) Cumulus Cu Puffy and piled up. Below 6, 500 feet (Vertical clouds) Stratus St Uniform, flat, thick to thin layered clouds will ill-defined edges Mostly composed of liquid droplets Below 6, 500 feet (Low-altitude clouds) Nimbo-stratus Ns Uniform, dark, flat, low, featureless clouds that produce precipitation Mostly composed of liquid droplets Below 6, 500 feet (Low-altitude clouds) Fog Very low stratus clouds Mostly composed of liquid droplets In contact with the gound (Ground-hugging clouds) Mostly composed of ice crystals Altitude (height) Above 18, 000 feet (High-altitude clouds)

Review • Three types of clouds • Altitude each is found • Characteristics of each