Weather

Physical Properties and Heat Transfer

Thermal Energy: A form of energy that describes the motion of atom and molecules

-we feel thermal energy as heat

Heat Transfer: movement of heat -always from a warmer object to a cooler one

**Conduction: the transfer of thermal energy between things that are touching

Ex. Hot summer day, your feet feel the hot from the sand.

Conductor: A material through which heat can move easily (iron, silver, copper, aluminum, stainless steel)

Insulator: A material that heat does not move through easily (plastic, wood, rubber, glass)

**Convection: The transfer of thermal energy by movement of liquids or gases

Ex. Pot on the stove

**Radiation: the transfer of energy by electromagnetic waves (the sun is Earth’s main source of electromagnetic waves)

Physical Change: A change in which no new materials form (ice melts into water)

Chemical change: a change in which one or more types of materials form (burning paper, the paper changes when it is burned)

Mass: the amount of matter that makes up an object

Weight: the measure of the pull of gravity on an object’s mass

Water Cycle Vocabulary

https://www.youtube.com/watch?v=TWb4KlM2vts (listen to the song)

Water Cycle: the journey water takes as it circulates from land to the sky and back again

Evaporation: Change from liquid water to water vapor (gas)

Condensation: water vapor (gas) condenses to form small droplets of water

-occurs inside of clouds

-cold drink on a hot day

-mirror after a hot shower

Transpiration: water that is released from trees and plants in the form of a gas

Precipitation: any form of water that falls from the sky

-rain, sleet, snow, hail

-type of precipitation depends on temperature of clouds and temperature close to earth

Runoff: after/during precipitation, water flows downhill as runoff

-or when snow melts

-can form springs

-flow is controlled by gravity

Collection: when precipitation accumulates in a body of water, in the ground, or as a runoff to a body of water

Rain: Liquid precipitation in the form of water drops that falls from clouds

Sleet: solid precipitation in the form of ice pellets

Snow: precipitation that is composed of white ice crystals falling from clouds

Hail: precipitation in the form of balls or irregular lumps of ice

Clouds

Cloud: A visible collection of tiny water droplets or, at colder temperatures, ice crystals floating in the air above the surface. Classified by their different shapes and altitudes. Can form at ground level, which is fog, at great heights in the atmosphere, and everywhere in between. They offer important clues to understanding and forecasting the weather.

Cumulus: middle level clouds (6,500-18,000 feet); means "heap" or "pile;" look puffy, like cotton; grow vertically from a flat base to rounded towers; results in fair weather

Cirrus: high level clouds; (above 18,000 feet); means "curl of hair;" look thin and wispy, like feathers; composed of ice crystals (high altitude = cold temperatures)

Stratus: low level clouds (up to 6,500 feet); means "to spread out" looks like layers or blankets that cover the sky; result in overcast weather and sometimes produce precipitation; fog is this type of cloud at ground level

Nimbus: a rain cloud; may be used as a prefix or suffix for rain clouds

Cumulonimbus: all cumulus clouds (grow vertically up to 50,000 feet tall); looks like an anvil; results in heavy precipitation, especially thunderstorms

Nimbostratus: blanket-like cloud that produces rain and snow

Fog: A cloud at ground level

Weather

Weather: state of the atmosphere at any given time and place with respect to wind, temperature, cloudiness, moisture and pressure

Temperature: degrees warm or cold *influenced by cloud cover*

Air Pressure: the weight of air pressing down on earth

Humidity: the amount of water vapor in the air

Wind: horizontally moving air

Wind speed: the rate of motion of the air on a unit of time

Wind Direction: the direction from which the wind is blowing

Thermometer: measures air temperature

Barometer: measures air pressure

-rising pressure = sunny and dry conditions

-falling pressure = stormy and wet conditions

Anemometer: measures wind speed

Hygrometer: measures humidity

Wind Vane: determines the direction from which the wind is blown

-northerly wind blows from the north to the south

Rain Gauge: measure the amount of rain that has fallen over a specific period of time

Meteorologist: scientist who studies the weather

Weather Fronts

Weather Forecast: a prediction of the future atmosphere conditions

Air Mass: A large region of the atmosphere where the air has similar properties throughout, such as temperature, humidity, and air pressure

Front: A boundary between 2 masses, resulting in stormy weather; usually a line of separation between warm and cold air masses

Cold Front: cold air mass moves under warm air mass and causes it to rise

-brings heavy rains, thunderstorms, snow

-usually moves from the Northwest to the Southeast

Warm Front: warm air mass moves up and over a cold air mass

-warm air slowly replaces cold air

-brings rain/drizzly weather

-warm, clear weather

-usually moves Southwest to Northeast

Stationary Front: A front that stops moving or is moving very slowly.

-warm and cold air masses meet, but neither has enough force to move the other

-It may stall over an area and bring many days of clouds and precipitation

Occluded Front: A warm air mass is caught between two cooler air masses.

-denser cool air moves underneath warm air and pushes the warm air upwards

-temperatures near the ground become cooler