Advertisement Upgrade to remove ads


using one or more of your senses to gather information


deal with a number or amount


deal with descriptions which can not be expressed in numbers


explaining or interpreting the things you observe


making a forecast about what will happen in the future based on past experience or evidence


process of grouping together items that are alike in some way

making models

involves creating representations of complex objects or processes


a way of learning about the natural world

scientific inquiry

refers to the diverse ways in which scientists study the natural world and propose explanations based on the evidence they gather


possible explanation for a set of observations or answer to a scientific question


factors that can change in an environment

manipulated variable

variable that is purposed changed to test a hypothesis

responding variable

factor that may change in response to the manipulated variable.

controlled experiment

experiment in which only one variable is manipulated at a time

scientific theory

well-tested explanation for a wide range of observations or experimental results.

use of SI

allows scientists to compare data and communicate with each other about their results


refers to how close a measurement is to the true or accepted value


refers to how close a group of measurements are to one another

line of best fit

line that reflects the overall trend of a graph


condition of the earth's atmosphere at a particular time and place.


form of oxygen that is made of three oxygen atoms instead of the usual two


instrument used to measure air pressure

atmosphere layers

Troposphere, Statosphere, Mesosphere, thermosphere

photochemical smog

formed by the action of sunlight on pollutants such as hydrocarbons and nitrogen oxides

electromagnetic waves

a form of energy that can travel through space


energy that is radiated or transmitted in the form of rays or waves or particles

ultraviolet radiation

a type of energy that comes to Earth from the Sun, can damage skin and cause cancer, and is mostly absorbed by the ozone layer


the physical process in which particles are deflected haphazardly as a result of collisions

infrared radiation

the bundles of light energy that transfer heat

greenhouse effect

natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases


the average kinetic energy of the individual particles

thermal energy

total amount of energy associated with the random movement of atoms and molecules in a sample of matter


An instrument used to measure temperature


a form of energy that is transferred by a difference in temperature


the direct transfer of heat from one substance to another substance that it is touching


the transfer of heat through a fluid (liquid or gas) caused by molecular motion

convection currents

circular movement of a substance due to changes in temperature and density


air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure


an instrument used to measure wind speed

wind-chill factor

An index that uses air temperature and wind speed to determine the chilling effect of the environment on humans.

local winds

winds that blow over short distances

sea breeze

movement of air from sea to land during the day when cooler air from above the water moves over the land, forcing the heated, less dense air above the land to rise

land breeze

movement of air from land to sea at night, created when cooler, denser air from the land forces up warmer air over the sea

global winds

winds that blow steadily from specific directions over long distances

Coriolis effect

The way Earth's rotation makes winds in the Northern Hemisphere curve to the right and winds in the Southern Hemisphere curve to the left.

trade winds

prevailing winds that blow from east to west from 30 degrees latitude to the equator in both hemispheres

polar easterlies

Prevailing winds that blow from east to west between 60degrees-90degrees latitude in both hemisphere.

prevailing westerlies

winds that blow west to east between 30 and 60 degrees in the northern and southern hemispheres


distance north or south of the Equator, measured in degrees

jet stream

a high-speed high-altitude airstream blowing from west to east near the top of the troposphere

water cycle

the continuous process by which water moves from Earth's surface to the atmosphere and back


the process by which water changes from liquid form to an atmospheric gas


a measure of the amount of water vapor in the air

relative humidity

the percentage of water vapor in the air compared to the maximum amount the air could hold


instrument used to measure relative humidity


the process of changing from a gaseous to a liquid or solid state

dew point

the temperature at which the water vapor in the air becomes saturated and condensation begins

cirrus cloud

A high-altitude cloud with a featherlike shape, made of ice crystals

cumulus cloud

big, puffy clouds that have fair weather. is made when warm air rises (generally low altitude)

stratus clouds

clouds that form in flat layers and often cover much of the sky

air mass

a huge body of air that has similar temperature, humidity, and air pressure at any given height

types of air masses

Maritime Polar, Maritime Tropical, Continental Polar, Continental Polar

tropical air mass

A warm air mass that forms in the tropics and has low air pressure

polar air mass

A cold air mass that forms north of 50° north latitude and south of 50° south latitude and has high air pressure

maritime air mass

A humid air mass that forms over oceans

continental air mass

A dry air mass that forms over land


(meteorology) the atmospheric phenomenon created at the boundary between two different air masses

cold front

forms when cold air moves under warm air which is less dense and pushes air up (produces thunderstorms heavy rain or snow)

warm fronts

faster-moving warm air collides with cold air and rises over the cold air; bring warm, humid weather

stationary front

when a warm air mass and a cold air mass meet and no movement occurs

occluded front

a front that forms when a cold air mass overtakes a warm air mass and lifts the warm air mass off the ground and over another air mass


(meteorology) rapid inward circulation of air masses about a low-pressure center


An atmospheric condition of high central pressure, with currents flowing outward.


a violent disturbance in the atmosphere


a small storm often accompanied by heavy precipitation and frequent thunder and lightning

cumulonimbus clouds

Are thunderclouds and are likely to generate lightning, hail and fierce convection currents.


the flash of light that accompanies an electric discharge in the atmosphere (or something resembling such a flash)


a localized and violently destructive windstorm occurring over land characterized by a funnel-shaped cloud extending toward the ground


A severe storm that develops over tropical oceans and whose strong winds of more than 120 km/h spiral in toward the intensely low-pressure storm center

storm surge

a dome of water that sweeps across the coast where a hurricane lands


the removal of persons or things from an endangered area


scientists who study the causes of weather and try to predict it

weather satellite

Satellites used to record temperature, cloud cover, precipitation, etc.


lines joining places on the map that have the same air pressure


lines that connect points that have the same temperature


the weather in some location averaged over some long period of time


climate within a small area that differs significantly from the climate of the surrounding area

tropical zone

near the equator, between 23.5 degrees North and 23.5 degrees South latitudes

polar zone

the region between 66.5 degrees north and south latitudes and the poles; the sun's rays strike at a very small angle in this zone

temperate zone

the area between the tropical and polar zones, from about 23.5 degrees to 66.5 degrees north and 23.5 degrees to 66.5 degrees south latitudes

marine climate

the climate of an area near an ocean or large lake. Such an area has mostly mild winters and cool summers.

continental climate

The climate of the centers of continents with cold winters and warm or hot summers

leeward side

the side facing away from the wind. by the time the prevailing winds reach the top of the mountain, they have lost most of their mositure in the form of precipitation. relatively dry air moves down the leeward side of the mountain.

windward side

the side that faces toward the wind. receives a great deal of precipitation. has a wet climate on this side.


a seasonal wind pattern in southern Asia that blows warm, moist air from the southwest during the summer, bringing heavy rains, and cold, dry air from the northeast during the winter

main climate regions

tropical rainy, dry, temperate marine, temperate continental, polar, and highlands.

rain forest

dense forest that receives high amounts of rain each year


a region of grassland with scattered trees lying between the equatorial forest and the hot deserts in either hemisphere


A type of biome characterized by low moisture levels and infrequent and unpredictable precipitation. Daily and seasonal temperatures fluctuate widely


the term used for the temperate grassland region in the Northern Hemisphere.

humid subtropical

hot, rainy summers and mild Winters with some rain


Weather pattern characterized by severely cold, bitter winters and short, cool summers.


Treeless arctic or alpine biome characterized by cold, harsh winters, a short growing season, and potential for frost any month of the year; vegetation includes low-growing perennial plants, mosses and lichens


permanently frozen layer of soil beneath the surface of the ground

ice age

any period of time during which glaciers covered a large part of the earth's surface

causes of climate change

variations in the position of earth relative to the sun, changes in the sun's energy output, major volcanic eruptions, movement of the continents


areas on the sun's surface that are cooler and less bright than surrounding areas, are caused by the sun's magnetic field, and occur in cycles

El nino

the name given to the periodic warming of the ocean that occurs in the central and eastern Pacific

la nina

a cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns.

global warming

an increase in the average temperature of the earth's atmosphere (especially a sustained increase that causes climatic changes)

greenhouse gases

Gases in the earth's lower atmosphere (troposphere) that cause the greenhouse effect. Examples are carbon dioxide, chlorofluorocarbons, ozone, methane, water vapor, and nitrous oxide.


group of chemical compounds used in refrigerators, air conditioners, foam packaging, and aerosol sprays that may enter the atmosphere and destroy ozone

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording