| A | B |
|---|
| density | the amount of matter in a given space. |
| humidity | how much water vapor is in the air |
| buoyancy | The property of an object to rise or sink is called. |
| pressure | a force spread over an area. |
| wind | created by air moving from an area of high pressure to an area of low pressure. |
| local winds | created by the unequal heating of Earth's surface. |
| global winds | caused by the movement of air between the equator and Earth's poles |
| Coriolis effect | The effect of the Earth's rotation on the direction of winds and currents. |
| jet streams | Bands of high speed winds 10 kilometers above Earth's surface that blow from west to east. |
| air mass | A huge body of air that has similar temperature- humidity- and air pressure. |
| fronts | The area where air masses meet and interact. |
| cold front | a cold dry air mass moves in- pushing up a warm-moist air mass |
| warm front | warm-moist air mass moves in- pushing over a cold dry air mass |
| stationary front | two air masses push against each other without moving |
| currents | A large stream of moving water that flows through the oceans |
| surface currents | driven mainly by winds. |
| El Niño | A change in winds and currents in the Pacific that changes the weather for the American continents. |
| air parcel | an amount of air that moves as a unit |
| air pressure | force caused by the weight of air above |
| atmosphere | a mixture of gasses surrounding the planet |
| cloud | liquid water droplets suspended in the air |
| condensation | process that changes gas into liquid |
| energy | the ability to do work |
| evaporation | process that turns liquid to gas |
| precipitation | rain, snow, sleet, hail falling from clouds |
| troposphere | the layer of the atmosphere where weather happens |
| vapor | a gas |
| weather | conditions such as rain, clouds, and wind for a particular time and place |
| wind | the movement of air in a direction |
| sleet | rain that freezes as it falls through cold air |
| hail | rain that freezes and grows as it is blown up and down in a cloud. |
