| A | B |
|---|
| vortex | 涡流 circulation of gases or water |
| hurricane | 飓风 a big rotation storm, wind speed: 119 km per hour or more |
| tornado | 龙卷风 a violent windstorm that turns around a vortex and moves in a narrow path over land. |
| water cycle | movement and exchange of water between the earth's land, atmosphere and seas. |
| convection current | a flow of air or water caused by temperature differences. (Heat goes up, cold goes down.) |
| El Nino | a warm flow of water in the Pacific Ocean once every 3 to 7 years |
| Doppler radar | It finds out how air is moving. If its frequency is +, a storm is moving toward the radar. |
| satellite | 人造卫星 It flies around the earth and is made by people. |
| Tornado Alley | Most tornadoes happen here. |
| Sea Breeze | Air flows from water to land. |
| Land breeze | Air flows from land to water. |
