| A | B |
|---|
| weather | the condition of Earth's atmosphere at any given time and place. |
| meteorology | the scientific study of the atmosphere |
| Gabriel Fahrenheit | developed a temperature scale with its zero point at the coldest temperature he could create using a frezzing saltwater solution |
| Anders Celsius | developed a metric temperature scale based on the same two properties of water, but with 100 degrees between them. |
| 100 degrees celsius | Boiling point of water in celsius |
| 0 degrees | freezing point of water in celsius |
| 212 degrees | Boiling point of water in fahrenheit |
| 32 degrees | freezing point of water in fahrenheit |
| atmospheric pressure | weight of atmospheric gases on the earth's surface |
| barometer | instrument we use to measure air pressure |
| wind | moving air |
| humidity | measure of the amount of invisible water vapor in the air |
| relative humidity | ratio of the amount of water the air does hold to the amount of water it can hold at that temperature |
| hygrometers | measures absolute and relative humidity |
| anemometer | used to measure wind speed |
| rain gauge | collects falling rain and measures it in a cylinder |
| weather balloon | carries battery powered instruments which measure data and send it back to a weather station |
| doppler radar | sends out microwave radio signals to measure precipitation in storms, wind speed, and provides info about approaching severe weather |
| weather satellites | takes pictures of cloud cover and measures temperature in the atmosphere |
| weather buoys | in the ocean measures sea and air temperature, atmospheric pressure, and wind |
| pressure gradient | the rate the air pressure changes with distance |
| coriolis effect | deflects a wind perpendicular to its path over the earth's surface |
| friction effects | acts on moving air as obstacles such as trees, mountains, hills, slow winds down. |
| cyclonic wind pattern | pattern in which winds flow counter-clockwise in a circular pattern outward from high pressure area |
| anticyclonic patter | pattern in which winds flow clockwise in a circular pattern outward from high pressure area |
| trade winds | reliable breezes that blow from the northeast and southeast in their respective hemispheres. |
| Prevailing westerlies | winds that direct air masses across the United States |
| dew point | temperature at a relative humidity of 100% resulting in liquid or solid water droplets forming clouds or mist |
| cloud | a mass of extremely tiny liquid water droplets or ice crystals in the air |
| condensation nuclei | microscopic particles suspended in the air that easily attract water molecules |
| freezing nuclei | ice crystal deposits |
| stratus | clouds in thin layers or sheets |
| cumulus | clouds that are piles or billows |
| cirrus | clouds that are high, wispy curls |
| strato | less than 1 mile high |
| alto | 1-4 miles high |
| cirro | 4-12 miles high |
| cumulo | spans two or more altiltude zones |
| fog | when stratus like clouds form at ground level |
| freezing rain | rain drops that remain liquid all the way to the ground and then freeze if the surface is below freezing |
| dew | condensation of water vapor that forms on grass, cars, bicycles, etc. |
