| A | B |
|---|
| meteorology | the study of atmospheric phenomena |
| weather | the current state of the atmosphere |
| climate | the long-term variations in weather for a particular area |
| air mass | a large body of air that takes on the characteristics of the area over which it forms |
| air mass modification | when an air mass starts to acquire some of the characteristics of the new surface beneath it |
| coriolis effect | where moving particles such as air are deflected to the right in the northern hemisphere and to the left in the southern hemisphere |
| trade winds | a sinking of air that moves towards the equator at 30 degrees north and south latitude |
| prevailing westerlies | flows between 30 degrees and 60 degrees north and south latitude where air rises and flows away from the equator |
| polar easterlies | lies between 60 degree and the poles where air sinks and flows toward the equator |
| jet stream | narrow bands of fast, high-altitude, westerly winds |
| front | a narrow region separating two air masses of different densities |
| thermometer | device used to measure temperature |
| barometer | a device used to measure air pressure |
| anemometer | used to measure wind speed |
| hydrometer | measures relative humidity |
| ceilometer | meaures the height of cloud layers and estimates the amount of sky covered by clouds |
| radiosonde | a balloon-borne package of sensors tat measure temperature, air pressure and humidity |
| doppler effect | the change in wave frequency that occurs in energy, such as sound or light, as that energy moves toward or away from an observer |
| station model | a record of weather data for a particular site at a particular time |
| isopleth | lines that connect points of equal or constant values |
| digital forecast | a forecast that relies on numerical data |
| analog forecast | a forecast that involves comparing current weather patterns to patterns that took place in the past |
| air-mass thunderstorm | a rising of air because of unequal heating of Earth's surface within one air mass |
| sea-breeze thunderstorm | local air-mass thunderstorms caused in part by extreme temperature differences between the air over land and the air over water |
| frontal thunderstorm | produced by advancing cold fronts and more rarely, warm fronts |
| supercell | self-sustaining, extremely powerful storms which are characterized by intense, rotating updrafts |
| downburst | violent downdrafts that are concentrated in a local area |
| tornado | a violent, whirling column of air in contact with the ground |
| Fujita tornado intensity scale | ranks tornadoes according to their path of destruction, wind speed, and duration |
| tropical cyclone | a large, rotating, low pressure system |
| eye | the calm center of a storm |
| eyewall | the strongest winds in a hurricane are found in this band that is immediately surrounding the eye of a storm |
| Saffir-Simpson hurricane scale | classifies hurricanes according to wind speed, air pressure in the center, and potential for property damage |
| storm surge | occurs when hurricane-force winds drive a mound of ocean water toward coastal area, where it washes over the land |
| drought | extended periods of well-below-normal rainfall |
| heat wave | an extended period of above-normal temperatures |
| cold wave | an extended period of below-normal temperatures |
| wind-chill factor | when cold air, worsened by wind, transports heat away from the body |
| climatology | the study of Earth's climate and the factors that affect past, present and future climatic changes |
| climate | the long-term weather patterns of an area |
| normal | standard values for a location |
| tropics | the area between 23.5 degrees north and south that receives the most solar radation |
| temperate zone | lie between 23.5 and 66.5 degrees north and south where temperatures are moderate |
| polar zone | located from 66.5 degrees north and south of the equator to the poles |
| Koeppen classification system | a widely used classification system for climates |
| microclimate | a localized climate that differs from the main regional climate |
| heat island | a location where the climate is warmer than in surrounding rural areas |
| ice age | periods of extensive glacial coverage |
| season | short-term periods of climate change caused by regular variations in daylight, temperature, and weather patterns |
| El Nino | a warm ocean current that occasionally develops off the western coast of South America |
| Maunder minimum | a period of very low sunspot activity |
| greenhouse effect | the natural heating og Earth's surface caused by certain atmospheric gases called greenhouse gases |
| global warming | a rise in global temperatures |
