FORMATION OF AIR MASSES

Transcription

1 Chapter 24: Weather (air mass, fronts, Weather instruments, and forecasting the weather) Name: Period: Due Date: Air Mass Use the terms from the following list to complete the sentences below. Each term may be used only once. High pressure Poles Low pressure Wind patterns Equator Air pressure 1. Differences in are caused by unequal heating of Earth s surface. 2. The region along the receives more solar energy than the Polar Regions do. 3. Heated equatorial air rises and creates a belt of. 4. Cold air near the poles sinks and creates a belt of 5. Differences in air pressure at various locations on Earth create. How Air Moves 7. There is a general world-wide movement of air from the a. poles toward the equator. b. equator toward the poles. c. Northern Hemisphere to the Southern Hemisphere. d. Southern Hemisphere to the Northern Hemisphere. FORMATION OF AIR MASSES 8. What happens to air when the air pressure differences are small? 9. What is an air mass? TYPES OF AIR MASSES 12. Air masses are categorized according to their a. destination region. b. source region. 13. Cold air masses come from a. polar areas. b. tropical areas. 14. Warm air masses come from a. arctic areas. b. temperate areas. c. polar region. d. tropical region. c. equatorial areas. d. temperate areas. c. tropical areas. d. polar areas. 15. What are air masses that form over the ocean called? a. oceanic b. maritime 16. Air masses that form over land are called a. wet. b. maritime. c. continental d. dry c. grounded. d. continental. 19. Name and describe the two types of continental air masses. 21. What weather conditions do maritime air masses generally bring when they travel to a new location? 22. Name and describe the two types of maritime air masses.

2 Section: Fronts 1. When two unlike air masses meet, what usually keeps them separate? a. temperature differences c. differences in density b. moisture differences d. differences in pressure 2. The boundary that forms between two air masses when they meet is called a a. front. c. squall line. b. storm line. d. midlatitude. TYPES OF FRONTS In the space provided, write the letter of the definition that best matches the term or phrase. 3. cold front 4. warm front 5. stationary front 6. occluded front a. a front of air masses that moves either very slowly or not at all b. the front edge of a moving mass of cold air that pushes beneath a warmer air mass like a wedge c. the front edge of an advancing warm air mass that replaces colder air with warmer air d. 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 7. Describe the storms that form along a cold front. 8. How does a slow-moving cold front differ from a fast-moving cold front? 9. How does a warm front form? 10. What kind of weather does a warm front generally produce? 11. Describe how a stationary front forms. Drawing: Warm Front Cold Front Occluded Front Symbols Warm Front Cold Front Occluded Front Stationary Front

3 POLAR FRONTS AND MIDLATITUDE CYCLONES Use the terms from the following list to complete the sentences below. Each term may be used only once. Some terms may not be used. midlatitude cyclone anticyclone polar front warm front waves wave cyclones 13. The boundary where cold polar air meets the tropical air mass of the middle latitudes, especially over the ocean, is called the. 14. Bends that form in a stationary or cold fronts that are the beginnings of low-pressure storm centers are called. 15. Also known as midlatitude cyclones, are low-pressure storm centers. 16. An area of low pressure that is characterized by rotating wind that moves toward the rising air of the central low-pressure region is called a. 17. Unlike the air in a midlatitude cyclone, the air of a (n) sinks and flows outward from a center of high pressure. 18. Four statges of a midlatitude cyclone: (figure 3) Describe an anticyclone.

4 21. What kind of weather does an anticyclone bring? SEVERE WEATHER In the space provided, write the letter of the description that best matches the term or phrase. 23. thunderstorm 24. lightning 25. mature stage 26. dissipating stage 27. cumulus stage 28. thunder a. the first stage of a thunderstorm, in which warm, moist air rises and water vapor in the air condenses to form a cumulus cloud b. electricity that is discharged during a thunderstorm c. an effect created when electricity heats the air, and the air expands rapidly d. a usually brief, heavy storm that consists of rain, strong winds, lightning, and thunder e. the third stage of a thunderstorm, in which strong downdrafts stop air currents from rising and the storm dies out as water vapor decreases f. the second stage of a thunderstorm, in which condensation continues as the cloud rises and becomes a dark cumulonimbus cloud, perhaps producing torrential rain and hail Use the terms from the list below to complete the sentences that follow. Each term may be used only once. Some terms may not be used. Safir-Simpson scale Cumulonimbus cloud bands Water vapor Tornado Eyewall Hurricane Storm surge Eye Latent heat 30. A severe storm that develops over tropical oceans and whose winds of more than 120 km/h spiral in toward the intensely low-pressure storm center is called a(n). 31. During a hurricane, large amounts of are released, increasing the force of the rising air. 32. A fully developed hurricane consists of a series of thick that spiral upward around the center of the storm. 33. Winds increase toward the calm, clear of the storm and may reach speeds of 275 km/h. 34. The most dangerous aspect of a hurricane is a rising sea level and large waves, called a. 35. Every hurricane is categorized on the by using several factors, including central pressure, wind speed, and storm surge. 37. Explain how a tornado forms. 39. When and where do most tornadoes occur? 40. What makes a tornado so destructive?

5 WEATHER INSTRUMENTS 2. How do meteorologists use these measurements? MEASURING LOWER ATMOSPHERIC CONDITIONS In the space provided, write the letter of the definition that best matches the term or phrase. 3. thermometer 4. electricalthermometer 5. thermistor 6. barometer 7. anemometer 8. wind vane a. an instrument that measures atmospheric pressure b. a thermal resistor that measures temperature and responds quickly to temperature changes c. an instrument that measures wind speed d. an instrument that measures and indicates temperature, often in the form of a sealed glass tube filled with mercury or alcohol e. an instrument that determines the direction of wind with an arrow shaped device that turns freely as the tail catches the wind f. an instrument that measures and indicates temperature using an electric current MEASURING UPPER-ATMOSPHERIC CONDITIONS 12. Why do meteorologists study upper-atmospheric conditions? 13. What is a radiosonde? 14. Explain how a radiosonde works. 15. What is radar? 16. How does radar track a storm? 17. Explain what Doppler radar can tell meteorologists. 18. What important purpose do weather satellites serve? 19. How do weather satellites measure the direction and speed of the wind at the level of the clouds? 20. How do weather satellites monitor weather at night? 21. What types of marine conditions do weather satellites monitor?

6 22. Explain how meteorologists use supercomputers to forecast weather. Forecasting Weather 3. List seven types of weather observations reported from weather stations around the world. WEATHER MAPS 5. The data that weather stations collect are transferred a. onto weather satellites. c. onto weather maps. b. to weather stations. d. to weather instruments. 6. What do meterologists use to communicate data on a weather map that can be understood around the world? a. words and colors c. symbols and letters b. words and numbers d. symbols and colors 7. A pattern of meteorological symbols that represents the weather at a particular observing station and that is recorded on a weather map is a. a station model. c. the station forecast. b. a station report. d. the station weather. 8. Lines that connect points of equal temperature on a weather map are called a. isolines. c. thermal lines. b. isotherms. d. isobars. 9. Lines on a weather map that connect points of equal atmospheric pressure are a. isopressures. c. pressure lines. b. isotherms. d. isobars. 10. Closely spaced lines of atmospheric pressure indicate high wind speeds and a. no change in pressure. b. wet weather. c. a gradual change in pressure. d. a rapid change in pressure. 11. Isobars that form circles on a weather map are marked with an H or an L and indicate centers of a. heat and light. b. high pressure and low pressure. c. high temperature and low temperature. d. high clouds and low clouds. 13. Besides cloud cover, wind speed and direction, and weather conditions, what else do stations models indicate? 14. What is the dew point and what does it indicate about the air? 15. Describe the number and the line in the upper right hand corner of the station model and explain what they show.

7 16. On a weather map, what identifies a front? 17. How are areas of precipitation commonly marked on weather maps? WEATHER FORECASTS 18. How do meteorologists forecast the weather? 19. How do computers use information supplied by Doppler radar and satellite images? 20. Explain why meteorologists use more than one computer model to forecast weather. 21. What types of weather information can be predicted most accurately? 22. What types of weather information are more difficult to predict accurately? 23. Explain how meteorologists use computers to make more accurate forecasts. Skills Practice Lab: Follow the instructions on page 626 and then answer the analysis and conclusion questions: