CHAPTER 9 ATMOSPHERE S PLANETARY CIRCULATION MULTIPLE CHOICE QUESTIONS 1. Viewed from above in the Northern Hemisphere, surface winds about a subtropical high blow a. clockwise and inward. b. counterclockwise. c. counterclockwise and outward. d. clockwise and outward. 2. Viewed from above in the Southern Hemisphere, surface winds about a subtropical high blow a. clockwise and inward. b. counterclockwise. c. counterclockwise and outward. d. clockwise and outward. 3. Dry climates characterize the flank of subtropical highs. ern b. western c. equatorward d. poleward 4. The western flank of a subtropical anticyclone is characterized by a. relatively stable air. b. mostly descending air. c. moist climates. d. All of these are correct. 5. A broad region of light winds or calm air prevails a. along the horse latitudes. b. near 60 degrees latitude. c. along the Tropic of Capricorn. d. in subpolar lows. e. in the trade wind belts. 6. Subtropical anticyclones are -core circulation systems. a. cold b. warm
7. Over a broad region about the center of a subtropical high, the horizontal air pressure gradient is relatively and winds are. a. weak...light or calm b. steep...light or calm c. weak...strong d. steep...strong 8. The trade winds blow out of the flank of the subtropical anticyclones. a. poleward b. equatorward c. eastern d. western 9. In the Northern Hemisphere, trade winds blow from the. a. north b. east c. southeast e. northeast 10. In the Southern Hemisphere, trade winds blow from the. a. north b. east c. southeast e. northeast 11. The global westerlies blow out of the flank of the subtropical anticyclones. a. poleward b. equatorward c. eastern d. western 12. The tropical deserts of the world are found at latitudes near 30 degrees latitude because a. the intertropical convergence zone occurs there. b. of the doldrums. c. of the sinking air associated with the polar front. d. of the sinking air associated with the subtropical highs. 13. Viewed from above in the Northern Hemisphere, winds above the atmospheric boundary layer blow about the center of a subtropical high. a. clockwise and parallel to isobars b. clockwise and across isobars toward low pressure c. counterclockwise and parallel to isobars d. counterclockwise and across isobars toward high pressure
e. None of the above is correct. 14. Viewed from above, surface winds blow about the Icelandic low. a. clockwise and outward b. clockwise and inward c. counterclockwise and outward d. counterclockwise and inward 15. The intertropical convergence zone (ITCZ) is usually located where Earth s mean annual surface temperature. a. is the lowest b. is the highest c. varies drastically depending on the season 16. The trade winds of the two hemispheres a. diverge at the equator. b. are highly variable in speed and direction. c. flow toward the east in a pattern of long-waves. d. are very persistent in direction. e. None of the above is correct. 17. The ITCZ a. is a discontinuous belt of cumulonimbus clouds. b. marks the convergence of the trade winds of the two hemispheres. c. is located near the equator on average. d. is a discontinuous belt of thunderstorms. e. All of the above are correct. 18. A front is a narrow zone of transition between air masses that contrast in a. temperature. b. humidity. c. density. d. Any of these is correct. 19. Hadley cells are located in latitudes of both hemispheres. a. tropical b. middle c. high 20. Hadley cells are a. located in middle latitudes. b. similar to huge convection cells. c. linked to the subpolar lows. d. driven by the westerlies.
21. Hadley cell circulation causes air to in the ITCZ and in the subtropical anticyclones. a. sink..rise b. rise.sink 22. In the Northern Hemisphere, with the shift from winter to summer, the semi-permanent subtropical highs shift. ward ward c. southward d. westward 23. In the Northern Hemisphere, with the shift from summer to winter, the semi-permanent subtropical anticyclones shift. ward ward c. southward d. westward 24. In the Southern Hemisphere spring, the subtropical highs shift ward. b. poleward. ward. d. equatorward. 25. The middle latitude westerlies are energetic in winter than in summer. a. less b. equally as c. more 26. When viewed from above, subtropical gyres rotate in a direction in the Northern Hemisphere and in a direction in the Southern Hemisphere as a result of the Coriolis Effect. a. clockwise counterclockwise b. counterclockwise clockwise. c. both clockwise d. both counterclockwise. 27. A monsoon circulation characterizes regions where seasonal reversals in prevailing winds cause summers and relatively winters. a. wet dry b. dry wet 28. On a typical day, Rossby long-waves encircle the globe. a. 1 to 2
b. 2 to 5 c. 3.5 d. dozens of e. more than 100 29. Which one of the following westerly wave patterns favors the maximum north-south exchange of air masses? a. zonal flow b. meridional flow c. split flow 30. The westerly wave pattern that is likely to persist for the longest time is a. zonal b. meridional 31. A blocking pressure system is associated with a flow pattern in the westerlies. a. zonal b. meridional 32. Across the United States, temperature contrasts are generally greatest during a circulation pattern in the westerlies. a. strong zonal b. strong meridional c. weak meridional d. weak zonal 33. In the Midwest, drought is most likely with a circulation pattern in the westerlies. a. strong zonal b. split-flow c. weak meridional d. blocking 34. Narrow corridors of very strong winds within the atmosphere are known as a. short waves b. Rossby waves c. jet streams 35. Horizontal divergence occurs to the of an upper-air trough. 36. Horizontal convergence occurs to the of an upper-air ridge.
37. Horizontal divergence occurs to the of an upper-air ridge. 38. Horizontal convergence occurs to the of an upper-air trough. 39. A synoptic-scale cyclone is most likely to develop on the side of an upper-air trough. 40. A synoptic-scale cyclone is most likely to develop on the side of an upper-air ridge. 41. In an essentially straight jet streak viewed from above, the strongest horizontal divergence takes place in the quadrant. a. left rear b. right rear c. left front d. right front 42. The polar front jet stream is usually located in southern Canada in a. summer b. winter 43. The Southern Oscillation a. was discovered by Sir Gilbert Walker early in the 20 th century. b. is a seasaw variation in air pressure across the tropical Indian and Pacific Oceans. c. is linked to the development of El Niño. d. All of these are correct. 44. In the Northern Hemisphere, Ekman transport of surface ocean waters is about
the surface wind direction. a. 45 degrees to the left of. b. 90 degrees to the left of c. 90 degrees to the right of d. 30 degrees to the right of 45. Upwelling a. brings cold bottom water to the ocean surface. b. is the long-term average condition off the northwest coast of South America. c. is suppressed during El Niño. d. supports important fisheries. e. All of the above are correct. 46. El Niño can be described as the phase of the Southern Oscillation, and La Niña the phase. a. warm...cold b. cold.warm 47. An extreme and persistent El Niño a. can be expected every year in mid-december. b. may be accompanied by weather extremes in various parts of the world. c. involves an interaction between the tropical Atlantic ocean and atmosphere. d. seldom lasts longer than a few weeks. 48. During neutral conditions, sea surface temperatures are highest in the tropical Pacific. a. western b. central c. eastern 49. In the ENSO Alert System, an El Niño or La Niña is issued when El Niño or La Niña conditions have developed and are expected to continue. a. watch b. advisory c. warning 50. The ENSO Observing system consists of a. island and coastal tide gauges. b. satellites. c. an array of instrumented buoys. d. ship-based instruments. e. All of the above are correct.