ATSC 2000 FINAL EXAM Spring 2005 (16%) T/F ____/15 MC ____/33 Short Answer ____/21 Essay ____/12 Total ____/81 True/False Indicate whether the sentence or statement is true or false (one point each). ____ 1. In order to conserve angular momentum, an object's rotational velocity must decrease if its distance from the axis of rotation increases. ____ 2. The trade winds originate at the ITCZ. ____ 3. Descending Hadley Cell air is the source of both the midlatitude westerlies and the trade winds. ____ 4. Maritime polar air masses rarely affect the weather of Washington and Oregon. ____ 5. Continental tropical air masses form in the Great Plains region of the United States and Canada. ____ 6. Long, gentle rains are associated with cold fronts. ____ 7. Occluded fronts occur at the surface boundary between two polar air masses. ____ 8. Mountain ranges may trigger cyclogenesis. ____ 9. The warm conveyor belt is located ahead of the cold front. ____ 10. Wintertime anticyclonic regions over the United States interior usually carry mT air masses. ____ 11. In general, the higher the vertical wind shear, the more severe the thunderstorm. ____ 12. Cold weather and deep inversions are a sure sign that thunderstorms will occur. ____ 13. Cloud-to-ground lightning is more common than in-cloud lightning. ____ 14. What appears to be a single bolt of lightning is actually a series of rapid return strokes. ____ 15. Lightning requires the presence of strong updrafts and supercooled water droplets. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.(one point each) ____ 16. During his voyage across the Atlantic, Columbus wanted to spend the least amount of time here a. horse latitudes. b. midlatitude westerlies, on his way back to Europe c. northeasterly trades, on his way out d. the New World. e. Cuba ____ 17. If Earth had no land, jet streams would typically be found at about ___ degrees and ___ degrees. a. 0, 90 b. 15, 45 c. 15, 75 d. 30, 60 e. 45, 75 ____ 18. This/these are not typically found near the equator a. deserts. b. convective thunderstorms. c. the ITCZ. d. high humidity. e. warm temperatures. ____ 19. Trade winds a. begin in an area of low pressure. b. pick up much water vapor from tropical oceans. c. flow out of the ITCZ. d. are not part of Hadley Cell circulation. e. none of the above ____ 20. In the vicinity of the polar front you would expect to find a. midlatitude westerlies. b. polar easterlies. c. cold polar air. d. warm subtropical air. e. all of the above ____ 21. This is the most significant source of atmospheric transfer of heat poleward a. midlatitude cyclones. b. blocking highs. c. zonal flow. d. split-flow patterns. e. hurricanes. ____ 22. The characteristics of a maritime tropical air mass is a. very cold and dry. b. bitter cold and dry. c. warm and dry. d. warm and humid. e. cool and humid. ____ 23. Air masses a. are humid. b. typically form over heterogeneous surfaces. c. typically move away from the source region after they have formed. d. often form over medium-sized lakes, like Lake Powell in Utah. e. have large horizontal temperature gradients. ____ 24. Continental polar air masses that affect North America a. usually form over the southeastern United States. b. provide the moisture for much of the precipitation of the eastern United States. c. are typically unstable. d. always form over snow-covered regions. e. none of the above ____ 25. This North American air mass category forms over high latitude regions of Canada a. Air Canada b. mP. c. mT. d. cT. e. cP. ____ 26. Hot and humid summer weather in the eastern United States is usually caused by this type of air mass a. mT. b. mP. c. cP. d. cT. e. none of the above ____ 27. Fronts a. require two distinct air masses. b. can be several hundred miles long. c. are often associated with precipitation. d. all of the above e. none of the above ____ 28. Stationary fronts a. are usually cloudless. b. are the same as occluded fronts. c. occur when two cold fronts meet. d. occur inside a single air mass. e. are often accompanied by steady precipitation. ____ 29. This occurs earliest in an extratropical cyclone a. warm front. b. cold front. c. occluded front. d. occluded cyclone. e. open frontal wave. ____ 30. The most intense extratropical cyclones have lows of about ____ mb. a. 870 b. 910 c. 960 d. 999 e. 1010 ____ 31. A cut-off cyclone a. has well-developed fronts. b. is found at the level of the jet stream c. does not cause precipitation. d. is the initial stage of extratropical cyclone development. e. is rarely found over North America. ____ 32. Which occurs first? a. a stationary front b. cut-off cyclone c. occluded cyclone d. cold front approaching the warm front e. fully developed cold front ____ 33. Which of the following can trigger cyclogenesis? a. mountain barriers b. temperature gradients c. a strong jet stream d. all of the above e. none of the above ____ 34. In spring, the low-level flow in heavy snow storms that hit eastern Wyoming comes from the a. west. b. east. c. north. d. south. e. southwest. ____ 35. The southern tail of a comma cloud is caused by a a. cold front. b. warm front. c. occluded front. d. stationary front. e. dry slot. ____ 36. Divergence in the jet stream a. diminishes precipitation. b. inhibits cloud formation. c. causes cyclones to dissipate. d. is common east of troughs in the jet stream. e. all of the above ____ 37. Anticyclones a. have strong winds. b. are identified by their tightly spaced isobars. c. do not appear in the continental United States. d. have skies that are mostly clear. e. cause violent weather events. ____ 38. Air in an anticyclone a. converges aloft and subsides b. flows along the surface toward the center of the high. c. is moved by strong horizontal pressure gradients. d. rises and produces precipitation. e. all of the above ____ 39. Thunderstorms a. contain cumulonimbus clouds. b. can penetrate up to the tropopuase. c. contain rapidly rising saturated air. d. all of the above e. none of the above ____ 40. Which of the following is not conducive to the formation of thunderstorms? a. a lifted index of -5. b. warm moist air near the ground. c. a capping inversion. d. strong daytime heating. e. vertical wind shear. ____ 41. Precipitation in an ordinary single-cell thunderstorm a. usually falls as snow. b. does not occur in the dissipating stage. c. ceases in the cumulus stage. d. is highest in the mature stage. e. none of the above ____ 42. In the dissipating stage of an ordinary single-cell thunderstorm a. tornadoes are often spawned. b. severe lightning is most likely to occur. c. precipitation reaches a maximum. d. downdraft is stronger than updraft. e. all of the above ____ 43. Most tornadoes descend from a. air-mass thunderstorms. b. hurricanes. c. multi-cell lines. d. warm frontal nimbostratus. e. supercell thunderstorms. ____ 44. A mesocyclone a. forms in the lee of the Rockies. b. is essentially a F5 tornado. c. is often found in a supercell thunderstorm. d. is also called a left-mover. e. all of the above ____ 45. A tornado with 305 mile-per-hour surface winds is a class ___ on the Fujita scale. a. F1 b. F2 c. F3 d. F4 e. F5 ____ 46. Tornadoes a. are most common in late summer. b. affect both halves of the United States about equally. c. are most likely to occur between midnight and dawn. d. are quite frequent in Oklahoma. e. all of the above ____ 47. Charge separation in clouds a. requires collisions between ice particles and either snowflakes or graupel. b. is part of the collision-coalescence precipitation-formation process. c. is caused by the voltage difference between the ground and the tropopause. d. is most common in altocumulus clouds. e. is usually horizontal, not vertical. ____ 48. On average in the United States, of people killed by weather related events, the most fall victim to a. cold fronts. b. tornadoes. c. blizzards. d. hurricanes. e. lightning & flashfloods. Short Answer Fill out the blank (one point each) 49. The _______ ___________ lie at about 30 degrees north and south, and they were disliked by sailors. 50. The ________ _______ meet at the ITCZ. 51. The circulation of air from the ITCZ through the upper atmosphere down through the subtropical highs and back to the ITCZ is called a ________ _______ after the person who first explained it. 52. Calm winds near the equator are called the ____________. 53. The warmer winds of the ____________ ___________ meets the colder winds of the polar easterlies at the polar front. 54. The jet stream typically has several waves called _______ waves. 55. A comparatively low levels of precipitation on the leeward side of the Coast Range in the Pacific Northwest is termed a ______ ________. 56. Air masses are characterized by the ____________ and moisture characteristics of their source regions. 57. The North Pacific is a common source region for __________ ________ air masses. 58. _____________ ________ air masses often form over northern mainland Canada. 59. _____________ ____________ air masses form over the Southwest in summer. 60.