ch20 review questions

If there's a seven second time delay between observed lightning and the sound of thunder, how far away is the lightning? 7 mi 0.7 mi 2 mi 1.7 mi 1.4 mi

1.4 mi Lightning travels at the speed of light, so a person sees it essentially at the moment it happens; thunder travels at the speed of sound, which is roughly 1 mile every 5 seconds, so 7 s / 5 s/mi = 1.4 mi away. (Section refs: 20.6, p. 700)

Which of the following statements is false? Earth's atmosphere: at the time of Earth's beginning would not have sustained life as we know it. was initially water vapor and nitrogen. was initially composed of gases pulled from the surrounding solar nebulae, but soon changed to one composed of volcanic gases. interacted with the solid and liquid Earth and thus changed its composition. released enough moisture as Earth cooled to fill the ocean basins.

was initially water vapor and nitrogen. The initial atmosphere was hydrogen and helium. (Section refs: 20.2, p. 681)

A maritime tropical air mass: originates over warm seas. is a minimum of 1,500 km across. creates hot humid weather in the area it's affecting. expands when it rises, cools adiabatically, and condenses out clouds. All of the possible answers are correct.

All of the possible answers are correct.

A monsoon is a major reversal in wind direction that causes a shift from a very dry season to a very rainy season.

True Seasonal rains brought on by the monsoons are essential to successful farming in southern Asia. See Fig. 20.32. (Section refs: 20.7, p. 710)

Which of the following statements is false? Prevailing winds: are surface winds. are the base of convective cells. are named according to the direction they blow toward. include the northeast and southeast tradewinds, which blow westward between the equator and 30° N and S latitudes. blow approximately parallel to the high- and low-pressure belts surrounding Earth.

are named according to the direction they blow toward. Winds are named according to the direction they blow from. See Figs. 20.11 and 20.13. (Section refs: 20.4, p. 690)

Which of the following statements is false? Clouds: at Earth's surface are called smog. form when water condenses on preexisting solid or liquid particles. form when the air is saturated. may form when the air cools at night. may form when the air rises and cools adiabatically.

at Earth's surface are called smog. Surface clouds are called fog. (Section refs: 20.5, p. 696)

Which of the following statements is false? Hurricanes: begin as tropical disturbances off the east coast of South America. can be several hundreds of kilometers in diameter. are called typhoons in the western Pacific, and cyclones in the Indian Ocean. track across the Atlantic and do damage in the Caribbean and along the Gulf Coast and eastern coast of North America. have their strongest winds in the eye wall, but their calmest region in the eye.

begin as tropical disturbances off the east coast of South America. Hurricanes begin in the central Atlantic, off the west coast of Africa. See Figs. 20.30 and 20.31. (Section refs: 20.6, p. 703)

Identify the false statement. The primary atmosphere: consisted mainly of water, carbon dioxide, carbon monoxide, and methane. had so much thermal energy it escaped Earth's gravity. that escaped from Earth was then blown away by the solar wind. was replaced by a secondary atmosphere consisting mainly of gases melted out of minerals within the Earth and released through volcanoes. was replaced by a secondary atmosphere that, arguably, consisted partially of gases brought to Earth by comets.

consisted mainly of water, carbon dioxide, carbon monoxide, and methane. It consisted mainly of hydrogen and helium derived from gas and dust rings surrounding the Sun. (Section refs: 20.2, p. 681)

Clouds that form over the plains of an ocean island do so because of: orographic lifting. convergence lifting. convective lifting. frontal lifting. the Bergeron process.

convective lifting. Convective lifting does occur when air warms more over the ground surface than over the adjacent water surface; orographic lifting refers to air pushed up over mountains; convergence lifting happens when two air masses push together; frontal lifting happens along the fronts between air masses; and the Bergeron process is the growth of ice crystals in a cloud at the expense of water droplets. (Section refs: 20.5, p. 696)

Which of the following statements is false? The Coriolis effect in the northern hemisphere: deflects a northward-moving object to the left (west). causes exactly the opposite deflection as does the Coriolis effect in the southern hemisphere. affects the atmosphere, causing winds to curve. exists because an object moving across Earth's surface has two components to its direction of travel: one is the direction it is aimed, and the other is imparted by Earth's rotation beneath it. deflects high-altitude winds that are moving north and causes them to move due east.

deflects a northward-moving object to the left (west). Deflection in the northern hemisphere is always to the right as viewed from the point of origin, so a northward-moving object would be deflected toward the east. (Section refs: 20.4, p. 688)

Which of the following statements is false? Thunderstorms: form where a cold front moves into a region of warm moist air. are common both in North American mid-latitudes and in tropical rainforests. last from one to a few hours. end when the updrafts become stronger than the downdrafts. with strong updrafts can produce ice balls of hail.

end when the updrafts become stronger than the downdrafts. During the mature stage of the storm, both updrafts and downdrafts exist, but eventually downdrafts dominate and cut off the supply of moist air from updrafts, ending the storm. (Section refs: 20.6, p. 699)

Identify the false statement. Storms: form where large pressure gradients exist. form where local conditions cause warm moist air to rise. are fed by warm moist air and die when this supply is cut off. develop clouds when moisture condenses out of the rising air. require the input of latent heat energy to release precipitation from the clouds.

require the input of latent heat energy to release precipitation from the clouds. Latent heat energy is released as the moist air condenses at higher elevation. (Section refs: 20.6, p. 699)

Which of the following terms is not a correct description of atmospheric conditions at the equator? doldrums equatorial low intertropical convergence zone sinking air slow wind flow, almost due west

sinking air Air at the equator is rising. (Section refs: 20.4, p. 689)

The aurora are curtains of light in both north and south polar regions caused by the interaction of charged particles (protons and electrons) from the Sun and ions in the ionosphere.

true The statement is a correct summary of the cause of both the northern and the southern auroras. (Section refs: 20.3, p. 687)

The troposphere is thicker at the poles than it is at the equator, so high-altitude winds flow from the poles to the equator.

False The troposphere is thicker over the equator, because the hotter air here has expanded, and therefore the pressure gradient initiates flow from the equator to the poles; the Coriolis effect deflects these flows, toward the east in the northern hemisphere, toward the west in the southern hemisphere. (Section refs: 20.4, p. 688)

Air that is saturated at 60°F would become undersaturated if its temperature dropped to 50°F.

False Cooler air can hold less moisture than warm air, so the reverse would be true, and moisture would condense out as the temperature dropped. (Section refs: 20.3, p. 685)

The presence of clouds always results in cooler ground temperatures.

False During the day the clouds scatter and reflect some sunlight back into space and this does lower ground temperature, but at night clouds prevent infrared radiation (heat) from escaping and thus keep the ground warmer. (Section refs: 20.5, p. 696)

If your local radio station broadcasts a tornado warning, you should stay tuned to see if a tornado does develop. If it issues a tornado watch, take cover immediately, because a tornado has actually been seen.

False Reverse the terms warning and watch, and then the statements are true. (Section refs: 20.6, p. 703)

The current atmosphere of Venus is largely the poisonous gas carbon monoxide; this accounts for the absence of life there.

False The atmosphere of Venus is almost all carbon dioxide. This greenhouse gas causes Venus to be so hot lead would melt on its surface, so it obviously cannot support life forms similar to us. (Section refs: 20.2, p. 681)

The Fujita scale runs from 0 to 10, and rates tornadoes on the basis of wind speed, the path dimension, and possible damage.

False The statement is true except for the numbers; the scale runs from 0 (weak) to 5 (incredible strength). See Table 20.2. (Section refs: 20.6, p. 702)

Which of the following statements is false? Saturated air has a relative humidity of 100%. If the dewpoint temperature is below freezing, frost forms instead of dew. Moist rising air cools adiabatically. Latent heat must be added to an air mass to cause water vapor in it to condense. Sweating will cool a person more efficiently when the relative humidity is 20% than when it is 50%.

Latent heat must be added to an air mass to cause water vapor in it to condense. Latent (hidden) heat is released during the change of state, vapor to liquid. (Section refs: 20.3, p. 685)

Which of the following statements is false? Tornadoes occur most frequently during late summer and into late fall. Doppler radar detects rain and rotating winds in clouds and thus can "see" tornadoes. Tornadoes result when opposing updrafts and downdrafts push on existing horizontal cylinders of rotating air and tilt them upright. Tornado alley, an area of frequent tornadoes, runs from Texas to Indiana. Dozens of tornadoes may develop from a single thunderstorm system.

Tornadoes occur most frequently during late summer and into late fall. Tornado season is from spring through summer (March through September). (Section refs: 20.6, p. 701)

Identify the false statement. Sunsets are red rather than sky-blue because the denser near-surface atmosphere scatters more of the blue light rays back to space, leaving the red ones to reach Earth. Radon is a radioactive trace gas that is a health hazard when it collects in basements. Ozone is a trace gas that protects Earth's surface from excessive infra-red radiation. The troposphere, stratosphere, and mesosphere, all homogenous mixtures, are collectively called the homosphere. The thermosphere has distinct layers of gases of different densities, and therefore is called the heterosphere.

Ozone is a trace gas that protects Earth's surface from excessive infra-red radiation. Ozone protects Earth's surface and living organisms from ultraviolet radiation. (Section refs: 20.2, p. 681)

If you are in the stratosphere, you: can experience weather phenomena. are below the tropopause. will encounter the ozone layer. will be affected by convection currents. will see the beginning of the burning of meteors (shooting stars).

will encounter the ozone layer. Weather phenomena and convection currents occur only in the troposphere, which is below the stratosphere; the tropopause is the boundary between troposphere and stratosphere; and meteors begin to burn in the mesosphere, which is above the stratosphere. (Section refs: 20.3, p. 686)

Earth's atmosphere: is composed of 78% nitrogen, 21% oxygen, and 1% trace amounts of various gases. contains aerosols, which are tiny droplets of water and acid and particles of sea salt, volcanic ash, clay, soot, and pollen. is becoming more polluted due to the burning of fossil fuels. in some locations contains enough sulfates and nitrates to create acid rain. All of the possible answers are correct.

All of the possible answers are correct.

Identify the true statement about the 2005 storm Hurricane Katrina. It had hurricane strength when it crossed Florida and became stronger as it crossed hot waters in the Gulf of Mexico. It reached maximum strength, Category 5, over the Gulf, but diminished to Category 4 when it made land at New Orleans. Its winds did do damage, but the catastrophic happenings were the result of storm surge and levee failure along Lake Pontchartrain. New Orleans is built on delta land, between a river and an ocean bay, which has subsided and is now below sea level. All of the possible answers are correct.

All of the possible answers are correct. Statements A through D are all true. The disaster should have come as no surprise. (Section refs: Box 20.3: Hurricane Katrina!)

Which of the following statements is false? Isobars are lines on a weather map that connect places of equal barometric pressure. Winds begin blowing in a perpendicular direction away from one isobar toward a lower-pressure isobar. Areas receiving oblique solar radiation experience more insolation than areas receiving direct solar radiation do. Winds develop whenever a pressure gradient exists, and they always blow from high- to low pressure. Because of the tilt of Earth's axis, the amount of solar radiation received by any point on its surface changes with the seasons.

Areas receiving oblique solar radiation experience more insolation than areas receiving direct solar radiation do. The more direct the radiation, the greater the insolation (incoming solar radiation). See Fig. 20.9. (Section refs: 20.4, p. 688)

Carbon dioxide is an atmospheric pollutant that reacts with and destroys ozone.

False Chlorofluorocarbons (CFCs) release chlorine, which breaks down ozone; carbon dioxide is a greenhouse gas that contributes to global warming. (Section refs: 20.3, p. 683)

Occluded fronts form where faster-moving warm fronts overtake slower-moving cold fronts and slide under them.

False Cold fronts move faster than warm fronts; when a cold front overtakes a warm front, it flows under the warm air and lifts it. (Section refs: 20.5, p. 694)

Which of the following statements is true? Wind is air molecules in motion. A northwest wind blows from the southeast toward the northwest Tiny rain droplets collide and coalesce to form hail. Sleet is ice that forms when rain freezes on cold surfaces on the ground. All of the possible answers are correct.

Wind is air molecules in motion. Winds are named by the direction they blow from; a northwest wind is blowing out of the NW toward the SE. Tiny rain droplets do collide and coalesce, but simply form larger raindrops heavy enough to fall. Sleet is rain that freezes as it falls. (Section refs: 20.1, p. 680)

Which of the following statements is false? Atmospheric circulation zones include: an intertropical convergence zone that produces an equatorial low. a subtropical high at 30° latitude, which has downward-moving, diverging air. a Hadley cell-Ferrel cell convergence at 60° latitude, which produces a zone of rising air called the subpolar high. an equatorial low that creates regions of heavy rainfall and tropical rainforests. a subpolar low, which has rising air and is located at 60°.

a Hadley cell-Ferrel cell convergence at 60° latitude, which produces a zone of rising air called the subpolar high. Hadley and Ferrel cells do converge, but at 30° latitude, to create a subtropical high with sinking air; at 60° a polar cell and a Ferrel cell converge, resulting in rising air of the subpolar low. Note Figs. 20.11 and 20.13. (Section refs: 20.4, p. 689)

Which of the following statements is false? Tornadoes: have maximum wind speeds up to 500 km/h (300 mph). in North America generally travel from southwest to northeast at speeds up to 100 km/h (60 mph). begin when high altitude westerlies flow over low altitude southeasterlies and the resulting shear produces rotating air. are rated on the Saffir-Simpson scale, which runs from 1 to 5. do damage because their winds batter the surroundings and their low pressures induce the outward explosion of buildings.

are rated on the Saffir-Simpson scale, which runs from 1 to 5. They're measured on the Fujita scale, which runs from F0 to F5; the Saffir-Simpson scale, which does run from 1 to 5, rates hurricanes. (Section refs: 20.6, p. 702)

Which of the following statements is false? The ionosphere: is the atmospheric layer in which solar energy strips electrons from nitrogen and oxygen atoms, causing them to become positive ions. transmits radio waves by bouncing them back and forth between Earth and itself. hosts the aurora borealis and aurora australis. includes most of the stratosphere and the lower part of the mesosphere. gets its name because it's composed of electrically charged atomic particles called ions.

includes most of the stratosphere and the lower part of the mesosphere. It's at a higher altitude than choice D states, and includes most of the mesosphere and the lower part of the thermosphere. (Section refs: 20.3, p. 687)

Identify the false statement. Seasons: would not occur on an Earth that sat upright (vertically) in space. occur because the Sun's perpendicular (directly overhead) rays migrate across Earth's surface, from the Tropic of Cancer in the north to the Tropic of Capricorn in the south. are influenced by whether the hemisphere in question is tilted in toward or away from the Sun. are reversed in the northern and southern hemispheres. involve two solstices, in March and September, and two equinoxes, in June and December.

involve two solstices, in March and September, and two equinoxes, in June and December. The solstices are in June and December, the equinoxes are in March and September. (Section refs: Box 20.2, The Earth's Tilt: The Cause of Seasons.)

The air-flow pattern at 60°N latitude: is a divergence zone. is a zone of sinking air. is called the subpolar low, and the place this happens is called the polar front convergence zone. reverses itself with changing seasons. All of the possible answers are correct.

is called the subpolar low, and the place this happens is called the polar front convergence zone. The area at 60° N latitude is a convergence zone where surface polar air moving south collides with surface mid-latitude air moving north and rises; the exact position of the convergence shifts with seasonal changes but does not reverse. (Section refs: 20.4, p. 689)

Which of the following statements is false? A cumulonimbus cloud: is one of vertical development. produces rain. may be topped by an anvil cloud. is filled with updrafts, not downdrafts of air. may extend to the top of the troposphere.

is filled with updrafts, not downdrafts of air. A cumulonimbus cloud has both updrafts and downdrafts, and therefore is stirred so violently it appears to boil. (Section refs: 20.5, p. 697)

Air pressure: is inversely related to elevation. on Mt. Everest's summit is only 1/10 as much as air pressure at sea level. at sea level is expressed as 14 bars. is nonexistent at elevations higher than 5 km. All of the possible answers are correct.

is inversely related to elevation. The relation is an inverse one: the higher the elevation, the lower the air pressure. Mt. Everest's summit has 1/3 the air pressure found at sea level; sea-level pressure is about 14 lb/in2 but this is equivalent to only 1 of the units called bars; and at 5 km the air pressure is about 1/2 sea-level pressure. The upper boundary of the atmosphere, and therefore some air pressure, reaches 100 km. See Fig. 20.4. (Section refs: 20.3, p. 683)

Identify the false statement. El Niño: Spanish for "the Christ child," was named this because the phenomenon occurs in late December. is regulated by air pressure cells shifting back and forth across the Atlantic. is regulated by the southern oscillation. involves eastward flowing warm surface currents that suppress upwelling of nutrient-rich cold water along the coast of South America. can cause temporary climate changes worldwide.

is regulated by air pressure cells shifting back and forth across the Atlantic. The cells are shifting across the Pacific, not the Atlantic. (Section refs: 20.7, p. 712)

Which of the following statements is false? Atmospheric oxygen: is necessary for the respiration of multicellular organisms. provides the raw material for ozone. was originally introduced by the photosynthesis of blue-green algae (cyanobacteria). is supplied mainly by chemical breakdown of carbonate rocks like limestone. reached a peak of about 35% during the late Paleozoic (coal age).

is supplied mainly by chemical breakdown of carbonate rocks like limestone. It's supplied by the activity of photosynthetic organisms (green plants). (Section refs: 20.2, p. 681)

When air moves from a region of high pressure to a region of low pressure, with no addition or subtraction of heat: it contracts. its molecules speed up. it begins to move vertically upward. it undergoes adiabatic heating. All of the possible answers are correct.

it begins to move vertically upward. The lower pressure would allow it to expand, slow its molecular motion (cool), rise, and experience adiabatic cooling. (Section refs: 20.3, p. 685)

Which of the following statements is false? Hurricanes: by definition have minimum winds of 119 km/h (74 mph). die out when they cross over cold waters or onto land. occur, on the average, several dozen times per year on the North American east coast. do damage with their intense winds and rainfall, huge waves, and storm surges. result when tropical depressions grow stronger.

occur, on the average, several dozen times per year on the North American east coast. The North American east coast averages five hurricanes per year, although 2005 saw an exceptionally high number of named storms. (Section refs: 20.6, p. 706)

Which of the following statements is false? Lightning: occurs when a positively charged cloud base induces a negative charge in Earth's surface. involves a conductive path or leader of negative ions from cloud to ground. is composed of both upward and downward flows of ions. can stay within a cloud or travel back and forth between the cloud and the ground. may be accompanied by the sound of explosively expanding hot air called thunder.

occurs when a positively charged cloud base induces a negative charge in Earth's surface. A cloud has a negatively charged base that repels negative ions of the ground surface, thus creating a positively charged ground surface. (Section refs: 20.6, p. 700)

Jet streams in the northern hemisphere: are zones of especially fast-moving high-altitude easterlies. flow at speeds between 50 and 100 km/h. originate where pressure gradients are at their lowest. originate over the polar front (60° latitude) and over the horse latitudes (30° latitude). All of the possible answers are correct.

originate over the polar front (60° latitude) and over the horse latitudes (30° latitude). Jet streams are westerlies that originate where pressure gradients are extremely steep and flow between 200 and 400 km/h. See Fig. 20.13. (Section refs: 20.4, p. 692)

A high-pressure air mass: has rising air at its center. produces clear dry weather. in the northern hemisphere has counterclockwise circling winds. is associated with fog and clouds. is called a cyclone.

produces clear dry weather. A high-pressure mass, called an anticyclone, rotates clockwise in the northern hemisphere and has sinking air at its center; low-pressure cyclones are associated with fog and clouds. (Section refs: 20.5, p. 694)

Which of the following is not a contributing factor to regional climate? latitude and altitude proximity of water proximity to especially warm or cold ocean currents proximity to isothermic barriers proximity to high- or low-pressure zones

proximity to isothermic barriers Isothermic barriers is a nonsense term. The correct term is orographic barriers; these are landforms like mountain ranges that divert airflow upward or laterally. Isotherms are lines on a map that connect places of equal temperature. (Section refs: 20.7, p. 707)