University Of Arizona ATMO 170A Weather Quiz #5 Chapter 13 1)A biogeophysical feedback mechanism in the Sahel relates

Question

University Of Arizona

ATMO 170A

Weather Quiz #5

Chapter 13

1)A biogeophysical feedback mechanism in the Sahel relates .

a. reduced cloud cover to increasing surface temperatures and an increase in rainfall

b. reduced vegetation to a decrease in surface temperatures and a reduction in rainfall

c. an increase in vegetation to an increase in surface temperatures and a reduction in rainfall

d. a decrease in vegetation to a lowering of surface albedo and an increase in rainfall

2. A high concentration of oxygen 16 found in the ice caves of Antarctica and Greenland would indicate at the time the ice was formed.

a. cold air temperatures

b. mild winters

c. intense ultraviolet radiation

d. the caves were under the ocean

3. A positive feedback mechanism .

a. acts to reinforce an initial change

b. acts to weaken or oppose an initial change

c. will cause a positive change

d. will cause a negative change

4. Additional clouds in a warmer world .

a. would have a net warming effect

b. would have a net cooling effect

c. would have no warming or cooling effect

d. could enhance or reduce warming

5. An increase in atmospheric CO2 concentrations will most likely lead to in the troposphere and in the upper atmosphere.

a. warming; warming

b. cooling; warming

c. warming; cooling

d. cooling; cooling

6. Climate models predict that if average global temperatures rise, both global precipitation and drought will .

a. increase

b. decrease

c. remain the same

d. vary from year to year

7. During a period when the earth's orbital tilt is at a minimum, what would most likely to occur?

a. There should be less seasonal variation between summer and winter.

b. There would be more snowfall during the winter in polar regions.

c. There would more of a likelihood of glaciers at high latitudes.

d. There would be less seasonal variations at middle latitudes.

8. During the climatic optimum, .

a. the climate favored the development of certain plants

b. average temperatures were colder than at present

c. continental ice sheets began to melt

d. alpine glaciers began to advance down river valleys

9. During the Little Ice Age, .

a. the climatic optimum occurred

b. sea level lowered by about 280 ft

c. alpine glaciers grew in size and advanced

d. continental glaciers covered large portions of North America

10. During the Pleistocene epoch, .

a. continental glaciers continuously covered large parts of North America and Europe

b. it was much warmer than now

c. continental glaciers alternately advanced and retreated over large portions of North America and Europe

d. tropical vegetation was growing over vast regions of the Central Plains of North America

11. Everything else being equal, a gradual increase in global CO2 would most likely bring about .

a. an increase in surface air temperature

b. a marked decrease in plant growth

c. a decrease in evaporation from the earth's oceans

d. no change in global climate

12. If the earth were in a cooling trend, which process below would most likely act as a positive feedback mechanism?

a. increasing the snow cover around the earth

b. increasing the water vapor content of the air

c. decreasing the amount of cloud cover around the globe

d. increasing the carbon dioxide content of the air

13. If the earth were in a warming trend, which of the processes below would most likely act as a negative feedback mechanism?

a. increasing the water vapor content of the air

b. increasing the snow cover around the earth

c. decreasing the amount of cloud cover around the globe

d. increasing the carbon dioxide content of the air

14. It appears that, as the number of sunspots increases, the sun's total energy output .

a. increases slightly

b. decreases slightly

c. begins to alternately increase and decrease above average values

d. does not change

15. It is now known that, overall, clouds .

a. have a net warming effect on climate

b. have a net cooling effect on climate

c. have no net effect on climate

d. are the single most important feature in determining climate

16. It now appears that if global temperatures continue to rise, the oceans .

a. will increase the amount of CO2 in the atmosphere

b. will reduce the amount of CO2 in the atmosphere

c. could increase or reduce the amount of CO2 in the atmosphere

d. will have no effect on atmospheric CO2 concentrations

17. Large volcanic eruptions with an ash veil that enters the stratosphere, tend to at the surface.

a. increase temperatures

b. increase precipitation

c. decrease temperatures

d. have no significant effect

18. Over the past 100 years or so, it appears that average global temperatures have .

a. increased slightly

b. fluctuated widely but shown no overall change

c. decreased slightly

d. remained constant

19. Ozone is a greenhouse gas that role in the enhancement of the greenhouse effect.

a. plays a minor

b. plays a major

c. plays the most important

d. has no

20. Plate tectonics "explains" certain climatic changes by showing that these changes may be related to .

a. mountain building

b. the position of the continents

c. the paths taken by ocean currents

d. all of these

21. Precession of the equinox refers to .

a. changes in the shape of the earth's orbit as the earth revolves around the sun

b. changes in the tilt of the earth as it orbits the sun

c. changes in the seasons, especially from winter to summer

d. the wobble of the earth on its axis

22. Presently, ice sheets and glaciers cover of the earth's surface.

a. about 10 percent

b. less than one percent

c. about one-quarter

d. about two-thirds

23. Studies reveal that during colder glacial periods, CO2 levels during warmer interglacial periods.

a. were higher than

b. were lower than

c. were about the same as

d. were more variable than

24. The "year without a summer" may have been caused by .

a. soot from coal fires

b. particulate matter and gases from volcanoes

c. a dust cloud produced when a meteorite collided with the earth

d. deforestation

25. The "year without a summer" occurred in . a. 1950

b. 1816

c. 1735

d. 1681

26. The CLIMAP project was able to reconstruct the earth's ocean surface temperature in the past by examining .

a. deep ocean water

b. rock layers on land

c. thousands of feet of sediment at the bottom of the ocean

d. soils deposited over the North American continent

27. The higher the ratio of oxygen 18 to oxygen 16 in the shells of organisms that lived in the sea during the geologic past, the the climate at that time.

a. Colder

b. Warmer

c. Wetter

d. drier

28. The Maunder Minimum refers to a time when .

a. the tilt of the earth's axis was less than it is now

b. there were fewer sunspots

c. the earth was closer to the sun than it is now

d. few snowstorms occurred over the United States

29. The Milankovitch cycles in association with other natural factors explain how glaciers may advance and retreat over periods of .

a. hundreds of millions of years

b. several million years

c. hundreds of thousands of years

d. ten thousand to one hundred thousand years

30. The Milankovitch Theory proposes that climatic changes are due to .

a. variations in the earth's orbit as it travels around the sun

b. volcanic eruptions

c. changing levels of CO2 in the earth's atmosphere

d. particles suspended in the earth's atmosphere

31. The Milankovitch theory suggests that climates changes on the earth could be caused by changes in .

a. the shape of the earth's orbit around the sun

b. the direction of tilt of the earth's axis

c. the amount of tilt of the earth's axis

d. all of these

32. The most recent North American glaciers reached their maximum thickness and extent .

a. in 1,700 A.D.

b. in 2,000 B.C.

a. about 18,000 to 22,000 years ago

b. about two million years ago, at the beginning of the Pleistocene epoch

33. The most recent warming trend experienced over the Northern Hemisphere could be the result of .

a. light colored particles in the stratosphere

b. increasing levels of greenhouse gases

c. a decrease in the energy emitted by the sun

d. an observed decrease in snow cover

34. The Sahel .

a. is mostly a sand-covered desert

b. is a region of variable rainfall

c. always had a food surplus

d. is located in Saudi Arabia

35. The Viking colony in Greenland perished during the .

a. Pleistocene epoch

b. climatic optimum

c. Little Ice Age

d. explosion of Mt. Pinatubo

36. Volcanic eruptions that have the greatest impact on global climate appear to be those rich in

.

a. Nitrogen

b. water vapor

c. carbon dioxide

d. sulfur

37. Warming at the earth's surface will most likely occur when there is an increase in the amount of

.

a. low-level global cloud cover

b. sulfur-rich particles in the stratosphere

c. global snow cover

d. high-level global cloud cover

38. Which of the following decades was the warmest on record? a. 1930-1939

b. 1960-1969

c. 1990-1999

d. 2000-2009

39. Which theory explains how glacial material can be observed today near sea level at the equator, even though sea level glaciers probably never existed there?

a. Milankovitch theory

b. theory of plate tectonics

c. volcanic dust theory

d. Maunder theory

40. Climate models predict that oceans will warm more rapidly than landmasses in the northern high latitudes during the next 100 years.

a. True

b. False

41. Recent evidence suggests that the variations in the earth's orbit around the sun proposed by Milankovitch actually have very little effect on the earth's climate.

a. True

b. False

42. Some scientists believe the earth is in a comparatively warm part of an ice age.

a. True

b. False

43. The combined effect of trace greenhouse gases (such as methane (CH4), nitrous oxide (N2O), and CFCs) in enhancing the greenhouse effect is about equal to carbon dioxide.

a. True

b. False

44. Warm ocean water cannot contain as much dissolved carbon dioxide as cool ocean water.

a. True

b. False