Geog 3A:Ocean and Atmosphere

Mid-term Review TA: Rui Zhu Winter 2015

1. Ionic bonding is a. relevant to the sodium chloride molecule b. relevant to the water molecule c. a. and b. d. none of the above

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Topic: chemical bonding (Ch6, p.95) Key: Ionic bonding and hydrogen bonding sodium chloride moleculeà Ionic bonding water moleculeàhydrogen bonding Answer: a

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Rui Zhu Winter 2015

2. Of the following, which form of energy propagates over the greatest distances in the ocean? a. sound energy b. infrared energy c. visible energy

Topic: Electromagnetic energy (Ch7 p128-130 Figure 7-28, 7-29) ) Key: •  “Water strongly absorbs red and infrared light. Blue light is absorbed

the least, the ocean appears blue”. •  So, long wavelength is better to be absorbed by water. Thus

shortwave travel longer distance in the ocean. •  Sound energy travel the longest distance due to the

discompressibility of water.

Answer: a Rui Zhu Winter 2015

3. Three examples of greenhouse gases are: a. carbon dioxide, methane, oxygen b. methane, water vapor, DMS

(dimethylsulfide) c. methane, nitrogen, oxygen d. carbon dioxide, helium, DMS

(dimethylsulfide) e. helium, DMS (dimethylsulfide),

chlorofluorocarbons Rui Zhu Winter 2015

Topic: Greenhouse gases: (slides Ch7) Key: Answer: b

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4. Which of the following is a red tide phytoplankton?

a. diatom b. dinoflagellate c. coccolithophore d. all of the above e. none of the above

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Topic: phytoplankton (Chapter 7 slides) Key: Diatom (green) Dinoflagellate (red) Coccolithophore (blue) Answer: b

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5. Methane and carbon dioxide gases in the atmosphere:

a. trap visible radiation emitted by the earth b. trap radiation in the visible portion of

the electromagnetic spectrum emitted by the sun

c. have not varied with the Milankovitch cycles

d. all of the above e. none of the above

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Topic: Greenhouse gasses (Ch7 and lab 2) Key: Radiation (infrared longwave) stopped (trapped) at the atmosphere, absorbed, and heat up the earth. Answer: e

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6. Seawater density increases with both: a. increasing salinity and increasing

temperature b. decreasing pressure and decreasing

temperature c. increasing salinity and decreasing pressure d. decreasing salinity and increasing

temperature e. none of the above

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Topic: Density formula (Chapter 7 slides) Key: Answer: e

7. Ocean sea surface temperature is sensed with

a. satellites using color sensors b. satellites using infrared sensors c. satellites using acoustic sensors d. none of the above

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Topic: Satellite sensors: Key: •  Color sensors: ocean chlorophyll or concentration of

phytoplankton (Chapter 6 slides) •  Infrared sensors: temperature (Chapter 7 slides) •  Acoustic sensors: Deep Ocean (sound travel further in

ocean) Answer: b

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8. Argo floats a. measure temperature b. move up and down in the ocean c. use Archimedes Principle d. all of the above e. none of the above

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Topic: Argo floats (Chapter 7 slides) Key: CTD; Concept of Buoyancy Answer: d

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9. Compute the salinity of a sample of water collected in the open ocean with a chlorinity value of 20 ppt. The answer is

a. 34 ppt b. 35 ppt c. 36 ppt d. 37 ppt e. 38 ppt

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Topic: Dittmar’ Principle (Chapter 6 slides) Key: s=1.8*cl Answer: c

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10. The Milankovitch cycles are caused by variations in a. the eccentricity of the earth’s orbit around the sun b. the precession of the earth’s axis of rotation c. the tilt of the earth’s axis of rotation d. all of the above e. none of the above Rui Zhu Winter 2015

Topic: Milankovitch cycle (Chapter 7 slides, Chapter 5 p74-76) Key: Answer: d

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11. The Keeling curve a. proves that atmospheric carbon

dioxide concentrations have never been greater than at present over the entire history of the earth

b. shows generally increasing concentrations of atmospheric carbon dioxide over approximately the past 50 years.

c. does not display seasonal variability d. none of the above

Topic: Keeling curve (Ch6 slides or Ch6 p.102-103 Figure 6-18) Key: Answer: b

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12. One volcano’s active lava flow appears yellow whereas another appears red. Which has the hotter lava? a. red lava volcano b. yellow lava volcano c. both would have the same temperature

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Topic: Wien's Law (Ch7 p.126-127, Ch7 slides; lab2) Key: Answer: b

λ = 2890 /T

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13. Which of the following is true? a. Tree rings from mid-latitudes and deep ice cores from polar regions can be used to study climate change. b. The molecule with the greatest concentration in the atmosphere is oxygen. c. The albedo of polar regions is decreasing at the present time. d. a. and b. e. a. and c.

Topic: A comprehensive question (property of atmosphere and albedo) Key: (a). common knowledge not covered in the lecture. (b). 78.1% N2 (nitrogen) (Chapter 8 Figure 8.1 ) (c). global warming, ice melting, but ice has a high albedo value. So the albedo of polar region is decreasing Answer: e

14. Milutin Milankovitch’s climate theory a. helps to explain why the earth experiences periodic glacial and interglacial climatic conditions b. was developed while he was in prison c. argues that earth’s exposure to solar radiation is affected by astronomical and earth orientation factors d. a. and c. only e. a., b. and c.

Topic:: Milankovitch cycle (same to Q10) (Chapter 7 slides, Chapter 5 p74-76) Key: Answer: e

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15. If the Mir Russian-Finnish submersible descended to 2000 m. Approximately what pressure did it have to withstand?

a. 20 atmospheres b. 200 atmospheres c. 20,000 atmospheres d. 200,000 atmospheres e. none of the above

Topic: Pressure in ocean (Chapter 7 slide) Key: 10 meters =1 atmosphere Answer: b

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16. Which is a requirement for hurricane formation in the northern hemisphere? a. sea surface temperatures of about 80 deg F b. a disturbance with counterclockwise rotation c. minimal shear winds at the tropopause d. all of the above

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Topic: Formation of hurricane (Chapter 8 slides, Chapter 8 p.154) Key: Answer: d

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17. Which of the following is a major (macro) nutrient for phytoplankton a. nitrate b. aluminum c. chromium d. tritium e. helium

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Topic: Nutrient for phytoplankton (Chapter 6 p.99 and Chapter 6 slides) Key: Macronutrients: •  Nitrate •  Phosphate Micronutrients: •  Silicate •  Iron Answer: a

18. The atmospheric circulation around southern hemisphere low pressure center is: a. counterclockwise b. clockwise c. both a and b are correct d. neither a nor b are correct

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Topic: Atmosphere circulation (Coriolis effect) (Chapter 8 p.148 and Chapter 8 slides) Key: Answer: b

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19. In the wake of a hurricane, you may observe: a. a wake bloom of phytoplankton b. a cool temperature wake c. a warm temperature wake d. a. and b. e. none of the above

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Topic: The effect of hurricane Key: •  phytoplankton (nutrient to the surface); •  temperature (the formation of hurricane

needs heat; cold water to the surface); •  high current speed Answer: d

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20. The polar jet stream: a. can reach speeds of 200 mile per hour b. often lies between cold air north of it and warm air south of it c. moves north and south as a very long wave d. all of the above e.  none of the above Note: we changed the sentence in b, originally, it was “often lies between warm air north of it and cold air south of it”, which is wrong!

Topic: Polar jet stream (Chapter 8 P146-151) Key: •  North: cold dry air masses South: warm moist air masses •  It circulates around the polar region, and could move north and south; •  Polar jet stream is a long wave!

Answer: d

21. Which of the following statements about the Challenger expedition is true? a. It used the first deep submersible to view life in the deep see. b. It was led by Captain James Cook. c. It used lead lines to measure ocean depths. d. All of the above e. None of the above Rui Zhu Winter 2015

Topic: Early oceanography (Chapter 6 slides) Key: (a). There is no submersible at that time (Ships) (b). Captain Cook: 18th century; HMS Challenger: 19th (c). in the slides

Answer: c

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22. Sea level rise can be caused by: a. ice melt on land b. thermal expansion c. melting sea ice d. a. and b. e. a. and c.

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Topic: Sea level rise Key: •  Ice melt on land à more water to the sea; •  thermal expansionà volume increase, then

level increase •  Melting sea ice will not increase the mass of

sea water thus no increase of the sea level. Answer: d

23. Ocean acidification is likely being primarily caused by a.  increasing ocean temperature b.  increasing phytoplankton concentrations c.  increasing input of carbon dioxide at the sea

surface d.  all of the above e.  none of the above

Topic: Ocean acidification (Chapter 6 p.102, Figure 6-16) Key: (a). Temperature è density (b). phytoplankton concentrationà absorb carbon dioxide (c). Carbon dioxide reacts with water to form carbonic acid, which increase the ocean’s acidification.

Answer: c Rui Zhu Winter 2015

24. Which of the following is true? a.  Water is about 800 times more dense than

air b.  Air is compressible c.  Seawater in the open ocean does not obey

Dittmar’s Principle d.  a. and b. e.  b. and c. Rui Zhu Winter 2015

Topic: Property of water and air. Key: Chapter 8 Figure 8.1 Answer: d

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25. Sea level is lower during : a.  interglacial periods than during glacial

periods b.  glacial periods than during interglacial

periods c.  Both d.  neither Rui Zhu Winter 2015

Topic: Sea level: Key: Is lower during glacial periods because water are frozen, which decreased the sea level. Answer: b

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What’s next (week 6): Lab 3. Ocean Circulation Please print your own lab manuals! Read your lab manual before class! Due of lab 2: next week! One hard copy per group; submit it at the beginning of class

Rui Zhu Winter 2015

Good Luck!