Unformatted text preview: Note this is an old sample exam So bear that in mind There will likely be fewer written questions Solutions will be posted separately YORK UNIVERSITY FACULTY OF PURE AND APPLIED SCIENCE Department of Earth and Atmospheric Science EATS 1010.06/EATS1011.3 Introductory Earth and Atmospheric Science
Atmosphere Section: Final Examination Supplemental Exam, 2000 3:00 hours The material that you will need for the calculations is listed among the quantities given below and on the following page. There are three (3) sections. Attempt all the questions in section A which are worth approximately 80%. Attempt four (4) questions only, made up of two in each of Section B and C for a total of 20%. Permitted Aids: A calculator and a standard dictionary. Answer the questions in Part A on the SCANTRON answer sheet provided using a soft pencil. Black or blue ball point pen will not be read properly. Write your answers to Part B and Part C in the Examination Book. Be sure that your name and student number appears on the SCANTRON answer sheet, and on rst page of the Examination Book. Useful quantities that you may need. Surface area of a sphere of radius r = 4 r2 . Circumference of circle of radius r = 2 r. 4 Volume, V, of a sphere of radius r: V = 3 r3 8 km. 1 AU = 1.50 10 Speed of light = 3.0 108 m/s. Density of air at sea level, air = 1.2 kg m;3 . The Coriolis parameter, f = 2 sin(latitude) The Coriolis parameter, f = 1.0 10;4 s;1 at 43.5 degrees latitude. The rotation rate of the Earth, = 7.27 10;5 s;1 . 10 latitude = 110 km. Dew point lapse rate = 20 C/km Cloud height, H = (Tsurface - Tdewpoint)/8 km Dry adiabatic lapse rate = g/cP (= 100 C /km for the Earth). Saturated adiabatic lapse rate = 60 C /km. Solar Constant, E , = 1.38 103 W m;2 s;1 . Stefan-Boltzman constant, = 5.67 10;8 W m;2 s;1 K;4 . 2 The e ective temperature, Teff = ((1 ; A)E =(4 Rp)1=4 where Rp is the Sun-planet distance in A.U. Universal gas constant R = 8:3143 103 J deg;1 kmol;1 Molecular weight of CO2 = 44, N2 = 28, CH4 = 16, CO = 28, H2 = 2.016 p = RT Density of liquid H2 O: H2 O , = 1.0 103 kg/m3 Wien's Law max T = 2.9 103 m deg Mean acceleration due to gravity on the Earth: gEarth = 9.8 m s;2 Mean acceleration due to gravity on Mars: gMars = 3.7 m s;2 Mean acceleration due to gravity on Jupiter: gJupiter = 26 m s;2 Mean acceleration due to gravity on Saturn: gSaturn = 9 m s;2 Mean radius of Earth = 6370 km The Hydrostatic Law: p(z ) = p(0) exp(;z=H ) The scale height, H = RT/g Degrees Kelvin = degrees C + 273 1 year = 3.16 107 s. 1 mb = 100 Pascals The geostrophic wind, Vg = 1f P n Mass of atmosphere = 5:1 109 MT speci c heat at constant pressure for air, cp = 1,007 J/K/kg speci c heat at constant volume for air, cv = 717 J/K/k Speci c heat of H2 , cp (H2 ) = 1.43 104 J/kg/K. Latent heat of evaporation, Lv = 2.6 106 J/kg R = R =m RP is the average distance from the sun to the planet. YP is the period of orbital motion around the sun. Planet RP (AU) YP (years) Earth 1.0 1.0 Mars 1.52 1.88 Jupiter 5.2 11.9 Saturn 9.5 29.6 Uranus 19.1 84.1 Pluto 39.3 248. Temperature
0 T( C) 30 20 10 0 Saturation Vapour Pressure (mb) over water over ice 42.43 23.37 12.27 6.11 6.11 Answer all the questions in this section on the SCANTRON sheet provided. Section A 1. How old is the earth thought to be? (a) 4.5 105 centuries. (b) 2.34 1011 weeks (c) One billion years. (d) 1.6 1010 days. (e) 4.5 106 years. 2. The air surface temperature is 300 C. If a dry parcel of air is lifted from the surface to a height of 3 km without any loss of heat, what will its temperature be? (a) 25 0 C (b) 20 0 (c) 30 0 C (d) 0 0 C (e) 10 0 C 3. Assume that the average depth of CO2 in rocks is about 1.0 km. If all this CO2 were in the atmosphere at one time, approximately how many times greater would the atmospheric pressure be than that of the current atmosphere? Assume that the density of the CO2 in the rock is about 4,000 kg/m3 . (a) about 39 times more. (b) about 390 times more. (c) about 4 times more. (d) about 4000 times more (e) roughly the same. 4. What is the rst most abundant gas in the Earth's atmosphere today? (a) N2 . (b) Ar. (c) CO2 . (d) O2 . (e) He. 5. What is the coolest region of the Sun? (a) Chromosphere. (b) Troposphere (c) Photosphere. (d) Corona. (e) Convective region. 6. What is the temperature of the Corona? (a) 10,000,000 K. (b) 400 K. (c) 6,000 K. (d) 1,000,000 K (e) 4,000 K. continued.... 1 7. Aphelion occurs (a) occurs at solstice. (b) is when the Earth is closest to the Sun. (c) is when the Earth is farthest from the Sun. (d) is the layer of the atmosphere closest to the Sun. (e) occurs at equinox. 8. Using our simple model, what would the e ective temperature of the Earth be if its albedo were 0.8? (a) 20K. (b) 186 K. (c) 367 K. (d) 255 K. (e) 264 K. 9. At 20 C an air parcel is saturated with water vapour. If the air parcel is heated 30 C with no addition or removal of water vapour, then the dew point is given by (a) 13 C. (b) 18 C (c) 20 C . (d) 30 C. (e) there is no enough information to evaluate the dew point. 10. The layer of the atmosphere above the tropopause is called the (a) Thermosphere. (b) Stratosphere. (c) Troposphere. (d) Mesosphere. (e) Ionosphere. 11. Inside your house the relative humidity is about 80% and the water vapour pressure is about 34 mb. What is the approximate air temperature in your house? (a) 25o C (b) 15o C (c) 20o C (d) -5o C (e) 30o C 12. Triton, a moon of Neptune, has an e ective temperature of 34 K. At which wavelength does the energy spectrum peak? (a) 11. m. (b) 5.0 m. (c) 10 A. (d) 8.5 m. (e) 0.085 mm. 13. In the three cell model of the general circulation of the atmosphere, the prevailing surface winds in the SH tropics are (a) southwesterly continued.... 2 (b) (c) (d) (e) southeasterly northwesterly northeasterly strong and variable 14. Albedo is (a) the fraction of total radiation absorbed by a surface. (b) the fraction of total radiation re ected by a surface. (c) amount of energy given o and described by Wiens law. (d) the radio part of the spectrum. (e) (a) and (d) are correct. 15. What are the balance of forces that apply for the geostrophic wind approximation? (a) The pressure gradient force and the centrifugal force. (b) The pressure gradient force and gravity. (c) The centrifugal force, the centripetal force and the pressure gradient force. (d) The Coriolis force and the pressure gradient force. (e) The pressure gradient and the Hadley thermal forces. 16. Which one of the following may be used to describe atmospheric pressure at a certain level? The pressure is (a) the mass of air above that level. (b) the product of the mass of air above that level times gravity. (c) given by the solution of the Stefan-Boltzman equation. (d) P (z ) = P (0) ez=H where z is the height and H is the scale height. (e) the product of the density times the gas constant divided by the temperature in degrees Kelvin. 17. In middle latitudes, which cloud will have the highest base? (a) cumulonimbus (b) cumulus (c) altostratus (d) cirrostratus (e) stratus 18. What type of cloud would most likely form in absolutely stable air? (a) Cumulonimbus. (b) altocumulus (c) cumulus congestus (d) stratus (e) fair weather cumulus 19. What does the nimbus in cumulonimbus refer to? (a) The fact that they are clouds of vertical extent. (b) The fact that rain is falling from these clouds. (c) Nimbus is the term given to denote extensive layering of clouds. (d) The fact that they are only associated with anticylonic (high) pressure systems. (e) Nimbus refers to the fact that the top of these clouds are glaciated. continued.... 3 Figure 1. Isobars at 430N.
20. How would you describe the direction of the geostrophic wind that you would estimate from Figure 1? (a) Westerly. (b) Westward. (c) Northerly. (d) Easterly. (e) Both (b) and (d) are true. 21. In Figure 1 what is the direction of the pressure gradient force? (a) vertical. (b) To the East. (c) To the South. (d) To the North. (e) To the west. 22. Estimate the speed of the geostrophic wind at location A for the data given in Figure 1? Use the Coriolis parameter given in the front of the exam paper. You will have to roughly estimate the density at these pressure levels. Which of the following values below is closest to the correct estimate? (a) 61 m s;1 . (b) 25 m s;1 . (c) 36 m s;1 . (d) 83 m s;1 . (e) 50 m s;1 . 23. Would you expect the geostrophic wind to be greater at B than at C? (a) No, because the isobars are closer together. (b) Yes, because B is further from the equator. (c) Yes, because the isobars are closer together. (d) No, because it is near the subtropic where there are deserts. (e) Yes, because we are in the roaring forties. 24. In the thermal circulation (a) the surface wind is from the cold air to the warm. (b) the surface hi-pressure region is warm (c) the wind aloft is from cold to warm regions. (d) it rains over the cold region. (e) all of the above are true. continued.... 4 25. Assume that on Mars the scale height = 10 km and that the pressure at the edge of the Valles Marineres, which is a ca~on about 10 km deep, is 0.6 kPa. What is the pressure n at the bottom of the ca~on? n (a) 1.63 kPa (b) 1.63 101 kPa (c) 22.0 102 kPa (d) 0.22 103 kPa (e) 100 104 kPa 26. The sky is blue (a) because the air molecules scatter blue light more than red light. (b) because ozone absorbs the yellow light. (c) because our retinas are not sensitive to IR light. (d) because aerosols absorb out red light leaving the blue radiation. (e) because CH4 abosrbs out the red light, just as on Uranus. 27. In a hurricane (a) the winds are most intense at the centre or core. (b) the rotation direction is opposite to that of a wave cyclone. (c) the Ferrel cell is reversed. (d) there is descent of air in the core. (e) all of the above are correct. 28. In which regions do hurricanes form? (a) They form where cold ocean currents merge with warm ocean currents. (b) Everywhere in the tropics. (c) Where the ocean temperature is above about 270 C. (d) Only near the coasts in subtropical regions. (e) Over the mid-western plains of the US where cold westerly air pushes under warm humid air from the Gulf of Mexico. 29. The ozone layer is found principally (a) between 15 and 50 km. (b) in the ocean. (c) thermosphere (d) troposphere. (e) (a) and (c) are correct. 30. The intertropical convergence zone (ITCZ) is a region where the (a) polar front meets the subtropical high. (b) northeast trades meet the southeast trades. (c) northeast trades converge with the subtropical high. (d) the Ferrel cell converges with the Hadley cell. (e) polar easterlies converges with the air at the doldrums. continued.... 5 Figure 2. The variation of temperature with height. 31. Figure 2 shows the variation of temperature with height on Jupiter. Assume that the moist adiabatic lapse rate is half that of the dry adiabatic and calculate the Environmental Lapse Rate and the dry adiabatic lapse rate for H2 , the main gas, to evaluate whether the air is likely to be (a) absolutely stable. (b) conditionally stable. (c) absolutely unstable. (d) neutrally stable. (e) none of the above. 32. Which of the following statements regarding the Earth's thermal balance is not true? (a) The greenhouse e ect is a natural phenomenon. (b) Clouds re ect solar radiation and so are important in the Earth's thermal balance. (c) The main Infrared (IR) active (greenhouse) gases are H2 O and CO2 . (d) The Earth's surface receives more IR energy from the atmosphere that it absorbs from sunlight. (e) The Earth absorbs less radiation from the Sun per m2 than Venus. 33. In terms of the 3 cell general circulation of the atmosphere, the driest regions would be near (a) the equator and the polar regions. (b) the equator and 30 degrees latitude. (c) the equator and 60 degrees latitude. (d) 30 degrees and 60 degrees latitude. (e) 30 degrees and the polar regions. 34. Which of the following is true of di erences between midlatitude or wave cyclones (WC) and hurricanes (H). (a) WCs have an eye: Hs have no eye at their centre. (b) WCs generally have weaker winds than Hs. (c) WCs are low pressure systems: Hs are high pressure systems. (d) WCs are formed by latent heat release: H form in the sub-tropics near cold and warm ocean currents (e) WCs are generally smaller weather systems than Hs. continued.... 6 35. The Gulf stream is (a) the name given to Norwegian shepherding. (b) where meteorologists take their clubs. (c) the name of a warm and narrow ocean current that goes along the east coast of north America carrying energy northwards. (d) describes the stream of warm air that form the jet stream. (e) is the name given to ground level convergence caused by friction in a surface circular low pressure system. 36. How long does it take light to travel from the Sun to Uranus? (a) 2 years 4 months. (b) 8 minutes. (c) 2 hours and 39 minutes. (d) 4 hours and 11 minutes. (e) 3.5 days. 37. What phenomenon is the main cause of loss of life that often occurs with the passage of a hurricane? (a) High winds inside the eye. (b) The latent heat release causes serious con agration. (c) Torrential rains in the eye of the hurricane. (d) Macrobursts, lightning and heavy hail. (e) Storm surge associated with the low pressure and wind driven seas. 38. Which of the following statements is true concerning hurricanes? (a) The wind is most intense within the wall of clouds surrounding the eye of the hurricane. (b) Hurricanes form in regions of warm ocean with the temperature above about 27 C. (c) The minimum wind speed is about 120 km/hr. (d) The sky is often clear within the eye. (e) all of the above. 39. In the southern hemisphere, if you face in the direction the wind is blowing the high pressure region is (a) behind you. (b) straight ahead. (c) to your right. (d) to your left. (e) to my left. 40. Given the Earth's climate history over the last 2 million years in the next 50,000 years we may be headed for (a) Jupiter. (b) an ice age. (c) a super-rotating Earth. (d) increased solar radiation. (e) more volcanic eruptions. continued.... 7 41. The Malenkovitch E ect describes (a) the sound when the orchestra tunes to the oboe. (b) the movement of the Earth's continents. (c) the intensi cation of a surface low. (d) the scale used to describe the intensity of Tornadoes. (e) the variation of insolation at the surface due to the Earth's orbital parameters changing. 42. Reduced column ozone in the atmosphere results in the increase of UV radiation of wavelength of about 300 nm at the ground. This results (a) an increased incidence of skin cancer unless social mores change. (b) possible deleterious e ects on crops. (c) possible modi cation of sh populations. (d) increased incidence of cataracts. (a) All of the above. 43. A planet's rotation axis is tilted by about 40 degrees with respect to the normal to the orbital plane (ie its obliquity is 40 degrees). Which one of the following is not true. (NB. Summer and winter are de ned wrt the northern hemisphere!) (a) All regions southward of 50 degrees S at winter solstice will experience 24 hours of sunlight. (b) There is 12 hours of daylight everywhere at vernal equinox. (c) All regions northward of 50 degrees N at winter solstice will experience 24 hours of sunshine. (d) The Sun is overhead at noon at the equator at winter solstice. (e) The solar zenith angle at noon at equinox at 70 N is 70 degrees. 44. Severe thunderstorms are di erent from air-mass thunderstorms in that they (a) contain thunder and lightning. (b) have an anvil. (c) contain hail. (d) have a strong updraft and downdraft. (e) have a tilted updraft in the mature stage. 45. What approximately is the scale height of the atmosphere of Saturn if it is all H2 and the temperature is 700 K? (a) 5 km (b) 11 km (c) 16 km (d) 25 km (e) 32 km 46. Over the last 100 years or so there has been 0.5 degree C warming of the average global temperature. It (a) would be larger except for the cooling impact of sulphate aerosols. (b) has an important contribution from the increase in CO2 in the atmosphere due to burning of fossil fuels. (c) appears to be outside the range of natural climatic variability of the Earth ocean climate system. continued.... 8 (d) has an important contribution due to increased water vapour in the atmosphere due the warmer temperatures. (e) all of the above are correct. 47. Clouds are important component of the greenhouse blanket because (a) they cool the Earth by re ecting solar radiation. (b) they may be a ected by sulphate aerosols acting as CCN. (c) they trap IR radiation from the surface. (d) (a), (b) and (c) are all correct. (e) None of the above are correct. 48. The climate at latitudes near 30 degrees is usually (a) warm and dry. (b) warm and moist. (c) cool and moist. (d) cool and dry. (e) hot and humid all the time. 49. What is the e ect of friction on the geostrophic wind? (a) To cause the wind to blow across the isobars from low pressure to high pressure. (b) To cause the wind to speed up. (c) To result in surface convergence for a circular low pressure system. (d) There is a modi cation of the pressure gradient force. (e) All of the above are correct. 50. On what day would you expect the Sun to be overhead at Lima, Peru (120 S)? (a) August 15 (b) December 22 (c) February 4 (d) March 20 (e) April 21 continued.... 9 51. UV radiation is important in the atmosphere. Which of the following statements is not true? (a) Stratospheric ozone is produced by wavelengths 200 nm. (b) Only light of wavelengths > 300 nm penetrate to the troposphere. (c) some UV radiation penetrates to the troposphere and is associated with nonmelanomic and melanomic skin cancer (d) shorter UV radiation is absorbed in the stratosphere and does not penetrate to the troposphere. (e) 800 nm is the longest wavelength for UV radiation. 52. ENSO (a) (b) (c) (d) (e) is an example of the thermal circulation. is the El-Ni~o southern oscillation. n is the Walker circulation and movement of the E-W ocean current. occurs when the upwelling ocean current o Peru is cut o . all of the above. 53. If the average snowfall over an area of Canada is about 100 cm/year, how long would it take for the snow to reach a depth of 3 kms, assuming that here is no melting (a) 3000 years (b) 2 years (c) 50 years (d) 500 years (e) 20,000 years 54. The higher the ratio of oxygen 18 to oxygen 16 in the shells of organisms that lived in the sea during the geological past, the the climate at that time (a) colder (b) warmer (c) drier (d) wetter (e) all of the above. 55. A high ratio of oxygen 16 to oxygen 18 found in the ice cores of Antarctica and Greenland would indicate that at the time the snow was laid down (a) and increase in sunspot activity (b) that nuclear reactions had occurred (c) the ice cores were contaminated during drilling (d) the ocean and air temperatures were colder (e) the ocean and air temperatures were warmer 56. The last interglacial occurred about (a) 18,000 years ago (b) 120,000 years (c) 11,000 years ago (d) 1,000 years ago (e) 1,000,000 years ago continued.... 10 57. During the last glacial maximum the current location of Toronto (a) was ice free (b) was under 100 m of snow (c) was under almost 3 km of ice (d) was part of the Boreal forest (e) part of the Atlantic ocean 58. The viking colony in Greenland perished during (a) the Little Ice Age (b) the last glacial maximum (c) the last interglacial (d) the Cretacious period (e) the Younger Dryas event. 59. Which of the following set of surface conditions would produce a convective cumulus cloud with the highest base? (a) air temperature 400 C, dew point 300 C (b) air temperature 250 C, dew point 100 C (c) air temperature 350 C, dew point 100 C (d) air temperature 450 C, dew point 250 C (e) air temperature 350 C, dew point 50 C 60. Tornadoes. Which one of the following statements describes some fact about a tornado? (a) They are associated with severe thundertorms and hurricanes. (b) A tornado is a large scale phenomenon 100 km wide. (c) The Coriolis force plays an important role in the force balance. (d) A tornado is a vertical microburst of air. (e) Winds are relatively weak, less than 50 km/hour. 61. The main source of stratospheric chlorine in the last 30 years (a) is from volcanoes. (b) is from chlorine released from water treatment plants. (c) is from the bleach used for diapers. (d) is from NaCl in the ocean. (e) is due to the release of Freon gases from refridgeration systems and foam blowing systems. 62. A storm surge is (a) the leading edge of a thunderstorm. (b) the initial gust that preceds the formation of a tornado. (c) the upper level low that remains over a hurricane during its formation. (d) a rise in the ocean of several metres or more associated with a hurricane low pressure and wave. (e) the line of cumulonibus clouds ahead of a cloud front stimulated by gravity wave propagation from the front. 63. If an air parcel is given a small push upward and it falls back to its original level, the atmosphere is said to be (a) adiabatic continued.... 11 (b) (c) (d) (e) unstable stable isothermal neutral 64. Which of the following is not true regarding changes of gases in the atmosphere? (a) CO2 is decreasing. (b) N2 O is increasing. (c) Northern hemisphere tropospheric ozone is increasing. (d) Stratospheric ozone is decreasing globally. (e) CH4 is increasing. 65. When an upper-level high lies directly above a surface low (a) the surface low will probably weaken. (b) thunderstorms will develop. (c) a hurricane will begin to form. (d) the surface low will probably intensify. (e) tornadoes will occur. 66. Although the polar regions radiate away more heat energy than they receive by insolation in the course of a year, they are prevented from becoming progressively colder each year by the (a) conduction of heat through the interior of the Earth. (b) absorption of heat by snow and ice surfaces. (c) circulation of heat by the atmosphere and oceans. (d) storage of heat in the soil beneath the snow cover. (e) release of latent heat to the atmosphere when the polar ice melts. 67. The sun emits its greatest intensity of radiation in (a) the radio wave portion of the spectrum (b) the infrared portion of the spectrum (c) the visible portion of the spectrum (d) the ultraviolet portion of the spectrum (e) the x-ray portion of the spectrum 68. The Northern Hemisphere Ferrel cell (a) is responsible for the NE trade winds in the tropics (b) is responsible for the surface westerlies in midlatitudes (c) is associated with the Intertropical convergence zone (d) generates an electric eld that causes lightning (e) both (a) and (c) continued.... 12 Attempt question 1 and one other in the book provided. 1. Suppose the sun were to change its wavelength of maximum emission from green (0:5 m) to violet (0:4 m). (a) Show that the \new" surface temperature of the Sun would be 5/4 of the former value? (b) Assuming that the radius of the sun does not change, and the Earth's orbit does not change, show that the \new" value of the solar constant be (5/4)4 times the former value? (c) Calculate the ratio of the new and old Teff for the Earth corresponding to the present and \new" values of the solar constant, assuming that the Earth's albedo does not change. (d) Is it reasonable to assume that the Earth's albedo would not change under such circumstances? (Give a reason.) 2. Show that the mass of air above 1 m2 is about 104 kg. Now, if the full solar constant was used to heat this air with no loss at constant pressure, how long would it take to raise the temperature by 30 C? Section B 3. (a) Compare the Latent heat energy release (in W m;2 ) due to 30 cm of rain falling in 24 hours, with the solar constant. (b) How long would it take to heat a room 10x10x3 m3 by 5 C with a 200 Watt light bulb if the room were completely sealed? (Hint: use cv ) Answer two questions in the note book provided. 1. With the aid of diagrams, identify and describe the development of a wave cyclone at mid-latitudes and indicate the clouds and precipitation one would see in winter as (a) a warm front approaches and moves through your area. (b) a cold front approaches and moves through your area. (Hint: Present your answer as a vertical cross-section through the frontal regions.) Section C 2. Discuss brie y the main features of the General Circulation. Mention the main physical mechanisms responsible for the wind patterns. You should have a diagram. Refer to desert formation, Hadley cell, trade winds, westerlies, ITCZ, jet stream location, Coriolis force, the role of the thermal circulation, etc. 3. Describe brie y the life cycle of a hurricane. Include typical wind speeds encountered, location, spiral rain bands, eye, wall clouds, upper level cirrus, latent heat, magnitude of pressure drop, the sequence of events as a hurricane passes overhead, storm surges. THE END 13 ...
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This note was uploaded on 06/05/2010 for the course EATS 1011 taught by Professor Johnm during the Winter '10 term at York University.
- Winter '10