(a) Deflection to the left, slower velocity means greater deflection, greatest deflection at the south pole

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1 1 Test 2 Aid Sheet Exam: A single 8.5 by 11 inch aid sheet (both sides) and Type 2 nonprogrammable calculators are permitted. The time allowed for this Test (Part A plus Part B combined) is 90 minutes. Answers are to be written on the answer sheet given NOT on this question sheet. ENV346 students take Part A ONLY. PART A 1. The three rules of the Coriolis force in the southern hemisphere are: (a) Deflection to the left, slower velocity means greater deflection, greatest deflection at the south pole (b) Deflection to the left, higher velocity means greater deflection, greatest deflection at the equator (c) Deflection to the left, higher velocity means greater deflection, greatest deflection at the south pole (d) Deflection to the right, higher velocity means greater deflection, greatest deflection at the South Pole 2. What is the primary cause of the formation of the Hadley cell? (a) Warm, moist air (b) Instability (c) The neighboring Ferrel cell (d) High intensity solar radiation over the equatorial region 3. A Chinook weather pattern is in place in southern Alberta, with the wind blowing from west to east across the Rocky Mountains. Clouds over the mountains can be seen from a small town, which is to the east of the mountains. The cloud base is at an altitude of 4,000 m and at a temperature of -10 o C. What will be the relative humidity in the small town if it is at an altitude of 2,000 m, once that air descends and reaches the town? (a) 23% (b) 100% (c) 40% (d) 44% 4. If the air at 1,000 m is 28 o C dry bulb temperature and at 4,000 m is saturated and at -5 o C wet bulb temperature, calculate the environmental lapse rate. (a) 11 o C per 1,000 m (b) 9.8 o C per 1,000 m (c) 6 o C per 1,000 m (d) 7.5 o C per 1,000 m

2 2 5. Which combination of forces is required for anticyclonic wind to flow around a centre of high pressure in the northern hemisphere at ground level? (a) Equal pressure gradient force, Coriolis force and frictional force (b) Greater Coriolis force than pressure gradient force plus frictional force (c) Frictional force plus Coriolis force less than the pressure gradient force (d) Greater pressure gradient force than Coriolis force only 6. In an unstable atmosphere, warm air rises up from a dry lake bed that is situated 1,500 m above sea level. If the dry bulb temperature at the lake bed level is 25 o C with 50% relative humidity, at what altitude will clouds form? (a) 800 m (b) 2,300 m (c) 3,333 m (d) 2,600 m 7. Which of the following is NOT a requirement for the development of a hurricane? (a) Sea water > 26.5 o C (b) The Coriolis effect (c) Light upper level winds (d) Winds at mid-level to introduce a turning motion into the storm 8. Calculate the specific gas constant for the atmosphere on a newly discovered planet that consists of 40% N 2 (molar mass of 28 gmol -1 ), 40% CO 2 (molar mass of 44 gmol -1 ), 10% O 2 (molar mass of 32 gmol -1 ) and 10% water vapour H 2 O (molar mass of 18 gmol -1 ). R, the universal gas constant = Jmol -1 K -1. (a) Jkg -1 K -1 (b) 246 Jkg -1 K -1 c) 33.8 Jkg -1 K -1 (d) 3,380 Jkg -1 K At all equal levels below the sea s surface: (a) The salinity is the same (b) The temperature is the same (c) The temperature AND salinity are the same (d) The density is the same 10. If water was collected into a 1 litre (0.001 m 3 ) volume container from the bottom of the ocean at a depth of 9,000 m then brought to the surface, what will the resulting volume of the water be at the surface? The bulk modulus of sea water = 2.34x10 9 Pa. The density of sea water = 1,020 kgm -3. (a) 1 litre (b) litres (c) litres (d) 1.02 litres

3 3 11. In an air mass that is conditionally stable, which of the following statements is correct? (a) The air is unstable below the dew point (b) The air will always hit the dew point (c) The air s stability is dependent on whether it is saturated or not (d) The environmental lapse rate is always greater than the dry adiabatic lapse rate 12. The vapour pressure in an air mass is 45 mb. The air mass has a relative humidity of 65%. Calculate the saturated vapour pressure for the air mass. (b) 69.2 mb (b) mb c) 100 mb (d) Cannot be calculated without knowing the air s dry bulb temperature 13. Water boils at 100 o C because: (a) Its latent heat of vapourisation is 2.26x10 6 Jkg -1 (b) At that temperature the vapour pressure above the water = atmospheric pressure at sea level (c) Water can be considered incompressible (d) Air is dissolved inside it 14. A downdraft wind is a phenomenon related to a thunderstorm. The downdraft is caused by: (a) High pressure air forming high up in the cloud resulting in a pressure gradient force (b) Heavy rain entraining a flow of air (c) Air compressing and warming as it falls (d) Centrifugal forces

4 4 PART B 1. (a) An athlete can choose one of two days to train outdoors. It is after sunset, so the sun s energy is no longer a factor. (4 marks total) The first day has a temperature of 30 o C and a relative humidity of 30%. The other day has a temperature of 22 o C and a relative humidity of 80%. Which day is the best to train on? Explain you answer (2 marks) y the psych. Chart, the wet bulb temperature on the 30C day is lower than the 22C day/enthalpy content of the air is lower. This is a measure of the energy content in the air / how easy it is to sweat in order to stay cool, hence the hotter day being better to train on. (b) The athlete lives in a big city. Due to a smog problem caused by a temperature inversion, the athlete cannot train outside for the following five days. Why does the smog form? Use a diagram to illustrate your answer showing the temperature variation with altitude. (2 marks) ANS Smog forms when warm pollutants generated at ground level cannot rise up and escape into the upper atmosphere. This is because within the inversion the atmospheric temperature increases with altitude. Any air that warms and rises at the surface gets trapped below the inversion layer. Note to Class: the only line you need to be concerned with is the red one. 2. A sealed room at atmospheric pressure (101 kpa) has dimensions of 20 m x 30 m x 3 m and contains air with a relative humidity of 50% and a temperature of 21 o C. Someone then spills 10 litres of water onto the floor (which is waterproof). The water begins to evaporate. R SP for air = 286 Jkg -1 K -1. For this question, assume no energy is transferred either to or from the walls, floor or

5 5 ceiling. (6 marks total) (a) Find the initial moisture content of the air in kg of water per kg of dry air (1 mark) ANS From the psychrometric chart, m = kg per kg of dry air(+/ is OK). (b) Calculate the mass of air inside the room. (2 marks) ANS Mass = volume x density. Density = P/RspT = 101,000 / 286 x 294 = 1.20 kgm -3 mass = (20x30x3)x1.2 = 2,162 kg (c) What is the total mass of water in the air before the water is spilled? Recall the units of Moisture Content from the psychrometric chart). (2 marks) From part a), total air mass = 2,162 kg = m water + m dry air 2,162 = x + x, where x = the mass of dry air x = 2,145.8 kg m water = 2,162 2,145.8 = 16.2 kg (d) What is the final temperature of the room after evaporation takes place? (1 mark) From the chart, 14.5 o C 3. (a) Why does a very high speed linear jet stream wind form high up in the atmosphere at a latitude of around 60 N? Feel free to use a diagram to help with your answer. (2 marks) (b) Why does the air flow approximately clockwise (from west to east)? (1 mark) t that specific (high altitude) location, air masses of very different pressures are brought into close contact by the Ferrel and polar cells The resulting very high pressure gradient force generates very high wind speed speeds. The wind flows straight as at altitude the PGF equals the Coriolis force. Air flow west to east as the highest pressure is to the south. Air moves south to north but the Coriolis force deflects it to the right and results in geostrophic flow (clockwise).