## Assignment 5

### Chapter 4

• QT6: On a clear, calm morning, water condenses on the ground in a thick layer of dew. As the water slowly evaporates into the air, you measure a slow increase in dew point. Explain why.
• PE1: On a bitter cold, snowy morning, the air temperature and dew point of the outside air are -7oC. If this air is brought indoors and warmed to 21oC, with no change in vapor content, what is the relative humidity of the air inside the home? (Hint: See Table 1, p. 98 and the formula on the same page.)
• PE2: (a) With the aid of Fig. 4.13b, p. 94, determine the average July dew points in St. Louis, MO; New Orleans, LA; and Los Angeles, CA. (b) If the high temperature on a particular summer day in all three cities is 32oC (90oF), then calculate the afternoon relative humidity at each of the three cities. (Hint: Either Fig. 4.10, p. 91 or Table 1, p. 98, will be helpful.)

### Chapter 5

• QT2: Explain why icebergs are frequently surrounded by fog.
• QT4: While driving from cold air (well below freezing) into much warmer air (well above freezing), frost forms on the windshield of the car. Does the frost form on the inside or outside of the windshield? How can the frost form when the air is so warm?
• QT10: Near the shore of an extremely large lake, explain why steam fog is more likely to form during the autumn and advection fog in early spring.
• PE1: The data in the chart below represent the dew-point temperature and expected minimum temperature near the ground for various clear winter mornings in a southeastern city. Assume that the dew point remains constant throughout the night. Answer the following questions about the data. (a) On which morning would there be the greatest likelihood of observing visible frost? Explain why. (b) On which morning would frozen dew most likely form? Explain why. (c) On which morning would there be black frost with no sign of visible frost, dew, or frozen dew? Explain. (d) On which morning would you probably only observe dew on the ground? Explain why.
Morning 1Morning 2Morning 3Morning 4Morning 5
Dew-point temperature2oC (35oF)-7oC (20oF)1oC (34oF)-4oC (25oF)3oC (38oF)
Expected minimum temperature4oC (40oF)-3oC (27oF)0oC (32oF)-4.5oC (24oF)2oC (35oF)