Chapter 4 Worksheet 2 Meteorology Name: Circle the letter that corresponds to the correct answer 1) If the air temperature remains constant, evaporating water into the air will the dew point and the relative humidity. a) increase, decrease b) not change, increase c) decrease, increase d) decrease, decrease e) increase, increase 2) Relative humidity depends on the water vapor present in the air and the: a) altitude. b) dew point. c) latitude. d) air temperature. e) pressure. 3) The air in Great Falls, Montana has a temperature of 5 C and a relative humidity of 50%. On the same afternoon, the air in Palm Springs, California has a temperature of 25 C and a relative humidity of 50%. What can be said about the amount of vapor in the air at these two cities? a) Palm Springs will have a higher vapor content than Great Falls. b) Great Falls will have a higher vapor content than Palm Springs. c) Great Falls and Palm Springs will have the same vapor content. 4) Assume that the actual vapor content of the air remains constant over the course of a day. How does the relative humidity at 2:00 p.m. probably compare to the relative humidity at 5:00 a.m.? a) The relative humidity at 2:00 p.m. is higher. b) The relative humidity at 2:00 p.m. is lower. c) The relative humidity is the same at 2:00 p.m. as at 5:00 a.m. 5) Which of the following is a good explanation for why dew tends to form in the grass at night? a) Temperatures are coolest in the grass. b) The atmosphere cannot form clouds at night. c) Pressure is greatest then. d) More water vapor is present at night. 6) During a clear, relatively calm day, the relative humidity will tend to from sunrise to early afternoon. a) decrease b) remain nearly steady c) increase
7) As the temperature of air is reduced to its dew point, which of these is most likely to occur? a) freezing b) condensation c) melting d) supercooling e) evaporation 8) An instrument used to measure relative humidity is called a: a) hygrometer. b) hydrometer. c) humidimeter. d) aquimeter. 9) In order to have significant snowfall accumulation, dew points must generally be above: a) 0 F. b) 10 F. c) 10 F. d) 32 F. 10) When the dry and wet bulb temperatures measured by a psychrometer are equal, all but one of the following is true. Which one is false? a) A rise in temperature would cause condensation. b) The air is saturated. c) Water vapor content is at a maximum. d) Relative humidity is 100 percent. 11) A wet bulb thermometer and a dry bulb thermometer are both parts of which meteorological instrument? a) an anemometer b) a thermistor c) a sling psychrometer d) a barometer 12) During the process of adiabatic cooling, the temperature decreases because the air has: a) been compressed. b) lost heat to the colder air at higher altitudes. c) lost some of its water vapor. d) expanded to a larger volume. e) emitted infrared radiation. 13) The most important process of cloud formation in the atmosphere is: a) cooling by release of latent heat of vaporization. b) cooling by compression of air. c) radiation cooling. d) cooling by expansion of air.
14) The buoyancy of a rising air parcel is greatly affected by: a) heat released if water vapor condenses. b) absorption of solar radiation. c) air pressure. d) convergence of the parcel. e) wind speed. 15) The temperature of rising air parcels as they move upward. a) decreases b) increases c) remains constant d) may either increase or decrease 16) Adiabatic processes are only important for air: a) masses which remain near the earth's surface. b) that is saturated. c) that is polluted. d) that is stagnant. e) which is rising or sinking. 17) An adiabatic process is one in which the: a) temperature remains constant. b) altitude of the air parcel remains constant. c) heat exchanged with the surroundings is zero. d) pressure on the air parcel remains constant. e) work done is zero. 18) Why does a rising air parcel cool off? a) Its relative humidity is less than 100 percent. b) It loses heat to its surroundings. c) It loses energy by radiation. d) It expands. e) It is unstable. 19) The moist adiabatic rate is different from the dry adiabatic rate because: a) an unstable air parcel expands more rapidly. b) latent heat is released inside a parcel of rising saturated air. c) saturated air is always unstable. d) a parcel of saturated air weighs less than a parcel of unsaturated air. e) unsaturated air is always stable. 20) All of the following are lifting mechanisms in the atmosphere EXCEPT: a) Orographic b) Divergence c) Convection d) Frontal wedging
21) An air parcel rises over a mountain and cools adiabatically. Which lifting mechanism has acted on this parcel? a) orographic lifting b) convective lifting c) convergence d) frontal wedging 22) Which type of lifting mechanism results from warm air lifting over cold air? a) orographic lifting b) convective lifting c) convergence d) frontal wedging 23) A convergence of winds near the surface is associated with cloud production because it: a) increases the lapse rate. b) creates a vortex or spiral pattern. c) increases the wind speed. d) increases the dew point. e) forces the air to rise. Circle T if the statement is true or F if the statement is false T F 24) The saturation vapor pressure is independent of temperature. T F 25) The capacity of air to hold water vapor is temperature dependent T F 26) Relative humidity is "relative" to pressure. T F 27) Relative humidity levels are always higher in St. Louis, MO than Anchorage, AK. T F 28) Relative humidity gives a measurement of the amount of water in the air, and is usually measured in grams per cubic meter. T F 29) The absolute humidity of the air is expressed as a percent. T 30) An area that is very cold in winter will probably also have a relatively dry winter. T F 31) On a calm night, the relative humidity a few inches above grass is lower than it is a few feet above the grass. T F 32) Stability is measured using a sling psychrometer. Answer the following questions 33) The instrument consisting of a wet bulb thermometer and a dry bulb thermometer is termed a. 34) Why does the wet bulb thermometer of a psychrometer read less than the dry bulb?
35) What is the most frequent cause of the air becoming saturated? 36) Why is the wet adiabatic rate of cooling less that the dry adiabatic rate?