1. During a clear, calm day, the relative humidity would tend to _______ from sunrise to early afternoon?
a. Increase
b. Decrease
c. Remain constant
d. It is impossible to determine
answer: b
2. In which of the following situations is the amount of water vapor in the atmosphere the highest?
a. When the relative humidity is 50 percent
b. When the relative humidity is 70 percent
c. When the relative humidity is 90 percent
d. We cannot tell without knowing the temperature in each situation
e. The amount of water vapor in the atmosphere is the same for all of these situations
answer: d
3. Adiabatic temperature changes occur as a result of:
a. The addition or removal of heat energy to an air parcel from the surrounding atmosphere
b. Changes in the humidity of the air parcel with the surrounding atmosphere
c. A rising parcel of air cooling through expansion or a sinking parcel warming through compression
d. Heating from the surface of the Earth
answer: c
4. What kind of weather conditions prevail when a large difference exists between the dry- and wet-bulb temperature readings?
a. Dry
b. Hot
c. Cold
d. Humid
e. Only b and d
answer: e
1. To determine the answer to this question, we need to understand the relationship between temperature and relative humidity. Relative humidity is a measure of the amount of moisture in the air compared to the maximum amount of moisture the air can hold at a given temperature.
During a clear, calm day, the temperature tends to increase from sunrise to early afternoon due to the heating effect of the sun. As the temperature increases, the air has the capacity to hold more moisture, which means the maximum amount of moisture the air can hold also increases.
However, the actual amount of moisture in the air remains relatively constant because there is no significant new source of moisture introduced. This means that the relative humidity decreases as the temperature increases. So, during a clear, calm day, the relative humidity would tend to decrease from sunrise to early afternoon.
Therefore, the correct answer is b) Decrease.
2. In order to determine the answer to this question, we need to consider that the amount of water vapor the atmosphere can hold depends on the temperature. This is because warm air can hold more moisture than cold air.
The relative humidity is a measure of the amount of moisture present in the air compared to the maximum amount it can hold at a given temperature. It is expressed as a percentage.
Therefore, when given the relative humidity alone, we cannot determine if the amount of water vapor in the atmosphere is the highest. We also need to know the temperature in each situation.
So, the correct answer is d) We cannot tell without knowing the temperature in each situation.
3. Adiabatic temperature changes occur as a result of the rising or sinking of air parcels in the atmosphere. These changes are not due to the addition or removal of heat energy from surrounding sources.
When an air parcel rises, it expands due to the decrease in atmospheric pressure. As the air parcel expands, it does work on the surrounding air molecules, and this work leads to a decrease in the kinetic energy of the air molecules.
Since temperature is a measure of the average kinetic energy of the air molecules, this decrease in kinetic energy results in a decrease in temperature. This is known as adiabatic cooling.
Conversely, when an air parcel sinks, it is compressed due to the increase in atmospheric pressure. As the air parcel is compressed, the work done on it leads to an increase in the kinetic energy and, consequently, an increase in temperature. This is known as adiabatic warming.
Therefore, the correct answer is c) A rising parcel of air cooling through expansion or a sinking parcel warming through compression.
4. The difference between the dry-bulb temperature and the wet-bulb temperature readings is used to determine the relative humidity. The dry-bulb temperature is the measure of the temperature of the air, while the wet-bulb temperature is measured by passing air over a wet surface and measuring the cooling effect.
When there is a large difference between the dry-bulb and wet-bulb temperature readings, it indicates that the air is drier. This is because the wet-bulb temperature is influenced by the evaporation of water, and evaporation is greater when the air is drier.
In such conditions, the air is less humid, and this can lead to dry weather conditions. So, the correct answer is e) Only b) hot and d) Humid.