Sample questions for Exam 1

Multiple Choice Examples

1. What is the approximate value of barometric pressure we would expect to find at sea level (in millibars)?
   A. 10000
   B. 1000
   C. 100
   D. 10
   


2. What term do we use for the lowest layer of the atmosphere?
   A. thermosphere
   B. troposphere
   C. tropopause
   D. stratosphere
   


3. Smoke rises vertically from a campfire. What heat transfer process causes hot air to rise from the campfire, to be replaced by cooler air from the surroundings?
   A. convection
   B. condution
   C. advection
   D. radiation
   


4. What is the change of temperature with height called?
   A. temperature inversion
   B. temperature range
   C. lapse rate
   D. radiosonde
   


5. When air descends, what must happen to its relative humidity?
   A. increases
   B. decreases
   C. no change
   D. None of the above
   

1. Explain why we experience colder temperatures in the Northern Hemisphere in January, even though the Earth is closest to the sun at this time of year?


2. Describe the daily temperature cycle, with reference to the typical daily radiation budget, with the time of day that we would observe the maximum, minimum, and most quickly rising temperatures.


3. What is the meaning of the dew point temperature?

Answers

Multiple Choice
1. B
2. B
3. A
4. C
5. B

Short Answer
1. The Earth is in fact closer to the sun in January, but the Northern Hemisphere is tilted away from the sun at this time of year. This means that the Northern Hemisphere receives less direct radiation, leading to less heating.


2. When the sun rises, outgoing longwave radiation balances incoming shortwave radiation. The temperature stops dropping from the night before, and we see our minimum temperature for the cycle. As the sun continues to rise, we receive more radiation from the sun than is emitted by the Earth, and increasing temperatures. At noon, we receive the highest radiation from the sun, with the greatest difference between incoming solar and outgoing Earth radiation, which is the time we see the most quickly rising temperature. In mid- to late afternoon, as the sun sets, the incoming solar and outgoing Earth radiation just balance again, which is when the temperature stops rising, and we see the maximum temperature for the diurnal cycle. As the sun continues to set, we see less incoming solar radiation than outgoing Earth radiation, causing the temperature to decline. After sunset, the Earth continues to emit longwave radiation, with no incoming radiation, causing the temperature to drop overnight before the minimum temperature is seen near sunrise the following morning.


3. The dew point temperature is the temperature at which a sample of air would reach saturation after being cooled at constant pressure.