Name:______

ATOC 3050 Homework 6 and and Formation

Instructions: Make sure that you answer all of the questions completely. Use appropriate units on all numerical answers and answer non-numerical questions with complete sentences. Please write neatly when completing this assignment – if we can’t read your answer you will not get credit for it.

Part 1: Convective

1a. On a spring morning in New York a observes the following profile. Plot this temperature data on the blank thermodynamic diagram on the next page of this assignment.

Pressure (mb) Temperature (°C) 1000 5 900 10 800 0 500 -10 300 -25 250 -25 100 -15

1b. What is the at the in this sounding?

1c. On the thermodynamic diagram mark the layer(s) of the atmosphere where an inversion is present.

2. At 6 AM an air parcel at the surface (1000 mb) is observed to have a temperature of 5°C and a temperature of 0°C.

2a. On the thermodynamic diagram on the next page show how the air parcel temperature and dew point temperature change as the air parcel is lifted adiabatically from 1000 mb to 250 mb.

2b. Mark the air parcel level of free , lifting condensation level, and on the thermodynamic diagram and list the pressure at each of these points in the space below. If any of these levels are not present or do not apply to this air parcel indicate this in the space below.

2c. Assuming that no external lifting mechanism is available to lift this air parcel would you expect a convective cloud to form at 6 AM? Explain your answer.

Name:______

0.1 0.4 1 2 4 7 10 16 24 32 40g/kg 100 16180 m

13608 m

200 11784 m

10363 m

300 9164 m

400 7185 m

Pressure (mb) Pressure 500 5574 m

600

700 3012 m

800 1457 m 900 766 m

1000 111 m

−80 −70 −60 −50 −40 −30 −20 −10 0 10 20 30 40 Temperature (deg C)

3. At 3 PM an air parcel at the surface (1000 mb) is observed to have a temperature of 25°C and a dew point temperature of 10°C.

3a. On the thermodynamic diagram above show how the air parcel temperature and dew point temperature change as the air parcel is lifted adiabatically from 1000 mb to 250 mb.

3b. Mark the air parcel , lifting condensation level, and equilibrium level on the thermodynamic diagram and list the pressure at each of these points in the space below. If any of these levels are not present or do not apply to this air parcel indicate this in the space below.

3c. Assuming that no external lifting mechanism is available to lift this air parcel would you expect a convective cloud to form at 3 PM? Explain your answer.

Name:______

3d. What is the pressure at the cloud base and cloud top for a convective cloud that would form from this air parcel? How did you determine the location of the cloud base and cloud top?

Part 2: Orographic Clouds

4. On a winter day in Boulder, CO an east is blowing towards the Rocky Mountains. The air at the surface has a pressure of 850 mb, a temperature of 0°C, and a dew point temperature of -10°C

4a. On the thermodynamic diagram illustrate the change in air parcel temperature and dew point temperature as this air is lifted from Boulder, CO to the crest of the Rocky Mountains. You may assume that the crest of the Rocky Mountains is at a pressure of 600 mb.

4b. Mark the air parcel level lifting condensation level on the thermodynamic diagram and list the pressure at the LCL in the space below.

4c. What is the largest initial dew point temperature that would result in no cloud forming as air from Boulder, CO was being lifted over the Rocky Mountains by an east wind? Illustrate how you determined this on the thermodynamic diagram above.

Name:______

Part 3: Fog Formation

5. On a fall day in Madison, WI the temperature at sunset is observed to be 15°C. At this time the dew point temperature was observed to be 10°C and the pressure was 950 mb.

5a. On the thermodynamic diagram below illustrate the change in air parcel state as the air cools overnight to a temperature of 5°C. In addition to indicating the air parcel temperature also mark the initial and final dew point temperature of the air parcel.

5b. Assuming that only condensation acts to change the dew point temperature of this air parcel at what temperature does fog initially form on this night?

5c. As the air continues to cool from the temperature given as the answer to problem 5b to the final morning temperature of 5°C how much condenses from this air parcel? (Hint: Give your answer in terms of g of water vapor that condense per kg of air parcel).

5d. Calculate the amount of latent released as a result of the condensation that occurs overnight in this air parcel. (Hint: Give you answer in terms of J of released per kg of air parcel)

Name:______

5e. Using the first law of calculate the change in air temperature, for a 1 kg air parcel, that would result from the release calculated in problem 5d.

5f. Explain why the air parcel, as stated in problem 5a, is able to cool from 15°C to 5°C, despite the warming that would result from the latent heat calculated in problem 5e.