Metfi 120 (introduction to Weather and Climato) Orline - Unit 2 Review Adiabatic processes in the mountaln. The diagram below shows the lapse rates that air parcel will encounter while it is forced to move over a mountain. If an alr parcel descends through the atmosphere the air will heat at the dry adiabatic rate as it will necessarily be unsaturated. In summary, while rising air cools at varying rates, descending air heats at a uniform rate. 16. Using the table below, fill in the blanks for temperature and dew-point temperature at various helghts on the windward and leeward sides of the mountain. Assume that the WALR is 0.5C/100m. (Note: temperature and dew-paint drop together above LCL when a saturated air parcel rises and water vapor condonses. In addition, start from the 500m at windward side 1000m1500m2000m Peak 2000m at leeward side 1500m1000m500m Sea Level at leeward side.) 17. Compare to those of on the windward side, how do air temperature and dew point on the leeward side? 18. From the previous question, Why? MEIR120 (introduction to Weather and CImate) Onine - Unit2 Review Here is a challenging question. Assume that the wet adiabatic lapse rate (WALR) is 0.6C/100m. Fill the blanks in the boxes in the figure. Here is how to get answers. 1. At the LCL, temperature (2C) and dew point (2C) are the same. Until air parcel reaches LCL, temperature falls at the DALR (1.0C/100m). At the LCL, temperature falls 25C from the surface (27C2C=25C). It means air parcel rises 2500m. Thus LCL is 2500m. 2. Below the LCL, dew point changes at the Dew Point Lapse Rate (DPLR, 0.2C/100m ), it means that dew point has changed 5.0C(0.2C/100m2500m). Thus dew point at the surface is 7C/100m 3. Above the LCL, both temperature and dew point fall at the WALR (0.6C/100m). Atthe peak, dew point is 1C. It is 3C cooler than the LCL. It means air parcel rises another 500m(0.6C/100m500m=3C). Thus, peak elevation is 3000m(LCL+500m=2500m+500m) 4. At the leeward side, temperature and dew point rise at the DALR (1.0C/100m) and DPLR (0.2C/100m), respectively. Elevation has changed 2500m(3000m500m). Thus temperature and dew point rise 25C/100m and 5C. Thus, temperature will be 24C(1C+25C) and dew point will be 4C(1C+5C). Chapter 6: Precipitation and its formation Steps in the formation of precipitation according to the Bergeron process. The Bergeron process relies on the fact that cloud droplets do not freeze until they reach a temperature below the freezing point, and even then only in the presence of freezing nuclei (solid particles that have a crystal form similar to that of ice). Because freezing nuclel are much less abundant than condensation nuclei, many clouds exist in the liquid state while at temperatures well below 0C. These are supercooled clouds. The freezing nuclei present promote the formation of a few scattered ice crystals. Since lce crystals are more efficient absorbers of water vapor, they consume the "excess" water vapor, which lowers the relative humid.

1. Metfi 120 (introduction to Weather and Climato) Orline - Unit 2 Review Adiabatic processes in
the mountaln. The diagram below shows the lapse rates that air parcel will encounter while it is
forced to move over a mountain. If an alr parcel descends through the atmosphere the air will
heat at the dry adiabatic rate as it will necessarily be unsaturated. In summary, while rising air
cools at varying rates, descending air heats at a uniform rate. 16. Using the table below, fill in the
blanks for temperature and dew-point temperature at various helghts on the windward and
leeward sides of the mountain. Assume that the WALR is 0.5C/100m. (Note: temperature and
dew-paint drop together above LCL when a saturated air parcel rises and water vapor condonses.
In addition, start from the 500m at windward side 1000m1500m2000m Peak 2000m at leeward
side 1500m1000m500m Sea Level at leeward side.) 17. Compare to those of on the windward
side, how do air temperature and dew point on the leeward side? 18. From the previous question,
Why?
MEIR120 (introduction to Weather and CImate) Onine - Unit2 Review Here is a challenging
question. Assume that the wet adiabatic lapse rate (WALR) is 0.6C/100m. Fill the blanks in the
boxes in the figure. Here is how to get answers. 1. At the LCL, temperature (2C) and dew point
(2C) are the same. Until air parcel reaches LCL, temperature falls at the DALR (1.0C/100m). At
the LCL, temperature falls 25C from the surface (27C2C=25C). It means air parcel rises 2500m.
Thus LCL is 2500m. 2. Below the LCL, dew point changes at the Dew Point Lapse Rate (DPLR,
0.2C/100m ), it means that dew point has changed 5.0C(0.2C/100m2500m). Thus dew point at
the surface is 7C/100m 3. Above the LCL, both temperature and dew point fall at the WALR
(0.6C/100m). Atthe peak, dew point is 1C. It is 3C cooler than the LCL. It means air parcel rises
another 500m(0.6C/100m500m=3C). Thus, peak elevation is
3000m(LCL+500m=2500m+500m) 4. At the leeward side, temperature and dew point rise at the
DALR (1.0C/100m) and DPLR (0.2C/100m), respectively. Elevation has changed
2500m(3000m500m). Thus temperature and dew point rise 25C/100m and 5C. Thus, temperature
will be 24C(1C+25C) and dew point will be 4C(1C+5C).
Chapter 6: Precipitation and its formation Steps in the formation of precipitation according to the
Bergeron process. The Bergeron process relies on the fact that cloud droplets do not freeze until
they reach a temperature below the freezing point, and even then only in the presence of freezing
nuclei (solid particles that have a crystal form similar to that of ice). Because freezing nuclel are
much less abundant than condensation nuclei, many clouds exist in the liquid state while at
temperatures well below 0C. These are supercooled clouds. The freezing nuclei present promote
the formation of a few scattered ice crystals. Since lce crystals are more efficient absorbers of
water vapor, they consume the "excess" water vapor, which lowers the relative humidity near the

2. surrounding liquid cloud droplets. In turn, the water droplets evaporate in order to replenish the
diminishing water vapor, thereby providing a continuous source of vapor for the growth of ice
crystals, which eventually grow large enough to fall. Difference between the collision-
coalescence process and the Bergeron process. Whereas the Bergeron process operates in
supercooled clouds, the collisioncoalescence process produces precipltation in warm clouds
(above 0C ). In the collision-coalescence process, large cloud droplets fall more rapidly than
smaller droplets, sweep up the smaller ones in their path, and grow. Experiments show that
atmospheric electricity may play an important role in this process. 1. Clouds are classified on the
basis of two criteria. What are they? Clouds are classified on the basis.of height and form. 2.
Why are low and middle clouds always thicker and darker in comparison to high clouds? 3.
What is condensation nuclel and why it is importance for the formation of precipitation? 4. List
types of fog and describe unique conditions that they form. Air cooled below its dew point:
Advection, radiation, upslope fogs. Evaporation fogs include steam fog and precipitation fog. 5.
What type of fog is common in the Great Plains? And Why? 6. If snow is falling from a cloud,
which process produced it? Explain 7. Describe sleet and glaze and the circumstance under
which they form. Why doesglaze result on some occasions and sleet on others? 8. If cloud
seeding is to have a chance of success, certain atmospheric conditions must exist. What are these
conditions? 9. Describe how smudge fires can prevent frost forming. 10. Describe how
sprinkling can present frost forming.
Chapter 8: Atmospheric Motion 1. Explain why air pressure decreases with an increase in
altitude 2. Explain why a warm, humid air mass produces a lower surface pressure than a cool,
dry airmass? 3. What is the fundamental force to generate wind? 4. What forces influence the
direction and intensity of a wind? 5. Write a generalization relating the spacing of isobars to the
speed of wind 6. What is Coriolis force? 7. Briefly describe how the Coriolis force modifies the
movement of air. 8. Compared to the upper-level winds, why surface winds are much more
complicated in the direction? 9. For surface high pressure to exist for an extended period, what
condition must exist aloft? 10. What are the general weather conditions to be expected when the
pressure tendency is rising? When the pressure tendenryy is falling? 11. A nartharly hlows from
the toward the