# Physical Geography 101Lab Practical IIPractice Problems

1. Define the term "Dew Point Temperature" and its relationship to relative humidity.

Using Table A and Table B from your lab manual, determine the Relative Humidity and Dew Point Temperature for the following dry and wet bulb measurements.

2. Dry Bulb = -2°C; Wet Bulb = -6°C
a. RH % = %
b. Dew Point Temperature = °C

3. Dry Bulb = 8°C; Wet Bulb = 7°C
a. RH % = %
b. Dew Point Temperature = °C

4. An air mass starts at sea level with a temperature of 16°C (plot this as a point on the Orographic Precipitation graph). The air is blown inland by an onshore wind and is forced up the flanks of a coastal mountain range. Initially, the air mass rises following the Dry Adiabatic Lapse Rate.

5. The air mass reaches the Level of Condensation at an elevation of 2000 meters (draw this as a bold, horizontal line and label it).

6. What is the air temperature of the air mass at the Level of Condensation? °C

7. What is the Relative Humidity of the air mass at the Level of Condensation? %

8. What was the dew point temperature of the air mass at sea level? °C

9. What was the Relative Humidity of the air mass at sea level? %

10. After reaching the Level of Condensation the air mass continues to rise up the flanks of the mountain range. As it rises it continues to cool but now because of the condensation it follows the Wet Adiabatic Lapse Rate of 3°C/1000 m (draw this as a line beginning at the point previously plotted).

11. The air mass reaches the summit and at a temperature of -10°C. What is the elevation of the summit? (plot this as a point on the graph) m

12. Precipitation is occurring as the air mass follows the Wet Adiabatic Lapse Rate. In what form is this precipitation occurring?

13. After reaching the summit, the air mass descends the lee side of the mountain range. As it descends in elevation it is compressed and warmed following the Dry Adiabatic Lapse Rate (draw this as a line beginning at the point previously plotted). The air mass descends to the bottom of the mountain range to an elevation of 0 meters.

14. As it descends what is the air temperature of the air mass at 3500, 1500 and 0 meters?
a. At 3500 m, air temperature is equal to °C
b. At 1500 m, air temperature is equal to °C
c. At 0 m, air temperature is equal to °C

15. What is the dew point temperature of the air mass at 0 meters? °C

16. What is the Relative Humidity of the air mass at 0 meters? %

17. What has happened to the Relative Humidity comparing the start and end conditions?

Give two explanation for this change.
a.
b.

18. Complete the following table of barometric pressure conversions. Report all values to 2 decimal places.
18a. 20.50 inches of Hg = millimeters of Hg
18b. 20.50 inches of Hg = millibars
18c. 27.80 inches of Hg = millimeters of Hg
18d. 27.80 inches of Hg = millibars
18e. 698.00 millimeters of Hg = inches of Hg
18f. 698.00 millimeters of Hg = millibars
18g. 759.00 millimeters of Hg = inches of Hg
18h. 759.00 millimeters of Hg = millibars
18i. 932.00 millibars inches of Hg
18j. 932.00 millibars millimeters of Hg
18k. 1018.00 millibars inches of Hg
18l. 1018.00 millibars millimeters of Hg

19. Using the pressure-elevation equation from your lab manual and given the elevation (h), calculate the atmospheric pressure (P). Report all values to 2 decimal places.
19a. 1200 m = millibars
19b. 2150 m = millibars
19c. 3120 m = millibars
19d. 4530 m = millibars

20. On the Pressure map, draw the isobars for every 4 millibars of pressure starting at 1000 mb (1000 mb, 1004 mb, 1008 mb, 1012 mb, etc.). On the map, due to space imitations, only the last two digits of the millibar pressure has been indicated. For example, 1000 mb would appear as 00, 1020 mb would appear as 20, and 995 mb would appear as 95. Draw each isobar line to just past the edge of the continent.

21. Using the completed map from Problem 20, label all high and low pressure centers with a bold H or L in the center of that feature.

22. Using the completed isobar map from Problem 20 and 21, draw wind arrows representing surface winds.

23. Using the data in the tables below, calculate the annual average wind speed for Cape Town, South Africa. Convert this average to miles per hour. Report all values to 2 decimal places.
Cape Town, South Africa: Average Wind Speed = kph
Cape Town, South Africa: Average Wind Speed = mph

Monthly Average Wind speed, kph
Location Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Cape Town, South Africa 6.27 6.43 6.14 5.98 6.20 6.69 6.90 6.49 6.36 6.68 6.32 6.18

24. Using the data in the tables below, calculate the annual average wind direction for Cape Town, South Africa. Convert this average to nearest quarter compass direction (i.e. N, SE, WNW, SSW). Report value to the nearest degree.
Cape Town, South Africa: Average Direction = degrees
Cape Town, South Africa: Average Direction = compass direction

Monthly Average Wind Direction, degrees
Location Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Cape Town, South Africa 186 181 179 182 198 218 236 241 242 233 226 223

25. Using the Global Surface Winds on an Ideal Globe diagram from your textbook, determine the wind belt in which each of the above locations is found.
Cape Town, South Africa: Wind Belt =

26. Using the diagram below, draw wind arrows representing geostrophic winds. Each arrow should be drawn as a short, straight arrow, between 0.5 and 1 cm in length that parallel the isobars. Geostrophic wind arrows are draw between the isobar lines, not on the isobar lines. Draw an arrow every 2 to 4 cm between all isobar lines (in other words, completely fill the map with wind arrows).

27. On the isobar map, label all high and low pressure centers with a bold H or L in the center of that feature.

28. Which two air masses most affect the weather here in the Quad Cities? What is the source region for these air masses? Enter the air masses and sources in order from northern air mass to southern air mass.
a. Air Mass =
b. Source Region =

c. Air Mass =
d. Source Region =

29. If a third air mass had to be selected that also has an influence on the weather in this area, which would it be and what is its source area?

30. Identify the air mass found at each location on the map as either maritime (m) or continental (c) and as Arctic (A), Antarctic (AA), Polar (P), Tropical (T) or Equatorial (E).
A =
B =
C =
D =
E =

31. Which air mass most affects the weather in Indonesia?

32. Which wind belt most affects the weather in the southern tip of South America?

33. What is the tornado days per year risk in the Dallas, Texas? Your answer must be in the following format: 1.0 to 1.2

34. What is the risk of an F2 tornado in Dallas, Texas per century? Your answer must be in the following format: 10 to 15

35. What is the risk of an F4 tornado in Dallas, Texas per millennium? Your answer must be in the following format: 10 to 15

36. What is the risk of 65 knot or higher winds in Des Moines, Iowa? Your answer must be in the following format: 1.25 to 1.50
wind days per year.

37. What is the risk of 2.54 cm or greater hail in Indianapolis, Indiana? Your answer must be in the following format: 1.25 to 1.50
hail days per year.

Examine the surface weather map below. For the Quad Cities (red dot), determine the following information.

38. On the map, label all high and low pressure centers.

39. Draw the surface wind arrows for the Midwest region.

40. Barometric Pressure: mb

41. Wind direction (compass direction):

42. What might the cloud cover be like for this date (clear, partly cloudy, partly sunny, cloudy):

43. What type of precipitation is expected for this date (no precipitation, widely scattered rain, heavy rain, thunderstorms, snow, freezing rain, sleet):

44. Given average monthly temperature data and the date, you should be able to estimate what the daytime high temperature and nighttime low temperature might be.

You should be able to answer the following questions.

45. How has road construction altered the behavior of the various slopes on campus?

46. What is mass wasting?

47. Describe the difference between human influenced vegetation and natural vegetation.

48. What is the difference between primary growth and secondary growth vegetation?

49. Is the vegetation on campus natural or human influenced?

50. Give three examples of locations on campus where the vegetation is human influenced.

51. Give three examples of locations on campus where the vegetation is natural (primary or secondary).

52. How has construction of the 34th Ave. bridge and beneath Building 4 altered the flow regime of the stream?

53. Describe how the vegetation changes from the north end of campus to the south end?

54. What was the land on campus used before BHC was built? How has the vegetation changed since the campus was built?

55. What conservation and land reclamation efforts are being done on campus? Where is erosion destroying the land on campus?

56. Where are the nature trails on campus located?

57. How have ravines and streams traditionally been used in the Quad Cities?