1. What is condensation and what conditions are nec-
essary for condensation to occur?
2. What is evaporation? What conditions make it
more likely to occur?
3. When we say that air is “saturated” what does that
mean?
4. What is humidity?
5. What is relative humidity? How do we calculate the
relative humidity of the air?
6. What are the two ways that we can increase or de- crease the relative humidity
of air?
7. What does the term “dew point temperature” mean? How is the difference be- tween the dew point and air temperature related to
relative humidity?
8. What are the four main cloud groups and their
types? Be able to recognize them in the sky.
5. HUMIDITY, CONDENSATION, & CLOUDS
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9. How can you distinguish altostratus clouds from
cirrostratus?
10. What happens to the general size of clouds as they increase in altitude?
low
middle
high
PUTTING IT INTO PRACTICE PART 1: THE ADIABATIC PROCESS
In this section, you will be calculating the air temperature as a parcel of air lifts up over a mountain range and back down the other side. Assume that the parcel of air starts off with a temperature of 65° F at sea level and a Dew-Point Temperature of 54° F. Dry Adiabatic Rate : 5.5° F for every 1,000 feet of elevation change. The rate at which unsaturated air cools while lifting or warms while descending. Saturted (Wet) Adiabatic Rate: 3.3° F for every 1,000 feet of elevation change. The rate at which saturated air COOLS. Warming air will never maintain 100% relative humidity, so you never use the saturated rate with warming air.
CACLCULATING THE TEMPERATURE OF A RISING PARCEL OF AIR:
1. If the dew point is 54° F and the air temperature is 65° F. At sea level (0ft) on the windward side of the mountain in the diagram below, is the relative humidity of the air starting out at 100%? Why or why not?
2. Assume that this same air is forced upward by a mountain range. When it starts to rise to 1,000ft, will it cool at the DRY or SATURATED adiabatic rate?
3. Using the rate that you chose from question 2, calculate the temperature change on the diagram below up to 2,000 feet. What is the temperature of the parcel of air at 2000 ft?
4. At 2,000 ft., is the relative humidity of the parcel of air 100%? Yes or No?
5. Above 2,000ft, will the rising air begin cooling at the DRY or SATURATED adiabatic rate?
6. On the diagram below, calculate the air temperature changes all the way up to 5,000 feet using the rate you chose in question 5. What is the temperature at 5,000 ft?
0 ft65° F