Question: part 4 atmospheric stability and convection in part 3 we...
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Part 4: Atmospheric Stability and Convection
In part 3, we looked at how clouds formed by forced lifting –– in this case, orographic lifting. In this section, we will examine how clouds can form by convection in an unstable or convectively unstable atmosphere. For this lab, we will assume that the environmental lapse rate on the day we examine is 8°C at Oklahoma City, OK (OKC).
1. First, let’s calculate the temperature of the environment at different heights above OKC. Use the environmental lapse rate to complete the following table:
Elevation (km) 
Environmental Temperature (°C) 
0 km 
30°C 
1 km 
22°C 
2 km 

3 km 

4 km 

5 km 

6 km 
2. Plot these temperature and elevation values on a graph (temperature( Celsius degrees) on horizontal axis & elevation(km) on the vertical axis), connect the points by a line, and label the line “Environmental Lapse Rate”.
3. Next, similar to what you did with the calculations on the windward side of the mountain, you will calculate the air temperature of an air parcel that is affected by adiabatic processes as it rises in the atmosphere. Assume that the air parcel begins unsaturated at the ground and then becomes saturated at 2 km in height. Recall the dry and moist adiabatic lapse rates from questions #2 and 3 in part 2. In the last column, note whether you used the dry adiabatic lapse rate (DALR) or the moist adiabatic lapse rate (MALR) to calculate the change in temperature from one height to the next.
Elevation (km) 
Parcel Temperature (°C) 
Rate (DALR or MALR) 
0 km 
30°C 

DALR 

1 km 
20°C 

2 km 

3 km 

4 km 

5 km 

6 km 

4. Plot these temperature and elevation values on the graph below, connect the points by line segments, and label the segments of the line “DALR” or “MALR”, as appropriate.
5. Look at the two lines that represent the change in temperature of the air parcel with height and the change in the temperature of its surrounding environment. Use what you learned in the reading to label the stable layer as “stable” and the unstable layer as “unstable”. Make sure it is clear what the depth of each layer is.