1. Group B (a) Module on Convective/Potential Instability Group Members: –Steve Chai –Tony Hansen –Shing Yoh

2. Convective Instability Experiment with lifting layers that are dry. Experiment with lifting layers containing adjustable amounts of moisture. Explore the changes in the stability of the layers. Eventually discover relationship of  E to stability of the layer. This experiment is to be performed BEFORE any lecture discussion of Convective Instability.

3. Lift Restart Height (km) Pressure (mb) Temperature (°C) 103020 Bottom of Layer Temperature (°C) 103020 Top of Layer Continue

4. “Spoon-feeding” Approach Questions: –How does the stability of the layer change as it is lifted? Gets more stable Gets less stable Stability doesn’t change –Can you make the layer unstable by lifting it? Yes No I don’t know!?!

5. Exploratory Approach Try to make the lifted layer become unstable by adjusting the temperatures at the bottom and top of the layer before it is lifted. Describe the change in the stability of the layer as it is lifted.

6. Height (km) Pressure (mb) Temperature (°C) Lift Restart Temperature (°C) 103020 Bottom of Layer Temperature (°C) 103020 Top of Layer Dew Point (°C) 103020 Top of Layer Dew Point (°C) 103020 Bottom of Layer Continue

7. Exploratory Approach Try to make the layer become unstable by adjusting the dew point temperature at the bottom and at the top of the layer before it is lifted. Describe the changes in the stability of the of the layer as it is lifted.

8. What next? Repeat the previous experiment, but now examine the profile of  E in the lifted layer. How can you predict the changes in stability based upon the profile of  E ?

9. Height (km) Pressure (mb) Temperature (°C) Restart Temperature (°C) 103020 Bottom of Layer Temperature (°C) 103020 Top of Layer Dew Point (°C) 103020 Top of Layer Dew Point (°C) 103020 Bottom of Layer Lift Show  E

10. Height (km) Pressure (mb)  E (°C) Restart Temperature (°C) 103020 Bottom of Layer Temperature (°C) 103020 Top of Layer Dew Point (°C) 103020 Top of Layer Dew Point (°C) 103020 Bottom of Layer Lift Show T, T d

11. How does this actually occur in the Atmosphere? Show lifting along a frontal boundary with the attendant formation of stratus and, in some cases, convective clouds as the layer is lifted along a warm front, for example.