Consider an air parcel that is lifted from the surface to 3 kilometers. The surface temperature is 25oC
and condensation occurs when the parcel reaches a height of 1.4 km above the surface. MALR is 5oC/km. Complete the table below with the parcel temperatures as it ascends from the surface to 3 km. The environmental temperatures may be calculated using an environmental lapse rate of 12oC/km, beginning with the same surface temperature.
Temperatures for Air Parcel and Environment
Height Parcel temp Environment temp
(km) (oC) (oC)
b. Plot the parcel and environmental temperatures from the above table vs height. Height will be the vertical axis, temperature the horizontal axis. Indicate the height at which condensation occurs.
c. Indicate on the graph the layers of the atmosphere that are stable, unstable or neutral. Recall that stability is assessed by comparing the temperatures of the rising air and surrounding air at the same height. If the rising air is colder than the surrounding air it will be heavier, have a tendency to sink and therefore the atmosphere will be stable. If the rising air is warmer than the surrounding air, it will be lighter and the atmosphere will be unstable. If the temperatures are the same the atmosphere is neutral.