The cloud disappears when the air temperature is raised by compression. The change in temperature results in evaporation of the cloud droplets.
9. It can be inferred from this investigation that in the open atmosphere where it is cloudy, air is generally rising and cooling. Burgan (123) asserts that where the atmosphere is clear, the air is generally moving in the opposite direction.
10. Generally, high pressure areas in the atmosphere tend to be clear because air in them experiences downward motion. Low pressure areas tend to have clouds because air in them experiences motion in the reverse direction.
13. In the eastern U.S., the front that had slowly been moving eastward was positioned near Buffalo, New York. The temperature and dewpoint at Buffalo at map time were 62 F and 61 F, respectively. Because the temperature and dewpoint at the surface were not equal, it indicated the air in Buffalo was not saturated.
19. On the Steve diagram, the bold irregular curve to the right is the temperature profile while the bold curve to the left is the dewpoint profile. Where the curves are superimposed, the temperatures and dewpoints are equal. The separation of the temperature and dewpoint values at and near the surface indicates that the surface air was not saturated. (From the radiosonde text data, not shown, there is a 1.7 C difference between the temperature and dewpoint at the surface.)
23. The temperatures were equal to the dewpoints from 975 mb up to about 600 mb. These equal temperature-dewpoint conditions do suggest there was an extensive, thick layer of clouds over Buffalo (Bunch,