Exam 2 (critical thinking questions - chapter 4)

Question 1

How would analyzing recent rainfall patterns help temperature forecasting?

Answer 1

Recent rainfall is important to temperature forecasting because daytime air temperatures tend to be higher when the ground is dry rather than wet. In response to the same intensity of solar radiation striking Earth’s surface, air over a dry surface warms more than air over a moist surface. Over a dry surface, absorbed radiation is used mainly for sensible heating of the air. Over a wet surface, much of the absorbed radiation is used to evaporate water (latent heating), leading to less sensible heating and lower air temperatures.

Question 2

Air, especially still air, is a poor conductor of heat. Provide examples of how this property of air is used to conserve energy for space heating and cooling.

Answer 2

Air is used to insulate heat as in thick fiberglass blankets that are used as attic insulation in homes. Air is trapped between the fiberglass elements. Also double glassed storm windows make use of air’s very low heat conductivity; air is trapped between panes of glass. The air space between panes is so thin that convective circulation of air is inhibited.

Question 3

How and why would the temperature of an Arctic air mass change as the air mass moves from snow-covered ground to bare ground?

Answer 3

Air mass properties depend on the surface over which they form. An Arctic air mass that forms over snow-covered ground would be relatively cold but would become warmer as it moves over bare ground.