Tornadoes

Unfortunately, pressure differentials can create extremely powerful forces that are destructive in nature. For instance, tornadoes and cyclones are extremely powerful local winds generated by rapid mixing of cold, dry air and warm, wet air. They powerful forces can cause high levels of destruction including loss of life.

“Greenhouse Effect”

Another extremely important aspect of the atmosphere is what is called the 'greenhouse effect". Of the energy that comes from the sun, and impacts on the top of the earth's atmosphere, only about half of the energy reaches the surface of the earth. The energy that is absorbed by the surface of the earth is changed to a lower quality heat energy, and most of that energy is re-emitted as infrared energy. Much of this energy is reflected back to the earth to be absorbed and re-emitted again, particularly when there is high cloud cover. Trapping of the energy with in the earth's atmosphere causes the earth to be warmer than it otherwise would be...like a greenhouse. Notice that the presence of cloud cover greatly changes the reflectivity and absorptivity of the earth, called the albedo. One of the major variables in the greenhouse effect is the presence of cloud cover.

Дата добавления: 2015-09-01