Fog in Tucson
Fog formation For the formation of fog, there should be two basic conditions. The first condition is the air inthe atmosphere should be cool to the dew point. The second condition is a temperature change of about 5 degrees F. When there is increased humidity in the air, and the temperature has changed by about 5grerees F, there are chances for the formation of fog.
In Tucson, there are limited chances of having a fog formation because of the dry air. Therefore, for there to be a fog in Tucson, there should be an increase in the amount of humidity in the air. The relative humidity ration should be almost 100%. Radiation fog can be formed easily in Tucson by adding moisture to the air. During the night, the ground will cool down emitting heat to the air above making it dry. The thin layer of air above the ground remains moist, as the temperature on the ground is cold. Thus, in between the cool and the warm air, radiation fog is formed.
The radiation fog formed around valleys is referred to as the valley fog. When forming the valley fog, the condensed cool air would move down into the valley and accumulate. After several layers pile up, fog is formed. The sun cannot heat up the moisture because fog reflects sunlight. Steam fog usually forms in the morning after a cold night. There should a surface of a small pool of water to provide moisture. After evaporation begins, moisture would rise from the surface forming a fog. The physical difference between the radiation and steam form is that latter rises from the ground while the former appears to cover a region while moving across.
Ahrens, C D, Peter L. Jackson, and Christine E. J. Jackson. .Meteorology Today: An Introduction to Weather, Climate, and the Environment. Toronto: Nelson Education, 2012. Print.