UNIT 5—LESSON 4
OVERVIEW Identify the
characteristics of electrometers (thunderstorms, lightning, auroras, and
airglow). Thunderstorms Lightning Auroras Airglow ELECTROMETEORS An electrometer is a visible or audible mani-festation
An electrometer is a visible or audible mani-festationof atmospheric electricity. The more important electrometers are thunderstorms, lightning, and auroras.
Learning Objective: Identify thecharacteristics of electrometeors (thunder-storms, lightning, auroras, and airglow).
The thunderstorm represents one of the mostformidable weather hazards in temperate and tropical zones. Though the effects of the thunder-storm tend to be localized, the turbulence, high winds, heavy rain, and occasional hail accompany-ing the thunderstorm are a definite threat to the safety of flight operations and to the security of naval installations. The Aerographer’s Mate must be acquainted with the structure of thunderstorms and the types of weather associated with them.
The thunderstorm represents a violent andspectacular atmospheric phenomenon. It is usually accompanied by lightning, thunder, heavy rain, gusty surface wind, and frequently hail. A cer-tain combination of atmospheric conditions is necessary for the formation of a thunderstorm. These factors are conditionally unstable air of relatively high humidity and some type of lifting action. Before the air actually becomes unstable, it must be lifted to a point where it is warmer than the surrounding air. When this condition is brought about, the relatively warmer air continues to rise freely until, at some point aloft, its temperature has cooled to the temperature of the surrounding air. Some type of external lifting ac-tion must be introduced in order to raise the warm surface air to a point where it can rise freely. Many conditions satisfy this requirement; an air mass may be lifted by heating, terrain, fronts, or convergence.