Initiation
A thermal column (or thermal) is a vertical section of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation. The Sun warms the ground, which in turn warms the air directly above it. The warmer air expands, becoming less dense than the surrounding air mass, and creating a thermal low. The mass of lighter air rises, and as it does, it cools due to its expansion at lower high-altitude pressures. It stops rising when it has cooled to the same temperature as the surrounding air. Associated with a thermal is a downward flow surrounding the thermal column. The downward moving exterior is caused by colder air being displaced at the top of the thermal. Another convection-driven weather effect is the sea breeze.
Read more about this topic: Atmospheric Convection
Famous quotes containing the word initiation:
“Until the end of the Middle Ages, and in many cases afterwards too, in order to obtain initiation in a trade of any sort whatever—whether that of courtier, soldier, administrator, merchant or workman—a boy did not amass the knowledge necessary to ply that trade before entering it, but threw himself into it; he then acquired the necessary knowledge.”
—Philippe Ariés (20th century)
“The difficult and risky task of meeting and mastering the new—whether it be the settlement of new lands or the initiation of new ways of life—is not undertaken by the vanguard of society but by its rear. It is the misfits, failures, fugitives, outcasts and their like who are among the first to grapple with the new.”
—Eric Hoffer (1902–1983)