RE: Can someone explain thermals???
Soarrich,
Very simply, a thermal is some-what like a dust-devil. In a dust-devil, air heated by the earth's surface rises. Warm air is lighter than cooler air and therefore rises. You can see the dust-devil because of rising and rotating silt, sand, paper, and other trash. Once in Hawaii, while on training manuvers with the army on the "Big Island", a very large and strong dusd-devil made its way through our compound. Its vertical force carried silt, sand, rocks, doors, windows, and other heavy objects hundreds of feet upward; it was much like a tornado in that it had rotating winds, but had no weather associated with it. Our models or full scale sailplanes use the rising warm air to "lift" them upward. The rising warm air cools at altitude and falls downward as "sink". As a pilot, to gain altitude, you must learn to seek out the "lift" and stay out of the "sink".
Welcome to our sport,
Ernie