A vocabulary of landscape — a landscape of words
1068 entries
thermal
A column of rising warm air generated by differential heating of the earth’s surface — a dark plowed field, a sun-baked cliff, a parking lot surrounded by cooler ground. Raptors, vultures, and soaring birds ride thermals to gain altitude without flapping.
Etymology
Greek: thermē (heat), from thermos (warm, hot). The atmospheric sense dates to the 1930s.