Literally, in order for a vortex to be classified as a tornado, it must be in contact with the ground and the cloud base. Weather scientists haven't found it so simple in practice, however, to classify and define tornadoes (per this essay by Doswell).
Bikini Island, 2015. Credit: Emlyn Hughes. (Phys.org)âA team of researchers from Columbia University in New York has found that all of the Marshall Islands involved in nuclear tests by the U.S. are now habitable, except for Bikini Atoll.
Contribute to our Open Dictionary. an island in the form of a ring, made of coral (=the pink or white outer structure of very small sea animals) Synonyms and related words. Islands:archipelago, Atoll, desert island... Explore Thesaurus. a. Atoll. used in the names of places Bikini Atoll.