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.
Welcome to Kwajalein Atoll. Nowhere in Micronesia is the US military presence so pronounced as on Kwajalein Atoll, a US$4 billion space tracking and missile defence facility operated by the US Department of Defense Measured by lagoon size Kwajalein is the world's largest coral atoll, its 97 islands surrounding an immense 2175 sq km body of water.