Mass of air which has been over tropical or subtropical regions for several days and which, therefore, has become fairly warm and moist.
A very warm air mass originating in subtropical anticyclones near latitude 30 degrees. It can be very moist after a long sea passage (Maritime Tropical). If it comes mostly overland it is Continental Tropical and gives very high temperatures in summer.
A type of air mass with characteristics developed over low latitudes. Maritime tropical air ( mT), the principal type, is produced over the tropical and subtropical seas. It is very warm and humid and is frequently carried poleward on the western flanks of the subtropical highs. Continental tropical air ( cT) is produced over subtropical arid regions and is hot and very dry. See airmass classification, trade air; compare polar air.