tropical region exposure EO:0007061 This area lies approximately between 23.5 N latitude and 23.5 S latitude, and includes all the parts of the Earth where the sun reaches a point directly overhead at least once during the solar year (north of the Tropic of Cancer and south of the Tropic of Capricorn the sun never reaches an azimuth of 90 or directly overhead). An exposure involving growth of a plant in the geographical region of the Earth limited in latitude by the two tropics, the Tropic of Cancer and the Tropic of Capricorn, and thus centered on the equator. PECO:0007061 tropical region treatment (narrow) plant_experimental_conditions_ontology ecological environment exposure