Science / Tides and Currents / Tropic Intervals: Tropic higher high water interval (tchhwi) is the lunitidal interval pertaining to the higher high waters at the time of the tropic tides. Tropic lower low water interval (tcllwi) is the lunitidal interval pertaining to the lower low waters at the time of the tropic tides. Tropic intervals are marked a when reference is made to the upper transit of the Moon at its north declination or to the lower transit at the time of south declination, and are marked b when the reference is to the lower transit at the north declination or to the upper transit at the south declination. See tropic tides.
Science / Weather / Tropical Cyclone: A warm core low pressure system which develops over tropical, and sometimes subtropical, waters, and has an organized circulation. Depending on sustained surface winds, the system is classified as a t MORE
Science / Weather / Tropical Depression: A tropical cyclone in which the maximum sustained surface winds are 38 miles per hour (33 knots) or less. Characteristically having one or more closed isobars, it may form slowly from a tropical distu MORE