Science / Tides and Currents / Diurnal: Having a period or cycle of approximately one tidal day. Thus, the tide is said to be diurnal when only one high water and one low water occur during a tidal day, and the tidal current is said to be diurnal when there is a single flood and a single ebb period of a reversing current in the tidal day. A rotary current is diurnal if it changes its direction through all points of the compass once each tidal day. A diurnal constituent is one which has a single period in the constituent day. The symbol for such constituent is the subscript 1.See stationary wave theory and type of tide.
Diurnal Adjective Synonyms: daily, circadian, day-to-day, regular, everyday, quotidian, daytime
Science / Tides and Currents / Semidiurnal: Having a period or cycle of approximately one-half of a tidal day. The predominant type of tide throughout the world is semidiurnal, with two high waters and two low waters each tidal day. The tidal c MORE
Science / Tides and Currents / Great Diurnal Range (GT): The difference in height between mean higher high-water and mean lower low water. The expression may also be used in its contracted form, diurnal range. MORE