What does the term "Semi-Diurnal" tide refer to?

The term "Semi-Diurnal" tide specifically describes a tidal pattern characterized by two high tides and two low tides occurring approximately each lunar day. This means that over the course of a typical day, an area experiencing semi-diurnal tides will see the water level rise and fall twice, with the timing and heights of the tides being relatively consistent.

This tidal cycle is influenced by the gravitational interactions between the Earth, the moon, and the sun, with the semi-diurnal pattern being common in many coastal areas around the world. Recognizing this pattern is crucial for understanding tidal behaviors and their impact on navigation, marine activities, and coastal ecosystems.

In contrast, other tidal patterns such as diurnal tides involve only one high tide and one low tide each day, while irregular tidal patterns do not follow a set schedule, making "Semi-Diurnal" distinctly defined by its dual high and low tides within the same period.