The up and down of ocean tides

Ocean tides represent more than 80% of the variability of the surface in the open ocean. High tide, low tide... the rhythm of the tides seems to rock the oceans, reflecting the movements of the Moon and Sun. Precise knowledge of them is vital for many maritime and coastal activities. It is not easy to ignore tides, given that variations in sea level can reach 10 metres in some ports, and that currents change with the ebb and flow. Satellite altimetry now provides regular measurements of sea level in the middle of the ocean, which means that forecasting of tides has been improved. In addition to the publication of tide calendars, we have improved our understanding of the influence of the Moon on the Earth and, somewhat unexpectedly, on its climate.

  • Moon and Sun

    The combined attraction of the Moon and the Sun is behind this phenomenon and its variations.

  • Forecasts

    To calculate tides, they have to be broken down into sinusoidal waves.

  • Tides and climate

    In addition to their direct effects on maritime and coastal activities, tides appear to have a less well-known impact on the Earth's climate.

  • Tides around the world

    The tidal amplitude, the tidal period and wave propagation that they cause are not homogeneous around globe. Some examples in Atlantic Ocean and Meditarranean Sea.

  • Internal Tides

    Internal tides are tidal waves created by the bottom topography. They propagate at the interfaces between ocean layers. The 2D capability of Swot, and its high resolution, will also enable the mapping of internal tides.

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