Equinoctial Tides

Equinoctial Tides

As we have seen the earth is tilted at 23.5° from its vertical axis as it travels on its 365 day ecliptic orbit around the sun. There is a event twice a year, during the Spring and Autumn equinox when the Sun is at 23°N or 23°S, and forms a straighter than usual line with the moon and earth. This increases the gravitational pull and produces extraordinary tides which we call the Equinoctial Tides. Sometimes when this happens the three heavenly bodies may line up enough to form a solar eclipse with the moon blocking the light from the sun. This is the period of maximum gravitational pull and therefore experience extreme tides. We call these tides Highest Astronomical Tide HAT and Lowest Astronomical Tide LAT. Its only during these extreme and rare astronomical events will the effects of gravity on the tides have any pronounced tidal effect.

Its just not possible for the heavenly bodies to get any closer together and are most extreme tides we will experience from the gravitational pull of the sun and moon. However when we look at the Meteorology module we will see that on very rare occasions these extreme tides may occur at the same time as meteorological active weather patterns. A surge of water and changes in barometric pressure may influence sea level further with sometimes dire storm-surge consequences.