What term describes the tidal levels and character which would result from gravitational effects, e.g. of the Earth, Sun and Moon, without any atmospheric influences?

• A. Astronomical Tide
• B. Amphidromic Point
• C. Wavelength
• D. Wind Wave

Answer: (A)

The term Astronomical Tide describes the tidal levels and character produced by gravity alone, from the Moon and Sun, without any atmospheric influences. Tides arise because the Moon and Sun pull on Earth’s oceans, creating bulges that move as the Earth rotates. This baseline tidal signal is what you’d expect if wind, air pressure, and weather effects were removed, giving the pure gravitational forcing. Real tides are then modified by atmospheric conditions and coastal features, but the astronomical tide is the gravity-driven pattern. The other options don’t fit: an amphidromic point is about a zero-tide location around which tides rotate, wavelength concerns wave properties, and wind waves are driven by wind rather than gravity.