Tide - Tidal lag

The tide is the regular rising and falling of the ocean's surface caused by changes in gravitational forces external to the Earth. The main changing gravitational field is due to the Moon while a lesser field is caused by the Sun. Since tides generate currents of conducting fluids within the Earth's magnetic field, they affect in return the magnetic field itself. The loss of rotational energy of the earth, due to friction within the tides, and the gravitational effects caused by tidal deformations of the earth's body, ar ...

Including:

• Tide - Tidal terminology
• Tide - Timing
• Tide - Tidal physics
• Tide - Tidal amplitude and cycle time
• Tide - Tidal lag
• Tide - Alternative explanation
• Tide - Tides & fluids
• Tide - Tides and navigation
• Tide - Other tides

Read more here: » Tide: Encyclopedia - Tide

Ignoring external forces, the ocean's surface defines a geopotential surface or geoid, where the gravitational force is directly towards the centre of the Earth and there is no net lateral force and hence no flow of water. Now consider the effect of added external, massive bodies such as the Moon and Sun. These massive bodies have strong gravitational fields that diminish with distance in space. It is the spatial differences in these fields that deform the geoid shape. This deformation has a fixed orientation relative to the influenci ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Tidal physics

In addition to oceanic tides, there are atmospheric tides as well as terrestrial tides (land tides), affecting the rocky mass of the Earth. Atmospheric tides may be negligible for everyday phenomena, drowned by the much more important effects of weather and the solar thermal tides. However, there is no strict upper limit to the Earth's atmosphere, and the tidal pull increases with the distance from the Earth's centre. Theoretically, the Earth's atmosphere extends beyond the Roche limit of the Earth in the Moon's gravitat ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Other tides

In addition to oceanic tides, there are atmospheric tides as well as terrestrial tides (land tides), affecting the rocky mass of the Earth. Atmospheric tides may be negligible for everyday phenomena, drowned by the much more important effects of weather and the solar thermal tides. However, there is strictly no upper limit to the Earth's atmosphere, and the tidal pull increases with the distance from the Earth's centre. Theoretically, the Earth's atmosphere extends beyond the Roche limit of the Earth in the Moon's gravit ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Other tides

Tides and tidal effects happen in general whenever a mass with some volume moves in a gravitational field that is not uniform. This is, they always happen. For example, in one way or the other, all objects moving in space will see some form of tidal forces. By acting on an ideal rigid body, by definition tides will not deform the body. Many bodies which are moving within the solar system, for example, are not rigid but merely balls of gas or fluids, hovering in empty space (Sometimes they have a very thin solid crust). Tidal forces generate ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Tides & fluids

In most places there is a delay between the phases of the Moon and its effect on the tide. Springs and neaps in the North Sea, for example, are two days behind the new/full Moon and first/third quarter, respectively. The reason for this is that the tide originates in the southern oceans, the only place on the globe where a circumventing wave (as caused by the tidal force of the Moon) can travel unimpeded by land. The resulting effect on the amplitude, or height, of the tide travels across the oceans. It is known that it travels as a s ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Timing

The maximum water level is called "high tide" or "high water" and the minimum level is "low tide" or "low water". High water occurs as two bulges in the height of the oceans; one bulge faces the moon and the other, on the opposite side of the earth, faces away from the moon. For an explanation see below under Tidal physics. There are two low waters positioned at about 90° of longitude from the high waters. At any given point on the ocean, there are normally two high tides and two low tides each day. The common names of the two high tides ar ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Tidal terminology

Tidal flows are of profound importance in navigation and very significant errors in position will occur if tides are not taken into account. Tidal heights are also very important; for example many rivers and harbours have a shallow "bar" at the entrance which will prevent boats with significant draught from entering at certain states of the tide. Tidal flow can be found by looking at a tidal chart or tidal stream atlas for the area of interest. Tidal charts come in sets, each diagram of the set covering a single hour between on ...

See also:

Tide, Tide - Tidal terminology, Tide - Timing, Tide - Tidal physics, Tide - Tidal amplitude and cycle time, Tide - Tidal lag, Tide - Alternative explanation, Tide - Tides & fluids, Tide - Tides and navigation, Tide - Other tides

Read more here: » Tide: Encyclopedia II - Tide - Tides and navigation