In the Northern Hemisphere, several smaller gyres develop with a center of rotation at 50 degrees. Similar patterns do not develop in the middle latitudes of the Southern Hemisphere. In this area, ocean currents are not bound by continental masses. Ocean currents differ from each other by direction of flow, by speed of flow, and by relative temperature. The cyclical rise and fall of sea water is known as a tide.
Tides develop because of gravitational interactions between the Earth, sun, and moon.
The timing of tidal cycles is related to the rotation of the Earth on its axis and the revolution of the moon around the Earth. Extreme tidal events, known as spring tides, occur when there is an alignment of the gravitational forces of the sun and the moon. When the sun and moon's forces are perpendicular to each other, moderate neap tides develop. The nature of the three major types of tides is described in detail. Finally, describe the effect of an intense 1 hour storm on streamflow over 24 hours using a hydrograph.