The reason is that darknessâor, to put it the other way, the absence of lightâstimulates the production of a hormone, melatonin, from its immediate precursor, the neurotransmitter serotonin. Like serotonin, melatonin plays important roles in our physical and mental well-being.
The five major ocean gyres. A gyre in oceanography is any large system of circulating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis effect; planetary vorticity along with horizontal and vertical friction, determine the circulation patterns from the wind curl (torque).
â¢ A Gyre is a naturally occurring vortex of wind and currents that rotate in a clockwise direction in the northern hemisphere and counter-clockwise in the southern hemisphere. These create a whirlpool effect, whose vortex moves more slowly at the center and that is where marine plastic debris collects.