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).
The troposphere is the atmospheric layer closest to the earth. It is often. referred to as the âlower atmosphere.â This layer holds the most dense composition. of gases and molecules. Almost all of our weather is created within the troposphere. The stratosphere is just above the troposphere, starting at an average altitude. of about 7 miles above sea level.