More than 70 percent of the Earth’s surface is covered by oceans, seas and lakes, and another 5 percent is covered by glaciers and ice caps. Just more than two thirds of this water area is in the Southern Hemisphere, and the oceans are 4 to 5 kilometers deep.
The atmosphere cannot warm until the underlying surface warms first. The lower atmosphere is transparent to direct solar radiation, preventing it from being significantly warmed by sunlight alone. The surface atmosphere thus gets its warmth in three ways: from direct contact with the oceans; from infrared radiation off the ocean surface; and, from the removal of latent heat from the ocean by evaporation. Consequently, the temperature of the lower atmosphere is largely determined by the temperature of the ocean.
Inland locations are less restrained by the oceans, so the surface air experiences a wider temperature range than it does over the oceans. Land cannot store heat for long, which is why hot days are quickly followed by cold nights in desert regions. For most of the Earth, however, the more dominant ocean temperatures fix the air temperature.
This happens through several means:
(1) The oceans transport heat around the globe via massive currents which sweep grandly through the various ocean basins. As a result, the tropics are cooler than they would be otherwise, and the lands of the high latitudes are warmer. The global circulation of heat in the oceans moderates the air temperatures around the whole world.
(2) Because of the high density/specific heat of sea water, the entire heat in the overlying atmosphere can be contained in the top two meters of the oceans. This enormous storage capacity enables the oceans to “buffer” any major deviations in temperature, moderating both heat and cold waves alike.
(3) Evaporation is constantly taking place at the surface of the seas. It is greatest in the tropics and weakest near the polar regions. The effect of evaporation is to cool the oceans and thereby the surface atmosphere.
Warming the ocean is not a simple matter, not like heating a small glass of water. The first thing to remember is that the ocean is not warmed by the overlying air.
Let’s begin with radiant energy from two sources: sunlight and infrared radiation, the latter emitted from the “greenhouse” gases (water vapor, carbon dioxide, methane, and various others) in the lower atmosphere. Sunlight penetrates the water surface readily, and directly heats the ocean up to a certain depth. Around 3 percent of the radiation from the Sun reaches a depth of about 100 meters.
The top layer of the ocean to that depth warms up easily under sunlight. Below 100 meters, however, little radiant energy remains. The ocean becomes progressively darker and colder as the depth increases. It is typical for the ocean temperature in Hawaii to be 26°C (78°F) at the surface, and 15°C (59°F) at a depth of 150 meters.
The infrared radiation penetrates but a few millimeters into the ocean. This means that the greenhouse radiation from the atmosphere affects only the top few millimeters of the ocean. Water just a few centimeters deep receives none of the direct effect of the infrared thermal energy from the atmosphere! Further, it is in those top few millimeters in which evaporation takes places. So whatever infrared energy may reach the ocean as a result of the greenhouse effect is soon dissipated. … -Dr. Robert E.Stevenson, 2000
Robert E. Stevenson, an oceanography consultant based in Hawaii, trains the NASA astronauts in oceanography and marine meteorology. He was Secretary General of the International Association for the Physical Science of the Oceans from 1987 to 1995, and worked as an oceanographer for the U.S. Office of Naval Research for 20 years. A member of the scientific advisory board of 21st Century, he is the author of more than 100 articles and several books, including the most widely used textbook on the natural sciences. http://www.21stcenturysciencetech.com/articles/ocean.html
-effects of an underwater volcano seen from Tonga in January 2015; newly formed islands are often short-lived as well
-undersea volcanic eruption near Japan
The Gakkel ridge is a gigantic chain of underwater volcanoes snaking 1,800 kilometers (1,100 miles) beneath the Arctic Ocean from the northern tip of Greenland to Siberia.
With its deep valleys plummeting 5,500 meters (3.4 miles) beneath the sea surface and its summits rising 5,000 meters (3.1-miles) above the seafloor (but still a third of a mile beneath the sea surface), the Gakkel ridge is far mightier than the Alps.
The Gakkel Ridge has in the recent past pulsed massive amounts of heat into the overlying ocean and thereby melted large portions of the ice that floats above the heated ocean column, says geologist J. Kamis.
Climate scientists who favor the theory of man-made global warming maintain that the higher melt rate of Arctic sea ice from 1999 to 2007 was entirely due to man-made CO2 emissions, Kamis continues. However, it is clear to most scientists, he continues, that non-atmospheric natural forces play the dominate role in sea ice extent and thickness. https://www.iceagenow.info/underwater-volcanoes-melting-arctic-ice-says-geologist/
-near Fiji a mile underwater is 2200 degree F. magma from an undersea volcano http://ocean.si.edu/ocean-photos/superheated-magma-underwater
by Warren Keelan