The oceans of the world comprise approximately 3/4 of the Earth's surface, thus, the oceans absorb most of the radiation energy coming from the Sun compared to what the land's surface does. Solar radiation is absorbed by land masses, the air and the ocean at different rates. The transfer of energy within the Earth's surface, atmosphere and the ocean occur by radiation, convection and conduction processes. The ocean possesses an enormous capacity to store heat, more than land surfaces, therefore, it plays a major role in the Earth's weather and long-term climate change.
The ocean and atmosphere
Both the ocean and atmosphere influence the transfer of heat across the globe. Wind and ocean current circulations move warm surface ocean water to the poles and cold deep water and surface air back to the equator. Major ocean current circulations, such as the Gulf Stream, move great amounts of heat to the Arctic and influences many types of weather patterns. The Gulf Stream is an ocean current that moves warm surface ocean water from the Gulf of Mexico to the north Atlantic and is believed to be responsible for the warm weather of northern Europe, which would otherwise be cold.
The ocean currents, which are driven mainly by atmospheric winds, greatly affect the Earth's climate by transferring heat from the tropics to the poles. The ocean distributes large amounts of heat by pumping warm water to the north Atlantic and cold water back to the tropics. These current patterns maintain parts of Europe and New Zealand warm and regions, such as southern California and Peru cold. Ocean currents affect atmospheric temperature, for instance, the evaporation of ocean water in the atmosphere provides the energy necessary to form cyclones and hurricanes.
Transfer of heat
When the ocean absorbs enough heat and comes in contact with a current of air at a lower temperature, heat is transfered to the colder object until both acquire similar temperatures. The ocean also releases stored energy when in comes in contact with precipitation. Solar radiation heats the ocean air and land differently and the transfer of heat among them leads to the creation of air layers of different temperatures and densities. These layers rise and fall, creating convection currents which are influenced by the rotation of the Earth, eventually causing strong winds, storm and ocean currents.
Oceanic evaporation, which occurs due to the water cycle, creates most rainfall in the world. The ocean delivers thermal energy through the evaporation of sea water. As water evaporates, it rises and cools down in the atmosphere. Air currents move water vapor around the planet. Water vapor condenses and falls back to the surface of the Earth as rain, ice or snow. Water collects in lakes, rivers, land and the ocean. Eventually the collected water ends up in the ocean. The water cycle, which involves an exchange of energy in the form of heat, involves temperature changes that influence climate around the Earth.
The ocean's acidification
The ocean plays an important role in short-term weather variations and long-term climate change. The ocean possesses a great capacity for the storage of heat. It is estimated that the top eight feet of the ocean's surface may hold as much heat as the entire atmosphere. The ocean also receives much of the carbon dioxide (CO2) that is emitted into the atmosphere, thus affecting global warming. It's been estimated that the ocean absorbs approximately from one quarter to one half of CO2 emissions of anthropogenic origin. This lowers the ocean's pH and leads to the acidification of the ocean waters.
The ice in the ocean also greatly affect global climate. When the radiation from the Sun falls over ice sheets at the poles, it is reflected back into the atmosphere. thus, functioning as a heat shield that helps maintain the temperature of the Earth, but when the ice sheets melt, the ocean acquires a greater surface area, absorbing more energy from the Sun, and becoming warmer and less salty. A greater volume of ocean, leads to more absorption of CO2 concentrations, threatening marine biodiversity, as well as human life.
Heat absorption on the ocean leads to a rise in sea levels. As the ocean water warms, it expands, leading to a rise of the ocean's surface. It's been estimated that much of the excess heat in the ocean accumulates in a layer of the surface just a few hundred meters in depth. In the near future, this heat will difuse to greater depths, leading to a greater expansion of the ocean. This will affect coastal regions and related activities. Studies have predicted that the sea level will rise from 1/2 meter to a meter in the next one hundred years, although a rise higher than that is possible by the end of this century.
The ocean and the atmosphere are closely interrelated and they work together to distribute heat around the globe. According to IUCN, the ocean plays an important part in climate change and is closely related to the atmosphere through processes that include heat transportation, evaporation, heat absorption, storage, distribution of CO2 and freezing and thawing in polar regions. instabilities due to climate change could considerably change weather and climate patterns and could produce human migrations in the future.