Ocean consists almost entirely of water and salt. The oceans play an important role in storing and redistributing heat absorbed from incoming solar radiation near the equator, where the radiation is most strong. The currents then redistributed this heat throughout the oceans in the process known as thermohaline circulation. Ocean thermohaline circulation is an oceanic circulation that is driven by change in water density caused by variation in temperature and salinity
Cooling and formation of sea ice in the Polar Regions makes the surface ocean water denser than the underlying water, so that the surface water sinks and moves towards the equator. In the central basin a variety of processes, occur such as the vertical mixing that move the dense bottom water upwards toward the surface where it is warned by the intense equatorial solar radiation. Then the warned moves poleward to take the place of the sinking dense water hereby completing the thermohaline circulation process.
The ocean currents are controlled by complex factors such as the shape of ocean seafloor and the earth rotation. The North Atlantic site is where strong cooling creates dense sinking water, while the equatorial Atlantic /Pacific are site where water has upwelled form great depths to the surface and is warmed by incoming radiation.
Importance of thermohaline process to climate change.
The ocean circulation depends on strongly on the sinking of dense water at high latitudes, it is very sensitive to changes in formation of rain, snow or hail( precipitation) , increased in precipitation at high latitudes will lower the density of the surface and slow down sinking of dense water, hereby slowing the thermohaline circulation. In extreme case, the circulation process is shut down. Considering ice response the warming of the atmosphere and oceans, cause rises in temperature result changes in climate system. The two components are sea ice and ice sheets. The sea ice acts as an insulating blanket between the ocean and the atmosphere, limits the exchange of heat and gas between the ocean and atmosphere. The sea ice act as an insulator because sea ice is excellent reflector, the more the sea ice, the more solar radiation is reflected back into space and the less is absorbed by the ocean. The ice sheets important because it prevent freshwater such as rain, snow; and river runoff that could have added to ocean. In addition, the glacier retreating is also considered, as sea ice is decreasing, ice on land is decreasing as well due to warmer atmosphere temperature and change the precipitation patterns.
Ocean warming has impacts on the following:
Sea level rise
Man’s impact on climate
The temperatures of the earth and oceans are increasing; sea ice and glaciers are decreasing. The human activities are changing the composition of the atmosphere, increasing the concentration and changing mix of greenhouse gases. It is not the natural resource that harms the earth’s environment; it is what human do with the natural resource. The burning of fossil fuels in factories to make products and power, and fuels used by automobiles and planes cause a great increase in carbon dioxide gas in the atmosphere.
Climate change is one huge and most pressing issues facing humanity in the 21st century and beyond. There is need to create awareness of negative impacts of climate change and globe warning. The trend towards warmer temperatures is increasing from studies and such increases would cause multiple problems for the earth including ecosystem dislocations, species extinction, sea level; and changes in the frequency and magnitude of severe weather events.
The impacts of change are possible large and adverse, but remain sufficiently uncertain what measurable estimates are in the 21st century and beyond