The temperature of sea water generally decreases with depth, and the layer of water of a certain thickness where the rate of decrease is maximum is called an oceanic thermocline.
In the low and mid latitudes of the ocean, the thermocline between the water layer of approximately 200 meters and 1000 meters is called "permanent" because it does not change with the “sexual” seasons. thermocline” or “main thermocline”. The thermocline is found in deeper marine areas. At different depths, the temperature and pressure of sea water change significantly. It constitutes a natural barrier allowing submarines to hide. It can effectively prevent detection by sonar, but it also comes with dangers.
The permanent thermocline is the result of a combination of physical processes such as heating by solar radiation, rotation of the earth, atmospheric wind stressric, the rise of the oceans and the halothermal circulation. The metaphor is that the density of cold water is high and that of hot water is low. If there is no disturbance due to external factors, the stratification of cold water at the bottom and hot water at the top is stable. Obvious delamination limits can be observed during testing.
The source of ocean temperature differences
Sea water on the ocean surface shows obvious vertical movements under the action wind waves, currents and tides, so that the sea surface The absorbed solar radiation energy can spread deeper. This layer of seawater with vertical mixing motion is the mixed layer mentioned above. The thickness of the mixed layer generally reaches 100 meters, and can reach 200 meters in monsoon areas.
While absorbing solar radiation, the surface of theThe ocean also dissipates heat in the form of seawater evaporation and long-wave radiation to the atmosphere. The heat absorption and dissipation of the mixed layer are in dynamic equilibrium, which means that the seawater temperature of the mixed layer is relatively stable. Especially in tropical and subtropical seas between 20° north and south latitude, the temperature of the mixed layer is above 25°C all year round.
The mixed layer temperature in tropical sea areas can be 28-30℃. Solar radiation exhibits periodic diurnal and seasonal changes, so the seawater temperature of the mixed layer also exhibits corresponding diurnal and seasonal changes. Due to the huge heat capacity of sea water, the temperature variation range between day and night is only 0.
Reference for the above content: Baidu Encyclopediaopedia-Ocean Thermocline