What the heck is a thermoreactive current? I spent a lot of time in school studying water and stuff and I don't remember that term.
In a nutshell, it's a current caused by differences in water temperature, Salinity and landscape that creates upshoots and downdrafts.
Oceanic fronts are boundaries between water masses of different density. Density is a function of temperature and salinity (the amount of dissolved salts in water); therefore, both
thermal (temperature) fronts and
haline (salinity) fronts exist in the ocean. A thermal front is a zone with a pronounced horizontal temperature gradient, while a haline front exhibits a horizontal salinity gradient. Ocean fronts can extend from the surface to the very deep layers of the ocean, often separating very large volumes of ocean water.
Using IR satellite imagery on a relatively cloud-free day, it is possible to detect ocean thermal fronts in the surface layers of the ocean. This is accomplished by locating in an image a distinct gray shade difference that results from the horizontal temperature gradient across a thermal ocean front. Since these temperature differences are often on a magnitude of 2­5° C, image enhancement techniques are often used to highlight the temperature range of the ocean surface and improve the contrast between small differences in sea surface temperature.
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Oceanic fronts can be permanent or transient features. Permanent oceanic fronts include the Gulf Stream front , located off the east coast of North America, and the Kuroshio Current front, located off the east coast of Asia. These frontal boundaries always exhibit a pronounced horizontal temperature gradient and can be up to 1000 meters deep. Transient oceanic fronts usually occur seasonally and are generally weaker, with more diffuse boundaries. Transient fronts may only appear in the ocean for a few weeks during the year; however, they are important components of the ocean system. [/SIZE]
The global conveyor belt thermohaline circulation is driven primarily by the formation and sinking of deep water (from around 1500m to the Antarctic bottom water overlying the bottom of the ocean) in the Norwegian Sea. This circulation is thought to be responsible for the large flow of upper ocean water from the tropical Pacific to the Indian Ocean through the Indonesian Archipelogo. The two counteracting forcings operating in the North Atlantic control the conveyor belt circulation: (1) the thermal forcing (high-latitude cooling and the low-latitude heating) which drives a polar southward flow; and (2) haline forcing (net high-latitude freshwater gain and low-latitude evaporation) which moves in the opposite direction. In today's Atlantic the thermal forcing dominates, hence, the flow of upper current from south to north.
Hope that helps.
Safe diving...
