The temperature of water situated in the subtropical Atlantic experienced a drop of 0.15C between 1998 and 2006. This has been revealed by a study led by the IEO (Spanish Oceanography Institute) which suggests that circulation caused by wind could be responsible for this "unusual" behaviour.
Whilst the water temperature in this area, situated along the 24.5 north parallel, from the African coast to the Caribbean, rose by 0.27C between 1957 and 1998, researchers have recorded a drop of 0.15C in the same area between 1998 and 2006.
"In the ocean there are very pronounced cycles of change, and therefore, changes like those which took place in the coordinates analysed can reoccur in any location and at any time", Pedro Joaqun Vlez Belch, main author and researcher for the IEO's Canarian Oceanography Centre, stresses to SINC.
According to the study, which was published recently in the Journal of Physical Oceanography, this phenomenon should not be linked to climate change. "The ocean's natural variability mechanisms are more significant than we thought", declares Vlez Belch. The team is considering various hypotheses to explain the change in temperatures.
For the scientists, this cooling could be due to "circulation forced by the wind". "Changes in the global structure of winds in the north Atlantic cause oscillations on the ocean's surface layer which can be felt up to 2000 metres deep", the expert points out.
However, the scientists discard the hypothesis of thawing despite the fact that some water masses, originating in the Antarctic and the Mediterranean, have an influence in the area analysed. The temperature drop "should have been observed clearly in the areas close to the North Pole", maintains Vlez Belch. And this was not the case.
The scientists measured the temperature and salinity of three oceanic layers: waters from the thermocline (300-800 metres), surface ocean (600-1800 metres) and inte
FECYT - Spanish Foundation for Science and Technology