In recent days, news has circulated according to which one of the main ocean currents would have reversed for the first time in history, with potential catastrophic effects on the global climate. The alarm started from an article by Intelliginethen taken up by various international media, which referred to a study published at the end of June in the magazine Proceedings of the National Academy of Sciences (Pnas). According to the relationship, the Deep Western Boundary Current (DWBC), a fundamental component of the southern Atlantic circulation upside down (Amoc), would have suddenly changed direction.
The news, however, is not reflected in the published scientific data. The alleged alarm on the reverse of the DWBC would merge on an incorrect interpretation – and communication – of the results of the research, as the same authors of the article have clarified to the newsweek site.
What the study really says
The study in question, conducted by an international team led by Alessandro Silvano of the University of Southampton, focused on aAnalysis of changes in surface salinity in the Antarctic Ocean. No direct reference, therefore, to the inversion of the DWBC nor to an imminent collapse of the AMOC.
Between the 80s and 2015, the surface water of the Antarctic Ocean tended to become less salty, probably due to the expansion of sea ice. But in the last ten years, satellite data show a turnaround: salinity has increased, while ice coverage has drastically reduced.
“Our study found that surface salinity in the Antarctic Ocean has increased while sea ice has reduced,” Silvano explained to Newsweek. “This has been unexpected, since it is generally believed that the dissolution of the sea ice refresh the ocean surface”.
An incorrect press release confused the waters
Media confusion was born, at least in part, from an initial press release of theInstitut de Ciències del MarSpanish research body involved in the study. Antonio Triel, co -author of the research, clarified that some phrases of the press release were inaccurate, due to an “incorrect translation” and “improper use of words”. These inaccuracies have brought some media, such as Intellinews, to erroneously interpreted the results, claiming that a DWBC reversal had occurred.
“We are not talking about the DWBC in our recently published work. Ampo is not in crisis this year,” Silvano specified in Newsweek. Triel also stressed that the study shows “a change in the structure of the Antarctic Ocean”, but not a current reversal.
Real but less spectacular effects
Beyond the exaggerations, the study offers disturbing food for thought. The increase in surface salinity and the reduction of vertical stratification could make the ocean more subject to a greater mixing between deep and superficial layers. This process could report heat from the abysses to the surface, accelerating the dissolution of the sea ice and triggering a potential vicious circle.
“If this increase in continuous salinity could increase vertical mixing, subtracting warmth from the deepest ocean strata to the surface and further accelerating the dissolution of the sea ice,” said Silvano. A dynamic that, if confirmed, could also have consequences for the marine ecosystem and the global climate.
In fact, the reduction of antarctic sea ice is not an isolated phenomenon. THEinfluence the reflectivity of the earth’s surface (the albedo), alters atmospheric currents And It can encourage the formation of Iceberg. All phenomena that interact in a complex way and can contribute to climatic instability on a planetary scale.
What remains after the clamor
The scientific analysis published on PNAS does not show any overturning of the ocean currents, as erroneously reported by some newspapers. However, the data indicate a rapid and anomalous evolution of the Antarctic Ocean, which is becoming salted on the surface while sea ice retires.
It is a change that could alter the delicate balances between ocean, atmosphere and global atmosphere, but which must be observed for what it is: a signal to be monitored, not an epochal event already underway. The reality of the collected data is less spectacular than the news circulated, but no less relevant for this.
The study suggests the need to review some models and hypotheses on the behavior of Antarctic waters. And above all, it indicates that we are entering a phase in which small local imbalances can have wider effects than expected. No reversal, therefore, but a process to follow carefully.
