It is not any marine. Its collapse or even its mere slowdown is capable of Generate “devastating and irreversible” effects on climate of medium planet. It is the surrounding circulation of the Atlantic (AMOCfor its acronym in … English) and works as a ‘heat pump’ for Europe. When almost 13,000 years ago he stopped, part of the continent was under arctic climatic conditions. In recent years, this system of currents has become one of the topics of greatest concern and controversy among climatic scientists: some recent studies have pointed out that the current slows down and approaches its collapse, influenced by global warming . But a new study has joined the debate. And concludes that at least for now, There are no slowdown signs.
The study published a few days ago in ‘Nature Communications’ By a team of researchers from the Oceanographic institution Woods Hole (WHOI) concludes that there is no evidence that the Atlantic Corrientes System has decelerated In the last 60 years. The results were obtained by using the latest generation of available climatic models, much more sensitive to the concentration of greenhouse gases in the atmosphere.
«Our study does not mean that AMOC will not slow down (in the future). Definitely, will decrease strongly and most likely very soonor right now. And a decline will have extremely serious consequences, ”explains to ABC the author of the Jens Terhaar study, scientist affiliated with whoi and senior scientist at the University of Bern. Nor does it rule out the complete collapse of the current. “It could still happen and it could happen soon,” he says. But with the new data, the uncertainty about whether this will happen and when it is very high.
The Gulf current
It could slow down
The Atlantic cools,
Europe cools
Global warming is increasing
the average temperatures of the planet,
But the thaw of Greenland is
cooling a north Atlantic area.
Some scientists believe this could
slow down or stop currents
Warm marinas that soften the weather.
Attention focuses on the current
Gulf, which borders the US coast
And it reaches Scandinavia. Is part of a
circulation system that influences
In the weather and meteorology of America
North and Western Europe.
Heat release zones to the atmosphere
Currents are continuous flows of water
oceanic created by winds,
the differences in temperature and salinity, the
tides and the rotation of the Earth:
It is the system known as circulation
Thermhaline
Oceans absorb most of the
solar heat and currents distribute it by
All the globe, acting as a thermostat
of the weather. Water evaporates and increases the
temperature and moisture of the air, forming
rains and storms.
In fact, almost all the rain that falls on the
Earth originates in the ocean.
Fountain: NOAA / NY Times /
Julian de Velasco, Gonzalo López / ABC
The Gulf current could slow down
The Atlantic cools, Europe cools
Global warming is increasing the average temperatures of the planet,
But the thaw of Greenland is cooling an area of the North Atlantic.
Some scientists believe that this could slow or stop currents
Warm marinas that soften the weather.
Attention focuses on the Gulf current, which borders the US coast
And it reaches Scandinavia. It is part of a circulation system that influences
in the weather and meteorology of North America and Western Europe.
Heat release zones to the atmosphere
The currents are continuous flows of oceanic water created by the winds,
The differences in temperature and salinity, tides and the rotation of the Earth:
It is the system known as thermohaline circulation.
The oceans absorb most of the solar heat and the currents distribute it
Throughout the globe, acting as a weather thermostat. The water evaporates and
Increases the temperature and humidity of the air, forming rains and storms.
In fact, almost all the rain that falls on the earth originates in the ocean.
Fountain: NOAA / NY Times / Julian de Velasco, Gonzalo López / ABC
The AMOC flows throughout the Atlantic and includes the Gulf current. Is comparable to a giant conveyor belt that moves warm and superficial waters from Florida to the north. There they cool and interact with the fresh water of the thaw of Greenland and the rains, sinking. Once in the depths, the mass of water flows back to Ecuador, where the cycle is repeated. But global warming can stop this cycle.
Few direct data
The magnitude and complexity of the AMOC have made difficult your analysis until now. The first time that direct data of this ocean current was achieved in 2004 and, since then, a slight deceleration is seen. However, it is not clear if it is part of the normal climate variability or if it indicates something else. That is why experts need to go back further over time.
For this, scientists use indirect records, that are far from being perfect. They look for patterns in the surface temperature of the sea, in the values of density or salinity of the water, in the sediments. And apply mathematical models. One of the most used indicators so far has been The surface temperature of the sea In the North Atlantic, which with greater slowdown seemed to correlate with a “cold stain” of water in the North Atlantic. His analysis concluded in 2018 that the speed of the AMOC was the slowest in a thousand years, shooting the alarms.
The WHOI team tried to recreate these results by applying the latest generation of climatic models. They tested 24 in total, but their results differ from those of 2018. «The relationship between subpolar surface temperatures and the AMOC is substantially weaker in hundred -time scales of what was previously thought, and very weak in annual or decnal time scales, ”says Terhaar.
After applying the models, the team concluded that there was a more reliable indicator to see if the AMOC slows down, called «Mar-Aire Heat Flow», which simulates the exchange of heat between the ocean and the atmosphere. And that indicator does not show a slowdown of the ocean system between 1963 and 2017.
Debate
The proposal has generated controversy in the scientific community. Stefan Rahmsorf, author of the 2018 article, has answered in a long article that the new analysis «Does not change my evaluation of the weakening of the AMOC in no way “, considering that the data of loss of superficial heat” are much less precise “than the temperature data of the sea surface. In turn, Terhaar insists that there are more and more studies that doubt the reliability of the surface temperature of the sea in the North Atlantic as an indicator of the AMOC speed.
«There are still uncertainties With respect to the MAOC decline, ”acknowledges ABC Peter Ditlevsen, which in 2023 published another article in which he warned that the AMOC approaches collapse. It points to even the new models applied “are also uncertain”, with reconstructions that do not coincide everywhere. And although the study is “interesting,” says the models continue to show variability. “Our predictions of a collapse in the near future are based more on increasing fluctuations than on a constant slowdown.”
In any case, everyone coincides in one thing: the amoc It will weaken in response to global warming And it is a serious risk.
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