Posts Tagged ‘Arctic Ocean’

Prediction: The Arctic Will Melt Suddenly

September 12, 2018

So far, the Arctic sea ice has melted at a pace which is best fitted with lines. 10.4% per decade, more exactly. It sounds reasonable, in first approximation, to suppose that will keep on that way. However, most changes start, in first approximation, linearly, before fitting higher power curves.

In the case of Arctic sea ice, a number of mechanisms seem possible to go from linear to nonlinear.  For example, the more sea ice melts, the warmer the sea gets, the harder it is to form sea ice. Such a self-feeding mechanism is an exponential.

However, we, humanity just found a huge new mechanism to potentially melt all ice, and it is operative. It is even of our own making! As with the Fall of Rome, one cause leads to others, which then can feed back on the first.

The discovery?

A blob of warm water, 50 meters below the surface of the Arctic ocean. Why does not come to the surface, if it is warmer than the water above it? Because it is abnormally salty, thus denser.

How was it created? The Chukchi Sea has become ice-free much too much of the year. It is just north of the Bering Strait, and lies on top of the flooded Beringia land bridge between Eurasia and North America. So it is shallow: average depth, 71 meters only, and warms up well. The Chukchi Sea warms up so much it becomes salty, and that salty water sneaks north below cold upper waters (it is blocked from going south by the Strait.

The redder, the more heat content in the Chukchi sea… When the Arctic Ocean starts to churn, the sea ice will all melt…Study lead author Professor Mary-Louise Timmermans, of Yale University (yes, a woman) said: We document a striking ocean warming in one of the main basins of the interior Arctic Ocean, the Canadian Basin… the upper ocean in the Canadian Basin has seen a two-fold increase in heat content over the past 30 years.

The researchers traced the source to waters hundreds of miles to the south, where reduced sea ice has left the surface ocean more exposed to summer solar warming.

Professor Timmermans added: This means the effects of sea-ice loss are not limited to the ice-free regions themselves, but also lead to increased heat accumulation in the interior of the Arctic Ocean that can have climate effects well beyond the summer season.

 

What next? A strong storm, an Arctic hurricane (they happen!)  could push cold waters out, and that would force the warm water up. I would venture to say that this is exactly what happened in August 2012 (generating thereafter the smallest Arctic sea ice ever recorded, by a long shot).

The same will happen again in the future, on a grander scale.

And all the Arctic sea ice could melt, thus warming the Arctic ocean enough to melt all ice, and that in turn, could warm up the ocean enough that summer to prevent the return of the ice thereafter…

It goes without saying that, after the Arctic ocean is ice-free, trillions of tons of methane hydrates laying inside the shallow sea floor will fiercely erupt, freeing trillions of tons of methane. It has happened in the past, and can be violent enough for tsunamis. It is actually already started, albeit on a small-scale, relative to what it could become. Methane is a greenhouse gas with more than 25 times the warming power of CO2 (the “forcing” effectiveness to be a bit more technical). Thus our effort to engineer a man-made Jurassic climate will make great strides. Maybe we will see class 5 hurricane strike Canada?

Fun springs eternal!

Let’s re-engineer a few dinosaurs and pterosaurs, once Canada’s Arctic archipelago is covered with forests, as we are at it…

Patrice Ayme