Tag: arctic

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Refreezing Poles Could Be Done?

By Faye Holst

The poles are warming several times faster than the global average, causing record smashing heatwaves that were reported earlier this year in both the Arctic and Antarctic. Melting ice and collapsing glaciers at high latitudes would accelerate sea level rise around the planet. Fortunately, refreezing the poles by reducing incoming sunlight would be both feasible and remarkably cheap, according to new research published in IOP Publishing’s Environmental Research Communications (https://iopscience.iop.org/article/10.1088/2515-7620/ac8cd3).

Scientists laid out a possible future program whereby high-flying jets would spray microscopic aerosol particles into the atmosphere at latitudes of 60 degrees north and south – roughly Anchorage and the southern tip of Patagonia.  If injected at a height of 43,000 feet (above airliner cruising altitudes), these aerosols would slowly drift poleward, slightly shading the surface beneath.  “There is widespread and sensible trepidation about deploying aerosols to cool the planet,” notes lead author Wake Smith, “but if the risk/benefit equation were to pay off anywhere, it would be at the poles”.


Particle injections would be performed seasonally in the long days of the local spring and early summer. The same fleet of jets could service both hemispheres, ferrying to the opposite pole with the change of seasons.
Pre-existing military air-to-air refueling tankers such as the aged KC-135 and the A330 MMRT don’t have enough payload at the required altitudes, whereas newly designed high-altitude tankers would prove much more efficient. A fleet of roughly 125 such tankers could loft a payload sufficient to cool the regions poleward of 60°N/S by 2°C per year, which would return them close to their pre-industrial average temperatures.  Costs are estimated at $11 billion annually – less than one-third the cost of cooling the entire planet by the same 2°C magnitude and a tiny fraction of the cost of reaching net zero emissions.


“Game changing though this could be in a rapidly warming world, stratospheric aerosol injections merely treat a symptom of climate change but not the underlying disease. It’s aspirin, not penicillin. It’s not a substitute for decarbonization,” says Smith.


Cooling at the poles would provide direct protection for only a small fraction of the planet, though the mid-latitudes should also experience some temperature reduction. Since less than 1% of the global human population lives in the target deployment zones, a polar deployment would entail much less direct risk to most of humanity than a global program. “Nonetheless, any intentional turning of the global thermostat would be of common interest to all of humanity and not merely the province of Arctic and Patagonian nations,” adds Smith.
In summary, the current study is just one small and preliminary step towards understanding the costs, benefits, and risks of undertaking climate intervention at high latitudes. It provides further reason to believe that such tools could prove useful both in preserving cryosphere near the poles and slowing sea level rise globally.

https://ioppublishing.org/news/refreezing-poles-feasible-and-cheap-new-study-finds/

AR Issue #59
Could Arctic Hold Secrets of Alien Life

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Ice Age Trigger Mystery Solved?

By Daniel Stolte

Where did the ice sheets that rang in the last ice age more than 100,000 years ago come from, and how could they grow so quickly? A new study tries to solved both mysteries.

Understanding what drives Earth’s glacial–interglacial cycles—the periodic advance and retreat of ice sheets in the Northern Hemisphere—is no easy feat, and researchers have devoted substantial effort to explaining the expansion and shrinking of large ice masses over thousands of years. The new study from University of Arizona researchers, published in the journal Nature Geoscience, proposes an explanation for the rapid expansion of the ice sheets that covered much of the Northern Hemisphere during the most recent ice age, and the findings could also apply to other glacial periods throughout Earth’s history.


About 100,000 years ago, when mammoths roamed the Earth, the Northern Hemisphere climate plummeted into a deep freeze that allowed massive ice sheets to form. Over a period of about 10,000 years, local mountain glaciers grew and formed large ice sheets covering much of today’s Canada, Siberia and northern Europe.


While it has been widely accepted that periodic “wobbling” in the Earth’s orbit around the sun triggered cooling in the Northern Hemisphere summer that caused the onset of widespread glaciation, scientists have struggled to explain the extensive ice sheets covering much of Scandinavia and northern Europe, where temperatures are much more mild.
Unlike the cold Canadian Arctic Archipelago where ice readily forms, Scandinavia should have remained largely ice-free due to the North Atlantic Current, which brings warm water to the coasts of northwestern Europe. Although the two regions are located along similar latitudes, the Scandinavian summer temperatures are well above freezing, while the temperatures in large parts of the Canadian Arctic remain below freezing through the summer, according to the researchers. Because of this discrepancy, climate models have struggled to account for the extensive glaciers that advanced in northern Europe and marked the beginning of the last ice age, said the study’s lead author, Marcus Lofverstrom.


“The problem is we don’t know where those ice sheets (in Scandinavia) came from and what caused them to expand in such a short amount of time,” said Lofverstrom, an assistant professor of geosciences and head of the UArizona Earth System Dynamics Lab.


To find answers, Lofverstrom helped develop an extremely complex Earth-system model, known as the Community Earth System Model, which allowed his team to realistically recreate the conditions that existed at the beginning of the most recent glacial period. Notably, he expanded the ice-sheet model domain from Greenland to encompass most of the Northern Hemisphere at high spatial detail. Using this updated model configuration, the researchers identified the ocean gateways in the Canadian Arctic Archipelago as a critical linchpin controlling the North Atlantic climate and ultimately determining whether or not ice sheets could grow in Scandinavia.


The simulations revealed that as long as the ocean gateways in the Canadian Arctic Archipelago remain open, Earth’s orbital configuration cooled the Northern Hemisphere sufficiently to allow ice sheets to build up in Northern Canada and Siberia, but not in Scandinavia.


In a second experiment, the researchers simulated a previously unexplored scenario in which marine ice sheets obstructed the waterways in the Canadian Arctic Archipelago. In that experiment, the comparatively fresh Arctic and North Pacific water – typically routed through the Canadian Arctic Archipelago – was diverted east of Greenland, where deep water masses typically form. This diversion led to a freshening and weakening of the North Atlantic deep circulation, sea ice expansion, and cooler conditions in Scandinavia.


“Using both climate model simulations and marine sediment analysis, we show that ice forming in northern Canada can obstruct ocean gateways and divert water transport from the Arctic into the North Atlantic,” Lofverstrom said, “and that in turn leads to a weakened ocean circulation and cold conditions off the coast of Scandinavia, which is sufficient to start growing ice in that region.”


“These findings are supported by marine sediment records from the North Atlantic, which show evidence of glaciers in northern Canada several thousand years before the European side,” said Diane Thompson, assistant professor in the UArizona Department of Geosciences. “The sediment records also show compelling evidence of a weakened deep ocean circulation before the glaciers form in Scandinavia, similar to our modeling results.”
Together, the experiments suggest that the formation of marine ice in northern Canada may be a necessary precursor to glaciation in Scandinavia, the authors write.


Pushing climate models beyond their traditional application of predicting future climates provides an opportunity to identify previously unknown interactions in the Earth system, such as the complex and sometimes counterintuitive interplay between ice sheets and climate, Lofverstrom said.


“It is possible that the mechanisms we identified here apply to every glacial period, not just the most recent one,” he said. “It may even help explain more short-lived cold periods such as the Younger Dryas cold reversal (12,900 to 11,700 years ago) that punctuated the general warming at the end of the last ice age.”

https://news.arizona.edu/story/new-study-solves-long-standing-mystery-what-may-have-triggered-ice-age

AR #81

“Between Ice Ages”

By William B. Stoecker

 

 

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The Hunt for Shackleton’s Lost ‘Endurance’: Part II

The quest for ‘The Endurance’, the long-lost ship of famed Antarctic explorer Ernest Shackleton is scheduled to resume in 2022. Though a previous attempt in 2019 failed, organizers of the new expedition are undaunted, and more determined than ever to find the ship, lost since 1915. To succeed, the expedition will have to struggle through miles of pack ice and dive to 10,000 feet below the dark waters of the Weddell Sea. But though the target may be elusive, searchers, like Shackleton, perhaps may hope for some special help.

Author John Geiger’s 2010 book, The Third Man Factor, Surviving the Impossible, has many stories of how people at the very edge of death often sense a presence beside them who encourages them to make one final effort to survive.

Such anecdotes, it turns out, are quite common. In moments of great danger, stress and privation many find themselves accompanied by a stranger, or unseen presence, who comforts and guides them. The phenomenon is so common, in fact, that it has a name: ‘the Third Man factor’, described as an encounter with an unseen presence or spirit providing comfort in a traumatic situation.

Shackleton wrote about one such event in 1916 when he and two others were accompanied by a mystery companion during their arduous 36-hour hike across Elephant island to a whaling station in South Georgia on a mission to bring help to stranded colleagues. All three spoke later of their shared awareness of another individual who walked with them to the whaling station, but no further. Shackleton later wrote in his book South: “during that long and racking march of thirty-six hours over the unnamed mountains and glaciers of South Georgia, it seemed to me often that we were four, not three.”

The significance of such experiences are, of course, dismissed in orthodox circles as hallucinations brought on by stress—psychological disorders like sleep paralysis. When compared to the evidence, though, such explanations fall short. Shackleton and his companions, for instance, all experienced an encounter with the same individual, something unaccounted for by any theory of strictly subjective awareness.

Perhaps it is time to take another look at the notion of guardian angels. Certainly, in this tumultuous time, we could all use a little more angelic assistance.