A Stormy Arctic Is the New Normal

http://www.scientificamerican.com/article/a-stormy-arctic-is-the-new-normal-excerpt/

February 13, 2015 |By Edward Struzik

From Future Arctic: Field Notes from a World on the Edge, by Edward Struzik. Copyright © 2015, Island Press.

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Severe summer storms like this that cause considerable damage have been relatively uncommon in the western Arctic because of high pressure and sea ice that lingers long into the summer season. With so much heat being reflected back into the atmosphere, there was not enough open water in the past to produce the moisture needed to grow cyclones with any degree of consistency.

This promises to change as the Arctic Ocean becomes seasonally ice-free. In the “New Normal” that is opening up new pathways for killer whales and Pacific salmon to move into the Arctic, rising temperatures and disappearing sea ice are also fueling storms that used to be triggered later in the fall months.

With little or no sea ice to buffer the shoreline, storm driven surges are extending their reach several miles inland, flooding communities, killing wetlands, and accelerating the thawing of permafrost that is already eroding riverbanks and coastlines.

Climatologist Steven Varvus isn’t convinced that the era of storminess in the Arctic is here just yet. But in a recent study that he and his colleagues at the Center for Climatic Research at the University of Wisconsin-Madison published in 2013, they used historical climate model simulations to demonstrate that there has been an Arctic-wide decrease in sea level pressure since the 1800's. “Simulated trends in Arctic mean sea level pressure and extreme cyclones are equivocal,” says Varvus. “Both indicate increasing storminess in some regions, but the magnitude of changes to date are modest compared with future projections.”

If the recent past tells us anything about an increasingly stormy future, it’s that hell comes with high water. One relatively modest storm in 1970 sent a surge of water several miles inland, killing two men who were doing maintenance on a navigation tower on the Mackenzie River in Canada.

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The difference between now and then is that rising sea levels, sinking coastlines and receding sea ice have the potential to transport storm driven surges even farther inland than they have gone before, sending saltwater into places where it can cause catastrophic damage. The effects range from killing tundra plants and freshwater ecosystems to accelerating erosion that is washing the land out from under native communities.

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The storm surges that swept into the Mackenzie and the Yukon-Kuskokwim deltas may be considered extraordinary now, particularly for the length of their reach, but such storms are bound to become more common as sea levels rise, storms pick up steam— and as the western Arctic continues, literally, to sink. Unlike western Hudson Bay which is rebounding from the heavy weight of glaciers that compressed the landscape for tens of thousands of years, the more lightly glaciated regions of the western Arctic of Canada, Alaska and Arctic Russia are sinking at a time when sea levels are rising.

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Frank Günther, a scientist with the Alfred Wegener Institute in Germany, has been, in association with German and Russian colleagues, investigating the causes of the coastal breakdown in Eastern Siberia. In 2013, he and his colleagues reported that summer temperatures that have risen dramatically have exacerbated this breakdown. Between 1951 and 2012, for example, temperatures in the region exceeded the freezing point an average of 110 days. In 2010 and 2011, they did so 127 times. In 2012, the warmest year on record in the Arctic, it happened 134 times.

Over the past two decades, the number of ice-free days averaged 80 per year. In 2012, there were 96 ice-free days that significantly accelerated the erosion that is already taking place.

[This understates the change, since the current conditions are included in the base period.]

Günther predicts that sometime within this century, the island of Muostakh, which is east of the Siberian harbor town of Tiski, will break up into several sections and then disappear altogether.

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The impact of this is being exacerbated by rapid permafrost thawing that is occurring farther upstream along big Arctic rivers such as the Yukon and Mackenzie. Steve Kokelj and his colleagues have documented monumental slumpings of river banks in the Peel River that flows from the Yukon into the Northwest Territories into the Mackenzie. The collapse of these shorelines changes both the chemistry of the rivers and the shoreline soils in a way that may be lethal to fish and favorable for invasive plants species tat are migrating north and overtaking some tundra ecosystems.

All this has implications for Inuit communities as well as Arctic ecosystems.

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This pattern in public policy decision-making continued for decades. Whenever sovereignty, security and economic priorities came into play, environmental integrity and the cultural interests of indigenous people in the Arctic invariably suffered.

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Several years ago, the community embarked on a project that sought to find out what climate change effects elders and hunters were seeing first hand on the land and on the water. Those who responded noted that the spring melt was occurring earlier and the fall freeze up much later. They reported seeing lots of moose in the delta but fewer caribou. Caribou, they thought, were having a hard time finding food. Most everyone agreed that the weather was much harder to predict.

Local initiatives such as this have gone a long way in getting indigenous northerners to trust scientists and decision-makers. In Old Crow, a small Gwich’in town in the northern Yukon, the Vuntut people recognized some time ago that climate change threatened their very existence. Caribou were on the decline, some bird species were dwindling or disappearing and many of the 2,500 lakes in the Old Crow Flats were drying up or changing chemistry. To find the answers to the many changes that they were seeing, community leaders opened the door to hydrologists, permafrost and wildlife scientists to work with them to find the answers.

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