With the Arctic recording its second warmest year on record, despite global temperatures moderating slightly, the U.S. National Ocean and Atmospheric Administration (N0AA) on Tuesday warned that the polar ice cap “shows no sign of returning to the reliably frozen region it was decades ago.”
That latest warning comes at a time when Alaska is witnessing another unusually warm winter, and scientists from the Lawrence Livermore Laboratory in California are theorizing that the loss of Arctic sea ice could have a profound affect on the climate of the Pacific Rim even without global warming.
Ivana Cvijanovic and her colleagues, writing in Nature Communications earlier this month, argue there is evidence that sunlight heating dark, exposed Arctic Ocean waters instead of being reflected back into space by white, snow-covered ice there so alters the energy balance of the North Pacific Ocean that the atmosphere is effected.
“From 2012 to 2016, California experienced one of the worst droughts since the start of observational records,” they write. “As in previous dry periods, precipitation-inducing winter storms were steered away from California by a persistent atmospheric ridging system in the North Pacific. Here we identify a new link between Arctic sea-ice loss and the North Pacific geopotential ridge development. In a two-step teleconnection, sea-ice changes lead to reorganization of tropical convection that in turn triggers an anticyclonic response over the North Pacific, resulting in significant drying over California.”
Ignore California – if you are interested in Alaska – and focus on one key phrase: “persistent atmospheric ridging.”
Here’s what’s Cvijanoic’s paper says about that:
“We focus our analysis on the December–February season, because these months yield the largest impact of sea-ice changes on Californian precipitation in our model simulations. The most striking feature of the precipitation response to Arctic sea-ice loss is the reorganization of tropical rainfall and an apparent northward precipitation shift. The Arctic sea-ice decline also results in significantly less precipitation over California—a consequence of a geopotential ridge in the North Pacific that steers the wet winter air masses northward into Alaska and Canada, away from California.”
From an Alaska perspective, Cvijanovic only overlooks one thing. Along with the air mass being wet and the season winter, the air is also warm because its moving north out of the tropics.
To oversimplify this, what happens is that a ridge of high pressure air forms over California like a rock in a river. The atmospheric river flowing west to east into that rock is deflected north and south. The northward deflected weather moves up along the coast of Canada into Alaska.
The Copper River Basin was hit by a snow bomb last week. The state capital in Juneau saw a record temperature of 56 degrees on Friday. Cordova was blasted by warm weather and a Gulf of Alaska storm packing hurricane-force winds on Sunday.
“It was warmer in Juneau on Friday than it was in Houston. That’s the Houston in Texas, not the one in Southcentral Alaska,” the Juneau Empire reported. “And Juneau wasn’t alone.
“Sitka had an extraordinary event: The low temperature Thursday (53 degrees) was above the previous record high for the day (52 degrees).”
The 54 degree temperature at the Juneau International Airport tied for the highest ever there on Dec. 8.
And the warm air that hit Juneau just kept pushing north. Anchorage set a record on Sunday with 46 degrees, 21 degrees above the norm. Smaller communities to the north in the Matanuska-Susitna Borough and to the south on the Kenai Peninsula were similarly far above normal.
The cold air that is normal in these places was flowing down the backside of the “geopotential ridge” into the American Heartland and south from there, which is why Houston was colder than Juneau.
Blame what climate scientist Daniel Swain calls the “ridiculously resilient ridge,” or “The Triple R” for short. It’s a much catchier label than the “geopotential ridge,” and Swain dug up a color-coded graphic from the Global Ensemble Forecast System to illustrate what The Triple R does to weather.
What this all means over the long-term is hard to say. Most climate scientists, noting the ever increasing amount of carbon dioxide in the atmosphere, believe the globe is going to continue to warm and blame the human use of fossil fuels – coal, oil and gas – over the course of the past two centuries.
“The last time CO2 levels at Mauna Loa (Hawaii) were this high, Homo sapiens did not live there,” wrote David Biello in Scientific American. “In fact, the last time CO2 levels are thought to have been this high was more than 2.5 million years ago, an era known as the Pliocene, when the Canadian Arctic boasted forests instead of icy wastes. The land bridge connecting North America and South America had recently formed. The globe’s temperature averaged about 3 degrees C warmer, and sea level lapped coasts 5 meters or more higher.”
But that begs the question of how the earth grew so warm without the “anthropogenic” contribution of humans to the carbon cycle. Without doubt, humans are the most likely suspects in the current increase in CO2 in the atmosphere, but that does not mean that everyone who questions that conclusion is a heretic.
And no one can know what the future will bring. There are adequate reasons to worry about global warming. But where we are at now, well, humans have been here before.
About a thousands years ago, the Vikings colonized Greenland and apparently some parts of Canada as the climate warmed.
“The Vikings migrated from Iceland to Greenland in A.D. 985, with roughly 3,000 people eventually settling in the new land,” writes Mary Caperton Morton at the magazine “Earth.”
“The timing coincides with the Medieval Warm Period, a time of mild temperatures well documented in Europe between 950 and 1250. Between 1360 and 1460, however, around the time of the Little Ice Age, the Viking colonies in Greenland disappeared, leaving behind few clues as to why they were abandoned.”
“…In the 13th century, after three centuries, their world changed profoundly. First, the climate cooled because of the volcanic eruption in Indonesia,” writes Tim Folger at Smithsonian Magazine. ” Sea ice increased, and so did ocean storms—ice cores from that period contain more salt from oceanic winds that blew over the ice sheet. Second, the market for walrus ivory collapsed, partly because Portugal and other countries started to open trade routes into sub-Saharan Africa, which brought elephant ivory to the European market….and finally, the Black Death devastated Europe. There is no evidence that the plague ever reached Greenland, but half the population of Norway—which was Greenland’s lifeline to the civilized world—perished.
“The Norse probably could have survived any one of those calamities separately. After all, they remained in Greenland for at least a century after the climate changed, so the onset of colder conditions alone wasn’t enough to undo them. Moreover, they were still building new churches—like the one at Hvalsey—in the 14th century. But all three blows must have left them reeling. With nothing to exchange for European goods—and with fewer Europeans left—their way of life would have been impossible to maintain. The Greenland Vikings were essentially victims of globalization and a pandemic.”
Those threats remain today. Whether they are greater threats than planetary warming only time will tell for sure.
Pluses and minuses
“In August 2017, sea surface temperatures in the Barents and Chukchi seas were up to 4 degrees C warmer than average, contributing to a delay in the autumn freeze-up in these regions,” NOAA’s “Arctic Report Card” said.
Some will see that as frighteningly bad, but it’s not that simple.
“Pronounced increases in ocean primary productivity, at the base of the marine food web, were observed in the Barents and Eurasian Arctic seas from 2003 to 2017,” the report card said. “Arctic tundra is experiencing increased greenness and record permafrost warming.”
Those would appear to be pluses, but the changes are hard for people to weigh The human animal appears genetically hardwired to favor the status quo over any change.
And there appear to be big changes underway.
“One chapter in the Arctic Report Card shows, using historical data, that the current observed rate of sea ice decline and warming temperatures are higher than at any other time in the last 1,500 years, and likely longer than that,” NOAA said in a Tuesday press release.
“This year’s report card also includes special reports on how the warming trend is affecting valuable fisheries in the eastern Bering Sea; compromising roads, homes and infrastructure due to permafrost thaw; and threatening the high latitudes with increasingly frequent wildfires.”
Change brings change, which is both good and bad. But for Alaskans who love real winters with snow, there are only two words for what it has brought to the start of winter 2016/17:
A NOAA-sponsored report shows that the warming trend transforming the Arctic persisted in 2017, resulting in the second warmest air temperatures, above average ocean temperatures, loss of sea ice, and a range of human, ocean and ecosystem effects.
Now in its 12th year, the Arctic Report Card, released today at the annual American Geophysical Union fall meeting in New Orleans, is a peer-reviewed report that brings together the work of 85 scientists from 12 nations.
While 2017 saw fewer records shattered than in 2016, the Arctic shows no sign of returning to the reliably frozen region it was decades ago. Arctic temperatures continue to increase at double the rate of the global temperature increase.
One chapter in the Arctic Report Card shows, using historical data, that the current observed rate of sea ice decline and warming temperatures are higher than at any other time in the last 1,500 years, and likely longer than that.