(Greenland’s vast Jakobshavn Isbrae Glacier rushes toward the sea at 10 miles per year. Image source: The University of Washington)
Polar amplification. It’s kind of a dirty word in the climate science community. It’s, what would seem, a counter-intuitive displacement of much of the warming world’s heat over some of its coldest regions, during its coldest seasons.
It’s not the curse word that everyone can’t say. No, that’s more likely hydrogen sulfide gas — the veritable F-word of the oceanic climate community and only slightly worse than the M-word, methane. But it’s an uncomfortable term nonetheless because it brings up some rather uncomfortable issues.
Like why, for example, would the Arctic suck up so much of the world’s extra greenhouse gas accumulated heat during winter? And at what point, after taking on so much of this heat, do the seasons begin to change? At what point does winter, for the North, begin its slow and tumultuous, decades-to-centuries long, death? Are we now starting to see the strange attractors? Those excession offspring in the climate models. Emergent properties of Earth systems parameters wrenched into horrible forms by amplifying feedbacks?
(Temperatures above 80 North have remained above average since January 1. Temperatures in the same zone for the past ten days have averaged 13 C above the, already warmer than average, 1954 to 2014 mean. These temperatures are roughly equal to those typically seen in May. Other regions of the Arctic, as discussed below, have also shown extraordinary warmth. Image source: DMI.)
If there are people to look back at this time, hundreds of years from now, people who still retain the knowledge and tools today afforded to us by science and a clear, unadulterated recollection of this era of history, they would point to these years and say that this period was when the first evidence of winter’s eminent demise in the north became visible.
For winter is indeed dying, the victim of our ongoing and increasing emission of heat trapping gasses. And it would take a miraculous reversal and intervention, at this point, to save her.
A rash of Arctic heat in winter
Extreme heat in the high Arctic has been an ongoing theme throughout this winter. And whether you know it or not, if you live in the Northern Hemisphere, you’ve been affected. The ‘polar vortex’ collapse episodes that have been so prominent, if misreported, in the mainstream news have been directly spurred by this excess accumulation of heat in the North. The heat — kicking out and weakening the cold core cyclones that prefer to reside directly over the world’s roof. The after-affect of which was Arctic cold fleeing south over the continents as temperatures in the High Arctic climbed to readings 36 F+ higher than average for this time of year over broad regions.
This massive polar amplification, the consequence of the hottest Arctic conditions in at least 44,000 years, induced amazing sea ice losses since 1979, tripping the polar region and related weather patterns into new, far less stable, states. Such sea ice losses have been implicated in various far-reaching effects from a drying and baking of the American West to vicious alterations in the polar Jet Stream resulting in 11 month long blocking patterns and weather conditions that tend to remain stuck over regions for months and months on end.
This extreme heat and related atmospheric and environmental changes triggered some of the hottest temperatures ever recorded in Alaska this January, setting off a flush of spring-like melt and a freakish avalanche that cut off the city of Valdez.
And all this was happening during winter time. During the time when these furthest north locales were supposed to be coldest, certainly colder than down south, which, in many instances, was not the case.
200,000 square kilometers of sea ice lost in early February
But the above isn’t all in the long list of heat-caused extremes for the Arctic during the winter of 2013-2014. Now we can add to that tally a significant sea ice melt in the midst of winter.
As heat built in the Arctic over the most recent extreme warming episode, it tended to focus on two regions along the sea ice edge now vulnerable to episodes of winter-time melt. First, in the Bering Sea, where warmth has been almost continually flooding up along the high pulse of an 11 month blocking pattern and then in Baffin Bay, where warmer than normal winds have drawn heat up along coastal areas adjacent to the western slopes of Greenland creating anomalous conditions there.
For the Bering Sea, conditions were particularly grim. Throughout the season, sea ice measures have remained about half their normal values and by the end of January had settled about 100,000 square kilometers lower than during a normal season, leaving the ice state for this, typically frozen, sea a mere shade of past winter ice states. But in early February, with the flush of new warmth coming up from the south, ice totals fell by another 100,000 square kilometers at a time when the ice should have been expanding, leaving the Bering Sea about 250,000 square kilometers below average.
(Bering Sea ice area anomaly departures from the, already low, 1979 to 2008 mean. Image source: Cryosphere Today.)
As mentioned above, Baffin Bay went through a similar, if less extreme, melt in early February falling from about 1 million square kilometers of sea ice to about 900,000 square kilometers from January 30 to February 2 before showing a slight uptick over the past day. Overall, Bering Sea ice area is its lowest on record for this time of year while Baffin Bay is currently seeing its third lowest year in the record.
Now, with melt season less than a month away, it is still possible that the Bering Sea and Baffin Bay may yet see some added freeze through March. But the weather pattern, at least over the next seven days, is not favorable for such an event and long range models seem to indicate continued flows of warmer than normal air to both of these vulnerable regions.
Greenland shows sporadic melt during Winter
In addition to the fits of sea ice melt occurring during coldest months in nearby Baffin Bay, the West Coast of Greenland is also showing patchy melt during the period. Model and sensor measures of the Greenland ice sheet provided by DMI showed patchy melt and ice mass loss not only in the most recent assessment, but also throughout the month of January.
(Ice Mass Balance for Greenland on February 3 on the left, 2014 compared to the, already warm, 1990-2011 base period on the right. Note the small but visible areas of pink indicating patches of ice mass loss along Greenland’s Western and Southeastern Coastal zones in the 2014 map. Also note the notably larger areas of ice mass gain in the 1991-2008 base period map which shows almost no areas of ice loss. Image source: DMI)
Certainly, these are small melt zones, but any Greenland melt during February is worth sitting up and taking notice of.
New study shows Greenland’s fastest glacier tripled its seaward velocity
As Greenland struggled not to melt during what should be the frigid month of February, a scientific report released this week in the journal The Cryosphere provided yet more evidence of its ongoing thaw and glacial destabilization. The report, also covered in LiveScience, showed the Jakobshavn Isbrae glacier had more than tripled its 1990s speed as of 2013.
According to reports, the glacier had sped up to 150 feet per day (11 miles per year) during the summer of 2012 and had maintained this forward velocity through the summer of 2013. The glacier slowed somewhat during winter, but only to about 8.6 miles per year, resulting in a combined average speed of about 10 miles per year. By contrast, the glacier’s rush to the sea during the 1990s was considerably slower, at less than 3 miles per year and, by 2000, the glacier had sped up to around 6 miles per year, about half the current rate.
(Satellite Shot of Jakobshavn Isbrae collapse in 2010. Image source: Earth Observatory)
Overall, this single glacier has contributed about 1 millimeter to sea level rise over the past decade. It is worth noting that Greenland hosts hundreds of sea terminating glaciers, 99% of which are speeding up or increasing their melt rates.
“We’ve been watching it for over a decade now, so it was quite a surprise when it popped up in 2012 with these unusually high speeds,” said Ian Joughin, lead study author and a glaciologist at the University of Washington’s Polar Science Center in Seattle.
Unfortunately, glaciologists expect the Jakobshavn Isbrae glacier to speed up by a factor of 10 during the coming decades, dumping more than 35 miles worth of glacial ice into the ocean each year.