Arctic Sea Ice

PIOMAS January 2018

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Volume increases for December in the last 10 years aren't all that far apart, ranging from 3500 to 4000 km3 (rounded off). This year was on the lower side of that range, with 3547 km3. Only 2010 and 2014 were lower than that, just barely. This means that 2017 ends the year in third spot. The gap with 2012 has been reduced some more, from 733 to 497 km3, and the quickly widening gap with 2016 has stopped widening for now, going from 1482 to 1340 km3.

Here's how the differences with previous years have evolved from last month:

On Wipneus' version of the PIOMAS graph you can see how that difference with 2012 has become smaller again since September (red is 2017, purple is 2012):

Giant metaphor crashes through the ice

This ties in with the recent blog post about Consensus and consequences. From the Cantech Letter online magazine:

Giant metaphor crashes through the ice
in Canada’s North

An 80-thousand pound metaphor crashed through the ice in the Northwest Territories Saturday in the form of an off-white Western Star fuel tanker.

The CBC reports that the tanker was carrying heating fuel to Deline, a town of about 500 near the Great Bear Lake. The accident happened just three days after the territory’s transportation department raised the allowable weight on the Great Bear Ice Crossing from 10,000 kilograms to 40,0000 [you have got to be kidding; N].

The truck is currently semi-submerged in the top portion of the ice, which one official estimates to be between 100 and 120 centimetres thick. No one was injured in the incident.

The symbolism of a fuel truck trapped in the ice in Canada’s north will not be lost on anyone who follows news from the scientific community about climate change.

Recent data from the NASA and the National Oceanic and Atmospheric Administration confirms that global warning is particularly intense in the Arctic —a phenomenon referred to as “Arctic amplification”. In January, scientists confirmed a record low level for Arctic sea ice. And the data for January was particularly worrying.

“We’ve looked at the average January temperatures, and we look at what we call the 925 millibar level, about 3,000 feet up in the atmosphere,” says Mark Serreze, director of the National Snow and Ice Data Center. “And it was, I would say, absurdly warm across the entire Arctic Ocean.”

Read the rest of the article here (permafrost also gets a mention).

Speaking of which, here's a cool animation (in German) from the Alfred Wegener Instute explaining what Permafrost is:

 

Potential record ozone hole over the Arctic

The ozone hole as a phenomenon is mostly associated with the Antarctic, but the Arctic also has one, much more variable in size than its Southern Hemisphere sibling. This winter the stratosphere over the Arctic has been extremely cold, causing a lot of ozone to be destroyed. If things keep up, even more ozone will be lost in spring and the hole could become larger than the 2011 record ozone hole. Read more about it in this press release by the Alfred Wegener Institute.

A good article on the subject was posted on the Science website a couple of days ago, explaining what it all means and what the role of climate change is:

Record ozone hole may open over Arctic
in the spring

Lingering atmospheric pollutants and a blast of frigid air have carved an unusually deep hole in Earth’s protective ozone layer over the Arctic, and it threatens to get deeper. Atmospheric scientists are analyzing data from weather balloons and satellites for clues to how the ozone will fare when sunlight—a third factor in ozone loss—returns to the Arctic in the spring. But they are already worrying about how extra ultraviolet light might affect humans and ecosystems below and wondering whether climate change will make such Arctic holes more common or severe.Record cold temperatures in the Arctic stratospheric ozone layer, 15 to 35 kilometers up, are the proximate cause for this year’s losses, because they help to unleash ozone-destroying chemicals. “This winter has been stunning,” says Markus Rex, an atmospheric chemist at the Alfred Wegener Institute in Potsdam, Germany. By next week, about 25% of the Arctic’s ozone will be destroyed, he says.

This time of year, the stratosphere tends to warm up with the breakdown of the polar vortex, a cyclone that traps cold air. But if a strong vortex persists another month as light returns to the Arctic after the dark winter, ozone losses will get much bigger, Rex says. Conditions are ripe for losses to surpass a record Arctic ozone hole observed in the spring of 2011, he adds.

At Earth’s surface, ozone is a caustic chemical and a health hazard. But in the stratosphere, it shields the planet from ultraviolet light. Scientists noticed in the 1980s that chlorine-containing chemicals commonly used in refrigerants were reacting to form compounds that ate away stratospheric ozone, especially over the poles. The 1989 Montreal Protocol led to the phaseout of those chemicals, but their long atmospheric lifetime means that seasonal ozone losses will persist well into this century. Every year, a major ozone hole opens up over Antarctica, where winters are colder and polar vortices are stronger and more stable than over the Arctic.

But this year, the Arctic could be the poster child. Cold temperatures have allowed nitric acid, mostly from natural sources, to condense and form the peculiar, iridescent clouds that have been spotted all over northern latitudes this winter. “They’re beautiful, but once I see them, I’m concerned—they’re dangerous,” Rex says. That’s because the clouds catalyze the reactions that mobilize chlorine into active chemicals that can react in the presence of sunlight to destroy ozone.

Read the rest of the article here.

Although it is said that the Antarctic ozone hole may be a factor in the sea ice increase of recent years, I'm not sure what effect this will have on Arctic sea ice, if any. But it's noteworthy nonetheless.

Miscellanea

I have collected a couple of interesting news articles and interviews over the past few weeks, and now it's time to share with those of you who haven't seen them. I'm posting what I found the most interesting excerpts, follow the links if you want to read the rest.

First up, an interview on SciencePoles with Dr. Agneta Fransson, chemical oceanographer at the Norwegian Polar Institute, called Explaining ocean acidification and consequences for Arctic marine ecosystems:

Are Arctic waters more susceptible to ocean acidification compared to the rest of the world’s oceans? If so, why?

The Arctic Ocean has had high concentrations of CO₂ dissolved in it since historical times. This is due to physical processes such as cooling of the relatively fresh surface water, which causes this surface water to sink below the surface towards the bottom of the ocean. When this colder, denser water sinks, it sequesters atmospheric CO₂ in the Arctic Ocean. So this results in the Arctic Ocean having a much lower pH and concentrations of carbonate ions (CO₃^2-) compared to other oceans of the world.

The water in the Arctic is also colder. Since CO₂ is much more soluble in cold water than it is in warm water, this makes it easier for the ocean to take up more CO₂. In addition, as sea ice cover continues to retreat in the Arctic, there will be more open water, which may allow for more direct CO₂ uptake into the ocean, and further lowering the ocean’s pH. And, as I mentioned earlier, freshwater influx from rivers empyting into the Arctic ocean, along with melting sea ice, also contribute to lowering the pH of the ocean.

The interview fits in well with this article on other work by the Norwegian Polar Institute that was placed on the website of the Fram Centre. This research is extremely important as ocean heat flux is one of the most influential, but nonetheless relatively poorly understood, factors concerning Arctic sea ice loss.

The article is called New data on Atlantic inflow to the Arctic Ocean reveal effects on sea ice and marine ecosystems:

Ocean heat flux

There are many factors involved in the current long-term decline of Arctic sea ice. From relatively small ones like river discharge, precipitation and soot, to bigger factors like atmospheric patterns and air temperatures.
The possibly biggest factor of all is also the
factor that is the most unknown and uncertain: ocean heat flux. How much heat are ocean currents bringing into the Arctic?

To quote the first paragraph of this 2011 article by Ron Kwok and Norbert Untersteiner: "The surplus heat needed to explain the loss of Arctic sea ice during the past few decades is on the order of 1 W/m2. Observing, attributing, and predicting such a small amount of energy remain daunting problems."

Ocean heat flux is what separates the aggressive and famous forecast by Wieslaw Maslowski (Arctic essentially ice-free by September 2016, ± 3 years) from more conservative estimates that predict the thing to happen between 2050 and the end of this century. As explained in this BBC article from 2007:

An early opening of the Northern Sea Route?

A couple of days ago I noticed on the LANCE-MODIS satellite image that Vilkitsky Strait was already devoid of fast ice. This strait between the Siberian coast and the islands of Severnaya Zemlya is one of the key areas for navigating the Northern Sea Route, also known as the Northeast Passage. In this animation I made in 2010 the ice cleared around day 192 (July 11th), over a month later than this year.

But how about the rest of the Northern Sea Route? Well, we know that westwards from Vilkitsky Strait a lot of the ice has disappeared already, because the ice never really properly thickened there this winter. As to the regions eastwards of Vilkitsky Strait it so happens to be that the Alfred Wegener Institute issued a press release yesterday that tells us just that. I've translated some of it:

More on ice thickness from AWI

About two and half weeks ago the Alfred Wegener Institute for Polar and Marine Research (AWI) issued a press release to inform us of the fact that their research vessel and icebreaker Polarstern had arrived at the North Pole. In the blog post I dedicated to this news, I mentioned a snippet about their findings concerning ice thickness. I have finally come around to read a bit more on AWI's excellent Polarstern Blog, and have translated some more snippets about ice thickness. All the images come from the Polarstern Blog as well.

Schollensuche richtung Nordpol
the search for ice floes on the way to the North Pole

In order to document the ice conditions during our journey we observe the sea ice on an hourly basis. The ice conditions are logged following an international standard. Ice cover, type, thickness and the distribution and amount of melt ponds are recorded and documented with photographs. Ice thickness is estimated with a yardstick aboard the ship by observing the broken ice floes that are standing upright.

A broken ice floe with a thickness of approximately 1 m (image courtesy of Stefan Hendricks, Alfred Wegener Institute)

The first results from our observations show that the sea ice is relatively thin, young and unstable. Older multiyear ice, which used to be typical for this region in the past decades, makes up just 10 to 20% of the observed ice. Consequently we can travel and navigate through the ice much quicker than in the past, and do not get stuck. On top of that the journey is made easier by many stretches of open water which allow us to travel at a speed of 3 to 6 knots (5 to 10 km/h) from one measuring point to the other. This gives us more time for operating our ice and water stations.

Polarstern reaches North Pole

According to this press release by the Alfred Wegener Institute, the polar icebreaker Polarstern has reached the North Pole this morning, 22nd August at 9:42 AM CET.

The 55 scientists and technicians from 6 different countries are there to investigate the changes in the Arctic. Hence the name of their expedition: TransArc - Trans-Arctic survey of the Arctic Ocean in Transition.

I have translated one part of the press release that I found of particular interest:

Schauer was in the central Arctic for the last time in 2007 and this time around has found an ice cover that is similar to the one in the year that went into the history books as the year with the lowest sea ice cover since satellite measurements in 1979 began. The first ice thickness measurements confirm this: in 2011 as well as in 2007 most of the ice has an ice thickness of 0.9 m. In comparison, most of the ice in 2001 was measured at 2 m. That year total sea ice extent at the end of the melting season corresponded to the long term average.

This is the third time the Polarstern reached the North Pole. On September 7th 1991 it did so with the Swedisch research icebreaker Oden. Almost exactly 10 years later, September 6th 2001, there was a joint expedition with the American USCGC Healy.

Alfred Wegener Institute press release