After this 2012 blog post on Arctic pollution, it's time to return to the subject, if only because Arctic sea ice is proving to be a significant factor in changes in atmospheric chemistry, leading to increases in mercury concentrations in the Arctic. This happens through sea ice melting during summer, and an increase in leads and cracks during winter.
In the past couple of days two papers were published that show the relationships. The first, Convective forcing of mercury and ozone in the Arctic boundary layer induced by leads in sea ice by Moore et al., was published in Nature and deals with bromine. This Science Daily article explains it well:
Cracked Sea Ice Stirs Up Arctic Mercury Concern
Image credit: University of Hamburg, Germany
Jan. 15, 2014 — Vigorous mixing in the air above large cracks in Arctic sea ice that expose seawater to cold polar air pumps atmospheric mercury down to the surface, finds a NASA field campaign. This process can lead to more of the toxic pollutant entering the food chain, where it can negatively affect the health of fish and animals who eat them, including humans.
Scientists measured increased concentrations of mercury near ground level after sea ice off the coast of Barrow, Alaska, cracked, creating open seawater channels called leads. The researchers were in the Arctic for the NASA-led Bromine, Ozone, and Mercury Experiment (BROMEX) in 2012.
"None of us had suspected that we would find this kind of process associated with leads," said Son Nghiem, a scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Nghiem is the BROMEX principal investigator and a coauthor of a paper reporting the discovery published in Nature on Jan. 15.
The mercury-pumping reaction takes place because open water in a lead is much warmer than the air above it, according to study lead author Chris Moore of the Desert Research Institute, Reno, Nev. Because of that temperature difference, the air above the lead churns like the air above a boiling pot. "The mixing is so strong, it actually pulls down mercury from a higher layer of the atmosphere to near the surface," Moore said. The mixing, marked by dense clouds spewing out of the leads, extends up into the atmosphere about a quarter-mile (400 meters). Moore estimates this may be the height where the mercury pumping occurs.
Almost all of the mercury in the Arctic atmosphere is transported there in gaseous form from sources in areas farther south. Scientists have long known that mercury in the air near ground level undergoes complex chemical reactions that deposit the element on the surface. Once the mercury is completely removed from the air, these reactions stop. However, this newly discovered mixing triggered by leads in the sea ice forces down additional mercury to restart and sustain the reactions.
Leads have become more widespread across the Arctic Ocean as climate change has reduced Arctic sea ice cover. "Over the past decade, we've been seeing more new sea ice rather than perennial ice that has survived for several years. New ice is thinner and saltier and cracks more easily. More new ice means more leads as well," said Nghiem.
Read the rest of the article here, or the press release at NASA JPL.
The second study, High levels of molecular chlorine in the Arctic atmosphere by Liao et al., was published in Nature Geoscience and deals with chlorine.
For a background story we turn to the Georgia Tech News Center:
High Levels of Molecular Chlorine Found
in Arctic AtmosphereScientists studying the atmosphere above Barrow, Alaska, have discovered unprecedented levels of molecular chlorine in the air, a new study reports.
Lead author Jin Liao measuring molecular chlorine in the Arctic atmosphere
Molecular chlorine, from sea salt released by melting sea ice, reacts with sunlight to produce chlorine atoms. These chlorine atoms are highly reactive and can oxidize many constituents of the atmosphere including methane and elemental mercury, as well activate bromine chemistry, which is an even stronger oxidant of elemental mercury. Oxidized mercury is more reactive and can be deposited to the Arctic ecosystem.
The study is the first time that molecular chlorine has been measured in the Arctic, and the first time that scientists have documented such high levels of molecular chlorine in the atmosphere.
(...)
The level of molecular chlorine above Barrow was measured as high as 400 parts per trillion, which is a high concentration considering that chlorine atoms are short –lived in the atmosphere because they are strong oxidants and are highly reactive with other atmospheric chemicals.
Molecular chlorine concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone may be required for molecular chlorine formation.Previous Arctic studies have documented high levels of oxidized mercury in Barrow and other polar regions. The major source of elemental mercury in the Arctic regions is coal-burning plants around the world. In the spring in Barrow, ozone and elemental mercury are often depleted from the atmosphere when halogens — chlorine and bromine — are released into the air from melting sea ice.
(...)
In Barrow, snow-covered ice pack extends in every directly except inland. The ultimate source of the molecular chlorine is the sodium chloride in sea salt, Huey said, most likely from the snow-covered ice pack. How the sea salt is transformed into molecular chlorine is unknown.
“We don’t really know the mechanism. It’s a mystery to us right now,” Huey said. “But the sea ice is changing dramatically, so we’re in a time where we have absolutely no predictive power over what’s going to happen to this chemistry. We’re really in the dark about the chlorine.”
Scientists do know that sea ice is rapidly changing, Huey said. The sea ice that lasts from one winter to the next winter is decreasing. This has created a larger area of melted ice, and more ice that comes and goes with the seasons. This seasonal variation in ice could release more molecular chlorine into the atmosphere.
Read the rest here.
This I think may be a first..can anyone confirm? Some of the buoys that were left very near the North Pole last spring..totally escaped the Arctic.
155. Skyepony (Mod) 1:02 AM GMT on January 16, 2014
http://www.wunderground.com/blog/RickyRood/comment.html?entrynum=285#commenttop
Posted by: Colorado Bob | January 16, 2014 at 02:34
Yup, a bunch, if not most are gone, blown out of either the Fram ot Nares.
Posted by: jdallen_wa | January 16, 2014 at 02:43
New sea ice is thinner, less solid than multi-year ice. Therefore many more leads are created. These leads unleash a greater
onslaught of sea salts. These new leads are daily created by the thousands, they freeze quickly especially in darkness, some are compressed between older ice pans, these crush the new ice causing upwards piles of shingles or plates, this occurs especially when there is a lot of motion, these piles of new ice are rich in sea salts as well. The winds take care of spreading the salts more evenly. Come spring time photochemistry causes the said reactions. The whole thing is part of the process of the thinning of the overall sea ice pack.
Posted by: wayne | January 16, 2014 at 04:18
The arctic sea ice is one step above a 7-11, frozen drink.
Posted by: Colorado Bob | January 16, 2014 at 06:53
Colorado Bob, in scale, you may not be far off.
Posted by: jdallen_wa | January 16, 2014 at 08:55
Amazing how soon they found me after posting this. I just received an e-mail:
No need, I answered, eventually I will have even more mercury samples in my tissues, via the Arctic. ;-)
Posted by: Neven | January 16, 2014 at 09:16
Bob - It's not really "a first". The buoys seem to have survived a bit longer this year, and thus kept transmitting their position from further south.
However starting near the pole then getting washed out through the Fram Strait has certainly happened before. See e.g. http://imb.crrel.usace.army.mil/2012B.htm
For lots more information see also "What the buoys are telling us" on the forum: http://forum.arctic-sea-ice.net/index.php/topic,327.0.html
Posted by: Jim Hunt | January 16, 2014 at 12:31
Are these levels of mercury biologically significant? The chlorine surely isn't, except for possibly amplifying the mercury.
Posted by: Philip Cohen | January 16, 2014 at 15:04
You don't need very high levels of mercury for it to be biologically significant. IIRC, at a few parts per billion disruption fish schooling behavior has been seen.
On the high levels of atmospheric chlorine: As they say, it is highly reactive. Could these high levels be reacting with the methane that has been reported coming out of various parts of the Arctic, and could this help explain the seeming mis-match between the vast quantities of methane actually seen bubbling out of the oceans, and the (generally still) relatively slow rate of increase of atmospheric methane concentrations in the general region?
Posted by: wili | January 16, 2014 at 16:46
Slightly OT, but I just came across this statement by the vice president of the Russian Geographic Society :
"There should be a rise of a few more tenths of a degree in the average annual Arctic temperature for the development of minerals in the Arctic to be profitable, Chistyakov said."
http://en.itar-tass.com/russia/706413
"This is a matter not only of hydrocarbons, but also of other resources, for instance, rare earth metals. Russia sets itself an ambitious aim to increase the output of rare earth metals and to assume the leading position in high-tech production."
Who needs enemies of our planet's Arctic eco system and unique wildlife environment when you have the Russian Geographic Society as a friend ?
Posted by: Rob Dekker | January 17, 2014 at 08:53
We're wired up using copper compounds, mercury is easily substituted for copper atoms in these compounds, mercury may or may not fire and relay any signal or may delay the signal firing it later at random, copper reliably relays signals received. This way lies madness.
IIRC the Ozone hole is worst in the morning before 10:00 and repairs itself up until about 16:00 so I wonder if this has something to do with UV or does Ozone also inhibit any other part of the EM spectrum?
Posted by: johnm33 | January 17, 2014 at 14:24
Reasonable speculation, john33, but at this point of the year, there won't be a lot of UV around.
It strikes me, that the circulation and behavior is akin to that which you would see when performing fractional distillation as part of the synthesis of organic compounds. The heat source - leads - providing kinetic energy, activation energy (for reactions) and additional reagents, in the form of h2o, chlorine, and other ions from sea salt.
Circulation up the column then provides a gradient in temperature, both encouraging reactions, and the separation/ concentration of compounds in the air column. Not unlike distillation columns used to crack petroleum.
Posted by: jdallen_wa | January 17, 2014 at 18:26
jdallen_wa From above "Molecular chlorine concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone may be required for molecular chlorine formation." so not entirely my speculation, though I did wonder about the definition of early morning and late afternoon with 24 hour daylight. My figures work at 52N so are not altogether comparable.
Posted by: johnm33 | January 17, 2014 at 22:17
Keep in mind that greenhouse gasses cool the stratosphere, which increases ozone destruction even without considering added chlorine or bromine.
@Bob: In recent years some of the buoys are usually out into open water by now. The Transpolar Drift has always taken buoys from that area nearly straight out the Fram, although they can get hung up if they drift a little west. It was a speed record or nearly one this year, but other recent years haven't been much different. The Coriolis force depends strongly on ice thickness even if the drag doesn't, so the drift used to be much slower.
@Wili: Chlorine will destroy some methane, but this is insignificant compared to OH. The significant effects are ozone production as a byproduct of methane destruction, ozone destruction due to stratospheric chlorine, and slowing of destruction of all photodegrading aerosols due to depletion of OH by methane.
As an explanation of the currently ending methane concentration plateau, the unoxidized releases aren't really all that large yet, since most of the methane currently doesn't make it out of the ocean. I'm also convinced releases from Russia around the end of the Soviet Union are greatly underestimated, resulting in declining direct anthropogenic methane emissions in the immediate post-Soviet period.
@John: The diurnal variation of stratospheric ozone is rather weak. Since the reactions catalyzed by chlorine and bromine require both UV light and low-temperature stratospheric clouds, they occur only in the spring (austral spring in Antarctica) when light returns.
@Jdallen: There isn't much re-vaproizaiton as there would be in a distillation column, and the thermal energy is not anywhere sufficient for the stable contaminants we're talking about, requiring destruction by UV or biological reactions. The temperature gradient has nothing to do with the reactions in a column in any case. The greater concentration of pollutants in the Arctic much less due to higher deposition rates than to increased lifetime. All reactions just take much longer due to lower temperature and lower biological activity, so the same deposition rate leads to much higher concentrations.
Unlike the effects of direct mercury emissions, the described increase in mercury deposition due to lower sea ice and increased convection is probably mostly a shift of deposition time rather than a net increase, since the tropospheric air will eventually be mixed down eventually anyhow.
Posted by: Blaine | January 17, 2014 at 22:58
"--a few parts per billion" --wili
I think that with extremely toxic materials like mercury it is important to state actual numbers of molecules rather than parts per billion.
It is easily calculated how many molecules of water there are in a set volume of water.
http://chemistry.about.com/od/moles/a/How-Much-Water-Is-A-Mole-Of-Water.htm
A mole of distilled water contains 6.022 X 10^23 molecules of water and has a mass of just over 18 grams. 18 grams of distilled water at 4 degrees C occupies a volume of 18 milliliters.
1 part per billion =1/1,000,000,000 = 1/10^9
Therefore (6.022 X 10^23)/10^9 = 6.022 X 10^14
or about 602,200,000,000,000.
So at 1 part per billion mercury, every 18 milliliters of water contains just over 600 trillion molecules of mercury.
This sounds a lot different than 1 part per billion and I believe it represents a much clearer view of how much mercury is actually contained in the water,
Posted by: VaughnA | January 18, 2014 at 04:21
As always, reading these articles and comments is an education, this time Blaine especially. Thanks to all for attention to reality and detail.
Posted by: Susan Anderson | January 18, 2014 at 15:48
Note that many of the Greenland fjords, Umiivik and south, show open water.
Posted by: plus.google.com/102121405461486954917 | January 19, 2014 at 19:06
Some cracking movies here, now how do I slow them down. http://ozonewatch.gsfc.nasa.gov/monthly/NH.html
Posted by: johnm33 | January 19, 2014 at 21:40
Returning to anomalies in the USA. The situation is getting serious. And the world? Still the same - ignore the problem.
http://arcticicesea.blogspot.com/2014/01/ocieplenie-klimatu-w-arktyce-i-na-ziemi.html
In Poland and some other countries, global warming is still a touchy subject.
Posted by: Hubert Bułgajewski | January 21, 2014 at 22:56
More contaminants on their way north!
"About 670 million litres of waste spilled from a coal mine in Alberta on Oct. 31 (the original estimate was 1 billion litres) in what is believed to be Canada's largest ever coal slurry spill."
"Among the contaminants found were aluminum, manganese, lead, cadmium, mercury and cancer-causing compounds."
http://www.cbc.ca/news/canada/north/alberta-coal-spill-plume-slowly-moving-north-1.2438641
http://ecowatch.com/2013/11/14/water-contamination-coal-slurry-spill/
Have a great day!
Posted by: 1Rover1 | January 23, 2014 at 17:35
http://www.desdemonadespair.net/
Scroll down 5 articles to get to this one:
Toxic mercury pollution rising with Arctic meltdown
"Cracks in sea ice are funneling additional mercury to the Arctic surface, raising concerns about the toxic element seeping into the food chain of the delicate ecosystem, according to a new study."
There are graphs at top that are either redundant or new to this discussion, so either way thought I would make the link available.
Posted by: Hans Gunnstaddar | February 03, 2014 at 23:03
We are seeing the Arctic sea ice fracturing patterns redevelop that we saw last year. They may be a further contributor to the mercury or CH4 release.
Posted by: Apocalypse4Real | February 06, 2014 at 14:53