Polynyas are very important for marine life and cooling the oceans

IMG_7256An introduction to Polynyas

Guest essay by Eric Stephens

Many people think that once a sea freezes, it is one complete sheet. In reality, there are several open areas that never freeze. One such area is a polynya (common US spelling) or polynia (common UK spelling). It is a loanword from Russian: полынья (polynya), which refers to a natural ice hole, and was adopted in the 19th century by polar explorers to describe navigable portions of the sea.

Polynyas are large, persistent regions of open water and thin ice that occur within much thicker pack ice, at locations where climatologically, thick pack ice would be expected. Polynyas have a rectangular or oval aspect ratio with length scales of order 100 km; they persist with intermittent openings and closings at the same location for up to several months, and recur over many years. In contrast to polynyas, leads*another open water feature*are long, linear transient features associated with the pack ice deformation, are not restricted to a particular location, and generally have a much smaller area than polynyas. 

Polynyas can be classified into coastal and open ocean polynyas. Coastal polynyas form adjacent to a lee shore, where the winter winds advect the adjacent pack ice away from the coast, so that sea water at temperatures close to the freezing point is directly exposed to a large negative heat flux, with the resultant rapid formation of new ice.

Coastal polynyas are produced in the Antarctic by katabatic winds

This new ice is advected away from the coast as fast as it forms. For these polynyas, a typical along shore length is 100 – 500km; a typical offshore length is 10 – 100 km.

In contrast, the less common open ocean polynyas have characteristic diameters of 100km and are driven by the upwelling of warm ocean water, which maintains a large opening in the pack ice. Because the atmospheric heat loss from the open-ocean polynyas goes into cooling of the water column, they are sometimes called ‘sensible heat’ polynyas; because the heat loss from coastal polynyas goes into ice growth, they are called ‘latent heat’ polynyas. Finally, some polynyas, notably the North Water polynya in Baffin Bay, are maintained by both upwelling and ice advection.

NWP-MODIS--2008_web

Open ocean polynyas are self-maintaining, in that as heat is lost to the atmosphere at the surface, the surface water becomes denser and sinks, driving future convection. The convection ceases when the atmosphere warms in spring, or if sufficient fresh water, either produced locally by melting, or advected into the region, places a low-salinity cap on the convection

In the winter Canadian Arctic, because the marine mammals living under the ice need breathing holes, these mammals tend to concentrate in the polynya regions. For example, the North Water contains large concentrations of white whales, narwhals, walruses, and seals, with polar bears foraging along the coast. Also, the major winter bird colonies in the Canadian islands are located adjacent to polynyas.

Fluke of a narwhal in a Baffin Bay polynya.

Polynyas are persistent openings in the ice cover that in winter ventilate the warm ocean directly to the cold atmosphere. The major physical importance of the coastal polynyas is due to their large production of ice and brine, where the resultant dense water contributes to various Arctic, Antarctic, and North Pacific water masses.

http://polar.ocean.washington.edu/PAPERS/Polynya_encyclo.pdf

During the cold war the location of polynyas were classified as secret, because the Subs from both sides would use them to surface.

When submarines of the U.S. Navy made expeditions to the North Pole in the 1950s and 60s, there was a significant concern about surfacing through the thick pack ice of the Arctic Ocean. In 1962, both the USS Skate and USS Seadragon surfaced within the same, large polynya near the North Pole, for the first polar rendezvous of the U.S. Atlantic Fleet and the U.S. Pacific Fleet

http://en.wikipedia.org/wiki/Polynya

In January 2013 the media was reporting a pod of orcas were trapped in the ice in Hudson Bay. With headlines such as: “Little hope for killer whales trapped by ice in Hudson’s Bay”. Some people were calling for the government to send an ice breaker to rescue them. Just when the media had given up hope – they disappeared.

The truth was they were at a polynya. There are several known and studied polynya fields in the eastern side Hudson Bay, with the Belcher Islands being one. From there they can swim under the ice to other polynyas in the Hudson Strait.

Some notes:

Polynyas give off a lot of heat to the atmosphere. For example the area surrounding the polynya can be cloudy, but over the polynya it will be clear.

MODIS visible image (250m resolution)

In Antarctica many mainland penguin colonies are located near places where annual polynyas are known to recur, as there is a guaranteed source of food for the nesting penguins. There has been some concern that with increased sea ice around Antarctica that the penguins would be in danger, because they have to walk further. This is not a concern because they use polynyas.

This blog found some open water where they were to drill. Instead of blaming AGW/ CAGW etc. he correctly said it was a polynya.

http://blogs.jcvi.org/2009/11/polynya-opens-in-the-ross-sea/

This is just an introduction to polynyas as the title says. There is much more available on the net such as thermodynamics of polynyas – how they cool the water. Also there are many pictures of them.

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46 thoughts on “Polynyas are very important for marine life and cooling the oceans

  1. Great read. Simple, direct, factual. No obfuscating conjecture. No weird condescension. No justification statement (this is important because……). It carries itself. Very well. Kudos, Eric.

  2. The Guardian reporters probably thought they’d be going for a cruise round a polynya only to find someone shut the back door. Never mind, like all journos, they’ll be ok as long as the bar stays open.

  3. Interesting and very useful!
    Question: This past summer they were hyperventilating about a ‘hole’ near the North Pole. That sounds very much like the Polynya you describe re: submarine at the Pole in the 50s and 60s?

  4. Lookit! Lookit! scream the warmists when they point to ice free areas when having a jolly to the polar ice caps. The existence of polynyas kicks the arctic death spiral nonsense into a cocked hat, doesn’t it. But then, there is a large vested interest in turning natural occurrences into hysterical alarmism in certain camps.

  5. An excellent, excellent article bringing new knowledge to readers of this site.

    Many thanks for writing it and, Mr Watts, many thanks for publishing it.

  6. So little gets written about how sea ice actually forms that most don’t understand how open water at the poles contributes so much to cooling.Sea ice acts as a barrier to cooling while open water contributes to it. Wind blowing across sea ice does not have the same cooling effect as it does when blowing across open water.Stephen’s piece point us in the right direction in regards to what happens when the sun don’t shine at the poles, and the wind blows over the oceans.When the polar waters cool , they sink out of sight,and we know that out of sight is out of mind. When they wonder where the missing heat went, I just say it got gobbled up by the sinking cold water at the poles.

  7. I am not a huge contributor to responses about articles but I am a huge contributor to hits on this site, maybe up to 10 times a day, it is where I get so much unbiased information from, so thank you Anthony for such a wonderful professional and informative site. The article about Polynia’s is just one of the reasons I visit so much, it was well written clear with no agendas, and I had not known of them before. So all the best to you and your contributors for the New Year in the continuing the search for truth and knowledge.

    Best regards to all
    Keith Gordon

  8. Great post Eric Stephens … loved the factoid matter of it all. Imagine whales knowing where to find open water. ;)
    So the US military knows the locations of consistent polynyas, hmmmmm perhaps a FOI request would be good here. Arctic Ice Holes (i love how that reads) that have existed as long as the subs have been passing under the ice.
    Thank you Sir

  9. Thinking about it; if there is an increased sub-sea volcanic activity then the resulting increase in up-welling warm water must melt more sea ice, whether it exists north of Iceland or south of Argentina.

    What is needed now is a bit of “Volccanology” as little seems to be known when it comes to ‘heat-escape holes’ on the bottom of the sea.

  10. “Arctic Ice Holes (i love how that reads) ”

    Not be confused with the Antarctic Ice Holes that have been so much in the news this week ;)

  11. There is actually a third type of polynya where water is kept open by a strong current. They are called “ocean-strait polynyas” and the Bellot Strait and Cape Storm polynyas in Arctic Canada are classic examples.
    The largest, most famous and most reliable of all polynyas is probably the Ross Sea in Antarctica which is invariably ice-free in summer, and the target for normal tourist tours to East Antarctica (which are smart enough to keep away from dense ice)

  12. Actually, right now, just look at real figures from today’s date for NSIDC’s sea ice plots: you “might” just find that 1.500 million km^2 “positive” above normal IS present around the Antarctic, while the Arctic is about 0.550 million km^2 below normal for this date. The sea ice deficit so often claimed by the CAGW theory (required by the CAGW theories!) is a POSITIVE at this date.

    For the past two years, Antarctic sea ice has been consistently two std deviations ABOVE normal levels for sea ice, AND that sea ice extends around the continent to latitude 60 south at maximum extents in September. Arctic sea ice (through this year) been right at 1.5 to 2 std deviations low from normal. BUT! The Antarctic sea ice extents maximum is just under 20 Mkm^2, but the entire Arctic ocean is only 14 Mkm^2: There is much more Antarctic sea ice than Arctic. At minimum extents, the difference is more impressive: Antarctic continental ice (14 Mkm^2) is as large as the entire Arctic itself, but that rock-based icecap is in turn surrounded by 3.5 Mkm^2 of permanent ice shelves, and then by the ever-changing Antarctic sea ice. So even at today’s minimum Antarctic sea ice extents 2-3 Mkm^2 (and increasing!) the total southern ice is 14 + 3.5 + 2.5 = 20 Mkm^2. At maximum southern extents, those become 14.0 + 3.5 + 19.5 = 35 Mkm^2 is frozen. 2-1/2 times the maximum of what sea water is available up north.

    On the other hand, Arctic sea ice lately (last 12 years) is only 3.5 – 4.0 million sq km AT ITS MINIMUM in September. We can lose AT MOST only another 3.5 million sq km2. That is it.

    How much larger can Antarctic sea ice get? There is no limit. At today’s rate of Antarctic sea ice increase, Cape Horn itself could be closed to ship traffic due to sea ice within 8-10 years for months at a time every September and October. It probably won’t happen, but the trend is there: we have been seeing just under 1.0 Mkm^2 more sea ice each year for several years now.

    To the specific point of open Arctic waters being a heat loss area from the earth. Notice that we are assuming far-north openings here, not a theoretical physics textbook ice mass of theoretical albedo = .95 floating off the ice-filled (Equatorial) waters of Polynesia where the sun is directly overhead (Air Mass = 1.0) with perfectly clear skies and no humidity. 8<)

    But this little bit of remaining 3.5 Mkm^2 Arctic sea ice is actually in the water up between latitude 78 north to 83 north. At that latitude, in mid and late September when arctic sea ice is at its minimum extents, there is MORE heat lost from open waters due to more evaporation losses, more conduction losses, more convective losses, and more radiation losses from open sea water than can be gained from that exposed water getting heated by the ever-lower sun angles! At those latitudes, at that time of year, the HIGHEST the sun can get is 8 – 12 degrees above the horizon, air masses are 18 to 34. There simply is no solar heat penetrating the atmosphere at those low solar angles to be gained if the Arctic ice continues to melt.

    The more the Arctic sea ice melts from today’s minimum extents in August and September, the more the planet loses heat energy to space and cools down ever more. Your CAGW’s religiously amplified but majestically feared “arctic amplification” due to sea ice meltdown is totally, completely backwards.

    But it is worse than you think!

    At today’s levels of BOTH minimum AND maximum extent in the Antarctic seas, today’s (and last year’s!) record breaking sea ice extents DO reflect much more solar energy than the exposed waters! At the edge of the Antarctic sea ice at 60 – 70 south latitude, ALL YEAR, every day, the record-breaking Antarctic sea ice extents IS reflecting MORE solar energy and IS cooling the planet down even more.

    And thus we slide quickly into the next major ice age.

  13. Rob says:
    December 31, 2013 at 7:26 am

    Does the heat rotate the opposite direction in the antarctic ice holes?

    Well, sort of. See, the AC current on Australian, Chilean, and South African icebreakers always goes backwards half the time, but that is only because they use a cosine wave in their generators. The US, Nordic and Canadian ice breakers use a “regular” sine wave at 60 Hz (US and Canada) or 50 Hz (European), so they can simply turn off all of the power and then restart it as they cross the Equator to stay in synch. 8<) Russian ice breakers (and their submarines and naval ships) use 55 Hz, so they are never in phase with anybody else anywhere anytime at any latitude. China and India are also 50 Hz @ 220/230 volts on shore, but I don't know what they use shipboard systems.

  14. Rob says:
    December 31, 2013 at 7:26 am

    Does the heat rotate the opposite direction in the antarctic ice holes?

    (A little bit more seriously than the above …)

    It depends actually on what latitude and day-of-year and time of day the open water is.

    These three combine mathematically to set the maximum height the sun will be above the horizon, the number of hours the sun will be visible at any elevation angle, the time of day it is (whether the sun is actually above the horizon, and how high up it will be.)

    Day-of-year and latitude lets you assume average air temperature (which determines air convective losses from ice or water), average wind speed (which also sets air convective losses from water or ice), average cloud levels (which control both inbound radiation from the sun and outbound radiation losses), average difference between maximum and minimum air temperatures at each location, average water temperatures (which vary slightly by latitude as well).

    Solar elevation angle varies hour-by-hour through each day. Air mass (how much solar energy is lost to atmospheric filters even on clear days) varies according to solar elevation angle. So, air mass at the same latitude might be 3.0 at noon in mid-summer (when the sun is highest) but be at 13 to 16 at noon on a different day of year. Losses are exponential, so higher air masses equate to much, much more solar energy losses.

    Measured albedo of open ocean water, and the proportion of direct sunshine to indirect sunshine hitting that open ocean water, vary very strongly with solar elevation angle (SEA): At lower SEA’s, albedo (the amount of energy reflected from the water) goes up from 0.06 (sun overhead) to measured values between 0.35 to 0.45 below 8 degrees. Ice albedo doesn’t vary much with SEA angles, but DOES vary through the year as the “fresh” clean white original sea ice becomes older and dirtier and more water-laden.

    Day-of-year also determines average daily solar radiation levels (yearly maximum in January and February – when Antarctic sea ice is lowest but days have the most sunshine, but as Arctic sea ice is under dark skies in winter but when Arctic sea ice is increasing towards its March-April maximum. Yearly solar minimums are in July and early August when Arctic sea ice is reducing but Arctic skies do have sunshine; but at that time the Antarctic sea ice is increasing yet is still under more darkness than light. (Confusing and contradictory, isn’t it?)

    So, at any specific hour of the day, net planetary heat loss from radiation, convection, conduction, and evaporation out of the open water or ice AND relative heat gain from solar radiation into any piece of open water may be neutral, positive (heating up the planet) or negative (cooling the planet.)

    Over a total 24 hour day over almost every day of the year under today’s conditions, more heat is lost from the planet around the Antarctic when sea ice expands and polyna’s contract.

    Over a total 24 hour day over almost every day of the year (except the melt season between early June to mid-August!) under today’s conditions, more heat is lost from the planet up in the high Arctic when sea ice contracts and polyna’s (open water) expand.

  15. Thank you Eric Stephens for this most excellent and informative posting.

    “In the winter Canadian Arctic, because the marine mammals living under the ice need breathing holes, these mammals tend to concentrate in the polynya regions. For example, the North Water contains large concentrations of white whales, narwhals, walruses, and seals, with polar bears foraging along the coast. Also, the major winter bird colonies in the Canadian islands are located adjacent to polynyas. ”

    We see how open water is essential to life at the poles. This sort of information is not welcomed by the alarmists, who would have us believe that open water is death to polar life.

  16. Can coastal polynyas contribute to glacier formation on land from the moisture it injects into the atmosphere? It seems to me it might unless the polynya is due to offshore winds.

  17. I’ll confess to having pulled a muscle laughing at the irony of this report. ‘Scientisits’ so convinced of their ‘models’ they get trapped in Antarctica’s ice sheet trying to find ‘proof’ the ice is vanishing.

    http://www.dailymail.co.uk/news/article-2531159/Antarctic-crew-build-ice-helipad-help-rescuers.html

    Am I alone at thinking there is something very curious about these folk being so concerned at the ‘damage’ of vanishing ice that they have to plough it up with fleets of ice breakers to prove their point?

  18. Thanks Eric,
    This new (for me) information is enlightening and lends more credence to research I have been doing into how mankind crossed from Eurasia to North America. It also supports the Ewing and Donn theory about how Ice Ages start.

  19. At first glance, I read it as “‘Pollyanas’ are very important for marine life and cooling the oceans.” Aside from needing stronger reading glasses, a Freudian slip, perhaps?

  20. Looks like I am better off waiting a couple of weeks til I get back home to my PC before I make any comments here – or anywhere else – as this I-Pad thing is by far too sencetive to my fingertouch to produce anything readable.

  21. “During the cold war the location of polynyas were classified as secret, because the Subs from both sides would use them to surface.”

    If the subs from both sides used them, then both sides knew where they were. Who was it being kept secret from?

  22. Thanks for a very informative article on Polynyas. Polynayas are obviously a lot more useful to the World than the PolyAnnas of CAGW World-Wailing.

  23. Thanks.
    I find your illustration ‘Coastal polynyas are produced in the Antarctic by katabatic winds’ particularly interesting juxtaposition of different physical processes.

    p.s. my ‘rusty’ Russian tells me that word ‘полынья’ is a version of far common Russian word поляна (polyana) which translates to English ‘clearing’ or ‘glade’, Leo Tolstoy was born and lived in the place called Ясная Поляна

  24. Thanks Eric. Very good article. Happy New Year!
    The sudden opening of a coastal polynya is what could save the Ship of Fools, if it’s still capable of floating, that is. Better still, a Pollyanna!

  25. This fits so well with other recent post on tropical storms and the climate working like a massive heat engine taking heat from the equator to the poles.
    Thank you very much

    James Bull

  26. One more major influence Warmists are either unaware of or covering up or misconstrue by 180°. Par for the course, and a very Weird course it is!

  27. RACookPE1978 says: @ December 31, 2013 at 7:37 am
    I read that out loud to my husband, when he finally quit laughing He said “I don’t know whether to send them poles or zeros.”

  28. RoHa says: @ December 31, 2013 at 3:35 pm

    …If the subs from both sides used them, then both sides knew where they were. Who was it being kept secret from?
    >>>>>>>>>>>>>>>>>>
    Rank and file CAGW true believers.

  29. Excellent article, very clearly written with good illustrations.

    Thanks for expanding my knowledge. There is always something new to learn here at WUWT :>)

  30. This is an nice little introduction to Polynyas, which I have never thought about much. About six or eight years ago Walter Pittman came to UW and proposed a new hypothesis regarding polynyas and the end of “ice ages”. As many readers here probably know, glacial advances end very abruptly, and explaining how this occurs is a major problem in glacial geology. Pittman proposed that large polynyas open in the Arctic ocean and transfer so much heat into the atmosphere that they effectively reverse the climate. I asked Pittman why the transfer of heat would be directed toward warming the polar climate rather than radiated out to space and primarily end up cooling the ocean. He admitted his hypothesis was pretty crude at that time. I wonder if anyone has looked at this more closely. In view of Eric’s little summary I see that polynyas might present many interesting problems to explore.

  31. Very nice indeed. I’m interested in Hudson’s Bay fisheries research, and wonder if these occur in Hudson’s Bay proper as well, or if the hydrography would limit polynias there? Until the Second World War, when flyovers occurred with some frequency, it was assumed that Hudson’s Bay remained open in mid-winter; but ice cover is in fact around 95%, IIRC.

  32. Thank you very much for your fascinating, informative and clear explanation of something I had seen in various pictures of Antarctica – apparent large areas of open sea surrounded by ice.

    The most recent was an satellite photo of the location of the ‘Ship of Fools’. I just thought it was a fault in the satellite image… Like many others I have now been educated by the world wide community of WUWT ladies, gentlemen and scholars.

    …And live like it’s Heaven on Earth.

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