ARCTIC SEA ICE –Icebreaker Trapped Resupplying MOASiC–

In my last post I mentioned that the Russian icebreaker  Kapitan Dranitsyn had to battle thick sea-ice to resupply the Polarstern at the MOSAiC site. Contact was successful, and cranes began to  unload and load supplies that were hauled by tractor between the two ships.

PS1 polarstern-1-e1583402517868

A fresh crew of scientists relieved the crew that has been working there.

PS2 polarstern-unloading-2-credit-michael-gutsche

With temperatures down around -30ºC, the open water in the wake of the Kapitan Dranitsyn froze over swiftly. Men could walk on the new ice within 24 hours.

PS3 polarstern-and-icebreaker.1f7f58

By the time the transfer of men and supplies was complete the ship was frozen so fast it could not extract itself. The news is now that the Russians are sending a second icebreaker, the Admiral Makarov, to help the first icebreaker free itself. (Note the twilight in the above picture. The are located close enough to the Pole to see a very swift transition from noontime night to midnight day. Currently it is dark at midnight, but the twilight is bright enough at noon to read by. In around a week the sun will peek over the horizon, and a few weeks more will see the daylight become constant. But the chilly sun remains so low that no thawing occurs until the end of April.)

Despite the ice trapping the icebreaker, it is important to remember we are talking about sea-ice, a mass of ice in constant motion with enough “leads” (cracks) to allow seals to breathe and be seen hunting arctic cod, by the MOSAiC underwater cameras. Sea-ice is by no means stable. The Polarstern radar recently saw a lead open roughly a mile from the ship.

And the infrared view of the Pole shows plenty of cracks in the sea-ice,

.PS4 go.nasa.gov2TJSpHR-shears-

In other words, sea-ice is not the same thing as the gigantic icebergs that make life interesting for fishermen in Newfoundland, icebergs that are so vast that they can run aground in water 300 feet deep.

Newfoundland Icebergs view-of-twillingate-harbour

Newfoundland Iceberg u41bdg57z4k41

These giant, awesome bergs calve off glaciers, (largely Greenland’s), and, while they have been seen in the Arctic Ocean, they usually head south down either side of Greenland, and are rare up north. For the most part the sea-ice affecting the icebreakers is thin in comparison, roughly six feet thick.

The problem is that, besides cracking apart, which is helpful to icebreakers, the ice claps back together again. In such cases the baby-ice which swiftly forms in the open water, (as we saw in the wake of the Kapitan Dranitsyn), has little hope of resisting the compression it undergoes; even if it is two feet thick it is clamped in the jaws of ice at least three times as thick, which has the power of wind pressing across miles and miles of fetch. Consequently the new ice in leads crumples up like eggshells between elephants, and what was open water on Monday may become a pressure ridge of crumbled slabs of ice by Friday. And, because this process goes on all winter long, the surface of the Arctic Sea is far from smooth. There are smooth areas, basically big slabs, but finding a smooth area large enough for the yearly Barneo blue-ice airstrip often involves a considerable search.

Considering the sea-ice is constantly tortured and contorted, the “thickness” maps portray an average, for in fact the ice can vary between open water and a towering pressure ridge in a hundred yards. (This was made visual back in the days we had cameras on buoys bobbing about the Pole.) Because both pressure ridges and leads are often too narrow to be seen by satellite, and also because how numerous they are varies a lot between stormy years and calm years, a certain amount of guess-work (also called “modelling”) goes into the creation of “thickness” maps…..which in turn leads to disagreements. For example the NRL map can show ice six feet thick

Thickness 200303 arcticictnnowcast

Whereas the DMI map shows sea-ice twelve feet thick:

Thickness 200305 CICE_combine_thick_SM_EN_20200305

These disagreements suggest the captains of icebreakers face uncertainty, as they face the sea-ice.  Not only are the captain’s initial maps to some degree “modeled”, but the circumstances they are sailing into are in constant flux. Though their radar may show an open lead ahead, a shift in the winds may turn that lead into a pressure ridge in a mere hour.

One then is led to wonder why these icebreakers are not ever crushed like a nut in a nutcracker. The compression involved when wind-shear creates two masses of sea-ice converging is hard to imagine. We are talking about fifty miles of ice colliding headlong with fifty miles of ice; even sea-ice nine feet thick can buckle, creating the arctic’s biggest pressure ridges, thirty feet high and (because nine tenths of an iceberg is under water) with “keels” extending downwards 270 feet. A 1880’s ship like the Jeanette, with a greatly reinforced hull, might survive 21 months clamped in sea-ice, but it stood little chance when the sea-ice concentrated its squeeze. (Descriptions of the moaning noise the Jeanette made as it went down are amazing.) Therefore men learned to structure hulls in a manner that caused squeezing from the side to lift the ships upward, rather than crushing inward. Icebreakers utilize such uplift, as the entire ship rides up and over the ice, which is then crushed down and broken by the sheer weight of the ship.

The Russian icebreakers are huge. The Kapitan Dranitsyn has seven stories of windows above the main deck. Let’s look at the picture again:

PS3 polarstern-and-icebreaker.1f7f58

Besides riding up over the ice moving forward, such ships are designed to ride over ice when moving astern. When the ice is especially thick they can back up and plow forward repetitively, crunching the ice downwards and making their way to where radar indicates a lead may provide an easier path.

The fact Kapitan Dranitsyn requires help indicates, to me at least, that the sea-ice is especially thick in the Central Arctic this year.

Stay tuned.

 

 

 

 

 

13 thoughts on “ARCTIC SEA ICE –Icebreaker Trapped Resupplying MOASiC–

  1. I can’t find any other source that says the Kapitan Dranitsyn was stuck in the ice and could not free itself. Most other ‘sources’ indicate that it needed a fuel resupply due to expending so much fuel just to get to Polarstern. Do you have any other source for that bit of the news? Great article BTW …. and your about page is really interesting! People who have lived interesting lives are … well, interesting. Thanks!

    • I think the main reason for the second icebreaker may be that the first has had to use so much fuel it is in some danger of running out, as it bashes its way south. The ice is averaging over five feet thick around the MOSAiC site, which is thicker than I recall in recent years.

      I know a lot of people are teasing the fellows enduring the Arctic winter aboard the Polarstern at the Mosaic site, but I’m glad they are getting some on-the-scene data. After all, I am a sea-ice fanatic, and suffered when they stopped funding the buoys with cameras.

      One thing that is very interesting is an underwater camera MOSAiC has, which has seen plenty of arctic cod, and even a seal hunting the cod in the dead of winter near the Pole. I don’t know if you remember, but it wasn’t all that many years ago Alarmists were suggesting that the Arctic Sea was sterile, once you got away from the shore, and that the polar bears and seals would starve if they had to move further out because Global Warming caused sea-ice melted close to shore. I think those Alarmists failed to account for all the stuff that used the underside of the ice to create an entire unexpected ecosystem. But what has surprised me is that things don’t go into some sort of hibernation under the ice during the dark of winter. But that is why on-the-scene observations are better than armchair speculation.

      Great to hear from you. Hope you’re doing well. Spring is nearly here!

      • under the ice is a relatively stable environment, insulated from the worst of the cold.

      • Yes, but the MOSAiC is studying “turbulence” that occurs in that quiet. Using the word “turbulence” may be a bit much, but apparently a stirring occurs when a wind blows the ice the opposite way of the under-ice current. Because 9/10th of ice is under water, wherever there is a pressure-ridge on top of the ice there is a “keel” under the ice, sticking down much farther than the pressure-ridge sticks up, and these keels are like the blade of a spoon stirring the soup of the Arctic Sea, at least at the very top. I’m not sure what they have learned about this “turbulence”; we’ll have to wait for them to write their papers.

        They have also been watching how the sea-ice gets thicker and thicker. While the five feet of sea-ice does insulate the water, the ice still manages to get thicker when the air temperature is at minus thirty Celsius. I heard the rate of thickening is still four inches per week.

        I think there is still much to learn about that world up there. Cheers!

  2. At 22,000 horsepower, Kapitan Dranitsyn is not a particularly powerful icebreaker. A number of professional ice navigators have previously voiced concerns that she’s not the right ship for a mid-winter resupply mission nearly to the North Pole. Yet, she made it to Polarstern, sailing further north than any ship has done under her own power this early in the winter. Last summer also saw the least powerful ship ever to reach the North Pole on her own as the Norwegian coast guard vessel Svalbard sailed there with slightly more than half of Dranitsyn’s power.

    To me, this is a sign that there’s less ice than before, but perhaps I’m mistaken.

    • Also the MOSAiC site was resupplied by the Akademik Fedorov, which wasn’t even an icebreaker, at the start of its trip last fall. The Akademik Fedorov was just a ship with a reinforced hull. There is a pretty good description of its struggles (with the typical BBC Alarmist slant) here:

      https://www.bbc.com/future/article/20191114-how-mosaic-expedition-avoids-getting-stuck-in-arctic-sea-ice

      I would not say that you are “mistaken” if you are comparing current sea-ice thickness with 1979. However I am comparing with the past few years. My contention has always been (if you look back through my posts to where they begin in 2012), that Arctic Sea-ice is not in a “Death Spiral” but rather a “Natural Cycle” governed by the PDO and AMO. I’ve posted plenty of historical examples of explorers finding open water where prior explorers found solid ice, and vice versa. For some reason this history is ignored, as is the admittedly scant satellite data prior to 1979. Therefore we are in wait-and-see mode, as the PDO and AMO are both teetering on the verge of shifting to their “cold” states, which I contend will lead to an increase in sea-ice. This very well may be the year my waiting is over, which may lead to suppressed excitement in my posts.

    • The Kapitan Dranitsyn made it about halfway back to port in the thick sea-ice, and then was met by the Russian icebreaker Admiral Makarov that refueled it. I think it took four days to complete the refueling. They then proceeded to the edge of the sea-ice in Barents Sea, but had to wait before venturing out into the open water because a gale was raging and the seas were too high. (I guess icebreakers are not designed for ocean storms.) They had to wait a week for the waves to subside under fifteen feet, but got to observe how sea-ice fractures under the duress of huge swells. When the gale subsided they rushed across Barents Sea and two days later safely arrived in Tromso. The trip took a total of three and a half weeks. (Likely some had further adventures getting back to their home countries through the travel bans of the Pandemic.)

      Meanwhile, back at the good ship Polarstern, research continues with no cases of the virus aboard, as far as I can tell. I think they are facing some resupply problems in the future, due to the pandemic, but currently they don’t talk about any problems beyond some snapped power cables caused by leads forming in the ice. The only mention of the virus I have seen was that they felt fortunate to be able to gather in a large group on Easter.

      Cheers!

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