We have reached the point where the average temperatures north of 80° latitude creep above freezing.
This does not mean we won’t see freezes, but the average is generally above freezing. The sea-ice gets very slushy, with melt-water pools increasing, until they find ways to drain down through the ice. At the same time the ice has lost the cold it remembered from the winter, and where there was some winter chill down deep in the ice a month ago, the ice is now generally just below the melting point from top to bottom, and has less resistance to melt. Much of the melting comes from beneath, but all the cameras and news-items focus on the surface.
A lot of what happens on the surface depends on whether it snows or rains. Rain increases the thawing, while snow lays down a white blanket that reflects sunlight and retards the thawing. Therefore a difference of a degree can make a big difference, but the sources we have to look at tend to vary quite a bit, when it comes to telling us what the temperature is For example, compare the GFS map of temperatures at 0600z today: (Greenland to the upper right)
The Canadian map shows the air much colder, especially north of the Canadian Archipelago. Who should I trust? I figure the Canadians must know more about their own coastal waters, but that is not a very scientific conclusion.
The Danes show this for 0000z:
That map shows more cold air on the Russian side, which may partly be due to it being six hours earlier and the end of the short arctic night, (or, if not actually night, the midnight-sun-time when the sun gets low on the horizon and heats less.)
If you have the time, it pays to look at several maps to be sure you see features that one model might glimpse and others miss. Also it pays to look at the temperatures recorded by the various cameras and buoys, as they can catch local features the “big picture” seen by the models miss.
The one thing that comes across is how few data-points they have, and how much of any map is an educated guess. There are many surprises during the course of a summer, for there are many opportunities for things to slip between the cracks.
Because the Canadian model starts out with colder air, it tends to generate bigger storms, due to a greater contrast between warm and cold. When the Canadian model is alone in seeing a storm ten days in the future, I tend to be dubious that it will occur.
So far this summer seems warmer than last summer, which was surprisingly slow at creating melt-water pools, and created smaller pools than normal, and saw them sometimes freeze over and be recovered with snow, even in July.
The first melt-water seen this year was from our most southerly camera, down near 70° north, right on the coast of Alaska. As always, there was a bit of a hub-bub about the melting, and then an Alarmist put a hex on the entire situation by stating it was melting earlier-than-normal. As always seems to happen, everything immediately froze over, and then was dusted by snow: Then melting resumed.
This particular buoy (2015A) will likely be bobbing in open water by July, as the coastal water usually thaws when the PDO is in its warm phase. However the last update (April) of the PDO shows it is still warm, but starting to plunge. (The last PDO measurement is the small “+” standing alone by the right margin; they haven’t extended the colored part of the graph yet.)
I hope to add more pictures later.
LATER —VIEWS FROM ANOTHER CAMERA—
I thought I’d tell a story with pictures from the camera that once was by Mass Balance buoy 2015B. They have parted ways, so the tale is a tragic one.
In order to get to the current sixty days of slush we had to go through 305 days of freezing, but the Arctic Ocean is not motionless during that time. Some people suffer from the preconception all is still under clamping ice on that sea, but that is not the case. An ocean is after all an ocean, subject to storms with waves. If a storm with twenty foot waves is at the edge of the ice, those waves are not going to stop at the edge, like waves hitting the granite shoreline of Maine. They pass under the ice, and the ice flexes to some degree, as swells pass under. Also winds roaring over the top of the ice make a sail of every pressure ridge, and propel the ice in various directions, often resulting in conflicts to the integrity of the ice, either smashing it together or tearing it apart.
Most arctic cameras are placed on thicker ice, so they will last, but Buoy 2015B, either by intent or by accident, bore witness to the traumas sea-ice endures long before it even thinks of melting. Partly this occurred because it was a stormy spring, and the camera was blown north, smashing into other ice. (All illustrations can be clicked to clarify and enlarge.)
The tale begins on March 25, with men placing the equipment on the ice. This is no job for sissies. Temperatures were between -4° and -13° (-20° and -25° Celsius) and there was a chance of meeting a 1600 pound bear.
By MARCH 26 the men were gone, and I could settle back for what is usually a long, peaceful wait for the sixty days of slush to arrive. Mostly I watch lots of sunrises and sunsets as the twilight grow less and the days get brighter and longer.
And by APRIL 25 it has reopened
By MAY 7 it has frozen over, with temperatures down around -15° Celsius By MAY 9 it is starting to close, with the new ice atop the lead offering little resistance, and instead piling up. But then by MAY 10 the winds have shifted and the lead abruptly opens to a wide expanse of water. Notice that the stakes across the lead have vanished from view.
By May 14 the freeze-up seems to making good progress, but the sun never sets. By MAY 16 the lead has reopened and the snow stakes have again shifted out of view, this time for keeps. By MAY 20 the water in the lead is choked with slush. On MAY 21 we see our first true thawing. All the open water we have seen before this point occurred with temperatures below freezing.
On MAY 22 the thaw continuesOn MAY 25 the lead is opening up again On MAY 27 the thaw is over. We’ve had a dusting of snow and the lead is freezing over. (This shows as a brief spike down to -7° C on the temperature graph.) Notice the iceberg across the lead just right of center.Two days later, on MAY 29 that iceberg has drifted nearer, and cold snap is over and we are midst a second thaw.On JUNE 1 the thaw is over, and we barely touch freezing even under bright sunshine, when the sun is highest. We are entering a prolonged late-season cold spell.By JUNE 3 the lead is again freezing over, and is again crunching closed.By JUNE 5 ice has piled up against our side of the lead to the lower right, as open water appears to the left. The floe we are riding upon is likely twisting, and stressed. On JUNE 6 the stress seemed to be slacking off to the lower right, but new ice was appearing to the upper left.On JUNE 7 the lead was crunching shut to the upper left. Can you guess what this is leading to?On JUNE 8 disaster struck! A crack appeared, using the hole bored for the Mass Balance Buoy tower as a weakness, and soon, as the grinding ice buckled and heaved at the ice at the point of the crack, the Mass Balance Buoy tilted, teetered, lost its mass balance, and fell into the brine. (Fortunately, someone somewhere had some brains, and they designed those expensive things to float.)Earlier today, on JUNE 10, the Mass Balance Buoy could still be seen bobbing across a lead straight ahead, but as the day passed we parted company.
,And what is the moral of this tragic tale? I can think of three.
First, nearly all the action we witnessed occurred when temperatures were below freezing. This is important to remember, when people state the break-up of ice was caused by “warming”. When you point out any warming wasn’t enough to melt any ice, they next will state the ice was thinner due to last summer, but the ice is actually on average thicker than at any time since 2006.
Some will say the ice only seems thicker, because the thin ice at the edges has melted away and is no longer averaged in. That would suggest the volume would be less, but the graph shows a recent uptick. It looks like we are back to 2006 levels.
Lastly, there were measurements made back before 1978. 1978 was the height of a cold-period, but unfortunately is where too many modern graphs begin. If you look back in time you come across many occasions during earlier warm-periods when men in ships measured the ice, and found it as thin as it is these days, going back to the days of the whaling ships.
Second, one becomes aware the Mass Balance Buoys are doing their work under conditions which are far from ideal. The Arctic Ocean is wild, and is not the carefully controlled environment of a laboratory. Sometime the buoy is measuring from the bottom of a melt-water pool, as 2015A looks like it is doing, and, as we have just seen, 2015B may be measuring from firm ice one moment, and then while bobbing in the brine the next.
This is not to say the fellows who go through all the hard work of getting the buoys out there should be scorned, or that they don’t bend over backwards to make sure the data they produce isn’t misinterpreted. However I do suggest one needs to be careful with such data.
Lastly, the 25 pictures I used are only a few from a treasure-trove available at http://ipab.apl.washington.edu/WEB_CAM/USIABP_WEB_CAMERAS.php and I am very thankful to have them. The real reason I like to study the ice has little to do with arguing. Rather it involves the healing escapism afforded to me by the beautiful views.
And that is what I’ll seek most, as the sixty days of slush begins. However, if someone says something ridiculous about sea-ice, I reserve the right to depart from my dreamy and harmless escapism, and engage in ferocious debate.