Talk about unprecedented

In the preceding post on Global sea ice minimum records getting broken for the third year in a row, I mentioned how the situation on the Pacific side of the Arctic was quite unprecedented, with the sea ice graph for the Bering Sea showing a sharp downturn (and even a small one for the Chukchi Sea). Well, there's an equally unprecedented event taking place on the Atlantic side of the Arctic as well. Yesterday, Prof. Dr. Lars Kaleschke from the University Hamburg tweeted out the following:

There is open water north of #Greenland where the thickest sea ice of the #Arctic used to be. It is not refreezing quickly because air temperatures are above zero confirmed by @dmidk's weather station #KapMorrisJesup. Wacky weather continues with scary strength and persistence. pic.twitter.com/YMnvCD8XvL

— Lars Kaleschke (@seaice_de) February 25, 2018

This probably has a lot to do with the splitting of the Polar Vortex due to a sudden stratospheric warming event a while back. I'm grateful for a bit of winter, finally, in my neck of the European woods, but not too happy about the consequences for the Arctic. The cause of all this heat and ice being pushed away from the northern coast of Greenland is an atmospheric set-up that during summer we'd be referring to as a Reverse Dipole (low pressure over the Canadian side of the Arctic, high pressure over the Siberian side). This animation of DMI SLP maps shows how the set-up got set up in the past 10 days, resulting in a pressure gradient as high as 75 hPa:

Such a pressure gradient means lots of winds. The animation in Kaleschke's tweet shows what happened to the ice between Fram Strait and the Lincoln Sea, but here are two images by ASIF commenters Uniquorn and A-Team showing the situation (from the 2017/2018 freezing season thread):

In the same thread bbr2314 comments:

I can't imagine reds, however faint, have ever appeared in Northern Greenland in February before.

He's referring to these DMI maps for the 24th and 25th, showing the day 's surface mass balance compared to the day before (in mm water equivalent per day):

Edit: Technically, the decrease in mass balance is caused by sublimation, rather than melting, due to warm winds. 

It wasn't winds causing the surface in Northern Greenland to melt, it was heat (edit: Apparently, according to this DMI scientist, it was a combination of Föhn winds and warm air). Robert Fanney posted a fantastic article on his Robertscribbler blog yesterday, describing the heat entering the Arctic during the past week: A Hole in Winter’s Heart: Temperatures Rise to Above Freezing at the North Pole in February.

An excerpt:

An extreme wave in the Jet Stream was developing and elongating over the North Atlantic, delivering more and more warm air northward.

By February 21st, the wave had extended into a knife-like extension east of Greenland and through the Barents Sea. Beneath this abnormal Jet Stream wave, which was starting to look more and more like a trans-polar river (of a kind predicted by Dr. Jennifer Francis as a result of human-caused Polar Amplification), was an intensifying thrust of outlandishly warm surface air.

Over the past 72 hours, gale force warm, southerly winds gathered in the Atlantic, then blasted north.

At this point, we were starting to see some seriously outlandish temperatures in the higher latitude regions. Cape Morris Jesup, which is the furthest north location on Greenland, by Friday the 23rd experienced a 6 C or 43 F temperatures on the shores of what should be a frozen solid Arctic Ocean just 400 miles from the North Pole.

The average high temperature in Cape Morris Jesup is -20 degrees Fahrenheit during February — making Friday’s reading a whopping 63 degrees F warmer than average. For reference, a similar departure for Washington, DC would produce a 105 degree day in February.

But it wasn’t just Cape Morris Jesup that was experiencing July-like conditions for the Arctic during February. For the expanding front of that ridiculously warm winter air by Sunday had expanded into a plume stretching tens of thousands of square miles and including a vast zone of temperatures spiking from 45 to 54+ degrees F above normal.

And at the center of the warm air pulse was today’s earlier reading of 1.1 C or or 34 F at the North Pole (see image at top of post). What would typically be a summer-time temperature for this furthest north location of our world happening during February. A highlight warm point in the midst of a vast plug of far warmer than normal air. A hole in the heart of winter.

Here's an animation of DMI temperature maps showing how these changes came about during the last 17 days:

See how the blue gets replaced with green? Here's how this year stacks up, compared to 2013, 2014, 2015 and 2017 (2016 is missing from my archive):

As I wrote in the preceding post:

There's so much heat coming into the Arctic from both sides that the temperature north of 80° is spiking to new record heights, as shown on Zack Labe's rendition of the DMI 80N temperature graph, and it will most probably climb some more.

And climb it did. I wonder if it will climb much more, as the current temperature is almost as high as the peaks for April:

To close off, all of this is now even having an effect on the Central Arctic Basin sea ice area graph (hat-tip to Wip):

Of course, that trend line will go up again, the open water north of Greenland will refreeze as soon as the winds turn, the surface of Greenland will stop melting. But talk about unprecedented!

Comments

[Sourabh Jain]

Thanks Neven.

I generally resist to comment on ASIF, if I do not have anything useful to say, but this time I just couldn't believe the 'scary' outlook. It really feels like a scene from a climate apocalypse movie.

Your post does put things in perspective and shows how rare current events are, even when compared to past four or five years. If current trends continue, I guess that would prime ice for building 'THE' melting momentum we have even seen.

[Neven]

Thanks, Sourabh. If you want more positive notes:

- That high pressure system really is very high, which means that there are open skies over the Siberian side of the Arctic, which means ice gets to thicken better than it would under overcast skies.
- Those winds pushing ice back into the Arctic instead of south through Fram Strait will cause ridging, with open water refreezing, so more volume.
- On that image of Greenland (left, 24th), you also see a lot of blue in the southeast, which means lots of precipitation. Sheet Mass Balance also shows an uptick.

But on the whole, it's not looking so great. And there seem to be a lot of unprecedented things going on. What that portends for the melting season, we don't know. Nevertheless, like I said in the preceding post:

As things stand right now, it looks like the Arctic will have to try and dodge another bullet/cannonball in the upcoming melting season. Because if it doesn't, it'll head our way.

[P-maker]

Neven , excellent SoMe summary of current events

However, areas you seem to have labelled as “melting” in Northern Greenland are in fact subject to sublimation. DMI and other authoritative sources on the recent Kap Morris Jesup observations have clearly labelled this as a “Föhn effect”.

More worrisome, may be the fact that thick snow is building up extensively in both Quebec and in NE Siberia this winter. Those future “cold poles” may have a significant influence on summer circulation in the NH, when we happen to grow most of our food out in the open.

Most alarming is however the risk that open water in February north of Greenland may lead to perpetual upwelling in this area from now on, if this equable climate jet stream pattern persists for another couple of months. Bringing up relatively warm water from the abyss of the Arctic Ocean cannot be a good thing in the long run…

[wayne]

That caught my eye too Neven,

But there is a lot going on, unprecedented would be what 2 models forecast
the GFS and ECMWF::

http://globalweatherlogistics.com/seaiceforecasting/gfs.850mb.height.vort.arctic.html

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1&type=0&archive=0

I have never seen this, and I don't remember ever seeing something remotely like this, a large High coming from Norway settling to Northern Quebec. when it is usually a Cyclone moving from Northern Quebec to Norway! Supremely interesting.

By the way the CAA Cold Temperature North Pole vortice is going bye bye.
Leaving some parts of Russia as the only cold spots, this I can explain, but a High reverse tracking the Cyclone North Atlantic alley causing central Russia to be very cold ? Remains to be seen....

[wayne]

Neven,

"That high pressure system really is very high, which means that there are open skies over the Siberian side of the Arctic, which means ice gets to thicken better than it would under overcast skies."

Not necessarily so, although this is standard meteorology 101, the continuous influx of moisture by the Pacific and Atlantic has been doing some very strange horizon effects:

http://eh2r.blogspot.ca/2018/02/clear-air-moisture-species-some-let.html

In fact saturating the Arctic with a continuous vapor spread may have similar consequences than when cloudy, there has been very little respite from moisture influx without giving a large area a chance to really dry the atmosphere above the Arctic Ocean....

[Neven]

However, areas you seem to have labelled as “melting” in Northern Greenland are in fact subject to sublimation. DMI and other authoritative sources on the recent Kap Morris Jesup observations have clearly labelled this as a “Föhn effect”.

Thanks, P-maker. These things are often discussed on the ASIF, but I'm too dumb to follow them, so don't bother to read. Sublimation is in a way similar to melting, but instead of turning to water, the ice is directly turned into water vapour, right? So, some of the ice at the surface of Northern Greenland did disappear due to the warm winds, which had to do with the described weather event, which is highly likely unprecedented for this time of year.

I'll update the text.

[P-maker]

Neven, you are absolutely right, but I think it is the diagram which need an update and not your text.
Cheers P

[Neven]

Robert has another good piece on this event: A Large Area of Open Water Forms in the Melting Sea Ice North of Greenland During February

Good article on Mashable as well, by Andrew Freedman: Drastic Arctic warm event stuns scientists, as record-breaking temperatures reach the North Pole

[P-maker]

Neven,

I think your 1-dimensional focus on temperature may be ascribed to something from your childhood ;o).

Considering this recent event N of Greenland, you will need to think of the following chain of physical processes in order to understand the full implications of what we are seeing at the moment.

1) Excess evaporation south of the Azores due to global warming
2) Extensive high pressure over the Eurasian continent driving air masses north
3) Extreme “Atmospheric River” transporting hot and moist air to Greenland
4) Humongous deposition of fresh snow on SE side of Greenland
5) “Trumpish” heating and drying of air mass as it descends over N Greenland
6) Downstream sublimation of snow and negative mass balance in N Greenland
7) Dry and warm air drains off N Greenland and opens up new KMJ polynya

I'll leave it to you.

[wayne]

The Guardian is at it again:

https://www.theguardian.com/environment/2018/feb/27/arctic-warming-scientists-alarmed-by-crazy-temperature-rises

Good journalism has no bounds with that paper.

I must do a very rare complaint about the strictures of the English language, it is usually easy, but the Polar Vortex has vortices within, if I start explaining that these vortices can't be written vortice, but vortex, it is difficult, because the Polar Vortex has several smaller vortex within? Sounds incredulous. So I defy the dictionary to come up with something more elegant than a singular vortice .....

At any rate, the explanation of Polar Vortex has been difficult ever since it was made popular about 3 years ago. The best way to explain it is with current weather.

Again the thorough Guardian covers it live...

https://www.theguardian.com/uk-news/live/2018/feb/28/uk-weather-beast-from-the-east-batters-britain-for-second-day-live

The current Polar Vortex has at least 4 vortices within. The main big vortices are to be found in the Canadian Arctic and Siberia, however the newish "vortice" hovering over Finland is of great interest, because it is single handily pushing a large Norwegian High towards Northern Quebec. Extraordinary. "The beast from the east" as they call it , key word, from the "East ", is perhaps a monster given the mild European winter so far. Current winter vortices are made smaller basically by the over all shrinking of the Polar Vortex.At locations where warm air meets these vortices exists the jet stream, so between Greenland and Norway there is warm air, therefore the jet stream heads towards the Southwest pushing this high along its unusual course. Smaller vortices will cause all kinds of weird winter weather. But the Guardian explained that segment pretty well.

[wayne]

It is not only wild in the Arctic, ENSO is appearing to turn towards El-Nino,
while we still await for a deep cold La-Nina like what happened after super El-Nino 1998:

http://eh2r.blogspot.ca/2018/03/back-towards-el-nino-no-post-1998-la.html

[Philip Cohen]

Wayne, one vortex, two vortices. Four subvortices in the Vortex. I don't see the problem.

[wayne]

Thanks Phillip,

From the stand point of my little essay, I am glad it is all clear for you. Not everyone explains the machinations of the Polar Vortex well.

Mass confusion starts when someone explains that the Polar Vortex caused this or that cold spell. But it is not necessarily the case in most instances.
It is usually one of the many vortices within the Polar Vortex which causes havoc.

I like sub-vortices, but vortices already implies the prefix "sub". I principally like to deal with one smaller vortex within the Polar Vortex in particular, the one doing the freezing damage. On most occasions TV presenters mix the entire Polar Vortex often with one of its vortices gone rogue Southwards .

I suggest the word vortice identifying a single one from a collection of vortices, which implies it is part of a larger Vortex system. Sub-vortex is not as elegant and a tad confusing.

[P-maker]

Wayne,
how about reserving the term Polar Vortex (including capitals) for the real thing and then label those those rogue vortices: vortex Ann, Bill..... Wayne etc.

[wayne]

Not a bad idea P-Maker!

[wayne]

Neven

You may say is close to the maximum?? I read it is a bit risky.. At any rate it is starting very bad for sea ice...

P-Maker

I suggest to call the name of vortices within the Polar Vortex vortice x of x.
If there are 4 vortices within, the coldest most significant one is v 1 of 4,
the smallest warmest one v 4 of 4. Is a Borg inspired assimilation thing so there is no choice but to be part of the collective! :)

Hi Jim,

Hope you had a chance to measure top of snow temperatures versus surface temperature... I am working out on the actual physics of T***=< Ts is very mysterious and fun.

[Neven]

You may say is close to the maximum?? I read it is a bit risky.. At any rate it is starting very bad for sea ice...

We're having fun discussing that on the ASIF. The maximum is always fun, because it's so hard to predict.

I'm curious what PIOMAS will say about February.

[AmbiValent]

I've just looked at Wipneus' graphs with the February numbers already in them. It appears another cannonball like last year is heading our way. Last year we dodged one due to low export, but now?

[Neven]

That's, as always, the million-dollar question, AmbiValent. I'll post the PIOMAS update later today. A couple of interesting things are going on, not least of all, the question whether the max has been reached or not.

[John Christensen]

"Sublimation is in a way similar to melting, but instead of turning to water, the ice is directly turned into water vapour, right?"

Hi Neven,

Let me also comment on sublimation: Basically, sublimation is a phenomenon that is possible, when the air temperature is below freezing point and the air pressure is sufficiently low.

At air temperatures lower than -20C sublimation of ice becomes nearly impossible, since the air pressure would need to be extremely low, but during winter if you had continuous temperatures of -2 to -10C in your back yard, then you would often observe sublimation when the air pressure drops.
Think of the Alps: The snow cover will slowly disappear even at altitudes with constant freezing, as the sporadic passage of low pressure fronts allows frozen water molecules to be converted directly to water moisture.

The Föhn wind often causes a sufficient drop in air pressure, when high altitude air masses move quickly down to sea level - especially when the Föhn as in this example from Northern Greenland is accompanied by air temperatures increasing to warmer than -10C.

Therefore, for many of the low pressure systems that move quickly across Greenland you will observe precipitation on the 'receiving' side of the ice cap and simultaneously sublimation on the opposite side of the ice cap, if the high altitude air mass is pushed down quickly enough and the freezing is sufficiently weak.

[wayne]

There is some sublimation below -20 C John:

Abstract In the Arctic, the simplest way to describe the winter surface moisture budget (in the absence of any net horizontal transport) is: snow-water-equivalent depth on the ground (D) equals precipitation (P) minus sublimation (S). D, P and S are the most fundamental components of the winter arctic hydrologic cycle and understanding them is essential to understanding arctic moisture-related processes. Unfortunately, accurate solid-precipitation (P) measurements have proven nearly impossible to achieve in the Arctic, ".....
"Resolving these is essential to closing local, regional, and pan-Arctic moisture budgets because some studies indicate sublimation may be as much as 50% of the total winter precipitation and 35% of the annual precipitation. This paper summarizes and analyzes the existing literature describing arctic sublimation."

ftp://ftp.cira.colostate.edu/ftp/Liston/papers/first_author/2004.liston.NH.pdf

It is a difficult thing to measure, because of topographical features, winds, and near constant Ice crystal precipitation.

An average temperature of -18.7 C in Mongolia may give .1 mm (water equivalent) a day as another paper reported.

[John Christensen]

Hi wayne,

I don't disagree; the boundary for sublimation to be possible is probably closer to -25C.

In plain words, this just highlights that the snow surface can be diminished during otherwise wintry conditions, and being very different from melting, the latter being associated with above-freezing temperatures.

I went through the DMI SMB images of Greenland and noticed slight sublimation occurring January 16-18 as well in north-western Greenland.

[Neven]

Thanks for the info, John Wayne. :-)

[John Christensen]

You're very welcome Neven! ;-)