« Global sea ice records broken (yet again) | Main | PIOMAS March 2018 »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

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! ;-)

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)