The 2016/2017 freezing season

[6roucho]

And Celsius is normally used for freezing degree days.

Surely a freezing degree day is the same regardless of the scale used?

No, since individual temperature units from different scales vary they would not be the same in every scale.  Calculated in °C or K they would be the same, but FDDs in Fahrenheit would be significantly different.  It's no different than miles versus km. 

It's always important to know the definition of the units one is using.

Of course. I remember my high school mathematics (all the way through to my postdoc). I meant to say that a freezing degree day is a binary, regardless of the scale used. It either is or it isn't. Measuring in Kelvin would produce the same set of days, even if the numbers on the scale are different. But Nevin is right: it was a lame question!

[Neven]

I didn't say it was a lame question per se. I said that a discussion on the minutiae was irrelevant to this thread.

So stop bringing it up, FCOL! 

[DoomInTheUK]

....

In this image -10C is still green and therefore it seems a lot worse than it is.

Welcome,

Yes -10 is damned cold, but in Arctic terms it's warm, which doesn't mean melting, but it slows thickening, and stops the ice getting good and cold. In absolute terms it's chilly, but in the terms of the freezing season it's nearly bikini time!

[Kratje]

....

In this image -10C is still green and therefore it seems a lot worse than it is.

Welcome,

Yes -10 is damned cold, but in Arctic terms it's warm, which doesn't mean melting, but it slows thickening, and stops the ice getting good and cold. In absolute terms it's chilly, but in the terms of the freezing season it's nearly bikini time!

Thanks,
I know it's bad, but what i meant was that in most graphics, green is associated with temperatures above zero, and therefore this one is a bit misleading.

[Pmt111500]

DMI Arctic +2m ASL temperture map hue and color remap for 20170211. DMI behaves exceptionally well for this! Left temperatures below -36C as they initially changed since I don't know how the colder temperatures feel. Sudden feeling of warmth was, I guess, one of the symptoms of freezing to death. I too would prefer something like this but we'll just have to check the scales.

Tried to fit the various blues so the amount of protective clothing needed would be immediately apparent  . Light blues (no special clothing needed, risk of frostbite minimal on short exposure) Blues (longjohns, warm gloves/mittens and headgear essential) Violets (expert winter clothing), Pinks & reds (nothing is enough, a stupid person gets a frostbite no matter what)

The other change is the highlighting of  -2C - +2C range to show the area around freezing point and possible microbiological activity on the surface better. (It can of course be that the warmest south facing surfaces start to gather enough light and warmth for lichen and other cold climate autotrophs pretty early but this is in general and over the sea.)

This won't become a regular feature.

[bairgon]

I noticed from two recent posts that there is a considerable amount of ice down in the Newfoundland Bay area - see this message and one just before it:

show the effects of the latest weather

And Cate pointed out the ice report along the east Canadian coast:

Canadian Ice Service analysis for east coast: fairly solid coverage at the moment along the Labrador Coast to NE Newfoundland waters with concentrations up to 100%. Mostly thin first-year ice with some grey and grey-white on the front. All looks pretty normal here for this time of year, but in another couple months we'll be praying for sou'westerlies. 

http://iceweb1.cis.ec.gc.ca/Prod/page2.xhtml?CanID=11091&lang=en&title=East+Coast

Wipneus psoted a gif of Fram today in the "Home brew AMSR2 extent & area" thread, showing the dramatic continuing effect of the recent damage due to the warm winds from the south. See

Continued...

Nullshcool is showing a low tracking up that eastern Canadian coast from 14th to 16th, with warm onshore winds followed by offshore. Looks like that will damage the ice in the same way as the recent damage to Fram.

[romett1]

As clouds, wind and warm air moved over Fram, we see the results - compared Sat vs Fri (Uni of Bremen maps). It's still pretty cloudy there, so no good real-time image.

[Neven]

DMI SAT for the last 10 days:

[shmengie]

Thanks Neven,
That animation explains the current temperature spike here:

[aslan]

Svalbard finally dip below zero degrees Celsius around 02UTC this day, ending a remarquable streak of above freezing temperatures. It has been since the early hours of the 05th February that the airport was above zero. During one full week, or 169 hours, the airport was above freezing. This is the longest streak in any winter months, beating out the previous thawing period of 155 hours at the end of December 2015 and the start of January 2016. Needless to say, this will be the February month with the lowest freezing days total for the station.



And the month to day is more typical of a February month in Deutschland with a Tnm of -2.5°C, a Tm of 0.2°C and a Txm of 2.8°C. A strong cooling is likely in the coming days, and beating out the monthly record of -1.4°C in February 2014 seems highly unlikely, but still this is remarquable for the a first half of February.

[viggovang]

FYI; This last month the yearly moving average for DMI's Daily mean temperature anomaly for the Arctic area north of the 80th northern parallel reached above 5°C:

First time around 20/01/2017 with 5.02°C and yesterday 12/02/2017 it reached 5.05°C. See graph at

https://dl.dropboxusercontent.com/u/11187117/DMI%2080N%20Temp%20Anomaly.pdf

[DavidR]

The North Atlantic appears to  be green according to  EOSDIS.  Can any one explain what is going on there?.

[Pmt111500]

http://www.opc.ncep.noaa.gov/mobile/mobile_product.php?id=NFDHSFAT1
Says there's heavy fog/freezing spray, watery low clouds?
M certain they look different than regular snow white clouds from above. May be the green is some reflection of the sea through these?

[Archimid]

Looking at nullschool and other places it seems to me that things will be looking up for the Arctic in the next 5 days. Some hopes I have:

1. DMI Temps above 80 graph drops  below 245 and stays there for a while. The next wave of hot air seems weaker that what I have seen before.

2. The Bering Sea has enough ice to generate ice growth at the periphery, buying us time. If it is more export from Chukchi, I don't think much is gained.

3. Maybe the Kara recovers some extent, stopping all that extra sunshine starting to bleed in.
 

[Tigertown]

The North Atlantic appears to  be green according to  EOSDIS.  Can any one explain what is going on there?.

I think that is just the angle of the sun there at this time of year, giving very weak light. Look at the Bering Sea in early January and it looks about the same.

[Tigertown]

Export looks strong for this week, and new storms coming next week. Here is a review of the "roller coaster" ride that has been going on the last few weeks.

10⁶ km²  NSIDC SIE


 2017,    01,  25,     13.763               2017,    02,  04,     13.834
 2017,    01,  26,     13.739               2017,    02,  05,     13.863
 2017,    01,  27,     13.701               2017,    02,  06,     13.956
 2017,    01,  28,     13.654               2017,    02,  07,     13.873
 2017,    01,  29,     13.623               2017,    02,  08,     13.901
 2017,    01,  30,     13.721               2017,    02,  09,     13.912
 2017,    01,  31,     13.774               2017,    02,  10,     13.926
 2017,    02,  01,     13.821               2017,    02,  11,     13.865
 2017,    02,  02,     13.826               2017,    02,  12,     13.898
 2017,    02,  03,     13.886

[lifeblack]

freezing degree days aren't binary (freeze or no freeze), it's a measure of how many degrees below freezing the average daily temperature is.

link:  https://nsidc.org/cryosphere/seaice/processes/thermodynamic_growth.html

And Celsius is normally used for freezing degree days.

Surely a freezing degree day is the same regardless of the scale used?

No, since individual temperature units from different scales vary they would not be the same in every scale.  Calculated in °C or K they would be the same, but FDDs in Fahrenheit would be significantly different.  It's no different than miles versus km. 

It's always important to know the definition of the units one is using.

Of course. I remember my high school mathematics (all the way through to my postdoc). I meant to say that a freezing degree day is a binary, regardless of the scale used. It either is or it isn't. Measuring in Kelvin would produce the same set of days, even if the numbers on the scale are different. But Nevin is right: it was a lame question!

[6roucho]

freezing degree days aren't binary (freeze or no freeze), it's a measure of how many degrees below freezing the average daily temperature is.

Apologies! I should have read some climatology! [/embarrassed]

[romett1]

Thick clouds have disappeared, so i compared today vs yesterday near Fram. Ice is pretty fragmented, so it can easily flow towards south. Those 4 big white blocks north of Greenland are also interesting to watch - they broke off last week, probably 4-6 m thick and therefore adding to potential volume loss. Images from https://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

[LRC1962]

I feel a very good write up of what has happened in the last week or so https://www.theweathernetwork.com/news/articles/arctic-storms-bring-another-winter-heatwave-to-north-pole/79190

[Jim Hunt]

Area has been hit a lot harder than extent. High res AMSR2:

http://GreatWhiteCon.info/2017/02/facts-about-the-arctic-in-february-2017/#Feb-13

[Tigertown]

That has been noticeable for a good while on the concentration maps.
Click Image Please
Click a second time to enlarge. Warning; the ribs are showing through. Very graphic.

[aslan]

Models are forecasting a major SSW for the end of the month. It is still in the 240h - 384h range, and so IFS -the european model- still does not show a major SSW. But the warming is gaining ground in this model also, with a wind reversal down to around 2 - 3hPa. And tomorow the forecast will probably show a wind reversal at 10 hPa also. The activity of the wave 1 is really strong and it is certain that in the coming days the IFS will also show a major SSW. In contrast with the displacement event earlier this winter, the baroclinic nature of the wave 1 is clear this time, with the minimum of the PV being displaced westward and somewhat poleward with height, and being almost 180° apart beetween lower stratosphere and higher stratosphere. In the end, the PV is set to be twisted and torn apart by the wave 1.



But the most unbelievable thing is the constancy of GFS to depict this event as a SFW... Every run, up to 384h, shows the end of the polar vortex. The wind forecast at 10 hPa and 384h :



And the temperature forecast :



Where are you, PV?

We will see what the IFS tell us in the coming days, but if this is the SFW and not SSW, this will be the earliest one, beating out the record of 2016... Crazy. This plot goes only to 192h, so the SSW is still not visible, but to put in perspective a SFW in the end of February...

https://ozonewatch.gsfc.nasa.gov/meteorology/figures/merra2/wind/u60n_10_2016_merra2.pdf

Atop this SSW looking like a SFW, global temperatures are still extremely high and forecasted to remain in the same range in coming weeks, and models are pointing out to an early retreat of the snow. March is set for some suprise in the synoptic situation.

May you live in interresting times, as the old say goes...

[aslan]

And also a monthly heat record in Island, with +19.1°C the 12th ( ! ), and in the first half of February... This was due to a foehn effect. It breaks old record of 18.3°C in 2005, the 21th; and 18.1°C in 1998, the 17th.

https://www.facebook.com/geoclimat.org/photos/a.832272180166905.1073741826.832246480169475/1355999204460864/?type=3&theater

[binntho]

And also a monthly heat record in Island, with +19.1°C the 12th ( ! ), and in the first half of February... This was due to a foehn effect. It breaks old record of 18.3°C in 2005, the 21th; and 18.1°C in 1998, the 17th.

I think you mean Iceland.

As I understand the foehn effect, this was something else. The foehn effect happens when moisture laden air is pressed over a mountain range. The elevation causes increased precipitation which warms the air. On the leeward side of the range, the air is dry and warm, on the windward side it is cool and wet. But it's still the same air.

The event in Iceland was, as I understand it from Icelandic weather blogs, caused by an unusually warm air mass passing at some height over Iceland, and "touching down" locally due to disruptions in the upper air flow caused by mountains.

But I believe the premier Icelandic weather blogger is reading this forum as well, and I'm sure he'll correct me if I'm wrong!

[P-maker]

Binntho.

Also in Greenland have we seen recent temperature records such as these: https://www.dmi.dk/nyheder/arkiv/nyheder-2017/februar/der-er-lunt-i-arktisk/ ascribed to an enhanced Föehn-effect.

When air masses become more moist, the potential for higher Föehn-effect temperatures on the downhill side of mountains should increase. Since only few of the mountains in question have become higher due to melting glaciers and glacial rebound, we should expect to see a pronounced anthropogenic effect through higher Föehn temperatures. Record-breaking Föehn wind temperatures in Svalbard, Greenland and Iceland are thus no coincidence. They are just adding to the catalogue of positive feedbacks we are seeing this season.

[Tigertown]

It seems like where the cool area of melt water, probably from land ice and Fram ice, meets warmer waters to the south of Greenland is causing regular disturbances. LP's set up in the nearby regions and move warm air and moisture to the Arctic, including lately Greenland. The last one moved a lot of this in at surface level and just above, also.

[Oddmonk]

Island=Iceland in Icelandic. 

[Tigertown]

Somewhat strong export over the next week. It is already hurting the concentration in the ESS and Chukchi, due to what has been pushed out to the Bering Sea.
CLICK IMAGE PLEASE

[gerontocrat]

Wind forecasts for 2 to 3 days suggest strong sea ice drift out through Bering Strait and general eastward movement of all the thick ice north of Canada and Greenland towards the Fram. One to watch?

[Archimid]

Island=Iceland in Icelandic. 

In Spanish, Islandia = Iceland.  In Spanish ice = hielo and isla = island. Notice Islandia is used, not Hielolandia. In Spanish the reference to ice is lost but the reference to being an island is gained. They were both equally good names. Looking at this freezing season, the English meaning of the world might eventually lose its descriptive capacity. It's a shame. I thought it was so appropriate.

[Paddy]

Eventually, but not right away. In addition to being so far to the north, there's a fair bit of Iceland over 1000m in elevation and peaks over 2000m. In addition, some of the glaciers in Iceland are pretty big; they include Vatnajökull, which at 3000 km3 is Europe's largest.

[Ice Shieldz]

@ aslan in regards to your post discussing tropical forcing . . .

MJVentrice
We have never observed a stronger MJO amplitude over the W. Hemisphere during this time of year before... Nearly +4 standard deviations!

So yup, Atlantic storms seem likely to be even more severe as the PV weakens. 

[Neven]

Northern Hemisphere snow cover has started to go down:

[crandles]

Northern Hemisphere snow cover has started to go down:

and it is quite patchy with below average snow depths around southern Okhotz, Kara coast, and Alaska. Will those area melt out early or manage to gain some more snow?

[subgeometer]

Northern Hemisphere snow cover has started to go down:

Over the next week the GFS forecasts loss of snow cover in a broad swathe of southern and central Canada especially the upper half of the MacKenzie catchment across to southern Hudson Bay, and also  in eastern Europe.

The big heat anomalies move to the midlatitudes of the continents, perhaps at just the wrong time

[Iceismylife]

Northern Hemisphere snow cover has started to go down:

And what day in January was the peek?

[Tigertown]

With all the export pushing and pulling on the ice in different directions, the leads in the ESS open up.

[Archimid]

North Polar sea surface temperatures anomalies for 14 February:

2015: http://polar.ncep.noaa.gov/sst/ophi/archive/20150214/color_anomaly_NPS_ophi0.png
2016: http://polar.ncep.noaa.gov/sst/ophi/archive/20160214/color_anomaly_NPS_ophi0.png
2017: http://polar.ncep.noaa.gov/sst/ophi/color_newdisp_anomaly_north_pole_stereo_ophi0.png

 

[Tigertown]

@Archimid
 Any ideas on the cause? Ekman pumping, maybe? I know the wind has blown around the ice in that area a lot, the ESS especially. We have has discussions about heat not being able to escape  surfaces as easily anymore, also.

PS  Not asking about the Barents, as we all know where that came from, but these little isolated areas.

[Hyperion]

Somewhat strong export over the next week. It is already hurting the concentration in the ESS and Chukchi, due to what has been pushed out to the Bering Sea.
CLICK IMAGE PLEASE

Are these thickness plots still being based on 10% freeboard or what ever similar figure is historically used for old fashioned firstyear ice? Eg/ where they are graphing 2m thick is it based on satellite measurements of  ~0.2m freeboard?
 I'm concerned that the real density might be significantly lower. if its mostly snow and  rotten honeycomb with thin ice crusts interleaved, it could be as low as 0.5 kg/litre which would make 0.2m freeboard actually ~0.4m thickness. And the blowtorch like melts in the killzone fram / svalbard / bering areas certainly look to me like what you would expect from thin and rubbish quality ice. Not solid 2m thick berg. 

[Archimid]

@Archimid
 Any ideas on the cause? Ekman pumping, maybe? I know the wind has blown around the ice in that area a lot, the ESS especially. We have has discussions about heat not being able to escape  surfaces as easily anymore, also.

I think the Atlantic is warmer for two reasons mainly.

1. Atlantification of the Barentz which I think is starting to intrude all the way into Kara and the CAB
2. Lack of ice in that region for the last several season, lowering albedo.

I think they are both cause and effect.

Around the ESS and Laptev I think it has mostly to do with snow melt runoff.

Around the Bering Sea I think the cold spot right outside the Bering straight is caused by melt  from exported ice from Chukchi. I fear that deeper water might be much warmer. It is also worth noticing that south of Alaska SSTAs are much lower now than in the past two year. Maybe that helps the Beaufort out.

[Tigertown]

@Hyperion
I am by no means the expert on this matter, but until one comes along, I have read that the instruments are more sophisticated now and can distinguish snow from ice. As far as honeycombed ice, I have never heard of that with sea ice so much, as with land based ice sheets.

[romett1]

Export clearly visible, Wed vs Tue. Danish website http://ocean.dmi.dk/arctic/icethickness/images/FullSize_CICE_combine_thick_SM_EN_20170214.png shows volume is pretty much same for a week already. Images from https://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

[gerontocrat]

Jaxa sea ice drift graph and weather-forecast.com also show moderate to strong west-to-east movement of all thick ice north of Canada And Greenland. Weather-forecast.com also forecasts strong southerly win9ds down the Fram from 21 Feb - after a couple of quiet days late this week.
Could this be a major destruction of the remaining thick ice? Time will tell.

[Lord M Vader]

How much distance does the "Big Block" with +4m thick ice have until it reaches the Atlantic "death zone" and is replaced by younger ice?

[Cid_Yama]

@Hyperion
I am by no means the expert on this matter, but until one comes along, I have read that the instruments are more sophisticated now and can distinguish snow from ice. As far as honeycombed ice, I have never heard of that with sea ice so much, as with land based ice sheets.

From 2012:

An Arctic researcher says the permanent northern sea ice that usually survives the summer has all but disappeared.

David Barber of the University of Manitoba, who is one of Canada's top Arctic scientists, just returned from a research trip to the Beaufort Sea. He said his team was shocked by the state of the sea ice there.

This year the ice is “rotten” practically all the way to the North Pole, says Barber, a veteran Arctic researcher and director of the Centre for Earth Observation Science at the University of Manitoba.

He says researchers on the expedition watched a multi-year ice floe the size of Winnipeg break up before their eyes.

“The multi-year ice, what’s left of it, is so heavily decayed that it’s really no longer a barrier to transportation,” he says, explaining how melt ponds have left much of the ice looking like Swiss cheese.

“You could have taken a ship right across the North Pole this year,” says Barber, whose research team was involved in a 36-day research cruise in the Beaufort on a Canadian Coast Guard ship.

The U.S. numbers are about “a 15-per-cent over-estimation of how much ice is actually there,” says Barber. That’s because satellites have trouble discerning ice conditions, he says, and will count heavily decayed ice as solid.

link

[romett1]

How much distance does the "Big Block" with +4m thick ice have until it reaches the Atlantic "death zone" and is replaced by younger ice?

It's about 270 km (block 1) and 500 km (block 4) to warmer waters. Actually some smaller blocks are already heading south. http://ocean.dmi.dk/arctic/nord.uk.php

[Tigertown]

It is kind of nice being on the other end for a change. I usually get accused of being the dramatic one. Others are always telling me, "it's not that bad." Well, maybe it just is.

That being the case, excellent point made by Hyperion.

[aslan]

The Canadian Ice Service is still showing massive amount of thin and medium first year sea ice with some patches of gray ice embedded. There is virtually no thick first year sea ice. As a remainder, for the Canadians, thin is up to 70 cms, medium is up to 120 cms, thick is above 120 cms :



Again, it is looking really bad.

In January 2017, downward infrared radiations were again quite high. Not as high as in January 2016, but it is quite close :





The normal :



And fact is that snow and ice are not so white for snakes (if any one is living on the sea ice  )

https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes



I am not sure how much this is a factor, but at least it is not helping...

For the MJO, yes a very big spike is ongoing. This is probably boosting the positive PNA pattern, which in the end is bringing record warmth to western Canada. In the same time, GFS is showing wave 1 after wave 1 into the stratosphere :



Ok it is 384h and even for the stratosphere forecast are a bit uncertain, but nonetheless the possibility of a very early SFW is gaining ground. At least VP is going to be heavily disrupted. Big changes in the synoptic situation are likely for March.