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Author Topic: The 2017/2018 freezing season  (Read 40961 times)

Brigantine

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Re: The 2017/2018 freezing season
« Reply #300 on: November 09, 2017, 12:51:23 AM »
I'm doubtful that much of this can be attributed to misgraphing of missing data.
Ok. Let's dive deeper.

Composite Plot of ITP T & S Profiles: In the top 40 meters, there is exactly one profile showing temperatures above -1.5C. Though the 34 PSU contour does reach up to only 20m depth.

Stripe 1: Days 261-268.
From the engineering data plot, the minimum pressure recorded during this period? Off the charts. Not a single profile during this period reached shallow depths. Motor current was also consistently high, which if I know anything about motors means it got stuck. (more than normal)

Stripe 2 & 3: Days 273-274 & 279.
Again, no profiles reaching shallow water. No obvious signs as to why though.

Stripe 4: Days 283-290.
This is a strange one, on the contour plot the first half of the stripe shows scorching temps down to 35m, then from 60m to 600m, but with normal temps around 35-40m and again right at the bottom (760m). The second half is just scorching from surface to depth.

On the engineering data, the battery voltage has now permanently transitioned to an abnormally low state. The first half of the stripe shows two profiles reaching up to 38m depth, but no better; the second half shows no shallow profiles at all.

Odd Feature at Day 293 - Warm surface feature above 35-40m. Engineering data shows a single profile reaching up to 39m depth, with a small spike in motor current. A similar but weaker surface feature occurs at Day 298, with a profile reaching up to 8m depth and another spike in motor current.

Stripe 5: Days 301-304. Zero shallow profiles, and a larger spike in motor current.

Note that in every gap between these stripes, i.e. everywhere the contour plot shows a fresh & cold surface layer, there are profiles recording pressures right up to 8m depth.

It would have been more conclusive info if the minimum pressure plot had had a wider range on the depth scale, but I'm quite comfortable concluding that the halocline *isn't* suddenly disappearing and then reappearing again.

I must say I'm no longer sure it's only a problem of *missing* data. I wonder if there might also be a factor of high temperature readings occurring when the profiler gets stuck and the motor draws a very high current for a short time - which happens to occur right at the end of the particular profile's range i.e. the one data point most likely to be extrapolated.

I still trust data from individual profiles, and the composite plot of profiles, but I just can't take stripes on the contour plot at face value.

Hyperion

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Re: The 2017/2018 freezing season
« Reply #301 on: November 09, 2017, 02:23:56 PM »
Durn!
Ok. Thats a pretty good case for some serious issues with the cable crawler data aquisition unit. I would of thought there would be some pressure sensor cross referencing automated to validate where it thinks its at on the cable, or at least some manual checks. Disapointing that a buoy launched just six months ago is looking so dodgy after a development of almost 100 mostly reliable predecessors.
I had been working on the hypothesis that this recent behaviour was probably due to eddy and vortex mixing from the 14c temp incoming water that is surfacing still west of svalberd doing a right turn and interacting with bottom topography and wave and current effects. Now it seems we have no direct data thats reliable on the Atlantic front at all. Probably growing kelp on its upper cable or some such.
The new ITPS in the north beaufort have also been giving us inconstant contour plots. The past two weekends have given the t&S flat readings surface to depth on all three I pointed out before. Until someone seems to get to work on monday and "Fix" the issue. Happened again today infact. The composit plots look more consistant and are perhaps worth a sqiz for comparison with early plots from 10years ago. ITPS 3,5,6:




Admittedly these are a much longer series, covering up to 3yrs from 2005in the same area as 100,101,108 are now charting, so there is somr data mixed in with open water and shallows. But they see to contrast with ten years later by having a less contiguous pacific warm layer just over 30psu at 50 to 60m depth and temps -1.5 to 0.5. And surface salinities as low as 22psu with generally 5-6psu differential between these depths.
Now we appear to be seeing a more consistant temperature peak at about 40m and only 1-2psu differential with surface.
The big thermal store is in the atlantic layer starting about 200m. But with the anticlockwise low pressure dominated circulation patterns we are increasingly seeing. This is like a spin cycle with fresh riverine influxes not replenishing the halo but expelled by coriolis out bering and CAA, greenland coasts. Big negative sstas in the nth pac and greenland  area presently look like this to me. New north beau buoys As  attached:
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2phil4u

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Re: The 2017/2018 freezing season
« Reply #302 on: November 09, 2017, 02:55:33 PM »
If a Low Minimum in average produce higher min next year, The onlY Option ist, thathat ICE is warming, ICE helps Not to lose energy, ICE triggerrd Indikation ist bigger Thema less albedo in Summer.
Smartphone writing ist awful.

Ich




« Last Edit: November 09, 2017, 03:11:00 PM by 2phil4u »

Daniel B.

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Re: The 2017/2018 freezing season
« Reply #303 on: November 09, 2017, 03:59:18 PM »
If a Low Minimum in average produce higher min next year, The onlY Option ist, thathat ICE is warming, ICE helps Not to lose energy, ICE triggerrd Indikation ist bigger Thema less albedo in Summer.
Smartphone writing ist awful.

Ich

Yes, smartphone writing is indeed awful.  But I was able to understand you.  I agree that the decreased ice cover results in greater heat loss, temporarily cooling the water.  This will result in a greater ice minimum the following year.  However, this may just be a temporary blip in the long-term decline.

Brigantine

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Re: The 2017/2018 freezing season
« Reply #304 on: November 09, 2017, 09:13:14 PM »
But with the anticlockwise low pressure dominated circulation patterns we are increasingly seeing. This is like a spin cycle with fresh riverine influxes not replenishing the halo but expelled by coriolis out bering and CAA, greenland coasts. Big negative sstas in the nth pac and greenland  area presently look like this to me.

Some interesting ideas there that I'll look at more when I have time. The overall freshwater budget of the arctic is definitely of interest.

Regarding the cold blob in the North Pacific, I was of the impression that it came from the direction of Japan, and was related to ENSO. Though what you say makes some sense as I remember a strip of cold anomalies last winter right down the eastern coast of Kamchatka into Okhotsk, and that's exactly what you would expect to see from a super fresh current.

Brigantine

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Re: The 2017/2018 freezing season
« Reply #305 on: November 10, 2017, 11:21:24 PM »
Your stripes... What happened? It seems the contour plots have had a little update!

They now show a more plausible story of active deep water formation.

Hyperion

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Re: The 2017/2018 freezing season
« Reply #306 on: November 11, 2017, 07:15:11 PM »
Your stripes... What happened? It seems the contour plots have had a little update!

They now show a more plausible story of active deep water formation.
Not sure which you alluding to. 95 still stripy. Not implausibility that pulses of salty water are sliding in under the icepack when basin wide seals do pressure drops. Get cooled to freezing point near surface and sink, and under rising pressure central basin surface waters washing out. Unless we go "Naah, must all just be mechanical!". The co-located imb-crrel-dartmouth.org is potentially able to shed some light if you can strip search it's thermistor string data. Water temp with ice in proximity is a proxy for salinity.

100,101,108. Are continuing to suffer from the case of the here today and gone tomorrow leading edge stripe syndrome.
LOLz, Perhaps Trump has invoked the patriot act and declared clear publication of real world Arctic data to be an act of terrorism by threats to future US oil revenues or military plans. If anyone wants to talk to Woods for any explanation they can give it be great.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
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Hyperion

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Re: The 2017/2018 freezing season
« Reply #307 on: November 11, 2017, 07:29:20 PM »
Amusing language hack by this smart assumption phone there. Basin wide sea level pressure drops. Not basin wide seals do pressure drops. Though I guess the effects could be similar.
It just added umption to my previous sentence I notice also. I am saddened by the censorship of the potentially slightly disturbing by big brother.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

Hyperion

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Re: The 2017/2018 freezing season
« Reply #308 on: November 12, 2017, 04:39:14 AM »
See. Here we go again. Six hours ago the contours were smooth.
Now it's back to mixed to 500m again.

And reading eg. itp100:
Last profile (number 109) on 2017/11/12 2 UTC
Last profile temperature: minimum = -1.5105, maximum = 0.85202 °C
Last profile salinity: minimum = 29.8848, maximum = 34.8585
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
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Neven

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Re: The 2017/2018 freezing season
« Reply #309 on: November 12, 2017, 10:40:11 AM »
If things get too specific, maybe take it to the Buoys thread?
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meddoc

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Re: The 2017/2018 freezing season
« Reply #310 on: November 12, 2017, 09:10:58 PM »
Anyone knows about Hycom Forecasts?
Hasn't been updated since 24th October.

numerobis

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Re: The 2017/2018 freezing season
« Reply #311 on: November 13, 2017, 01:54:30 AM »
If a Low Minimum in average produce higher min next year, The onlY Option ist, thathat ICE is warming, ICE helps Not to lose energy, ICE triggerrd Indikation ist bigger Thema less albedo in Summer.
Smartphone writing ist awful.

Ich

Add the 'english' language and the smartphone will autocorrect you to english rather than german.

(Or keep trying, and eventually the smartphone will be bilingual.)

Ice Shieldz

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Re: The 2017/2018 freezing season
« Reply #312 on: November 13, 2017, 07:27:06 AM »
2017 Nov 1st to 13th mean 2m air temperature anomalies.  Looks like more WACC-yness. Although this year 80-90 north is holding closer to average.

Pavel

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Re: The 2017/2018 freezing season
« Reply #313 on: November 13, 2017, 08:50:41 AM »
Anyone knows about Hycom Forecasts?
Hasn't been updated since 24th October.
It has now a Global version including Antarctica https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/POLAR.html

2phil4u

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Re: The 2017/2018 freezing season
« Reply #314 on: November 13, 2017, 12:45:19 PM »
I like to write on a normal  keyboard, because i know how to write with 10 fingers.
The  smart phone was a cheap replacement and it just suck,the technic is superbad, so i often missclick and  so  on.
What i wanted to illustrate is the fact, that after a summer with more open water, the next minimum tends to be higher.
With this logic it seems like the winter overcompensate and if it is not the case, that say the upper  lawyer i s cooler, but in depth its warmer,  what i dont think is the case, this means, that the arctic has a tremendous negative feedback and so discussions about multiyear ice and quality are just nonsens, just because no ice mans more cooling then the additional warming in summer.
And so  maybe even more true for the N80-90 region, the potential cooling effect of open water is huge,while in the more south regions warmer water from atlantic, pacific and the mild air from snowfree land has a much bigger impact.
But the  point is. If no ice means more ice the next year, then ice is  warming, so all the time when ice cover was big, the ice avoided the arctic  ocean to supercool down.
And another point, say if  arctic water would  be mixed, so salty,the density would be below the freezing point and so in  winter the ocean would cool down to  depth and maybe this is much more energy then the additional energy due to less albedo.
This is also noticed by some experts but very few people seems to care about,even the physic is really easy to understand. No ice arctis has more potential to eat the energy from the southern  region and send it to space.
Maybe im wrong, but this logic seems to be true.

Dharma Rupa

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Re: The 2017/2018 freezing season
« Reply #315 on: November 13, 2017, 01:31:58 PM »
More open water means higher humidity means more of the greenhouse gas H2O.

Neven

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Re: The 2017/2018 freezing season
« Reply #316 on: November 13, 2017, 04:36:44 PM »
For a belated PIOMAS update over on the ASIB, I produced this graph showing Arctic Temperatures (65-90N) for October since 2005. 2017 second lowest on record:

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2phil4u

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Re: The 2017/2018 freezing season
« Reply #317 on: November 13, 2017, 05:04:16 PM »
More water = more greenhouse effect ?
Is this allways true, more clouds means more snow, snow warms the cloud and cool earth with the cool water.
Sure if cloud gets warmer the energy is from the surface, so there is an energy change.
And the clouds energy will not be reflected as much as ir radiation from earth.
This is very simplificated, im also not an expert,  but clouds also reflect sunlight direct to space.
So many effects.
I dont want to underplay the climate effect, i only think climate sensitiy is propably at the lower end.
But we need to slow down co2, simply build renewables worldwid with some treaty that partners have to buy energy for some decades, so we can get the money back we invested at beginning, because prices will drop rapidly if we start to really build many.
Would  be an idea, take money, build reneables, get less money then invested,  price goes down, now the partner has to buy longer, so we can get the money back because we allready produce under the price handled out.
Money can be taken as a credit from central banks.
« Last Edit: November 13, 2017, 05:10:42 PM by 2phil4u »

A-Team

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Re: The 2017/2018 freezing season
« Reply #318 on: November 13, 2017, 05:42:13 PM »
Below is an update on Arctic Ocean open water from the 10 Sept minimum (fixed black outline) until 12 Nov with relative areas of ice-free regions for later dates (inset bar graph), with emphasis on the Chukchi-Beaufort and north Svalbard. Interior green represents 100% sea ice concentration in the UH AMSR2 assessment; there is little else this time of year except on the periphery.

The second animation compares 12 Nov 17 to the same date in 2013-2016. The magenta line shows the union of open water for these five years; 2012 data is not available at UH until the first of January. The multiplier relative to the low year 2013 and relative to five year mean are also provided.

year   rel 2013   rel mean
2017   1.88   1.27
2016   1.53   1.04
2015   1.32   0.90
2014   1.64   1.11
2013   1.00   0.68
« Last Edit: November 14, 2017, 11:30:51 AM by A-Team »

oren

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Re: The 2017/2018 freezing season
« Reply #319 on: November 13, 2017, 10:15:07 PM »
A-Team thank you for these wonderful animations. I had a "feeling" that 2017 was refreezing much better than 2016, but it seems on the Chukchi front that is not the case.

A-Team

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Re: The 2017/2018 freezing season
« Reply #320 on: November 13, 2017, 10:33:59 PM »
on the Chukchi front, refreezing is actually the slowest in years. while the Svalbard front is actually receding poleward.
That's right, Oren. It appears primarily attributable to influxes of Bering Sea and Atlantic Waters that are too warm, given their immense heat capacity relative to the freezing capacity of cold air in conjunction with net upwelling radiative energy flux loss. (Ice pack bulk motion, compaction and dispersion need to be factored in but have been fairly minimal.)

The 3.125 km resolution of UH AMSR2 sea ice concentration (previous post) does a better job at picking out open water than far coarser satellite data used elsewhere for the less intuitive extent/area graphs, especially as coastal complexity comes into play. However those have the longer history necessary to pull trends from natural variability. In my view, picking connected open water in this region is more appropriate than ad hoc regional definitions of Beaufort vs Chukchi vs East Siberian seas.

The UH SMOS sea ice thickness product below uses a quite different approach that is complementary to AMSR2 sea ice concentration. At the very margins of the ice pack where new ice is in the initial stages of formation, SMOS provides the opportunity to apply a specific thickness and brine content cutoff for what is to be considered as defining the effective ice edge. As depicted in the second animation, the thickness, salinity and snow surface temperatures have slightly different edges.

The freezing point of sea water at 34 psu salinity is -1.8ºC which corresponds to 271.35 on the kelvin scale shown. (While not considered politically correct today, ºK was used for the first 149 years for this scale, including by Kelvin himself.) Bulk ice salinity increases towards the edges and markedly so for ice age due to progressive brine exclusion.
« Last Edit: November 14, 2017, 11:22:16 AM by A-Team »

Hyperion

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Re: The 2017/2018 freezing season
« Reply #321 on: November 14, 2017, 03:58:14 AM »
Here's the data from the only warm buoy still functioning. At:
LAST UPDATE
Date: 11/13/2017
Position: 76.04N 147.81W
Battery Voltage: 11.40V
She appears to have done a small pirouette around the remnant of the Beaufort gyre since august and is currently about where the ice edge retreated to in September. This is probably the best place and time of year for the persistence of a low salinity lid in the whole Arctic. But between the surface and 50m where the shelf of pacific heat is is a scant 1 to 2 psu differential. With both extremes of depth experiencing excursions to around the 29psu point. The exclusion of salt from a metre of ice is sufficient to raise 30m of surface layer by a psu in salinity. This is I fear a tipping point upon us where the thermal inertia of the deep basin mixed layer precludes bottom thickening and little more than floating snow can be expected as a winter sea ice state. The Chukchi and Svalbard surge and retreat behaviour certainly looks to me like the halo has lost the strength to submerge pacific and Atlantic warm surges below the hurt zone.
« Last Edit: November 15, 2017, 12:18:48 AM by Hyperion »
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Niall Dollard

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Re: The 2017/2018 freezing season
« Reply #322 on: November 14, 2017, 08:38:12 AM »
For a belated PIOMAS update over on the ASIB, I produced this graph showing Arctic Temperatures (65-90N) for October since 2005. 2017 second lowest on record

Thanks Neven. But i would have phrased it as second highest on record.  :)

Troposphere warmed a lot in October going by Spencer's UAH data.
https://forum.arctic-sea-ice.net/index.php/topic,1225.msg133396.html#msg133396

A-Team

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Re: The 2017/2018 freezing season
« Reply #323 on: November 14, 2017, 12:43:43 PM »
Quite a change ... one of our long-time resources for sea ice thickness has been replaced. The ice is markedly thinner in the new products; whether it is any more accurate is questionable. Still, the forecasts give some idea what is coming.

The animations show the Beaufort barely closing over, the Chukchi and Svalbard remaining open and some moderate Fram export, to 20 Nov.

As of 30 Sept 2017, ACNFS will be replaced by the Global Ocean Forecast System (GOFS 3.1). Daily Arctic and Antarctic ice products are available from the GOFS 3.1web page. The ACNFS webpage will remain in service for historical purposes but will not be updated with real-time ice forecast products.

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/POLAR.html

Sterks

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Re: The 2017/2018 freezing season
« Reply #324 on: November 14, 2017, 02:45:02 PM »
Quite a change ... one of our long-time resources for sea ice thickness has been replaced. The ice is markedly thinner in the new products; whether it is any more accurate is questionable. Still, the forecasts give some idea what is coming.

Unless they have improved something very recently, this model is absolutely unreliable, it shows such a thin ice, (especially in summer), that nothing else out there supports or aligns with, whether PIOMAS, Cryosat, SMOS, or just what we have been seeing from the buoys or the Healy.

Expect however some extremely avid followers of this Glb thing in summer. A pity, the Acnfs of the last two or three years did not behave bad at all (for ice thickness; for ocean in general dont know, but probably this is an improvement, otherwise what's the point).

« Last Edit: November 14, 2017, 02:50:20 PM by Sterks »

gerontocrat

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Re: The 2017/2018 freezing season
« Reply #325 on: November 14, 2017, 02:56:36 PM »
This from cci-reanalyzer is quite impressive. It has been the same for some considerable time except now the Atlantic end high +ve temp anomalies is pushing into very high latitudes.

And this image from NSIDC (as at 12 Nov) seems to show a good correspondence between +ve , -ve, and 0 temp anomalies and where sea ice extent is above, below and average (whereupon A-team tells me it is sea temperatures at surface and depth that really matter ?).
« Last Edit: November 14, 2017, 03:05:46 PM by gerontocrat »
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Dharma Rupa

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Re: The 2017/2018 freezing season
« Reply #326 on: November 14, 2017, 04:22:11 PM »
(whereupon A-team tells me it is sea temperatures at surface and depth that really matter ?).

I would think that it is water vapor which is immediate cause, with ocean temperature at depth as the ultimate cause.

A-Team

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Re: The 2017/2018 freezing season
« Reply #327 on: November 14, 2017, 04:32:37 PM »
is GOFS an improvement, otherwise what's the point?
Good question. Ditto for RASM-ESRL which seems to offer a third version of similar products (below). But that could be asked as well for UH and UB SMOS. Hamburg has coordinated salinity polarizability with Cryosat thickness; Bremen with another soil satellite SMAP. Maybe the two could get together and offer one optimal product?

http://ieeexplore.ieee.org/document/7730367/
http://www.iup.uni-bremen.de/iuppage/psa/projects/SMOSice-project.php

sea temperatures at surface and depth matter
The air temperature at 2m can be quite cold relative to the sea water freezing point yet the re-analyzer temperature anomaly can still be a pronounced orange, especially for a 30 year base period that misses out on more recent Arctic Amplification (which is largely a fall and winter phenomenon).

Actually the temperatures of physical interest to the freeze season are those directly observable of the water and snow/ice surfaces themselves, not modeled meteorological 2m, though the three strongly influence each other.

Seductive computer graphics in many instances have gotten far ahead of actual data accuracy. Only a handful of products, such as UH SMOS, contain error analysis maps in their netCDF bundle. It is not rocket science, using 3rd party ImageJ 3D surface plugins, to drape say ice thickness over its error bump map, both as time series.

Note some open water north of the Bering Strait is still 3ºC above the freezing point. Given wind mixing (shown), thin dry air has a lot of work to do before stable frazil ice can form. Meanwhile upwelling net longwave cooling (provided by ESRL in Arctic11.gif, Arctic23.gif, and Arctic14.gif) is another consideration.

For all their shortcomings, we are probably better off using coupled radiative water-ice-snow-air-precip-cloud forecast models, which quantitatively integrate all the considerations, than intuiting off a single parameter such as a transient air mass.

https://www.esrl.noaa.gov/psd/forecasts/seaice/ navigate to Coupled --> Surface Fluxes

There are no active temperature gauges today in the Arctic Ocean itself, only a handful on the periphery and one daily sonde at Ny-Ålesund. This would be like producing a high resolution daily 2m temperature map of Europe using only station data from North Africa, Ireland and Finland, lol.

water vapor intrusions can have very significant impacts
Yes indeed, seems like last season had a number of notable and persistent events. Anybody recall the link to that very fine TPW web graphic? It showed counter-rotating water vapor trails sometimes rising up into the North Atlantic and beyond, bring warm vapor from the Caribbean.

Winter storms have been analyzed by L Boisvert and coworkers, including in several AGU2017 abstracts, notably:

GC43J-07: Increasing frequency and duration of Arctic winter warming events
http://onlinelibrary.wiley.com/doi/10.1002/2017GL073395/full open source
https://www.researchgate.net/profile/Linette_Boisvert/contributions
RM Graham et al

During the last three winter seasons, extreme warming events were observed over sea ice in the central Arctic Ocean. Each of these warming events were associated with temperatures close to or above 0°C, which lasted for between 1 and 3 days. Typically temperatures in the Arctic at this time of year are below −30°C. Here we study past temperature observations in the Arctic to investigate how common winter warming events are. We use temperature observations from expeditions such as Fram (1893–1896) and manned Soviet North Pole drifting ice stations from 1937 to 1991. These historic temperature records show that winter warming events have been observed over most of the Arctic Ocean.

Despite a thin network of observation sites, winter time temperatures above −5°C were directly observed approximately once every 3 years in the central Arctic Ocean between 1954 and 2010. Winter warming events are associated with storm systems originating in either the Atlantic or Pacific Oceans. Twice as many warming events originate from the Atlantic Ocean compared with the Pacific. These storms often penetrate across the North Pole. While observations of winter warming events date back to 1896, we find an increasing number of winter warming events in recent years.

Record low Arctic sea ice extents were observed during the last three winter seasons (March). During each of these winters, near-surface air temperatures close to 0°C were observed, in situ, over sea ice in the central Arctic. Recent media reports and scientific studies suggest that such winter warming events were unprecedented for the Arctic. Here we use in situ winter (December–March) temperature observations, such as those from Soviet North Pole drifting stations and ocean buoys, to determine how common Arctic winter warming events are.

Despite a limited observational network, temperatures exceeding −5°C were measured in situ during more than 30% of winters from 1954 to 2010, by either North Pole drifting stations or ocean buoys. Correlation coefficients between the atmospheric reanalysis, ERA-Interim, and these in-situ temperature records are shown to be on the order of 0.90.

This suggests that ERA-Interim is a suitable tool for studying Arctic winter warming events. Using the ERA-Interim record (1979–2016), we show that the North Pole typically experiences 10 warming events (T2m > −10°C) per winter, compared with only five in the Pacific Central Arctic (PCA).

C21B-1119: Winter Arctic sea ice growth: current variability and projections for the coming decades
https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/258297

C33C-1215: Rainy Days in the New Arctic: A Comprehensive Look at Precipitation from 8 Reanalysis
https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/253439
« Last Edit: November 14, 2017, 08:41:20 PM by A-Team »

Neven

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Re: The 2017/2018 freezing season
« Reply #328 on: November 14, 2017, 11:11:12 PM »
Thanks Neven. But i would have phrased it as second highest on record.  :)

Absolutely right you are!

Yes indeed, seems like last season had a number of notable and persistent events. Anybody recall the link to that very fine TPW web graphic? It showed counter-rotating water vapor trails sometimes rising up into the North Atlantic and beyond, bring warm vapor from the Caribbean.

You mean this one (link in case image doesn't show)?

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A-Team

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Re: The 2017/2018 freezing season
« Reply #329 on: November 14, 2017, 11:50:24 PM »
You mean this TPW?
Yes! Surprising that it display, original size is 1000 x 470

Turns out they offer quite a few specialized views, though not either pole. I found the netCDF files but they are not in the Geo2D format that would allow re-projection in Panoply with a more attractive palette (though Zack seems to have found a way of doing this.) It would be feasibly to string together multiple days, though they set everything at 100ms delay and then use multiples of first and last rather than setting ms properly.

http://tropic.ssec.wisc.edu/real-time/mtpw2/webAnims/tpw_nrl_colors/ archive
https://tinyurl.com/h4z357y front page
   
alaska
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« Last Edit: November 14, 2017, 11:57:54 PM by A-Team »

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Re: The 2017/2018 freezing season
« Reply #330 on: November 15, 2017, 01:19:11 AM »
A few specific and latent heat of fusion calculations to get a handle on the magnitude of effects we can expect from an expanding surface mixed salinity layer:

At 0 deg C one gram of seawater has to absorb 4.000 Joules of heat for the temperature to increase 1 degree celsius (°C).

Density is 1028 grams per litre so 4.112 kiloJoules is required to raise 1 litre 1 degree C.

Latent heat of fusion water is 334 kJ/kg

334kJ/4.112J = 81.23 dM = 8m of depth dropped 1degC for equivalent energy release to freeze 10cm of water.

If the temp drop required is 3.2 degC to -1.8 degC = 5 degC
then 80m/5 = 16m cooled is equal to 1m of ice frozen.

If its a 2 degC drop to -1.8 freezing point
then 80/2= 40m cooled is equivalent to a metre of ice freezing.

So even at an 0.2 degC average temp a 100m salinity mixed layer would require the equivalent energy removed to cool to the point ice can exist as is released by 2.5m of water becoming frozen into about 2.75m ice.

Unless I'm mistaken, the salt-water its floating in has to be at freezing point for its salinity,
for freshwater ice or snow not to be dissolved by it? ie/ bottom melt.
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Re: The 2017/2018 freezing season
« Reply #331 on: November 15, 2017, 01:21:49 AM »
Hey A-team.

There are no active temperature gauges today in the Arctic Ocean itself,

does IMB 2017B count?
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Re: The 2017/2018 freezing season
« Reply #332 on: November 15, 2017, 02:20:27 PM »
You mean this one?

You might also mention that it's the one linked at the bottom of your Arctic Sea Ice Graphs.

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Re: The 2017/2018 freezing season
« Reply #333 on: November 15, 2017, 05:31:49 PM »
You might also mention that it's the one linked at the bottom of your Arctic Sea Ice Graphs.

It's the one linked at the bottom of my Arctic Sea Ice Graphs.


 ;)  :P
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Re: The 2017/2018 freezing season
« Reply #334 on: November 15, 2017, 06:52:54 PM »
does IMB 2017B count?
Not if it wasn't used in producing the 2m Tropical Tidbits temperature model map. If independent, it  has some interest in terms of a reality check (validation point) for the later, though one point per 9 million sq km is rather sparse. Whatever, 2m is not what the snow/ice surface is experiencing which is 0.1m or better, Teff.

Improving the effective temperature estimation over sea ice using low frequency microwave radiometer data and Arctic buoys

https://tinyurl.com/yasghcmu  10 Nov 17 EUMET OSISAF

Looking at the polarview Svalbard anomaly map that has made numerous appearances here, note that the area for which it is defined makes little sense today to the south, as even in mid-February these days ice doesn't get at all close to that boundary. However the areal definition does fairly well in excluding Fram ice yet including the Yarmak Plateau that is important to bringing Atlantic Water up from depth.

Open water in the Chukchi is following the bathymetry fairly well (as expected for Bering Sea waters), including a protrusion into the Chukchi Borderlands. However west of Herald Canyon, the influence is non-evident (eg in the ESAS west of Wrangel).

http://polarview.met.no/Statistics/climatology.html
« Last Edit: November 15, 2017, 09:14:49 PM by A-Team »

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Re: The 2017/2018 freezing season
« Reply #335 on: November 15, 2017, 09:40:37 PM »
Warm winds also feeding up through the Bering Strait into the Chukchi. This has been a frequent pattern this autumn. Whatever happened to the Aleutian Low ? I guess semi-permanent is not all that permanent.

Warm SE flow also persisting north of Svalbard - however the same large blocking high pressure responsible, centred currently near Cape Chelyuskin, is feeding in some very low temperatures over the Kara Sea.

Not surprising then that ESRL is forecasting considerable ice development over the Kara in the next 5 days.

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Re: The 2017/2018 freezing season
« Reply #336 on: November 17, 2017, 10:07:25 PM »
Ice reported in Black Bay (Ontario shore of Lake Superior) by both CIS and GLSEA on Nov 16.

From what I can figure it's the 2nd earliest reported great lakes ice on record (since 1972/3 season). 2014 was 2 days earlier, 1995 was one day later.

All years with November ice: '95 '96 '05 '07 '12 '13 '14 '15 '17 - Correlated with decreasing arctic ice?

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Re: The 2017/2018 freezing season
« Reply #337 on: Today at 12:18:57 AM »
Ice reported in Black Bay (Ontario shore of Lake Superior) by both CIS and GLSEA on Nov 16.

From what I can figure it's the 2nd earliest reported great lakes ice on record (since 1972/3 season). 2014 was 2 days earlier, 1995 was one day later.

All years with November ice: '95 '96 '05 '07 '12 '13 '14 '15 '17 - Correlated with decreasing arctic ice?

Not sure if I follow what you mean by decreasing arctic ice? 12 and 07 were low arctic ice years but 1996 had substantial arctic ice all through the summer (the min was in the top 5 highest in the satellite era).

Over on the other side of the Atlantic, the Baltic has started its freeze. Early days yet. The SSTs through much of the Baltic are running circa 1 C above the 1971-2000 norm (denoted by the circled temps in chart attached).

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Re: The 2017/2018 freezing season
« Reply #338 on: Today at 06:44:17 AM »
True, 1996 doesn't fit. But '95, '05, '07 and '12 all had the lowest September volume on record at the time, and by a clear margin.

Though many other record years aren't on the list, and after 2012 the rules seem to change - and that's half the data.

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Re: The 2017/2018 freezing season
« Reply #339 on: Today at 09:47:29 AM »
Ok.

I havent looked through all the years but correlating between warm Arctic and early cold on Lake Superior would seem to fit in very much with Jennifer Francis' wobbly jet stream research.

https://www.npr.org/sections/thetwo-way/2014/02/16/277911739/warming-arctic-may-be-causing-jet-stream-to-lose-its-way