Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2015 melting season  (Read 1795679 times)

Michael Hauber

  • Grease ice
  • Posts: 896
    • View Profile
  • Liked: 74
  • Likes Given: 14
Re: The 2015 melting season
« Reply #650 on: April 29, 2015, 04:30:46 AM »
The other point on 2m temperature and salinity is that first year ice has much more salt in it, and a lower melting point (brine rejection pushes most of the salt out of sea ice over time).  Therefore if the ice surface is melting, then first year ice will have a colder surface.  So if most of the ice north of 80N is melting in summer, and if there is more first year ice than there used to be, and if the temperature is constrained closely to the melting point, the temperature will be cooler now than it used to be.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #651 on: April 29, 2015, 01:32:57 PM »
An image of the area north of Svalbard, courtesy of Worldview. The area of fractured ice currently stretches to Franz Josef Land:
« Last Edit: April 29, 2015, 01:43:36 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #652 on: April 29, 2015, 01:56:39 PM »
If there's a salient point to be made, I'd say that this kind of thing just reinforces the oft-made point than as we get closer to the endgame, things become a lot harder to predict, because the old rules don't always work anymore.

Here's a recording of a recent Sea Ice Prediction Network webinar on sea ice modelling:



Note amongst other things the emphasis on the sea ice ecosystem (~ 25:35) and clouds (~ 29:30), and Elizabeth Hunke's answer to Jennifer Francis' question about "the most important known unknown" (~ 43:15):

Quote
I think we don't have a very good handle on the snow in general and everything that has to do with the snow, including the amount of precipitation.



« Last Edit: April 29, 2015, 02:13:25 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Lord M Vader

  • Nilas ice
  • Posts: 1310
    • View Profile
  • Liked: 37
  • Likes Given: 24
Re: The 2015 melting season
« Reply #653 on: April 29, 2015, 08:12:09 PM »
Hi folks!

Latest GFS 12z run shows an interesting forecast for the kara and Laptev Sea by next week. A low pressure in conjunction with a high pressure over Russia may work together and push really warm air into first Kara Sea and later also Laptev Sea. The prospect in that scenario are temperatures above freeze point. This should do some really good damage to the ice there. This forecast scenario is almost supported by ECMWF 12z run but with the difference that the heat pulse won't reach Latev Sea... In addition, ECMWF 12z run developes an intensive Arctic cyclone in Laptev Sea by day 8...

My main question now is: which time at year did we see polynyas/opening of the ice in those areas by 2007, 2010-2012 and 2014?? 2013 did have an opening polynya in Laptev Sea by early May

Best, LMV
« Last Edit: April 29, 2015, 09:20:22 PM by Lord M Vader »

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #654 on: April 30, 2015, 12:06:20 AM »
Hi folks!

Latest GFS 12z run shows an interesting forecast for the kara and Laptev Sea by next week. A low pressure in conjunction with a high pressure over Russia may work together and push really warm air into first Kara Sea and later also Laptev Sea. The prospect in that scenario are temperatures above freeze point. This should do some really good damage to the ice there. This forecast scenario is almost supported by ECMWF 12z run but with the difference that the heat pulse won't reach Latev Sea... In addition, ECMWF 12z run developes an intensive Arctic cyclone in Laptev Sea by day 8...

My main question now is: which time at year did we see polynyas/opening of the ice in those areas by 2007, 2010-2012 and 2014?? 2013 did have an opening polynya in Laptev Sea by early May

Best, LMV

The biggest threats a cyclone right now suggest to me are (1) mechanical fracturing and (2) retrieval of heat from depth to the surface, at a time where it can't be easily re-radiated out.

That ice has been generally kept thin all season by persistent export - in part a side effect of an active Fram, and similar movement of ice into the Barents proper.  Early attack by weather will not be helpful to its preservation.
This space for Rent.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #655 on: April 30, 2015, 12:15:29 AM »
12z ECMWF seems to show a dipole anomaly starting at 168h.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 7
  • Likes Given: 4
Re: The 2015 melting season
« Reply #656 on: April 30, 2015, 12:50:46 AM »
2-3 days of southerly winds and warm temps in Kara should have some impact, but not more than that I would guess. I find it perhaps more interesting that the HP setting up those winds seems to get stuck over Siberia where it could potentially cause very intense snow melt over a broad area. Very interesting to see how the models develop over the next 3-4 days.

sofouuk

  • New ice
  • Posts: 82
    • View Profile
  • Liked: 0
  • Likes Given: 15
Re: The 2015 melting season
« Reply #657 on: May 01, 2015, 02:41:24 PM »
The other point on 2m temperature and salinity is that first year ice has much more salt in it, and a lower melting point (brine rejection pushes most of the salt out of sea ice over time).  Therefore if the ice surface is melting, then first year ice will have a colder surface.  So if most of the ice north of 80N is melting in summer, and if there is more first year ice than there used to be, and if the temperature is constrained closely to the melting point, the temperature will be cooler now than it used to be.

thank you for this literally brilliant comment - now it all makes perfect sense  :)

Peter Ellis

  • Grease ice
  • Posts: 617
    • View Profile
  • Liked: 34
  • Likes Given: 13
Re: The 2015 melting season
« Reply #658 on: May 01, 2015, 03:43:53 PM »
The other point on 2m temperature and salinity is that first year ice has much more salt in it, and a lower melting point (brine rejection pushes most of the salt out of sea ice over time).  Therefore if the ice surface is melting, then first year ice will have a colder surface.  So if most of the ice north of 80N is melting in summer, and if there is more first year ice than there used to be, and if the temperature is constrained closely to the melting point, the temperature will be cooler now than it used to be.
Interesting point - though it's worth bearing in mind that at least some of the surface water / melt ponding will come from snowmelt (i.e. fresh water).  I'll be amazed if anything like that amount of detail is built into the DMI temperature model, though.

Chuck Yokota

  • New ice
  • Posts: 83
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: The 2015 melting season
« Reply #659 on: May 01, 2015, 05:53:36 PM »
From the Encyclopaedia Britannica:
http://www.britannica.com/EBchecked/topic/939404/sea-ice/257553/Ice-salinity-temperature-and-ecological-interactions

Quote
Ice salinity, temperature, and ecological interactions

As seawater freezes and ice forms, liquid brine and air are trapped within a matrix of pure ice crystals. Solid salt crystals subsequently precipitate in pockets of brine within the ice. The brine volume and chemical composition of the solid salts are temperature-dependent.

Liquid ocean water has an average salinity of 35 parts per thousand. New ice such as nilas has the highest average salinity (12–15 parts per thousand); as ice grows thicker during the course of the winter, the average salinity of the entire ice thickness decreases as brine is lost from the ice. Brine loss occurs by temperature-dependent brine pocket migration, brine expulsion, and, most importantly, by gravity drainage via a network of cells and channels. At the end of winter, Arctic first-year ice has an average salinity of 4–6 parts per thousand. Antarctic first-year ice is more saline, perhaps because ice growth rates are more rapid than in the Arctic, and granular ice traps more brine.
The freezing point depression of first year ice at the end of winter would be 0.2 to 0.3 degrees.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #660 on: May 01, 2015, 09:42:00 PM »
Now all the long-range forecasts seem to show a low-pressure center sitting over the Arctic Ocean with a pool of cold air, almost resembling 2013, but it's too early to say for sure. It is of course a real possibility of having a third consecutive season with no aggressive melting.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 7
  • Likes Given: 4
Re: The 2015 melting season
« Reply #661 on: May 01, 2015, 11:48:49 PM »
The latest runs do indeed look 2013ish, but extensive ponding isn't to be expected in the central basin for a few weeks so I don't think a week or two of cyclonic activity will be able to cripple the entire melting season. Rather to the opposite, it now looks increasingly likely that there will be extensive melting of both snow and ice in peripheral regions during the coming week (as the cold air gathers in the high latitudes), snow cover has already taken a beating according to Rutgers.

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #662 on: May 02, 2015, 08:51:15 AM »
GFS appears to predict relatively cool (or is it just normal...) temperatures over most of the arctic during the next week.
This space for Rent.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 7
  • Likes Given: 4
Re: The 2015 melting season
« Reply #663 on: May 02, 2015, 07:46:59 PM »
Attached below are two maps showing the average sea ice concentration on 1. May for the last decade or so (2003-2014 with 2012 not included) and how 2015 compare to the average for this day.

Bering sea stands out as slightly below normal (the distribution of ice in this region seems a little bit odd), while on the other hand, ice extent in Baffin is way above average. Most regions are pretty close to the norm though, and the amazing anomaly in Okhotsk from previously this winter is virtually gone. Note as well that smaller breakups in Beaufort/Amundsen Gulf is unusual, but not entirely unprecedented this time around.

NB: False ice along the coasts has been removed in areas without proper ice cover (from the end products only!), this includes most of the ice in The Great Lakes and St. Lawrence of whom some might have been real ice. I would presume these are areas of minimal interest.

Click on the pictures to get the full Size.
« Last Edit: May 03, 2015, 12:29:21 AM by Rubikscube »

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #664 on: May 03, 2015, 02:09:29 AM »
Attached below are two maps showing the average sea ice concentration on 1. May for the last decade or so (2003-2014 with 2012 not included) and how 2015 compare to the average for this day.

Bering sea stands out as slightly below normal (the distribution of ice in this region seems a little bit odd), while on the other hand, ice extent in Baffin is way above average. Most regions are pretty close to the norm though, and the amazing anomaly in Okhotsk from previously this winter is virtually gone. Note as well that smaller breakups in Beaufort/Amundsen Gulf is unusual, but not entirely unprecedented this time around.

NB: False ice along the coasts has been removed in areas without proper ice cover (from the end products only!), this includes most of the ice in The Great Lakes and St. Lawrence of whom some might have been real ice. I would presume these are areas of minimal interest.
Nice graphic, Rubikscube.

Zeroing in on three areas - Bering, Chukchi and Beaufort - I think the story presented by extent maps belies the seriously bad condition of the ice in all three areas.

Attached are EOSDIS snapshots of the Bering, Chukchi and eastern Beaufort from the last couple of days.  The interior of the Beaufort Gyre in particular is very badly torn up, and has nearly as much new open water as we are seeing along the Alaska/Yukon/NWT coasts.

Worldview link for convenience and your own browsing:
https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor,Reference_Labels%28hidden%29,Reference_Features%28hidden%29,Coastlines&t=2015-05-01&v=-3898035.4255462093,-1614517.909299734,2655564.5744537907,1666378.090700266
This space for Rent.

epiphyte

  • Frazil ice
  • Posts: 384
    • View Profile
  • Liked: 21
  • Likes Given: 18
Re: The 2015 melting season
« Reply #665 on: May 03, 2015, 07:30:35 AM »
Attached below are two maps showing the average sea ice concentration on 1. May for the last decade or so (2003-2014 with 2012 not included) and how 2015 compare to the average for this day.

Bering sea stands out as slightly below normal (the distribution of ice in this region seems a little bit odd), while on the other hand, ice extent in Baffin is way above average. Most regions are pretty close to the norm though, and the amazing anomaly in Okhotsk from previously this winter is virtually gone. Note as well that smaller breakups in Beaufort/Amundsen Gulf is unusual, but not entirely unprecedented this time around.

NB: False ice along the coasts has been removed in areas without proper ice cover (from the end products only!), this includes most of the ice in The Great Lakes and St. Lawrence of whom some might have been real ice. I would presume these are areas of minimal interest.
Nice graphic, Rubikscube.

Zeroing in on three areas - Bering, Chukchi and Beaufort - I think the story presented by extent maps belies the seriously bad condition of the ice in all three areas.

Attached are EOSDIS snapshots of the Bering, Chukchi and eastern Beaufort from the last couple of days.  The interior of the Beaufort Gyre in particular is very badly torn up, and has nearly as much new open water as we are seeing along the Alaska/Yukon/NWT coasts.

Worldview link for convenience and your own browsing:
https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor,Reference_Labels%28hidden%29,Reference_Features%28hidden%29,Coastlines&t=2015-05-01&v=-3898035.4255462093,-1614517.909299734,2655564.5744537907,1666378.090700266

@jdallen - I  share your discomfort with the notion that extent (or even area) are informative in comparing the current state of the ice with past years. I've been watching EOSDIS every day since the sun came up... and this year, subjectively, at least, something is very different. I'm not talking about "rottenness" - rather it's something that can be directly observed even from space.

You mentioned open water in the Beaufort - and on any given day that certainly is striking -  but to me what seems even more telling is what's been happening to the open water in the days after it opens up. For the past month, newly opened leads have been refreezing, as they always have in the past in the CAB at this time of year... But slowly -  if you look at the Beaufort today, you can plainly see the outline of lower albedo ice that was open water as long as a month ago...

...and even though still thin enough to be translucent, the just-refrozen leads have not been compacted by MYI floes crushing them into thick ridges; the thinner areas are keeping the same shape that they had when they were open leads. Furthermore - there has been no snow in the Beaufort in the past month. None of the surface covered by that new, thin, high-salinity ice has had the benefit of the insulation and reflectivity afforded by even a half-inch of snow. If this doesn't change in the next few days, I think a large and widely dispersed area of ice in the heart of the CAB may be set to vanish very quickly.

To the east we can see greater than normal extent in the Fram... But what's different from 2013/2014 is that that extent is made up of different ice every day. The ice that was east of Svalbard yesterday has melted and been replaced by more ice of ever-decreasing density flowing from the west at a rate of thousands of km2/day. From the fram to the pole the ice ice more compact in area than of late... but it looks as though that's because its being pushed eastward fast and melting as it does so. If the wind changes, then IMO large cracks may open up to the east of the pole as well.

The only area I see which looks to be putting up much of a fight is the Laptev + Kara. Here the open water formed as the coastal ice ebbs and flows seems to be refreezing just as fast as it ever has. It will be interesting to see what happens next...






Neven

  • Administrator
  • First-year ice
  • Posts: 7704
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1059
  • Likes Given: 504
Re: The 2015 melting season
« Reply #666 on: May 03, 2015, 11:11:05 AM »
The trend line is about to cross the average into negative territory on the DMI 80N map, just like it did in previous years (just as freezing temps are about to reach the shores of the Arctic Ocean). The question is how much and how long it will stay below it, but cooler temps are forecast for the next week over much of the Arctic, with no large positive anomalies anywhere, except perhaps for the Kara and Laptev coasts.

A cold start to Melt Pond May...
Il faut comparer, comparer, comparer, et cultiver notre jardin

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #667 on: May 03, 2015, 12:20:15 PM »
For the past month, newly opened leads have been refreezing, as they always have in the past in the CAB at this time of year... But slowly -  if you look at the Beaufort today, you can plainly see the outline of lower albedo ice that was open water as long as a month ago...

As can also be plainly seen by Radarsat.

Further to a conversation on the ASIB about the Beaufort Sea, I also attach a MODIS image from April 29th. My apologies for the clouds, but bottom right is a still frozen section of the Mackenzie River. Joining it from the top left is the largely ice free Liard River:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

ktonine

  • Frazil ice
  • Posts: 363
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #668 on: May 03, 2015, 05:49:26 PM »
The trend line is about to cross the average into negative territory on the DMI 80N map, just like it did in previous years (just as freezing temps are about to reach the shores of the Arctic Ocean). The question is how much and how long it will stay below it, but cooler temps are forecast for the next week over much of the Arctic, with no large positive anomalies anywhere, except perhaps for the Kara and Laptev coasts.

A cold start to Melt Pond May...

Neven, any relationship that exists between DMI N80 temps and the September minimum would seem to indicate that 2015 is in the same class as 2007, 2010, and 2012.  These years show anomalous warmth throughout the winter, a heat pulse around day 100 and then quickly fall to or below the longterm average.  2007 and 2012 never significantly rose above the longterm average after about day 115.  2010 did go back above average until about day 140, then stayed below average until day 240.  (I'm using approximate days here from eyeballing the charts).

Here's 2015 to date overlayed on 2007:


I don't believe there's any discernible difference between 2007 and 2015 that can be seen from this overlay.

I've mentioned in years past on the forum that simply thinking the process through from a purely physical POV could lead one to believe that colder DMI temps at this time of year could be due to *more* open water, not less.  I believe this to be true especially at the height of the melting season. The confounding factors of sea water being colder than freshwater meltponds or freshwater snow/ice near its melting point makes interpreting DMI graphs very difficult without additional information.  I don't think it's really possible without breaking these temps down into smaller latitudinal bands so that insolation can be taken into account, plus I'd want to know the average snow depth and ice age.

Siffy

  • Frazil ice
  • Posts: 179
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #669 on: May 03, 2015, 06:36:15 PM »
Indeed doesn't DMI 80N only model temps north of the 80th parallel any way?

That's a very large part of the Arctic circle not being looked at with that, the Hudson looks like it remains solidly at or above 0C for the rest of the week and both the beaufort sea and chukchi + ESS seem to remain at around 0c as well with a big burst of heat coming into the beaufort around 6-7 days later.

Although obviously a week long forecast is unlikely to be very reliable.

epiphyte

  • Frazil ice
  • Posts: 384
    • View Profile
  • Liked: 21
  • Likes Given: 18
Re: The 2015 melting season
« Reply #670 on: May 03, 2015, 07:54:59 PM »
Here's a thing.

The ocean current w. of Svalbard is warm and coming from due south. The wind (and ice) are bitter and headed in precisely the opposite direction. No wonder the ice at the interface hasn't been lasting much longer than a day...


Neven

  • Administrator
  • First-year ice
  • Posts: 7704
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1059
  • Likes Given: 504
Re: The 2015 melting season
« Reply #671 on: May 03, 2015, 09:20:40 PM »
Neven, any relationship that exists between DMI N80 temps and the September minimum

I'm not looking at a relationship between DMI 80N temps and the minimum, but looking for anything that tells me something about how the second part of the melting season is developing. The first part being what the freezing season has left behind, and the third part being July and August weather.

The DMI 80N temp graphs is just one of several indicators (maybe) of melt pond cover fraction. It becomes interesting just now, which is why I'm looking at it.
Il faut comparer, comparer, comparer, et cultiver notre jardin

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #672 on: May 03, 2015, 10:15:09 PM »
Neven, any relationship that exists between DMI N80 temps and the September minimum

I'm not looking at a relationship between DMI 80N temps and the minimum, but looking for anything that tells me something about how the second part of the melting season is developing. The first part being what the freezing season has left behind, and the third part being July and August weather.

The DMI 80N temp graphs is just one of several indicators (maybe) of melt pond cover fraction. It becomes interesting just now, which is why I'm looking at it.

Not relevant immediately, as temps north of 80 are still 10-15C below freezing:  How much might increased open water and increased salinity of melt pond contents reduce the average?

It seems, that will lower the temperature at which phase changes take place, and lower the threshold for buffering of 2M temps.  Counter-intuitive perhaps (that poorer ice conditions could produce lower temperatures), but it makes some sense to me.
This space for Rent.

jai mitchell

  • Nilas ice
  • Posts: 2076
    • View Profile
  • Liked: 114
  • Likes Given: 24
Re: The 2015 melting season
« Reply #673 on: May 03, 2015, 10:46:12 PM »
I agree with JD  the only inference to take from the DMI at this time is how a slightly earlier dip below the average in 2012 and 2007 led to a return to *slightly* above average temps just as the average was going above the freezing average.  It is my belief that only a slight (3-5 day) rise above freezing before the date where the average line goes above freezing (about day 165 or June 14) will be enough of a head start to melt pond formation that it will produce a significant impact, possibly rivaling 2012.   If we achieve a jump above the freezing point 7-10 days before the average date (say by June 4th) and even 1C above the average temp line, we can easily see a drop nearly reaching 1,000Km^2

So far it seems that open water at the ice periphery somehow causes a temperature drop on the DMI right around May 5-12.  However none of this really matters until we approach the june 14 thaw date.
« Last Edit: May 04, 2015, 03:30:39 AM by jai mitchell »
Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

werther

  • Grease ice
  • Posts: 747
    • View Profile
  • Liked: 31
  • Likes Given: 0
Re: The 2015 melting season
« Reply #674 on: May 04, 2015, 12:08:43 AM »
Until today I’ve merely followed posting on this thread. First, I haven’t done much work. Second, conditions didn’t strike me as deviating much from the years I’ve been watching MODIS closely (’10-’14).
In that sense I concur with Rubikscube above, “…pretty close to the norm…”. OTOH I agree with JDallen that extent data and maps do not tell much about the quality of the ice. Through the last five years I’ve often commented on quality and illustrated that with detailed ‘CAD-counts’ at pixel-scale (250x250 m). In that context, I repeat Epiphyte’s words “…this year, subjectively, at least, something is very different…”.
It is not exactly clear to me in what sense. But I did do some work, so at least I can humbly weigh in.

I took out my visual assessment for day 109, april 2010/-11/-12 and did the same for 2015. To be clear, the assessment concentrates on the CAB and it’s five peripheral seas, the CA and Baffin Bay. The only two MODIS tiles that do stand out against these former years are those covering the Beaufort and Chukchi Seas and the adjacent parts of the CAB (r05c02/-03). Break-up within extensive leads is worse than ’12. It should be reminded that Feb ’13 also showed this pattern, but the effect in April is probably much stronger, like Epiphyte supposes.

Since day 109, nothing has essentially changed the outcome of that assessment. The present low extent is a fringe-matter and doesn't tell much about the coming melt.

Summarizing, I still have no clue whether this summer will bring a ‘07/’12 cliffhanger or a ‘13/’14 ‘good for the Polar Bear’-year. It is too early to tell. On 9 out of 11 MODIS-tiles, there’s no indication that the coming season will be particularly worse than ‘13/’14.

Neven calls for a “cold start for melt-pond May”. I don’t see that reflected in the Climate Reanalyzer forecasts. Maybe he refers to the +80N mean temp (DMI), which seems to cross the climatic mean into negative anomaly soon. Like it has for several years around day 130. I agree with Ktonine that  interpreting DMI graphs is very difficult. The +80N parallel covers about 4Mkm2, mostly matching the CAB-area. Like JDallen, I’ve been expressing a sense that “…poorer ice conditions could produce lower temperatures…”. Most pronounced in summer ’13, when fragmentation was highest in the record.

I could go on forwarding several conditions that might influence the coming melt. But as has often been stated, weather will decide. I am very interested what the Pacific teleconnection may present (PDO, ENSO).

Neven

  • Administrator
  • First-year ice
  • Posts: 7704
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1059
  • Likes Given: 504
Re: The 2015 melting season
« Reply #675 on: May 04, 2015, 12:52:38 AM »
Quote
The only two MODIS tiles that do stand out against these former years are those covering the Beaufort and Chukchi Seas and the adjacent parts of the CAB (r05c02/-03). Break-up within extensive leads is worse than ’12. It should be reminded that Feb ’13 also showed this pattern, but the effect in April is probably much stronger, like Epiphyte supposes.

We don't talk about it much, maybe because the cracking event of 2013 didn't mean much for the melting season after all (in fact, it seemed it strengthened the ice), but this one is notable too, and IMO the most interesting thing to keep an eye on in the Arctic right now.

Quote
Neven calls for a “cold start for melt-pond May”. I don’t see that reflected in the Climate Reanalyzer forecasts.

You're entirely right, Werther. The forecast has changed its tune, with above freezing temps rolling in from a warm Alaska, right over the Beaufort and Chukchi. But that's in 6-7 days, so the tune might change again.

I hope not, I want to see whether the ice in those big cracks can melt before being closed. That should look pretty cool this early in the melting season.

Oh, and the DMI 80N temp graph has flipped up again:  ;D
Il faut comparer, comparer, comparer, et cultiver notre jardin

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4086
    • View Profile
    • Arctische Pinguin
  • Liked: 830
  • Likes Given: 0
Re: The 2015 melting season
« Reply #676 on: May 04, 2015, 09:05:19 AM »
Indeed doesn't DMI 80N only model temps north of the 80th parallel any way?

That's a very large part of the Arctic circle not being looked at with that

Only North of the 80th parallel and " strongly biased towards the temperature in the most
northern part " of that:

http://ocean.dmi.dk/arctic/documentation/arctic_mean_temp_data_explanation_newest.pdf

(So it is more accurately regarded as the (model) temperature at the North Pole, not of the Arctic.)


slow wing

  • Grease ice
  • Posts: 807
    • View Profile
  • Liked: 150
  • Likes Given: 455
Re: The 2015 melting season
« Reply #677 on: May 04, 2015, 10:08:47 AM »
Wouldn't DMI 80N depend largely on wind direction?

For example, if there is a dipole setup with wind blowing ice out the Fram Strait then that means a high pressure system somewhere around Greenland and so that air came into the Arctic via Northern Canada and it will generally be COLDER.

Conversely, wind blowing in through the Fram Strait will be WARMER.

That's my intuitive guess. Does it make sense or are other factors more important around this time of year?

It will presumably be different later in the melt season, where surely the air will be warmer when there is little cloud cover and the sun is shining down on the ice?

What data is available to test these hypotheses?

Jim

  • New ice
  • Posts: 57
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #678 on: May 05, 2015, 12:57:47 AM »
This may have been noticed elsewhere, but have you noticed just how closely this year is following 2006? Looking at the NSIDC's Charctic Interactive graphs, 2015 is tracking 2006 almost exactly.
No predictor of the sea ice melt later on this season, but I thought the correlation to be quite remarkable!

JayW

  • Grease ice
  • Posts: 600
    • View Profile
  • Liked: 272
  • Likes Given: 254
Re: The 2015 melting season
« Reply #679 on: May 05, 2015, 12:10:36 PM »
I seem to remember someone mentioning a connection between temperatures in the Caribbean and arctic ice.  I'm totally unqualified to make any assumptions, but I was looking at some ocean temperature time series, and using the very unscientific "eyeball approach" thought that there site could be a relationship with the tropical north Atlantic.  It's the two big "peaks" near 2006 and 2011 that got me thinking. Both peaks preceded aggressive melting years.  I feel like it's these highly anomalous events that really impact the ice.  Really feels like we are simply rearranging the Titanic's seating until then. I'm not one to prognostic, as I feel weather is always capable of a surprise, but I wouldn't be totally surprised by another near "average" melt season.  I just think that we are to the point where we are waiting on one massive melt season that finally opens the eyes that have turned blind, could it be this year?  Perhaps, but I'll patiently watch till it does happen.  :) These are just my very novice opinions, and thoughts.

Attached is the temperature time series of the Tropical North Atlantic [60W-30W,5N-20N] from 1982-2015.  Which I fitted to the Cryosphere today Northern Hemisphere Sea Ice Anomaly.

http://www.cpc.ncep.noaa.gov/products/GODAS/ocean_briefing.shtml#Tropical Indian Ocean

http://arctic.atmos.uiuc.edu/cryosphere/
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #680 on: May 05, 2015, 12:24:08 PM »
There's quite a good view of the Mackenzie River on Worldview at the moment. It has now lost lots of ice on the section between the Liard and North Nahanni Rivers:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201415-images/#Mackenzie

Here's a video of the Liard River breakup in 2011, at Fort Simpson where it meets the Mackenzie. It seems to have taken place on May 5th:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 2
« Last Edit: May 05, 2015, 05:51:07 PM by Vergent »

Neven

  • Administrator
  • First-year ice
  • Posts: 7704
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1059
  • Likes Given: 504
Re: The 2015 melting season
« Reply #682 on: May 06, 2015, 01:01:52 PM »
Beaufort is getting torched in the coming week:
Il faut comparer, comparer, comparer, et cultiver notre jardin

DavidR

  • Grease ice
  • Posts: 732
    • View Profile
  • Liked: 32
  • Likes Given: 3
Re: The 2015 melting season
« Reply #683 on: May 06, 2015, 03:45:56 PM »
This may have been noticed elsewhere, but have you noticed just how closely this year is following 2006? Looking at the NSIDC's Charctic Interactive graphs, 2015 is tracking 2006 almost exactly.
No predictor of the sea ice melt later on this season, but I thought the correlation to be quite remarkable!

2006 had the warmest winter (Dec-Feb) on record in the Arctic circle in both Air and SS temps, approx 1.5c above 2015. However in the last two months the reverse has applied with the difference being that 2015 has been about 1.3c warmer than 2006.  By summer, 2006 was almost a full degree cooler than 2012 and 2007. with June being particularly cool.

With 2015 currently considerably warmer across the arctic than 2006, we should see a strong diversion from 2006 over the next couple of months.   May and June seem to be the critical months for determining the final outcome however. If either of those is relatively cold then overall melting is likely to lower.
Toto, I've a feeling we're not in Kansas anymore

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #684 on: May 06, 2015, 04:11:07 PM »
Beaufort is getting torched in the coming week:

Chukchi and Hudson too.
Barentz to a lesser degree, Kara too?

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #685 on: May 06, 2015, 06:16:31 PM »
Beaufort is getting torched in the coming week:

Note that as Chris Reynolds has recently pointed out on his blog:

Quote
The volume difference between April 2015 and April 2013 (after the 2012 crash) shows that 2015 has marginally less volume in Beaufort, Chukchi, and the East Siberia Sea

This thus seems like as good a time as any to share some of my recent reading matter:

"Seasonal ice loss in the Beaufort Sea: Toward synchrony and prediction", Steele et al. 2015: http://psc.apl.washington.edu/zhang/Pubs/Steele_etal2015_jgrc21105.pdf

"Effects of Mackenzie River discharge and bathymetry on sea ice in the Beaufort Sea". Nghiem et al. 2014: http://gsfcir.gsfc.nasa.gov/download/authors/232183/Journal%20Articles_232183

Here's the flow of the Mackenzie River measured where it's joined by the Arctic Red River:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim

  • New ice
  • Posts: 57
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #686 on: May 07, 2015, 02:49:40 PM »
DavidR
Absolutely, the melt season is a fascinating mix of trends (climate) and events (weather) - will the current El Nino impact the sea ice? if so, will it 'scorch' the ice, or maybe push a lot of cloud over the arctic and keep temperatures and insolation low? Only time will tell!
I love this time of year - so sensitive to small changes  ;D

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #687 on: May 07, 2015, 03:32:12 PM »
GFS Climate Reanalyzer is now forecasting 6 inches (~15 cm) of snow melt within the next week over the entirety of the Beaufort and Chukchi Seas, with smaller (but still noticeable) amounts of snow melt over the East Siberian Sea.

By comparing the ENS ensemble on Wetterzentrale to the GFS model, it looks like the rule of thumb at this time of year (May) is that a -7 or -8 C temperature at 850 hPa roughly corresponds to a "daily high" temperature of 0 C at the surface, implying snow melt for at least a portion of each day. Though it is still quite some time out, the long range ENS is calling for 850 hPa temps exceeding -8 C to invade the central Arctic by around the 19th or 20th of this month. If this comes to pass, it will be comparable to 2010 in terms of volume loss and melt ponds this month. Of course much can change when the forecast is still almost 2 weeks out, but I can't help but start anticipating what this means for the September minimum this year...
« Last Edit: May 07, 2015, 03:37:48 PM by Nightvid Cole »

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #688 on: May 07, 2015, 03:53:48 PM »
GFS Climate Reanalyzer is now forecasting 6 inches (~15 cm) of snow melt within the next week over the entirety of the Beaufort and Chukchi Seas

Cross posting from the ASIB, here's the weather forecast for the Mackenzie River on Saturday:

Fort Simpson, 23°C
Norman Wells, 14°C
Inuvik, 9°C
Tuktoyaktuk, 4°C
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #689 on: May 07, 2015, 04:22:06 PM »
GFS Climate Reanalyzer is now forecasting 6 inches (~15 cm) of snow melt within the next week over the entirety of the Beaufort and Chukchi Seas

Cross posting from the ASIB, here's the weather forecast for the Mackenzie River on Saturday:

Fort Simpson, 23°C
Norman Wells, 14°C
Inuvik, 9°C
Tuktoyaktuk, 4°C
Ugh. This early in the season? Those are just ugly.
This space for Rent.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #690 on: May 07, 2015, 05:14:01 PM »
Beaufort is getting torched in the coming week:

Chukchi and Hudson too.


Chukchi and Hudson too.
Bye bye snow, hellow melt pond starting mid-May?





jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #691 on: May 07, 2015, 07:08:42 PM »
Beaufort is getting torched in the coming week:

Chukchi and Hudson too.


Chukchi and Hudson too.
Bye bye snow, hellow melt pond starting mid-May?

OK NOW. YUP, THAT LOOKS LIKE A TORCH.

168 hours to find out.  Hits the Chukchi and Bering hard as well.  If that heat lasts a couple of days, ice in the Bering will just vanish.

All the snow should go, at the least, and yah, melt ponding, even if temporary.
This space for Rent.

cats

  • New ice
  • Posts: 48
    • View Profile
  • Liked: 0
  • Likes Given: 5
Re: The 2015 melting season
« Reply #692 on: May 07, 2015, 07:23:37 PM »
While the weather currently is pretty overcast in Churchill, this http://www.portofchurchill.ca/port-media/live-feed shows some melting, as opposed to a couple of weeks ago when everything was uniformly frozen.

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #693 on: May 07, 2015, 07:33:10 PM »
While the weather currently is pretty overcast in Churchill, this http://www.portofchurchill.ca/port-media/live-feed shows some melting, as opposed to a couple of weeks ago when everything was uniformly frozen.
... Complete with mist rising from the forming melt ponds.

Hudson's Bay is scheduled for torching as well, but is less relevant to the final minimum or early melt around the central basin.
This space for Rent.

Lord M Vader

  • Nilas ice
  • Posts: 1310
    • View Profile
  • Liked: 37
  • Likes Given: 24
Re: The 2015 melting season
« Reply #694 on: May 07, 2015, 07:58:03 PM »
The "torch" you're talking about should be just wishes. Both GFS 06z and 12z run depict a much cooler solution than the 00z run. Something that was speaking of both 2013 and 2014 was the mere fact that the forecasts had some warm air intrusions but they never really materialized fully. The same could be happening this year.

So, let's wait a little before we say "hallo melting"..

What seems likely is that there will be temps above freeze point partially during the coming days.

Finally, I don't see just how 2015 melting season would smash 2012.. We'll have to wait some years before we enter next stage of the Arctic sea ice..

Best, LMV

BornFromTheVoid

  • Nilas ice
  • Posts: 1067
    • View Profile
  • Liked: 190
  • Likes Given: 77
Re: The 2015 melting season
« Reply #695 on: May 07, 2015, 08:16:06 PM »
People need to remember that anything beyond 5 days is subject to a large amount of uncertainty, especially in the Arctic where measurements fed into numerical models are more sparse.
Look at ensemble means and trends beyond 5 days, as individual runs can change quite abruptly.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

ghoti

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 12
  • Likes Given: 15
Re: The 2015 melting season
« Reply #696 on: May 07, 2015, 08:34:04 PM »
Heck around here I'm amazed when the 12 hour forecast is close to correct!

jdallen

  • Young ice
  • Posts: 3182
    • View Profile
  • Liked: 394
  • Likes Given: 199
Re: The 2015 melting season
« Reply #697 on: May 07, 2015, 09:52:45 PM »
People need to remember that anything beyond 5 days is subject to a large amount of uncertainty, especially in the Arctic where measurements fed into numerical models are more sparse.
Look at ensemble means and trends beyond 5 days, as individual runs can change quite abruptly.

Quite so - and so my "168 hours to find out".

That established, anecdotally, GFS has seemed to have a pretty good track record recently.  Coin toss, but I'd put the probability at better than 50%. How much, can't say, but we will find out... In about 160 hours or so....
This space for Rent.

Neven

  • Administrator
  • First-year ice
  • Posts: 7704
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1059
  • Likes Given: 504
Re: The 2015 melting season
« Reply #698 on: May 07, 2015, 10:58:22 PM »
In the meantime, it's very cold up North:
Il faut comparer, comparer, comparer, et cultiver notre jardin

Jim Hunt

  • Young ice
  • Posts: 4647
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 515
  • Likes Given: 42
Re: The 2015 melting season
« Reply #699 on: May 08, 2015, 05:38:00 PM »
In the meantime, it's very cold up North:

Yesterday the temperature in Tuktoyaktuk reached 4.5 °C

http://climate.weather.gc.ca/climateData/hourlydata_e.html?timeframe=1&Prov=NT%20%20&StationID=26987&hlyRange=1994-08-30|2015-05-07&Year=2015&Month=5&Day=7

The forecast for today is 5 °C, and staying above zero until Monday night. The Mackenzie River flow measured at Arctic Red River has increased from ~4000 to 9000 m³/s so far this month
Reality is merely an illusion, albeit a very persistent one - Albert Einstein