Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2015 melting season  (Read 1666965 times)

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1950 on: July 08, 2015, 11:18:01 PM »
I suggest it indicates massive in-situ thinning.

Nobody seems to have really picked up on the significance of my IMB 2014F graph, so I'll repeat what I said on the blog earlier.

The floe (or floe + melt pond?) under 2014F is currently 89 cm thick. In approximate terms, half of the ice floe has melted away over the last month.

The latest temperature profile is even more intriguing:

« Last Edit: July 08, 2015, 11:26:51 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7077
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 670
  • Likes Given: 433
Re: The 2015 melting season
« Reply #1951 on: July 08, 2015, 11:25:26 PM »
I present my final piece of extremely Stark evidence 2015 is getting racked vs 2014.

This animation shows the very clear difference between 2014/15 and its not even close.

Friv, we're not in disagreement here. My whole point, the theme of the last ASI update, was that 2015 may have looked a bit like 2014 (on the extent and compactness charts, and relatively little movement), but the similarity is now falling apart. We're no longer in Kansas.
Il faut comparer, comparer, comparer, et cultiver notre jardin

Blizzard_of_Oz

  • New ice
  • Posts: 21
    • View Profile
    • 50-Day melt season forecast
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1952 on: July 08, 2015, 11:25:48 PM »
Did someone suggest there might be heat in the Arctic at the moment ...?



The shot of heat is earlier than what was seen in 2013 & 2014.
If you want to compare:  http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1953 on: July 08, 2015, 11:28:52 PM »
I suggest it indicates massive in-situ thinning.

Nobody seems to have really picked up on the significance of my IMB 2014F graph, so I'll repeat what I said on the blog earlier.

The floe (or floe + melt pond?) under 2014F is currently 89 cm thick. In approximate terms, half of the ice floe has melted away over the last month.

The latest temperature profile is even more intriguing:
Which, with current conditions, implies a life expectancy of no more than two weeks.
This space for Rent.

slow wing

  • Grease ice
  • Posts: 782
    • View Profile
  • Liked: 142
  • Likes Given: 380
Re: The 2015 melting season
« Reply #1954 on: July 09, 2015, 01:10:28 AM »
JDAllen & Gerrit,

   There should be plenty of data to directly determine the maximum Arctic ice ablation rate in sunlight, from the instrumentation on the ice, and to compare with JDAllen's estimate of 6 cm/day based on insolation energy data.

For example, Rubikscube has recently posted on an observed ablation rate of 3.5 cm/day
http://forum.arctic-sea-ice.net/index.php/topic,327.msg55836.html#msg55836


Jim Hunt, what is the maximum ice ablation rate you have observed due to sunlight?

slow wing

  • Grease ice
  • Posts: 782
    • View Profile
  • Liked: 142
  • Likes Given: 380
Re: The 2015 melting season
« Reply #1955 on: July 09, 2015, 01:25:03 AM »
Jim, now I see you have just posted on this very topic!

I suggest it indicates massive in-situ thinning.

Nobody seems to have really picked up on the significance of my IMB 2014F graph, so I'll repeat what I said on the blog earlier.

The floe (or floe + melt pond?) under 2014F is currently 89 cm thick. In approximate terms, half of the ice floe has melted away over the last month.

The latest temperature profile is even more intriguing:
Could you help us newbies in spelling out exactly what the plot shows?

How do you explain the large temperature inversion between sensor 8, at 0.6 degrees C, and sensor 11, 15 cm below it and at 4.0 degrees C?

Is it 4 degrees warm water in a hole around the sensor stake, with the surface around sensor 11,  but with the air temperature above the water quickly relaxing to the ambient air temperature ~0.6 degrees C, after around 15 cm of air (i.e. by sensor 8 )?










Frivolousz21

  • Nilas ice
  • Posts: 1506
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 140
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1956 on: July 09, 2015, 05:09:34 AM »
Reality is rearing its ugly head. 

And the ESS side is still obscured by clouds and part of the Beaufort/CAB.

So yeah


I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1957 on: July 09, 2015, 07:44:18 AM »
In the same vein as Friv...

Let's look at 2012 vs 2015 at about this date.

Edit: Relevant to Vergent's "Coles Correlation" thread, consider that the red portions of the images below are close to 60% concentration.
This space for Rent.

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1958 on: July 09, 2015, 07:55:04 AM »
More food for thought.

2007 vs 2015.
This space for Rent.

Frivolousz21

  • Nilas ice
  • Posts: 1506
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 140
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1959 on: July 09, 2015, 08:09:37 AM »


The 00z GFS totally roasts the CAB.


But decimates the Beaufort and SW CAB.





WOW THAT IS THE 2012 ICE DEATH PATTERN.

Stay tuned everyone.  DAMN








CHRISTMAS IN JULY!!!!
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1960 on: July 09, 2015, 09:25:35 AM »
But that smoke won't do much to melt the ice I suspect, it is just blocking the sun.

Interesting comments about airborne black carbon's effect on the Arctic, from http://www.epa.gov/blackcarbon/2012report/Chapter2.pdf Section 2.6.4
(EPA report to U.S. Congress, no doubt appreciated ::) ).

"Over a highly reflective surface like the Arctic, BC particles absorb solar radiation and warm the atmosphere above and within the haze layer, while simultaneously contributing to surface dimming. Rather than a cooling effect from surface dimming, however, the atmospheric heating increases the downward longwave radiation and causes warming at the surface (Shaw and Stamnes, 1980; Quinn et al., 2008; Mauritsen et al., 2011). Any warming particle above a highly reflective surface can lead to heating of the entire surface–atmosphere aerosol column. In addition, the stable atmosphere above the Arctic prevents rapid heat exchange with the upper troposphere, increasing surface warming in the Arctic (Hansen and Nazarenko, 2004; Quinn et al., 2008)."
Yep, this is exactly the same thing i meant when i was talking about Venus yesterday.

P.S. There are exceptions, though - that "any warming particle" of theirs, i believe, is incorrect. "Most" kidns of warming particles would indeed behave quite like they (and i) suggest, i believe; but not all. Which is the reason Welsbach seeding works, for example - quote, "wavelength-dependent emissivity or reflectivity, in that said materials have high emissivities in the visible and far infrared wavelength regions and low emissivity in the near infrared wavelength region. Such materials can include the class of materials known as Welsbach materials." I post this as an example of the case when certain partciles do the opposite to what black soot does: the net effect is not warming up of the column, but cooling it down. The point being, if those artificial matherials has the "opposite to usual" effect, then it is plausible that some other matherials - including some kinds appearing from forest fires, for example, - could do so also, at least in certain specific circumstances.
« Last Edit: July 09, 2015, 09:38:03 AM by F.Tnioli »

epiphyte

  • Frazil ice
  • Posts: 383
    • View Profile
  • Liked: 22
  • Likes Given: 17
Re: The 2015 melting season
« Reply #1961 on: July 09, 2015, 09:26:43 AM »
I can only describe Worldview this morning as acutely distressing...

It calls to mind the image of Hurricane Katrina right on top of New Orleans... the moment at which my perspective switched from "Wow - This is going to be exciting" to "Oh Crap. This is going to be horrible."

Except that this time it's the Whole. F...ing. Planet.

Is there any chance people will wake up in time to fix this?




F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1962 on: July 09, 2015, 09:50:11 AM »
...
Is there any chance people will wake up in time to fix this?
People will wake up when things really go south, - i.e. their daily life is much (and rapidly - important!) diminished at very least. Not earlier. By then, it'd be too late to "fix" things. It's like nuclear war. All the talks about nuclear threat, all simulated exchanges, all the research on post-effects, all the "preppers" - this is not "people" as in "mainstream" sense. The "people" will only wake up to the reality of overabundance of nuclear WMDs if said WMDs will be raining down not so far from where people are - i.e. around most of the globe, or at least much of the globe. Thing is, it's too late to "fix" the threat of mass nuclear WMD usage _after_ it happened, - and i believe, the same applies to catastrophic climate change. Until there is no "catastrophe", people won't wake up (powers that be won't allow it, too - an additional extra guarantee). When there is "catastrophe", then it's too late to "fix it".

edit: CT says, the area change for day 187 was +40k. A _gain_ of sea ice area. Sunny Arctic, high SSTs, and the area grows? I don't buy it. Should be an artifact of the model. Is it?
« Last Edit: July 09, 2015, 11:18:11 AM by F.Tnioli »

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7077
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 670
  • Likes Given: 433
Re: The 2015 melting season
« Reply #1963 on: July 09, 2015, 11:29:30 AM »
edit: CT says, the area change for day 187 was +40k. A _gain_ of sea ice area. Sunny Arctic, high SSTs, and the area grows? I don't buy it. Should be an artifact of the model. Is it?
Because of melt ponding and other stuff fooling sensors into thinking something is open water, you get a lot of back and forth from day to day. Wipneus pre-calculates the CT SIA numbers and explains where the losses/gains occurred in the extent and area thread. He discusses the +39/40 gain here specifically.

The gain is followed by -164K and -193K. It all evens out in the end.
Il faut comparer, comparer, comparer, et cultiver notre jardin

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1964 on: July 09, 2015, 11:32:57 AM »
Could you help us newbies in spelling out exactly what the plot shows?

Have you read the IMB buoy overview at:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/

Quote
How do you explain the large temperature inversion between sensor 8, at 0.6 degrees C, and sensor 11, 15 cm below it and at 4.0 degrees C?

Is it 4 degrees warm water in a hole around the sensor stake, with the surface around sensor 11,  but with the air temperature above the water quickly relaxing to the ambient air temperature ~0.6 degrees C, after around 15 cm of air (i.e. by sensor 8 )?

I've asked the CRREL what their explanation is, but have yet to receive an answer. My guess is that things have reached the stage where melt water is now seeping down the side of the buoy. However I'm struggling to conceive of a physical explanation for how the water reached such a high temperature when air temperatures did not. Does short wave absorption in fresh water generate that sort of profile? If it does then perhaps the buoy is sat in a "lake"?!
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Peter Ellis

  • Grease ice
  • Posts: 616
    • View Profile
  • Liked: 33
  • Likes Given: 11
Re: The 2015 melting season
« Reply #1965 on: July 09, 2015, 12:11:21 PM »
What was the air temperature over the last few hours?  Water has high thermal inertia.

F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1966 on: July 09, 2015, 12:18:59 PM »
Because of melt ponding and other stuff fooling sensors into thinking something is open water, you get a lot of back and forth from day to day. Wipneus pre-calculates the CT SIA numbers and explains where the losses/gains occurred in the extent and area thread. He discusses the +39/40 gain here specifically.

The gain is followed by -164K and -193K. It all evens out in the end.
Thanks a lot for the link, Neven. I'll read it right after replying here!

Melt ponding fools 'em sensors, yes, but with such weather i erratically - without any actual consideration - assumed that it's impossible to see average melt pond getting any shallower any given day. Which would be required - and quite much of it, - to "fool" sensors enough to more than compensate for real area loss during any given day. Lots of pools gotta get less deep to more than negate average daily (right now) century, i mean. %)

I think i was wrong, though. I guess now, average Arctic melt pond can become significantly less deep at some few select days, - initially "contained" on top of the ice, every melt pond sooner or later get to be "drained" into the ocean. At which point it can become less deep pond, and much so. And if we have large areas developing ponds "synchronized", then a day comes when lots of ponds drain into the ocean. Here we go, BAM, "ice area gain". I was rather silly not realizing it right away. Sorry!
« Last Edit: July 09, 2015, 12:29:56 PM by F.Tnioli »

Peter Ellis

  • Grease ice
  • Posts: 616
    • View Profile
  • Liked: 33
  • Likes Given: 11
Re: The 2015 melting season
« Reply #1967 on: July 09, 2015, 12:43:57 PM »
Not sure the melt ponds have to change in area / depth at all - a thin layer of water on top of ice could easily give quite a different signal depending on the precise angle of the sunlight, the satellite and the ambient temperature.  Sometimes the satellite will see through the pond and measure that bit as ice, sometimes it won't see through it and measure it as water.  Another variable is how much more water vapour (i.e. clouds) are between the ice/pond and the sun / the satellite.

Measurements over wet ice are just inherently variable, which is why you want to average over a few days to even out the variability rather than looking at every daily wiggle as indicative of Absolute Truth About Ice Area Changes (TM).

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1968 on: July 09, 2015, 12:47:13 PM »
What was the air temperature over the last few hours?  Water has high thermal inertia.

Quite so, but the air temperature has never been that high, in recent history at least:

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

Rubikscube

  • Frazil ice
  • Posts: 247
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1969 on: July 09, 2015, 12:50:18 PM »
Interesting comments about airborne black carbon's effect on the Arctic, from http://www.epa.gov/blackcarbon/2012report/Chapter2.pdf Section 2.6.4
(EPA report to U.S. Congress, no doubt appreciated ::) ).

"Over a highly reflective surface like the Arctic, BC particles absorb solar radiation and warm the atmosphere above and within the haze layer, while simultaneously contributing to surface dimming. Rather than a cooling effect from surface dimming, however, the atmospheric heating increases the downward longwave radiation and causes warming at the surface (Shaw and Stamnes, 1980; Quinn et al., 2008; Mauritsen et al., 2011). Any warming particle above a highly reflective surface can lead to heating of the entire surface–atmosphere aerosol column. In addition, the stable atmosphere above the Arctic prevents rapid heat exchange with the upper troposphere, increasing surface warming in the Arctic (Hansen and Nazarenko, 2004; Quinn et al., 2008)."
Thank you very much. That should settle the discussion.

The 850 hPa temps over CAB and Greenland will probably peak within the next 24 hours, but there will be a continued presence of abnormal heat in the high latitudes for a many more days to come. If one take into account the melt momentum and slight delay in SIA/SIE numbers, there is no reason to believe the drops will stall anytime soon.

It seems the heat finally touched down on Wrangel Island's only weather station as well. Yesterday's maximum temp of 18,1C is a mere 0,1 below the all time record for any date set way back in 1927.

http://www.pogodaiklimat.ru/monitor.php?id=21982&month=7&year=2015

Andreas T

  • Nilas ice
  • Posts: 1125
    • View Profile
  • Liked: 11
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1970 on: July 09, 2015, 01:05:50 PM »
What was the air temperature over the last few hours?  Water has high thermal inertia.
You have written before Jim, that temp sensors can give readings above air temp when the sun shines on them. I wonder whether reflection from the surface could explain the fact that the lower sensors read so much higher than the upper ones. The most telling would be seeing how these temps change over a day, the excessive temps usually show a clear pattern of high values at certain times of the day then dropping to air temps within a couple of hours or so. I don't have time to check right now.

F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1971 on: July 09, 2015, 01:13:38 PM »
Not sure the melt ponds have to change in area / depth at all - a thin layer of water on top of ice could easily give quite a different signal depending on the precise angle of the sunlight, the satellite and the ambient temperature.  Sometimes the satellite will see through the pond and measure that bit as ice, sometimes it won't see through it and measure it as water.  Another variable is how much more water vapour (i.e. clouds) are between the ice/pond and the sun / the satellite.

Measurements over wet ice are just inherently variable, which is why you want to average over a few days to even out the variability rather than looking at every daily wiggle as indicative of Absolute Truth About Ice Area Changes (TM).
Those factors add noise to the signal, yes. But i believe those factors alone would not suffice to account for the entirety of most unusual daily bumps and deeps; some real physics has to participate also. Purely statistically thinking, you know, - if we see majority of days being ~100k+ loss at this point of a season, and even daily 0k is statistically rare day, - then +40k daily gain is indeed likely to have "real" component of some sort (something which physically slows down daily ASI area loss for a single given day in compare to average daily for this stage of the melt season). %)

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1972 on: July 09, 2015, 01:55:45 PM »
IMB buoy 2015B and all associated ablation stakes are now bobbing about in the briny:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015B

The buoy thermistors are still going strong however, and report a water temperature of -1 °C or thereabouts:
« Last Edit: July 09, 2015, 02:06:06 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1973 on: July 09, 2015, 02:10:31 PM »
OSISAF/MyOcean is showing now that the <85% concentration area now occupies a "solid majority" of the Arctic Ocean:

F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1974 on: July 09, 2015, 02:17:43 PM »
OSISAF/MyOcean is showing now that the <85% concentration area now occupies a "solid majority" of the Arctic Ocean:
Ponds get deeper and thus ice under those ponds "disappear" from the picture, but not from reality, me thinks. How much % of pond water gets drained into the ocean some time later but days before the actual ice plates melt completely? I guess it's high. If so, we'll have more "bumpy" days, alternating between large dips up to multi-century and few more of daily area gains.
« Last Edit: July 09, 2015, 02:26:15 PM by F.Tnioli »

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1975 on: July 09, 2015, 02:56:56 PM »

Measurements over wet ice are just inherently variable, which is why you want to average over a few days to even out the variability rather than looking at every daily wiggle as indicative of Absolute Truth About Ice Area Changes (TM).


Instead of providing the area with two days of delay, CT might provide a three-day average with one day of delay for a good reason.

Edit. Yes, one can do the averaging himself/herself

F.Tnioli

  • Grease ice
  • Posts: 689
    • View Profile
  • Liked: 65
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1976 on: July 09, 2015, 04:07:58 PM »
Sure. But. "They might have make it" - i say, this is one excellent line for a grave stone of mankind, overall - not only CryoToday's feature. I.e., CT just does normal human thing: being less than perfect. One "might" always wish it'd not be the case with humans, sure - but once again, see, "might" wish... :D

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1977 on: July 09, 2015, 06:03:04 PM »
OSISAF/MyOcean is showing now that the <85% concentration area now occupies a "solid majority" of the Arctic Ocean:

Some of that 85%+ at 85N, 163E.  Note the melt ponds, and highly fractured surface.  Image is about 70KM top to bottom.
This space for Rent.

Steven

  • Grease ice
  • Posts: 547
    • View Profile
  • Liked: 119
  • Likes Given: 16
Re: The 2015 melting season
« Reply #1978 on: July 09, 2015, 07:43:06 PM »
Here is an animation of the weekly false-color MODIS composite images from Environment Canada, for the last 6 weeks.  (From the last week of May 2015 to the first week of July 2015):



plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1979 on: July 09, 2015, 09:21:34 PM »
I suggest it indicates massive in-situ thinning.

Nobody seems to have really picked up on the significance of my IMB 2014F graph, so I'll repeat what I said on the blog earlier.

The floe (or floe + melt pond?) under 2014F is currently 89 cm thick. In approximate terms, half of the ice floe has melted away over the last month.

The latest temperature profile is even more intriguing:

To ask a dumb question: Can one infer from the pond temperature that this pond is salty? In my naive mind, a sweet pond would develop convection that keeps the temperature near that of the ice surface?

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1980 on: July 09, 2015, 09:55:50 PM »
I suggest it indicates massive in-situ thinning.

Nobody seems to have really picked up on the significance of my IMB 2014F graph, so I'll repeat what I said on the blog earlier.

The floe (or floe + melt pond?) under 2014F is currently 89 cm thick. In approximate terms, half of the ice floe has melted away over the last month.

The latest temperature profile is even more intriguing:

To ask a dumb question: Can one infer from the pond temperature that this pond is salty? In my naive mind, a sweet pond would develop convection that keeps the temperature near that of the ice surface?

*Any* pond would develop convection like that, regardless of the salinity of the ice or depth of the melt pond.  Net heat flow will be towards the ice, or, if the ice is sweet (mp at zero vs -1.8) through it to the water. Even then, some fraction will get picked up in phase change.
This space for Rent.

Andreas T

  • Nilas ice
  • Posts: 1125
    • View Profile
  • Liked: 11
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1981 on: July 09, 2015, 10:47:15 PM »
I strongly recommend looking at the data http://imb.erdc.dren.mil/irid_data/2014F_clean.csv before drawing conclusions.
The graph shows temperatures from IMB2014F over the last 100 hours. Temperatures at sensor 1 (above ice at installation) and sensor11 (1.1.m below sensor 1) show strong fluctuations in a 24h cycle, air temperature does not cycle much and is well below the maxima of T1 and T11. With what we know about these sensors (because Jim has provided that information) the most plausible explanation is that they are warmed by sunlight. Why there are double peaks and offsets at T1 and why temps at T1 are below T11, I don't know, one possible guess would be reflection from the surface but I think it unlikely that these are actual air or water temperatures.
edit: I should say that it also is very clear that the sensor isn't covered in ice, so Jim is right about thinning at the surface.

By the way, fresh water and salt water have one important difference in their density / temperature curve, jdallen. Freshwater has a density maximum at 4degC saltwater has its density max at the freezing temp. So convection in saltwater and freshwater at these temperatures would be be very different.
« Last Edit: July 09, 2015, 11:37:20 PM by Andreas T »

pearscot

  • Frazil ice
  • Posts: 148
    • View Profile
  • Liked: 44
  • Likes Given: 21
Re: The 2015 melting season
« Reply #1982 on: July 10, 2015, 12:52:54 AM »
I can only describe Worldview this morning as acutely distressing...

It calls to mind the image of Hurricane Katrina right on top of New Orleans... the moment at which my perspective switched from "Wow - This is going to be exciting" to "Oh Crap. This is going to be horrible."

Except that this time it's the Whole. F...ing. Planet.

Is there any chance people will wake up in time to fix this?

I'm not arguing with you at all, but why do you say that all the sudden things look terrible. I have been following IJIS very closely all year and I was impressed with the 'rise' during the month of June.  That said, I think other factors, such as bottom melt, were at play that also reduced the thickness of the ice. Nonetheless, what to you is the most alarming that you have seen recently?
pls!

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1983 on: July 10, 2015, 12:53:48 AM »
The July edition of Arctic Sea Ice News is out:

http://nsidc.org/arcticseaicenews/2015/07/downwardly-mobile/

Quote
The pace of sea ice loss was near average for the month of June, but persistently warm conditions and increased melting late in the month may have set the stage for rapid ice loss in the coming weeks.

June snow cover for the Northern Hemisphere averaged 5.45 million square kilometers (2.10 million square miles), the second lowest of the 48-year record. This ranking also holds for June snow cover assessed for North America at 4.09 million square kilometers (1.58 million square miles) and Eurasia at 1.36 million square kilometers (525,000 square miles).

June snow cover was especially low over Alaska and western Canada.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1984 on: July 10, 2015, 01:18:26 AM »
It's not quite the obliteration predicted by Hycom, but Hudson Bay's ice cover has taken a pretty good hit:

pauldry600

  • Frazil ice
  • Posts: 196
    • View Profile
    • weathergossip
  • Liked: 9
  • Likes Given: 3
Re: The 2015 melting season
« Reply #1985 on: July 10, 2015, 01:28:26 AM »
I can see this year as a little more than 2012 and the two other lowest years

i think 4th lowest

August will slow down after drama in July and Winter will set in early September with volatile climate

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1986 on: July 10, 2015, 02:04:04 AM »
. . . Is there any chance people will wake up in time to fix this?
. . . Nonetheless, what to you is the most alarming that you have seen recently?

I understand where epiphyte is coming from. We are witnessing a major event in the history of Earth evolve rapidly before our eyes. Watching our predictions come true can be exciting and satisfying, but we also know that there is extraordinary risk in our grand experiment.

At times I have been struck with the feeling that we may be on the verge of creating problems that humanity cannot cope with. Assuming we haven't already crossed that line. I don't worry about that 24/7, but rapidly disintegrating Arctic ice can be enough to remind me that this isn't just a physics problem - it's an important piece of our planet's life support system.

slow wing

  • Grease ice
  • Posts: 782
    • View Profile
  • Liked: 142
  • Likes Given: 380
Re: The 2015 melting season
« Reply #1987 on: July 10, 2015, 04:10:41 AM »
University of Bremen have updated their AMSR2 ice concentration map; the melting continues to advance in the Chukchi and Beaufort Seas...

(click on .gif to animate)

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1988 on: July 10, 2015, 05:01:22 AM »
By the way, fresh water and salt water have one important difference in their density / temperature curve, jdallen. Freshwater has a density maximum at 4degC saltwater has its density max at the freezing temp. So convection in saltwater and freshwater at these temperatures would be be very different.
I concur, that there would be a difference; however, there would still be convection.

I'll add that as melt water tends to be more rather than less saline, as the water heated, that would work strongly in favor of moving heat from the top surface to the bottom of the pond; its highly unlikely meltwater would pass 4C in a melt pond.

Saltier ice has another serious problem - a lower melting point.  That means your melt pond still starts at a temperature below that of the highest fluid density, and would also start melt at a lower temperature.

In short, the dynamics for convection and heat exchange are still there, whether your ice is salty, or not.
This space for Rent.

jai mitchell

  • Nilas ice
  • Posts: 2033
    • View Profile
  • Liked: 74
  • Likes Given: 18
Re: The 2015 melting season
« Reply #1989 on: July 10, 2015, 05:05:19 AM »

I've asked the CRREL what their explanation is, but have yet to receive an answer. My guess is that things have reached the stage where melt water is now seeping down the side of the buoy. However I'm struggling to conceive of a physical explanation for how the water reached such a high temperature when air temperatures did not. Does short wave absorption in fresh water generate that sort of profile? If it does then perhaps the buoy is sat in a "lake"?!

a pool of water on a lake of ice with ambient air temperature reaching only 0.6 will never reach 4C.  Not in a million years.  I think that the sensor is exposed and receiving direct solar warming, possibly with the above sensors being shaded somehow.
Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

Michael Hauber

  • Grease ice
  • Posts: 838
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2015 melting season
« Reply #1990 on: July 10, 2015, 05:07:04 AM »
Looking closely at MODIS it strikes me that there are two sides to the current Arctic.  There is the Pacific side where the state of the ice is shocking, and as bad or worse than 2012, and probably any other year.  But for the rest of the Arctic the visual appearance is of a remarkably solid ice pack.  At least in two dimensions.  PIOMAS suggests the 3rd dimension might be healthy as well, but with current weather conditions this will be put to the test.  By solid I mean there is very little open water, or evidence that the pack is broken down into individual floes jammed together.  It does look like an area of continuous ice sheet with some ridges or fractures, and that this continuous ice sheet is much more extensive than in the last 3 years.  Of course this sheet is covered with a lot of melt water, which given conditions is probably more than 13 or 14, although I haven't made an effort to assess this.

One theory is that there has been less wind than normal this year.  The ice is melting much more in place, and there is much less break down of the continuous sheet into smaller floes as the ice is pushed around by wind.  Until the ice gets thin enough, at which point it falls apart big time.  Alternatively the passage of a strong low early in the melt season across the Arctic has diverged ice on the Pacific side of the low's path, and compacted it on the Atlantic side.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Frivolousz21

  • Nilas ice
  • Posts: 1506
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 140
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1991 on: July 10, 2015, 08:14:17 AM »


The 00z GFS is showing an epic near historical melt pattern for the CAB,CAA, and Beaufort.

From day 3-8 the Western CAB CAA and Beaufort get an epic beating.

This is the kind of pattern that will get the SW CAB out to 77N ice free come September.

This entire situation is truly awful for the MYI.  If this holds steady through July volume will end up near 2010 levels come the min.





16-18C weekly average on the Arctic shore of Banks Island.  That is just insane.

A few days reach 25C+ with Southerly winds

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1506
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 140
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1992 on: July 10, 2015, 08:18:59 AM »
Today's breman image shows the continued breakdown.



This is 2015D which has 2.25C surface temps on the most recent update.

Ice Melt has started to accelerate.

And this region is snow free.

Its at 87N just North of GIS



This is the sub surface for itp87.

It's at 76N.  You can see about 5 days ago the sub-surface exploded up to the 0.4 to 0.8C range.

Thats 2-3CM a day off the bottom.  Thats extremely rare for this early. 

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

jdallen

  • Young ice
  • Posts: 3011
    • View Profile
  • Liked: 181
  • Likes Given: 170
Re: The 2015 melting season
« Reply #1993 on: July 10, 2015, 09:09:32 AM »
I'm going to underscore some of what Friv is saying, and present something which contrasts with comments elsewhere about the quality of the central CAB.

Below are two images, the larger one stretching from Wrangel Island in the upper left, to the central  arctic basin at about 82N, 170E in the lower right.

Across it you can see the evolution of melt, and I think it's pretty clear that in it, from upper left to lower right, we have a gradient that demonstrates what happens to the current ice as it progresses through it.

The detail image is about 76N in the upper left, and about 82N in the lower right, a subset of the larger image.

In that detail, you can see clearly how as the melt progresses, the individual small floes become separated out, as interstitial ice formed during winter fracturing events melts out.

If the heat gets to it, that's the fate of the ice at high latitude, as I think the visual pattern pretty well illustrates.  There aren't large expanses of mesh pack; it is *all* pretty much the small, granular structure wall to wall, with the exception of relict MYI broken off and swept into the Beaufort (where it is doomed), or the bastion pressed hard against the CAA (which is due to get clobbered over the next two weeks or so, if the forecasts are to be believed.

What this means for September, I don't know yet, but I'm not optimistic, and I fear imagining the central pack is in a state such that it can resist strong heat is wishful thinking.
This space for Rent.

Michael Hauber

  • Grease ice
  • Posts: 838
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2015 melting season
« Reply #1994 on: July 10, 2015, 10:26:55 AM »
Chukchi to 82 N is not the central pack.  It is the part of the IUP bremen map that Friv posted which currently shows up as bright yellow.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Jim Hunt

  • Young ice
  • Posts: 4211
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 246
  • Likes Given: 26
Re: The 2015 melting season
« Reply #1995 on: July 10, 2015, 11:14:08 AM »
Courtesy of Kate on the blog, paw prints at the "North Pole" :

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#NPEO2

Actually the current cam position is 86.65 N, 3.86 W, where the air temperature is currently reported by 2015D as 2.24 C. It also reports some surface melt, but no noticeable bottom melt as yet.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7077
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 670
  • Likes Given: 433
Re: The 2015 melting season
« Reply #1996 on: July 10, 2015, 11:26:37 AM »
Indeed, jdallen, I also took a snapshot of yesterday's LANCE-MODIS Arctic Mosaic and this level of shattering, so far into the CAB, is simply amazing:
Il faut comparer, comparer, comparer, et cultiver notre jardin

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7077
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 670
  • Likes Given: 433
Re: The 2015 melting season
« Reply #1997 on: July 10, 2015, 11:32:40 AM »
Just imagine where we'd be with more melt ponds during May, or more compaction, or 2012 volume levels...

If all goes well, the Arctic won't become ice-free until after 2030, but just one freak year with persistent freak weather after a warm winter and lots of preconditioning...

If I'm reading the forecasts right, GFS has the high pressure moving back towards the Atlantic again. But that's 5-6 days from now (not reliable), with massive anomalous heat remaining.
Il faut comparer, comparer, comparer, et cultiver notre jardin

Peter Ellis

  • Grease ice
  • Posts: 616
    • View Profile
  • Liked: 33
  • Likes Given: 11
Re: The 2015 melting season
« Reply #1998 on: July 10, 2015, 11:51:11 AM »
Indeed, jdallen, I also took a snapshot of yesterday's LANCE-MODIS Arctic Mosaic and this level of shattering, so far into the CAB, is simply amazing:

Really? The shattering there goes up to about 80 degrees North.  This is 2013, at 87 degrees North, with the Pole itself at the bottom edge of the picture, just left of centre.
http://1.usa.gov/1KTYvfZ

It's looking quite bad, but I'm not yet ready to say it'll be as bad as 2012, or even 2010/2011.

Peter Ellis

  • Grease ice
  • Posts: 616
    • View Profile
  • Liked: 33
  • Likes Given: 11
Re: The 2015 melting season
« Reply #1999 on: July 10, 2015, 11:54:13 AM »
If you pushed me, I'd say that unless something happens soon to protect the Beaufort/Chukchi, then we're looking at a year quite like 2010, where there was a bunch of old ice in the Beaufort which got massacred by a huge high pressure dome, leading to a big volume drop but no new extent record.  It'll precondition things for bad years in 2016/2017, and I'd certainly expect dramatic new records by 2020 - but I'm not going to call it for this year.