The 2015 melting season

[sedziobs]

Your link clearly shows 2015 ahead of 2012.

Nightvid said UH compaction is at a record low.  UH is the blue set of lines in the chart - your reddish set is NSIDC.  UH compaction is indeed the lowest, but it is important to note that 2012 used SSMIS rather than AMSR2 data, as well as a coarser resolution.  Caution should be used when comparing 2012 with 2013-15 UH data.

[kingbum]

Waters approaching 10C are reaching north of Svalbard. Several other areas looking quite toasty too, including Baffin Bay.

Not all maps are created equal. The range of colors make that map impossible to interpret the SST's. A reality check shows SST's much cooler then your "10C".

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

[jr47]

@ Kingbum.
It is certainly looking like a large area of Hudson Bay is much colder than normal.An anomaly maybe as much as 6-8 degrees Celsius below normal.
http://weather.unisys.com/surface/sst_anom.gif

[sedziobs]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

[ChrisReynolds]

NCEP NCAR surface temperatures north of 80degN (to be comparable with DMI temperatures...

Warmest July in the data since 1948.

[ChrisReynolds]

During July Hudson has been part of a band of cooler than average temperatures from Alaska, through Canada, across the Atlantic and through the UK and Scandinavia.

This is under the band of low pressure that is part of the wider NH pattern driving the Arctic dipole dominance of July, and seems to be a result of that pattern. Now the recent temperature anomalies (last seven days) are warm around Hudson, with a patch of cold over Hudson. So it looks like Hudson hasn't really warmed through July as much as usual, and now that warmer than average temperatures surround it, it is acting as a big cold thermal mass, keeping air over the bay cold.

It might freeze early as it doesn't seem to have warmed as much as one would expect, but it still has August to soak up some heat. I think it will follow the thermal fortunes of the surrounding land and will only freeze if the land does.

[Rubikscube]

Attached below is the average sea ice concentration map for 2003-2014 (NB! the baseline is different from previous posts this season as 2012 for this date is available in AMSR2 and 2002 for some reason isn't available at all). The other two maps display 2015 vs average and 2015 vs 2012 respectively, with reds indicating a decrease in sea ice and blue meaning the opposite. All data is 1st August from Uni-Bremen.

It should come as no surprise, given the SIA/SIE numbers, that this year is currently well below the 2003-14 average. ESS, chukchi, Barents and Kara are mostly in the red, but the situation appears more mixed in Laptev, Beaufort and CAA.

2012 still seems quite far ahead though, even excluding Hudson and Baffin. I have a hard time imagining how 2015 is supposed to beat that year, also CAA is way behind, which is perhaps somewhat surprising given that this area has been subjected to intense heat this July, but not unheard of either given that there is significantly more MYI there now compared to 2012.

Regarding the SST discussion, I'm most exited about the intense anomalies in Kara. The first time Kara melted so early and scooped up such loads of heat was 2011, then it seemingly took Kara 18 months to recover (That is considering the 11/12 refreeze failure and subsequent early meltout in 2012 to be directly related to the 2011 crash, which may not be correct)

[jdallen]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Concur; Hudson, Baffin and the Greenland sea refreezing in September is wishful thinking.

[kingbum]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Ordinarily you would be right but a 6-8C anomaly is not normal either and its 6-8C on the cold side. The heat energy needed to warm that is leaving and will be gone by September...Its like Lake Superior last year, it didn't completely ice out until the beginning of June 2014....Ice began reforming a month and a half above schedule in late October because the water never warmed up...given these anomalies the Hudson usually starts freezing in October I'm calling for a 4 week early start if weather conditions are normal because there is no built in heat energy in the water to fight. Once its consistently below freezing that's it there won't be a delayed reaction you typically see

[Shared Humanity]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Concur; Hudson, Baffin and the Greenland sea refreezing in September is wishful thinking.

And he is actually suggesting that they will begin refreezing in mid August!

[Nightvid Cole]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Ordinarily you would be right but a 6-8C anomaly is not normal either and its 6-8C on the cold side. The heat energy needed to warm that is leaving and will be gone by September...Its like Lake Superior last year, it didn't completely ice out until the beginning of June 2014....Ice began reforming a month and a half above schedule in late October because the water never warmed up...given these anomalies the Hudson usually starts freezing in October I'm calling for a 4 week early start if weather conditions are normal because there is no built in heat energy in the water to fight. Once its consistently below freezing that's it there won't be a delayed reaction you typically see

No, plenty of other years (e.g. 2009) had Hudson Bay lagging in melt just as much as this year if not more, and had very cold water for much of the summer. Yet, the next freezing season did NOT begin in September. In 2009 for instance, there wasn't significant ice until late November (which is slightly later than the historical average.)

[ktonine]

...Ice began reforming a month and a half above schedule in late October because the water never warmed up...

Looking at last fall's newspaper reports, I don't see any for Lake Superior refreezing prior to mid-November; typical is this: "Lake Superior was the first lake to show signs of hardening and began freezing on November 15..."  This is still several weeks earlier than normal, but not a month and a half.

An early refreeze is not just dependent on water temperature being below average at *this* time of year, but on below average temperatures in the fall.  November 2014 saw numerous 'coldest temperature' and 'most snow' records through various portions of northern Wisconsin and the Upper Peninsula of Michigan.  I'd be a bit skeptical of anyone predicting similar cold/snow records this November at this point in time.

[DavidR]

NCEP NCAR surface temperatures north of 80degN (to be comparable with DMI temperatures...

Warmest July in the data since 1948.

The Sea Surface Temperatures in July were 4th highest on record compared to July 2012 which is rated 28th.  This is a reversal of June where 2012 was 4th and 2015 was 36th. With warmth staying in the water much longer than in the air this suggests we will see continued strong melt in August.

[kingbum]

I fish on Superior and regardless of reports done by newspapers I know around Halloween time I seen ice developing in shallow bays...its possible the papers were a few days late to the party and I can't remember if it was a couple days before or after Halloween...no cold records this year in North America given the strength of this El Niño lol...anyone predicting so is a lunatic....

<snip, you can discuss global SATs elsewhere; N.>

[jdallen]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Ordinarily you would be right but a 6-8C anomaly is not normal either and its 6-8C on the cold side. The heat energy needed to warm that is leaving and will be gone by September...Its like Lake Superior last year, it didn't completely ice out until the beginning of June 2014....Ice began reforming a month and a half above schedule in late October because the water never warmed up...given these anomalies the Hudson usually starts freezing in October I'm calling for a 4 week early start if weather conditions are normal because there is no built in heat energy in the water to fight. Once its consistently below freezing that's it there won't be a delayed reaction you typically see

I will say again, wishful thinking. I will now add cherry picking of data and lack of understanding of physical chemistry to the list.

Hudson's Bay, Baffin Bay and the Greenland sea are neither that cold nor consistently cold; mostly if you look at SSTs they are above rather than below normal for most of their extent.

Next you demonstrate lack of understanding by thinking cooler surface waters (about 4C) will accelerated freezing.  Succinctly, the energy to drop 4C worth of  sea surface heat is 1/20th of that required to freeze it.  That level of head start *might*give you a couple of days, but that's doubtful considering the heat available elsewhere.

[greatdying2]

Waters approaching 10C are reaching north of Svalbard. Several other areas looking quite toasty too, including Baffin Bay.

Not all maps are created equal. The range of colors make that map impossible to interpret the SST's. A reality check shows SST's much cooler then your "10C".

"Impossible" is quite strong language, and quite possibly less accurate than the map that you are dissing.

However, it's always good to consult multiple data sources. The NOAA map you posted shows SSTs approaching 10C just west of Svalbard instead of just north. Is this a red herring, or do you suppose that it contradicts the point that I was making?

If you didn't understand the point I was making, it is this: SSTs are anomalously warm in several areas, including a particularly warm finger of water gradually reaching further north in the area of Svalbard, the same area in which melting has accelerated in recent days. If you don't agree, I invite you to look at recent SST time series to confirm this, in particular July 30 - present. You can find one such time series of SSTs here: http://ocean.dmi.dk/arctic/satellite/index.uk.php . In addition, there are various sources to watch the sea ice edge retreat, as I'm sure you are aware.

I have also attached an anomalies map from today that perhaps has colours more easy for some to interpret, which shows that an even larger area of anomalously warm water sits east of Svalbard (and which has also grown and moved north, especially in recent days). Not, as I said previously, to mention various other regions.

[greatdying2]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

That would be a full two months ahead of when those seas typically begin freezing.  Especially in the case of Hudson Bay reaching almost 50 degrees latitude (thus receiving significant insolation for another couple months),  the energy budget simply won't allow it.

Ordinarily you would be right but a 6-8C anomaly is not normal either and its 6-8C on the cold side. The heat energy needed to warm that is leaving and will be gone by September...Its like Lake Superior last year, it didn't completely ice out until the beginning of June 2014....Ice began reforming a month and a half above schedule in late October because the water never warmed up...given these anomalies the Hudson usually starts freezing in October I'm calling for a 4 week early start if weather conditions are normal because there is no built in heat energy in the water to fight. Once its consistently below freezing that's it there won't be a delayed reaction you typically see

I will say again, wishful thinking. I will now add cherry picking of data and lack of understanding of physical chemistry to the list.

Hudson's Bay, Baffin Bay and the Greenland sea are neither that cold nor consistently cold; mostly if you look at SSTs they are above rather than below normal for most of their extent.

Next you demonstrate lack of understanding by thinking cooler surface waters (about 4C) will accelerated freezing.  Succinctly, the energy to drop 4C worth of  sea surface heat is 1/20th of that required to freeze it.  That level of head start *might*give you a couple of days, but that's doubtful considering the heat available elsewhere.

Yes, SSTs in the southern part of Hudson Bay are anomalously cold because the sea ice there has only recently melted or is still melting. However, even if this southern part remains very cold (doesn't mix with the warmer northern part of Hudson Bay, isn't warmed by heat coming off the land, etc.), it still won't start freezing until well after the extent minimum. Why? Because although sometimes referred to as the Great White North, that part of Canada just doesn't appear to get cold enough soon enough. Mean air temperatures near southern Hudson Bay don't drop below freezing until at least October. E.g., Here are data for Oct. 2014 from three weather stations bordering different parts of southern Hudson Bay. (You can easily see other years' data as well with a click or two.)




Churchill, Manitoba: http://climate.weather.gc.ca/climateData/dailydata_e.html?StationID=48969&timeframe=2&cmdB1=Go&Year=2014&Month=10&cmdB1=Go#


Moosone, Ontario: http://climate.weather.gc.ca/climateData/dailydata_e.html?StationID=48950&timeframe=2&cmdB1=Go&Year=2011&Month=10&cmdB1=Go#


Inukjuak, Quebec: http://climate.weather.gc.ca/climateData/dailydata_e.html?StationID=48974&timeframe=2&cmdB1=Go&Year=2014&Month=10&cmdB1=Go#

(See https://weather.gc.ca/canada_e.html for additional data.)

[12Patrick]

The tiny bit of ice left in Hudson Bay will be gone in a week..

[slow wing]

  More remarkable changes in the concentration map for the Pacific side as the low pressure system blows the ice around.

  An entire arm of ice in the Beaufort Sea is separating and looks like it is about to detach from the main ice pack.

Click to flick through the last 3 days' maps:

[greatdying2]

Beaufort, July 22 vs. Aug 3. As Wipneus said, it's getting stirred up.

http://1.usa.gov/1UjCppf

[greatdying2]

  More remarkable changes in the concentration map for the Pacific side as the low pressure system blows the ice around.

  An entire arm of ice in the Beaufort Sea is separating and looks like it is about to detach from the main ice pack.

Click to flick through the last 3 days' maps:

Whoa! If this melt pattern persists, there'll soon be nothing left in Beaufort besides a few lonely little rafts of MYI. And then those also will go.

It also looks like the big and the little triangular shaped Laptev Bites may be merging to form a single, much larger semi-circle.

[wili]

Yeah, the action in the Beaufort is quite stunning. Let's not name the growing swaths of open water there, though, please! 

[greatdying2]

Yeah, the action in the Beaufort is quite stunning. Let's not name the growing swaths of open water there, though, please! 

Wili's ... what?   
(Sorry, couldn't resist.)

[slow wing]

I wonder if some of the Beaufort ice arm is from misinterpreted cloud cover though and should really show at lower concentration? It's all broken up anyway, as the finer scale pictures show.

[Villabolo]

Yeah, the action in the Beaufort is quite stunning. Let's not name the growing swaths of open water there, though, please! 

Wili's ... what?   
(Sorry, couldn't resist.)

Wili's Polynyas. 

[cesium62]

the Hudson usually starts freezing in October I'm calling for a 4 week early start

I thought you said 1 Sep.  Now you're saying "late September"?  The Hudson normally starts freezing first in the northern Hudson which is not experiencing a temperature anomaly.  The portions that are experiencing an anomaly normally start freezing later.

http://arctic.journalhosting.ucalgary.ca/arctic/index.php/arctic/article/view/451/483

If you want to keep making stuff up and not provide references, you're really on the wrong web site.  You might want to try WUWT.

[greatdying2]

the Hudson usually starts freezing in October I'm calling for a 4 week early start

I thought you said 1 Sep.  Now you're saying "late September"?  The Hudson normally starts freezing first in the northern Hudson which is not experiencing a temperature anomaly.  The portions that are experiencing an anomaly normally start freezing later.

http://arctic.journalhosting.ucalgary.ca/arctic/index.php/arctic/article/view/451/483

If you want to keep making stuff up and not provide references, you're really on the wrong web site.  You might want to try WUWT.

Nice paper. To summarize: for the period 1971-2003, the earliest mean freeze-up begins the second week of November (Nov. 11; SD 10.5) in the northernmost part of Hudson Bay, near Coral Harbour. For the sake of argument, let's ignore the following: that the freeze-up date has been growing later at a rate of about 0.3 days/yr over this period (read the paper), that the water in northern Hudson Bay is currently much warmer than in the south (by about 6 C), and that there's a month or two remaining in which to continue adding heat.

Ignoring these factors, let's say Hudson Bay freeze-up begins earlier than usual. How early would it have to be to affect the extent minimum? If we take as our expected minimum date Sept 21 (again being generous), then for early freeze-up of Hudson Bay to affect the minimum, it would have to occur 50 days (whoa!) earlier than the long-term mean, or 4.8 standard deviations.

In other words, even being very generous with our assumptions, we find the probability that Hudson Bay freeze-up will begin before other areas of the Arctic to be effectively zero.

[F.Tnioli]

... or 4.8 standard deviations.
...

Ouch! 4.8 SDs! That's what i call "nailing down" allright.

[greatdying2]

The warm pocket between Svalbard and the nearby retreating ice continues to strengthen.

[greatdying2]

Or if you prefer NOAA's map (note the difference in orientation):

[greatdying2]

And so you don't have to scroll up, here's NOAA's color scale.

[seaicesailor]

Beaufort, July 22 vs. Aug 3. As Wipneus said, it's getting stirred up.

http://1.usa.gov/1UjCppf

Yeah the mechanical action of this W-PAC has been astounding. Following the CICE drift model (which I stand for despite the complete ACFNS model not working) there is action left starting tomorrow over Beaufort (further drift toward the coast) and over ESS and Chukchi with the SAC coming from Siberia (Tnioli I love these new acronyms).

Still, note the lighter blue color of current date image, which may mean much less surface melting.
That may also explain the darkness of the new arm in the uni bremen image. Surface is cold. Tomorrow we will see.

[Jim Pettit]

I fish on Superior and regardless of reports done by newspapers I know around Halloween time I seen ice developing in shallow bays...its possible the papers were a few days late to the party and I can't remember if it was a couple days before or after Halloween...no cold records this year in North America given the strength of this El Niño lol...anyone predicting so is a lunatic....

<snip, you can discuss global SATs elsewhere; N.>

I suppose it's possible some small, shaded shallows protected from wind and waves might have seen a bit of overnight ice. But NOAA says nothing measurable got started on Superior until mid-November:

[Frivolousz21]

Hi everyone, still novice at this whole thing but I'd appreciate any criticism of my posts.
I've tried to insert an image from the ICON/DWD model for 24 hours from now (annotated)

Nonetheless I have a "but".
The cold, weak low has lasted now for a few days, and cold temperatures, light snow and all, see below image. Diverging drift has made a mess out of Beaufort, part of Chukchi, and if you see right part of the image, it even has left some dents well into CAB. Oh, and "The Gap".
How it will continue?

Image AMSR2 max resolution today, from Wipneus server, thank you (if not OK that I use it , pls let me know here or PM)

The divergence certainty isn't good, however is there really enough energy in that part of the world to significantly melt. The wind direction is favorable and is not blowing air from the warm surrounding water, I can't help thinking that as bad as things are now, a significant change in pattern will be worse for us.

It's to late to save the Pacific side ice share
Anywhere

This is from a buoy in the Western CAB.

The low pressure is the driver for the bottom melt to have sky rocketed.

Some wet snow and a stop to surface melt can't save the ice in that area now.

[Jim Pettit]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

Here, again, the data say that is extremely unlikely. In fact, it is, statistically-speaking, pretty much an impossibility:



Source: Environment Canada

[seaicesailor]

Hi everyone, still novice at this whole thing but I'd appreciate any criticism of my posts.
I've tried to insert an image from the ICON/DWD model for 24 hours from now (annotated)

Nonetheless I have a "but".
The cold, weak low has lasted now for a few days, and cold temperatures, light snow and all, see below image. Diverging drift has made a mess out of Beaufort, part of Chukchi, and if you see right part of the image, it even has left some dents well into CAB. Oh, and "The Gap".
How it will continue?

Image AMSR2 max resolution today, from Wipneus server, thank you (if not OK that I use it , pls let me know here or PM)

The divergence certainty isn't good, however is there really enough energy in that part of the world to significantly melt. The wind direction is favorable and is not blowing air from the warm surrounding water, I can't help thinking that as bad as things are now, a significant change in pattern will be worse for us.

It's to late to save the Pacific side ice share
Anywhere

This is from a buoy in the Western CAB.

The low pressure is the driver for the bottom melt to have sky rocketed.

Some wet snow and a stop to surface melt can't save the ice in that area now.

Boom! The 2013F colocated to obuoy #10 shows 70 cm of bottom melt during the storm!! as well, 30 cm of snow.

EDIT: the non-existent 30 cm of snow were mostly caused by the sensors being fooled in mid-July. Maybe a few real cm during storm
But we have the accelerated bottom melting, 70 cm during storm certain

[plg]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

So, the starting temperature of the water makes relatively little difference. Se graph below (0 point arbitrarily set at -5°C), adjust for salt water (just shift the temperature a few degrees, same principle).

[jplotinus]

Heatwave Alert for Alert

[F.Tnioli]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

So, the starting temperature of the water makes relatively little difference. Se graph below (0 point arbitrarily set at -5°C), adjust for salt water (just shift the temperature a few degrees, same principle).

Not quite that simple in reality, i think. Starting temperature of relatively deep layer of surface water is quite important, because of mixing. Over-simplifying, imagine say 10m layer of water which is 4°C, then imagine upper 1m of the layer loses heat enough to chill to -1.8°C (freezing pojnt; radiating IR out into colder athmosphere, etc), what happens to this 1m upper layer - does is start to form ice on top of it "right after"? I doubt. Instead, it sinks down, because colder water is more dense than warmer water within deeper 9 meters. Instead of "former upper 1m" layer of water which "went down", more 4°C "from under" gets to the surface, and the process repeats itself as long as there's more 4°C water "just under". This obviously multiplies the role of water temperature as long as we talk about anyhow warmer-than-freezing-point waters of deeper than very few meters surface layer, which i recon usually is the case.

P.S. Fresh water behaves quite differently - and unusually, - in this regard, as it has density peak few degrees above its freezing point. But not ocean water, me thinks:


Which means, freezing mode for sea water is one thing (described above), but if there is precipitation AND there is not enough wind to mix waters any much, freezing would possibly start in a thin layer of fresh water from precipitation (especially if it's snow / wet snow and cold athmosphere) on the surface, with possibly many meters of quite warmer-than-freezing-temperature, but still more dense (because it's not fresh) water below.

[12Patrick]

Updated PIOMAS volume. 

[F.Tnioli]

2014: smoked. Next victim: 2013. I bet 2015 will cross 2013 line on ~25th august or earlier, in hereby PIOMAS terms. We'll see in two months.

[Gonzo]

Interesting times, so just seeing that ice volume is falling fast. This year could be a record.?

[plg]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

Not quite that simple in reality, i think. [...]

True. I was referring to  closed system. However., the effect of 1°C difference when the freezing season starts is still marginal.

[greatdying2]

Glad you posted this...it supports why I think Hudson Bay, Baffin Bay, and the Greenland Sea are going to refreeze in a couple weeks preventing a top 3 minimum.

Here, again, the data say that is extremely unlikely. In fact, it is, statistically-speaking, pretty much an impossibility:

Nice map!

[plinius]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

So, the starting temperature of the water makes relatively little difference. Se graph below (0 point arbitrarily set at -5°C), adjust for salt water (just shift the temperature a few degrees, same principle).

@plg as you try giving us a lesson in basic physics, may we possibly give you a lesson in basic geometry/weather? Could you perhaps tell us how the relative times/heat budget look like when you try to freeze 1m of ice after cooling down a 30m thick surface layer?

[F.Tnioli]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

So, the starting temperature of the water makes relatively little difference. Se graph below (0 point arbitrarily set at -5°C), adjust for salt water (just shift the temperature a few degrees, same principle).

@plg as you try giving us a lesson in basic physics, may we possibly give you a lesson in basic geometry/weather? Could you perhaps tell us how the relative times/heat budget look like when you try to freeze 1m of ice after cooling down a 30m thick surface layer?

I'm sure he can do the math now, be it 10m i exampled above or your 30m. I bet he had good intentions. Please have pity.

P.S. Why 1m of ice though? I imagine some ~40cm would quite suffice to count as a significant "freeze up", no?

[plg]

Re the refreeze discussion: To freeze 1 L water at 0°C requires removing about 334 kJ, to freeze water at 10°C requires 334+10*4.187 = 376 kJ, i.e. only about 12.5% more to remove.

So, the starting temperature of the water makes relatively little difference. Se graph below (0 point arbitrarily set at -5°C), adjust for salt water (just shift the temperature a few degrees, same principle).

@plg as you try giving us a lesson in basic physics, may we possibly give you a lesson in basic geometry/weather? Could you perhaps tell us how the relative times/heat budget look like when you try to freeze 1m of ice after cooling down a 30m thick surface layer?

Apologies if I came across sounding pedantic or <insert adjective of choice>. I am sure most if not all readers here do understand the basic physics.

However, the point was simply that it takes 334 kJ freeze the water, but only 4.2 kJ to change the temperature 1°C.  This implies that some a variations in the initial temperature when the freeze season starts will have limited impact.

[Peter Ellis]

Yup, but you have to chill ~30m depth of water before you can start freezing the top 1mm, which has a certain impact the other way as well.

[seaicesailor]

The GLB HYCOM+CICE model seems to have been fixed,

http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

[seaicesailor]

It's gonna be a cold, agitated rest of the week in the Pacific side