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Jim Hunt

Since a new month is upon us, and you're mentioning FDDs, here's the latest info from ice mass balance buoy 2015F:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-2015-16-imbs/#2015F-Temp

Firstly here's the temperature profiles:


(Click the image for a larger version)

There seems to be something of a glitch with thermistor number 5, but basically all the sensors are still working. Here's the buoy's summary information:

Pos: 81.51 N, 152.77 W
Air Temp: -33.51 C
Air Pres: 1029.53 mb
Snow depth : 17 cm
Ice thickness : 182 cm

Plus my own FDD calculation: 4261

This is of course only a very small sample from a very large Central Arctic, but it's currently still pretty cold up there, and the ice is still less than 2 meters thick.

There are also a few camera equipped O-Buoys scattered across the sea ice, but none have defrosted sufficiently to reveal any images as yet. In normal circumstances you'd expect the North Pole Environmental Observatory to be deploying more cameras and IMB buoys round about now, but there have been a few problems setting up ice camp Barneo this year:

http://forum.arctic-sea-ice.net/index.php/topic,1505.msg72981.html#msg72981

The freshly cleared runway near the North Pole has already cracked!

Neven
In normal circumstances you'd expect the North Pole Environmental Observatory to be deploying more cameras and IMB buoys round about now, but there have been a few problems setting up ice camp Barneo this year:

Jim, are these the same web cams of which it is said on the NOAA Arctic theme page:

Due to funding constraints, it may not be possible to deploy new Web Cams in Spring 2016, but deployments in Spring 2017 are planned.
John Christensen

Impressive data on the FDD from the NSIDC, thanks Neven!

- And what any 1st year student would have learned about manipulative statistical representation: The NSIDC couldn't resist the visual trick of letting the 2015/16 line exit the scale, rather than make the scale fit the lines.. ;-)

Jim Hunt

The self same web cams Neven. It's not clear from that page whether the "funding constraints" apply to the normal NPEO buoys or not.

Of course if Barneo can't ultimately manage to land their newly hired AN-74 near the North Pole that point becomes moot!

LRC

@ John C: Can not remember when or where Neven pointed out a problem developing with that graph and just did a quick edit of his own. As what has happened in the past with many other graphs, the originators and/or others that use those graphs just carry on with whatever the blog or forum has done until someone else comes along and resets the scale.
Ganted it would be nice if the original authors fixed things right, but it does show what kind of influence the blog and forum have in the world the Arctic studies. Congrats on influence :)

Neven

John, the graph is not from the NSIDC. It's from Dr. Andrew Slater, a research scientist at NSIDC, who makes these graphs in his spare time, AFAIK.

It takes time to make these graphs, sometimes a lot of time. The FDD graph I made for this blog post took me almost an hour, for instance. The graph was always big enough, until this year.

I'm sure Dr. Slater will adjust all those FDD graphs (from 1979-2016, 38 in all) at some point. As far as I'm concerned he doesn't need to rush. The fact that the trend line falls off the graph says something about the trend line, not about the graph.

Please, refrain from inferring that someone lets that trend line deliberately fall off the chart as a visual trick/manipulation (even as a joke). That's what climate risk deniers do, imply nefarious motives because of some conspiracy. It's the second time I see you doing that, if I remember correctly (last time with PIOMAS?). Next time will be last.

Neven
Can not remember when or where Neven pointed out a problem developing with that graph and just did a quick edit of his own.

I never saw it as a problem with the graph. The problem is the mind-blowing temperature anomaly we've witnessed in the Arctic this winter.

I did turn it into this piece of art several weeks ago (inspired by A-Team's notable art-science crossovers back in 2013):

Bill Fothergill

"terra incognita"

Also sometimes shown as "here be dragons".

Although, in this instance, "dragons" could be an acronym for...

Dramatically
Revealing
Arctic
Graphs
On
Neven's
Site


;-)

Chris Reynolds

Coincidentally I'd been perusing Dr Slater's pages this morning. It's a really useful resource that equals any of the 'team efforts' from other bodies. I was pondering doing a post tomorrow singing praise of Dr Slater's work and recommending it to people.

You just saved me some work Neven. :)

D

Fish here. The off the graph issue is no trick. It's what happens with live data reporting. In time Slater will find the time to rescale it. Thanks for informing us of his excellent work.

Neven, I beg to differ about the correlation between the warm winter & minimum winter sea ice extent and the coming summer season. The fine details don't correlate well, but in the big picture sea ice is declining in all seasons and there's a strong connection as the Arctic warms in all seasons. Clearly, from paleoclimate records, we know that spring and early summer warmth is the key to melting the Arctic over the past 2 million years so we should watch the next 4 months in great detail.

The loss of ice and presence of warm water in the Barents sea is raising water vapor levels in the Arctic. Water vapor is a powerful greenhouse gas that strongly amplifies the heat trapping of CO2 and CH4 as atmospheric water vapor increases.

And then there's the melting from below that an increasingly warm Atlantic water layer will bring as the Barents sea water warms.

It looks to me that this El Nino is pushing the Arctic past a tipping point.

Colorado Bob

New cause of exceptional Greenland melt revealed

As Robert Fausto of the Geological Survey of Denmark and Greenland, lead author of the study, says, "When we were analysing our weather station data, we were quite surprised, that the exceptional melt rates we observed were primarily caused by warm and moist air, because ice sheet wide melt is usually dominated by radiant energy from sunlight. "

https://www.sciencedaily.com/releases/2016/04/160401130828.htm

D

Moist air and rain are ice killers. As warm water originating in the Gulf Stream works its way further and further north both glacial ice and sea ice are driven into retreat. That new Greenland study amplifies the point I just made, Bob. Thanks for the link.

Bill Fothergill

RE: The off-scale "trick"

Further to the responses from Neven, Chris and the Fish...

Stuff going off-scale can happen in really quite odd ways. Those who are not already familiar with the long-term CT Area anomaly chart for the Arctic should have a look at...

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg

Nothing seems in any way out of kilter - except for 2007, 2011 and 2012. In each of those three years, the NH sea ice area dropped below 3 million sq kms, and that accounts for the weird "drop-ins" appearing in those years.

The chart would originally have been a composite, with actual area occupying the zone above the 3 million mark on the y-axis, and the corresponding anomaly value occupying the lower part of the graph in the +/- 3 million zone.

Further also to George's comment about the global effects attributable to major El Nino events, the latest UAH TLT at version 6 (+0.73 degC) has just appeared on Roy Spencer's blog. That should equate to a value of about +0.8 degC on version 5.6. (In both versions, this equates to the second largest anomaly recorded - behind February's whopper.)
http://www.drroyspencer.com/latest-global-temperatures/

Rather interestingly, version 6 produces an intriguingly different effect on the 97/98 El Nino than it does on the 2015/16 El Nino.

Dr Spencer's chart shows the 13-month smoothed average for Dec97-Dec98 at about +0.46 degC, with the most recent 13 month period lagging behind at about +0.38 degC.

When I do a simple equal-weighted 13-month smoothing exercise using UAH version 5.6, the Dec97-Dec98 value is +0.405 degC. However, the Mar15-Mar16 value comes out at +0.458 degC.

What's the betting that this little adjustment does not get much publicity from the usual suspects?

Colorado Bob

D -

Warm rain is going to be a real problem for ice at altitude as well.

The Hindu Kush Before and After the Great Pakistani Floods

I saw this image from the Swat Valley in August, and I was stunned . Not for what is in the foreground, I was in the Big Thompson Flood in 1976. I know what happens when it rains like hell in the mountains. What struck me are those mountains in the background. That is the Hindu Kush . These two pictures were shot in the last week of July (left), and from the same spot 3 weeks later. Look at all that missing snow.

http://coloradobob1.newsvine.com/_news/2010/11/10/5439030-the-hindu-kush-before-and-after-the-great-pakistani-floods

Yuha

In addition to the +80N 2m charts, it's also worth looking at Andrew Slater's Arctic Ocean 925hPa charts:

http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/

They include a wider area but still exclude peripheral seas such as Bering, Okhotsk and Hudson Bay as shown here:

http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/about_tair.html

For example, the 2010/2011 winter looks relative cold in the +80N 2m charts, as Neven mentions, but much warmer in the wider area charts.

The 925hPa temps exclude the effect of ice/sea surface conditions much better than the 2m temps which is particularly important in the summer (the thawing degree days chart at the bottom of the page).

Neven

For example, the 2010/2011 winter looks relative cold in the +80N 2m charts, as Neven mentions, but much warmer in the wider area charts.

You're right, Yuha. Now why didn't I think of that? I'll try and make a graph for the 925hPa charts as well later today.

Colorado Bob

Oil spill tests on ice prove Arctic quests risky

The skimmer is lowered from the rear of the icebreaker, its weight pushing massive pieces of ice under the water and forcing the spilt oil up to the surface, where the sticky black goo can be sucked up.

Luckily, this is just a test: as the world's superpowers eye the lucrative Arctic region with growing interest, unprecedented oil spill clean-up tests in icy Finnish conditions reveal just how hazardous and challenging an accident in the Arctic's pristine sea ice could be.


Read more at: http://phys.org/news/2016-04-oil-ice-arctic-quests-risky.html#jCp

AbbottisGone

What is the temperature of freezing, btw?

Jim Hunt

Bill - You may well also be interested in Snow White's latest investigation of the long-term CT Area anomaly chart for the Arctic.

Claim – Arctic Sea Ice Holds Firm?

Her interpretation is very different from Andrew Montford's. If this particular "usual suspect" possesses a pair of Mark 1 Eyeballs he very evidently wears blinkers over them!

Jim Hunt

AiG - The freezing point of Arctic sea water is generally taken to be approximately -1.8 degrees Celsius. Things are, of course, rather more complicated in practice than in theory:

https://youtu.be/lAupJzH31tc

Bill Fothergill

RE: Snow White & Bishop's Swill

Jim, back in February, one of the usual suspects (perhaps the good Viscount commenting on WUWT) tried to play the old "it's not a record sized anomaly, therefore it's not happening" malarkey when you decided to mention that CT Global Sea Ice Area had just hit an all-time low.

As Mr Montford has just tried to pull the same stunt, methinks this smacks of another desperate attempt at straw clutching.

Blinkers must be standard issue for those unable to take note of when the big anomalies tend to occur. For Global SIA, I think there have been 135 anomalies in excess of -2 million sq kms, and these have all occurred between Days 190-337.

For the Arctic, I make it 143 times that the -2 million sq km anomaly threshold has been breached. These have all happened during the August - October period.

I am a self-confessed fan of the rolling-365 day average. Therefore, as there are just over 13,600 days worth of data in the CT files, one can pull out the lowest 10-percentile for this rolling-365 average area by extracting those with a rank of 1324 or less. (Obviously, that number increments by 1 every 10 days.)

At the time of writing, the distribution of the lowest 10-percentile days for CT Arctic SIA rolling-365 average is as follows...

2007 - 117 days
2008 - 204 days
2011 - 308 days
2012 - 356 days
2013 - 244 days
2015 - 3 days
2016 - 92 days

(NB Every day since 29th Dec 2015 is currently in the lowest 10-percentile. By the end of April, the first 6 of these will have dropped out.)

That means the entire lowest 10-percentile lies within the last 9 years, and that 76% of this number lies within the last 5 years. (Funny how the word "lies" can have multiple meanings, isn't it?)

Sometime during April, I also expect the global rolling-365 to enter its own lowest 10-percentile. Things could get interesting a couple of months later as regards the absolute value of that particular metric. (However, it's too soon to make any prediction as regards anything as potentially wildly fluctuating as global SIA.)

wayne

Warmer temperatures, lesser sea ice and greater snow cover are the main features of this beginning of the melt season. I deal with thicker snow cover issues here:

http://eh2r.blogspot.ca/2016/04/illusions-and-implications-of-deeper.html

The very latest more normal seasonal temperature readings are not a surprise and may be temporary.

NeilT

Bob, your point about the snow is very much to my own mind.

Back in August 2000 I was working in Turin. I went home on Friday 13 Oct and my car swam, more than drove, to Milan to get the flight.

When I came back on the Sunday, it took me 7.5 hours to make the return journey. I found out, later, that the entire 6 lane autostrada bridge had gone south 100m.

But the key thing for me, at the time and later, was the impact of the freezing layer.

Whilst the demarcation line between rain and snow had been rising in previous floods, this year it hit 3,500m. Also the extreme heat, the extreme moisture content and the extreme rainfall caused large amounts of landslips allowing huge volumes of boulders to enter the river causing extreme destruction.

The analysis can be found here (pdf)

http://tinyurl.com/j6hyefl

There were many points in the analysis, but one here is to both our points.

"A decisive factor of this event, which also makes the difference from some other previous
floods (ref. [2], [3]), is the high temperature of atmosphere which has kept the
freezing level at very high altitude: so that heavy precipitation over the mountain areas
couldn’t be snow but have continually fed all the rivers of the basins."

Food for thought. Given that it only took 15 years to bring average world temps up to the last El Nino High....

Doesn't spell anything good for freezing days, Ice conditions or summer extent or area figure...


Colorado Bob

NeilT -

Thanks for the report , the rain/snow line is marching in 3 directions, north, up , and growing longer.
That 2010 flood in Pakistan had this as well -

The Swat Valley -
I never saw a number on just how bad the rainfall was there , until this story from the Guardian . " It was raining so hard, you couldn't see a man standing in front of you " ..............

" In more than 60 hours of non-stop torrential rainfall, the floods washed all that away. The north-west normally receives 500mm (20in) of rain in the month of July; over one five-day period 5,000mm fell. "It was incredible," said Sameenullah Afridi, a local United Nations official. "

That's 196.8 inches of rain , 16 feet .

http://coloradobob1.newsvine.com/_news/2010/11/21/5504169-the-extreme-rain-events-of-2010

Had it been cold enough at the top of the Hindu Kush, ( 4,500 to 6,000 meters ... 14,800 to 19,700 ft. ), the snow snow pack in those before and afters, up thread, would have jumped of the screen.

John Christensen

Hi Neven,

I stand by my comment: Dr Andrew Slater is with the NSIDC and has the NSIDC logo on this web page, with no disclaimer that this is unrelated to the NSIDC.

The issue of course with the graph not fitting the scale is that it alters the discourse to be around 'off the scale' data, and other blogs and news outlets can pick this up.

With his background, Dr Andrew Slater cannot be ignorant of this, which is the intentional piece: I don't see that he rigged the scale, but he decided not to fix the scale, before making the graph available.

But I respect this type of comment shouldn't be on your blog, so will go into hiatus, as we enter what may become the worst Arctic sea ice melting season so far.

- Never complained about PIOMAS though.. ;-)

LRC

"New cause of exceptional Greenland melt revealed

As Robert Fausto of the Geological Survey of Denmark and Greenland, lead author of the study, says, "When we were analysing our weather station data, we were quite surprised, that the exceptional melt rates we observed were primarily caused by warm and moist air, because ice sheet wide melt is usually dominated by radiant energy from sunlight. "

https://www.sciencedaily.com/releases/2016/04/160401130828.htm

Posted by: Colorado Bob | April 02, 2016 at 22:27"
Not sure why the big surprise. Granted in the era of stable weather systems almost all the melt did come from sunlight as the systems in play moved mainly west to est with little northern movement until they hit Europe. In the past few years all that has changed. You now are getting continuous major systems running up the east coast of NA and onto Greenland with lots of heat and moisture. This was predicted to happen decades ago. The surprise may be how soon it is starting to happen.
As with all things pertaining to the Arctic, it is now becoming a case of it being more a surprise we do not see a shocking result then a shocking result.

Al Rodger

The PIOMAS monthly volume page is showing March's volume at 20.621k - 770 cu km below the previous lowest (2011).
With that, it did occur to me that with the unprecedented Arctic temperatures for the first part of 2016, the PIOMAS model will be pushing into new territory. Interesting times for model-based data.

Jim Hunt

Bill - Perhaps not entirely unexpectedly, more of the usual suspects have been peddling Arctic sea ice porky pies over the weekend. For further details see:

More Of The Usual Hype About Arctic Sea Ice

Al - You will note that my alter ego is publicly quibbling with the GWPF's interpretation of the PIOMAS numbers. Further to our previous conversation on the matter, and not wishing to jump the gun in such circumstances, have you ascertained as yet precisely what the March number you quote means?

Is it final yet? Is it the March average volume, or the March 31st volume, or the average to a currently indeterminate date, or???

Interesting times most certainly!

Neven

Yes, I'd like to know that too, Al. I've compared March SAT and SLP maps and I'm not expecting the monthly volume increase to be much higher lower than that of 2011. Now that the month is over I'll have to check again.

Al Rodger

I know no more of the provenance of the monthly volume page I link to above. I only happened upon it a few months back. The numbers have in the past matched the daily data pointed to by the official PIOMAS page. Whether the monthly posting starts life as the final total or starts life as a provisional value, I know not? That the posted value isn't so far from any expected value wouldn't help in answering that.

GWPF? Gentlemen Who Prefer Fantasy!! The quote from NSIDC's Ted Scambos that the 'gentlemen' leave off their version of the blog is “The Arctic is in crisis. Year by year, it’s slipping into a new state, and it’s hard to see how that won’t have an effect on weather throughout the Northern Hemisphere” Homewood, their blogger, calls this "no longer a case of science" which is probably correct. Once the science is settled, the scientific findings can be freely adopted beyond science. That Homewood chooses to use anomaly time-series to cloak the "'slippage' into that new state" simply demonstrates he is an untrustworthy source of information. So he and the 'gentlemen' are probably well made for each other.

Neven
I know no more of the provenance of the monthly volume page I link to above. I only happened upon it a few months back. The numbers have in the past matched the daily data pointed to by the official PIOMAS page. Whether the monthly posting starts life as the final total or starts life as a provisional value, I know not? That the posted value isn't so far from any expected value wouldn't help in answering that.

Wipneus probably knows what it is.

Kevin O'Neill

By checking the monthly PIOMAS volume numbers against the daily numbers, the monthly values appear to be the average for the month.

The March results are in keeping with what I have expected since fall of last year. While the January PIOMAS value was "only" 4th lowest (behind 2011, 2012, & 2013) I predicted before the February numbers came out that we would per PIOMAS have the lowest volume ever heading into April.

The February numbers came out and 2016 moved into 2nd place. Now the March numbers show us that we *are* indeed heading into April with the lowest volume in PIOMAS' dataset.

Maslowski's prediction has a very high chance of becoming fulfilled this year right on schedule.

Jim Hunt

Neven - I have heard back from ERDC-CRREL, who confirm that their IMB funding has indeed been reduced.

We do have 1 SIMB that is about to be deployed at the North Pole through Woods Hole and that is our only spring deployment - there may be 2-3 this late summer/fall in the Beaufort Sea.

Neven

Okay, thanks for checking, Jim.

Neven
By checking the monthly PIOMAS volume numbers against the daily numbers, the monthly values appear to be the average for the month.

I'm going to have a more thorough look tonight, but this could be big.

Colorado Bob

Neven, Joe Romm gave you a shout out -


“This year’s trend line is not only way outside of the percentile zones,” Neven Acropolis notes at his must-read Arctic sea ice blog, “it’s falling off the chart.” This unusual warmth is a key reason Arctic sea ice extent just saw its lowest maximum on record.

http://thinkprogress.org/climate/2016/04/04/3765965/hottest-march-satellite-record/

jdallen_wa

Jim Hunt posted: "Neven - I have heard back from ERDC-CRREL, who confirm that their IMB funding has indeed been reduced.

We do have 1 SIMB that is about to be deployed at the North Pole through Woods Hole and that is our only spring deployment - there may be 2-3 this late summer/fall in the Beaufort Sea.
"

Both ironic and infuriating that funding for this research should be cut, just on the cusp of what may be the most dramatic environmental event of our lifetimes, exactly when we need the data the most.

Neven
I stand by my comment: Dr Andrew Slater is with the NSIDC and has the NSIDC logo on this web page, with no disclaimer that this is unrelated to the NSIDC.

You're wrong. His name is on every graph. Do NSIDC graphs have the name of the person who produces them on them?

Second, here's the standard disclaimer (at the bottom of this page):

"All viewers of these pages do so at their own risk. There is no guarantee as to the accuracy, completeness, timeliness, or correct sequencing of the data. None of those involved in creating, processing, or distributing this information shall be responsible for any errors or omissions, or for the use or results obtained from the use of this information."

Andrew Slater is under no obligation whatsoever to update graphs whenever you snap your fingers, especially if the graph isn't displaying a wrong interpretation/calculation of data. You are free to produce your own FDD graphs if you believe you can do better.

The issue of course with the graph not fitting the scale is that it alters the discourse to be around 'off the scale' data, and other blogs and news outlets can pick this up.

That's not the issue at all! The issue is that the Arctic has been so warm this winter that data that used to fit on a graph for 30+ years, suddenly doesn't fit anymore.

Why wouldn't blogs and news outlets pick up on that (the warming)? It is very big and important news, after all.

If you have an issue with anyone, it should be with me for making that comparison chart, not with Andrew Slater.

With his background, Dr Andrew Slater cannot be ignorant of this, which is the intentional piece: I don't see that he rigged the scale, but he decided not to fix the scale, before making the graph available.

There you go again, accusing a scientist of malicious intent. That graph is updated automatically. He doesn't "make it available" every day. If he has to fix the scale, he has to do so on every graph from 1979 onwards.

Maybe he doesn't have the time (he's a research scientist, you know), maybe he doesn't even know about it, maybe he thinks it's unimportant. No one knows what he thinks, but you're saying that he does it on purpose. This is climate risk denier talk, pure and simple.

What are you going to accuse him of next? That he deliberately heated up the Arctic to aid the instalment of world government?

But I respect this type of comment shouldn't be on your blog, so will go into hiatus,

Yes, please do.

Neven
Neven, Joe Romm gave you a shout out -

Cool. Just two days ago I was reading some of the stuff Joe wrote about Arctic sea ice in 2010 (about Maslowski's projection). If PIOMAS is indeed lowest on record when the data is updated, I'll drop him a line.

Colorado Bob

Earth’s internal heat drives rapid ice flow and subglacial melting in Greenland

The North Atlantic Ocean is an area of active plate tectonics. Between 80 and 35 million years ago tectonic processes moved Greenland over an area of abnormally hot mantle material that still today is responsible for the volcanic activity of Iceland. The mantle material heated and thinned Greenland at depth producing a strong geothermal anomaly that spans a quarter of the land area of Greenland. This ancient and long-lived source of heat has created a region where subglacial meltwater is abundant, lubricating the base of the ice and making it flow rapidly. The study indicates that about a half of the ice in north-central Greenland is resting on a thawed bed and that the meltwater is routed to the ocean through a dense hydrological network beneath the ice.

http://phys.org/news/2016-04-earth-internal-rapid-ice-subglacial.html#jCp

The graphic with is most telling when looking at the cold water spot southeast of Greenland -

http://cdn.phys.org/newman/gfx/news/hires/2016/1-earthsintern.png

Neven
I'm going to have a more thorough look tonight, but this could be big.

Okay, I had a look and I don't think it's big. Last time PIOMAS was updated, it was updated all the way to day 60 because it's a leap year this year. But PIOMAS doesn't do leap years, and so the final data point was for March 1st, at 20,660 km3.

The March average in the file that Al posted the link to, is 20,621 km3. The numbers are almost identical, and so my guess is the file hasn't been updated yet. The March average after one day is thus 20,660 (or 20,621) km3. This makes sense.

If not, PIOMAS sea ice volume hasn't increased at all during March, which doesn't make sense. Thank goodness.

My guess is that PIOMAS will still be second, behind 2011. But I still haven't updated my SLP/SAT maps comparison, and I'm off to bed now, happy to know that PIOMAS isn't suddenly crashing out of nowhere. :-)

Colorado Bob

"But PIOMAS doesn't do leap years,"

For some reason, I found this really funny, and there's so little to laugh at these days.

Al Rodger

Apologies, one and all.
Neven saying it looked like the value for March 1st jogged my poor fuddled brain, and memories returned of an extraneous value appearing last month on that monthly page at the same time as February was posted. I commented at the time. It is that same number.
Sorry for the false alarm.

Neven

No problem, Al.

Coincidentally the March 2016 number changed in that file last night and now stands at 21,527 km3, still behind 2011, but firmly in second place.

Jim Hunt

Al et al.

The March PIOMAS numbers have been released:

http://GreatWhiteCon.info/2016/04/more-of-the-usual-hype-about-arctic-sea-ice/#comment-214116

2016 Day 91 – 22.337 thousand kilometers cubed

Neven's prediction was spot on.

Neven

Thanks, Jim! March increase was fourth lowest in the 2007-2016 period, so no surprises there. It's 196 km3 behind 2011, but the difference with 2012 increased to 564 km3.

I'll post the PIOMAS update this evening.

Sneak preview:

Jim Hunt

The latest "Shock News!" from the North Pole:

http://forum.arctic-sea-ice.net/index.php/topic,1505.msg73177.html#msg73177

The floe of Barneo has cracked. There is only 650 meters left. So many efforts but all in vain.

The helicopters have taken off to search for another floe.

Al Rodger

A final cautionary tale on the PIOMAS postings. In the past I (& others) have encountered at the NASA sites what I shall call "sticky caching." That is, you link to a web page and it shows you what it looked like last time you linked to it - updates since then do not register. I now hit 'refresh' when I'm expecting NASA updates & they haven't appeared (although I think the problem is passed at NASA).
The relevance to PIOMAS is that I have just encountered "sticky caching" on the official PIOMAS page and that monthly page - the March update that I knew should have been there only appeared when I hit 'refresh'.

Greg Charles

I'm really having trouble understanding what the chart at the top of this post is showing.

The NSDIC definition is: "The cumulative FDD is simply daily degrees below freezing summed over the total number of days the temperature was below freezing." That sounds like only days below freezing are considered, but then how can the range go from positive to negative? Is it just a sum of all daily differences from 0C? That would make any temperatures above 0C count as negatives, and above as positives. However that would mean the about -900 value for July through March would be equivalent to roughly a +3C average for that time. That seems high to me for the 80N latitude. No?

Neven's clarification: "the sum of the number of days below 0 °C multiplied by the temperature for each day," is also confusing me. How do we multiply the sum of days below 0C by individual temperatures and get a single daily value? Does he mean to multiply by the average temperature up to that day?

Bill Fothergill

In meteorology, March is the first month of the boreal spring (or austral autumn) so I would ask for a little leeway in mentioning March temperatures in a post relating to winter analysis.

Followers of the adventures of Snow White will know that her favourite viscount just loves to (ab)use the lower troposphere temperatures from Remote Sensing Systems. The March RSS TLT was released today, and it plummeted all the way from February's all-time high (in their entire dataset) all the way down to a pathetically chilly 3rd highest of all-time in their dataset. (+0.974 degC down to +0.832 degC.)

Snow White's chum likes to play with trends, and if one extrapolates, that corresponds to whopping decline of 15.84 degC per decade. Therefore by the summer of 2182AD planet Earth is on track to hit absolute zero.

As for the current El Nino, you can soon kiss that quasi-cyclic phenomenon goodbye. If that cooling trend continues, even the Pacific warm pool should be iced over by about 2035. (Which is truly ironic justice, since that's when those commie environmentalist nut cases told us that the Himalayas would have boiled away.)

(NB In the above anal sys, I was, of course, merely trying to guess what Snow White's little pal will come out with next.)

;-)

On a more sober note, NOAA have released the March temperature for the Nino 3.4 region, and it was 29 degC dead. This was only the 7th time that we've hit 29 or above, and three of those have been in the last 5 months.

The last 12 months were all above 28 degC, and there was only one month below 27 (26.9) in the 12 months before that.

Although the present El Nino is waning, climatology teaches use that April - June are the warmest months for the 3.4 region. That means we should still be seeing a vast amount of moisture (and hence latent heat) getting pumped into the atmosphere.

For Arctic Sea Ice, this does not exactly represent good news.

Neven

Neven's clarification: "the sum of the number of days below 0 °C multiplied by the temperature for each day," is also confusing me. How do we multiply the sum of days below 0C by individual temperatures and get a single daily value? Does he mean to multiply by the average temperature up to that day?

Hi, Greg. I agree it is a bit confusing and I didn't word it particularly well (will correct that). The way I understand it, FDD is a cumulative number. The average temperature of a day is taken, and the value of the following day is then added or subtracted (depending on whether it froze or not).

In this case, Andrew Slater's graph shows the cumulative FDD anomaly. So, if it is freezing more than average on a given day, you get a positive value. If it is freezing less (ie it's warmer) the value is negative.

The past winter was warmer than normal, and so the FDD anomaly is negative. It's counterintuitive, because we associate negative numbers with freezing. But in this case the negative (anomaly) of freezing is warming.

Does that make sense?

cartographer

Greg,

My understanding of it is as follows:

If the temp is -10C for the day (average?), that would add 10 FDD to the season total. If, over the 1980-2010 period, the median temperature for that day is -8C, that day would have a +2FDD anomaly in the chart above.

I'd welcome corrections.

cartographer

Additionally, the line in the chart shows the sum of the daily anomalies for the season in question. This year, we've been much warmer than the 1980-2010 median temperatures, so most of the daily anomalies have been negative.

Add all those negative daily anomalies (not as cold this year as is typical), and you have the line that is headed off the graph.

NeilT

I looked through the descriptions here and tried to understand it. Then I realised the word which was missing for me was Cumulative.

This is a cumulative value. So on day1 the difference will be negligible. However after, say, 100 days with -10C (trend), the long term trend value will be 1000FDD at day 100.

If, however, the 100 days have only racked up 600FDD, in the current year (-6C average), then the anomaly will be -400

Therefore, also, to see any real difference in the chart, it would take several days of colder, or normal, weather to break the trend. i.e. 7 days at -20C where the long term average was -10C, for those 7 days, will add an additional 70FDD, to day 107 and will reduce the anomaly to -330 (in this example), for day 107.

Does that make sense? Looking at the current graph it is doing exactly that right now.

Also it might be interesting, in a vague way, to calculate out the heat energy of those anomaly days in terms, perhaps, of the little tracker on the top right???

NeilT

Just to add, if we look at 80N DMI temps, we are almost tracking to the trend line now.

NeilT

I see you used cumulative in the original post but not down here. Apologies.

Bfraser

A correction to the clarifications:

What you are describing could be called "Degree Days".

But we are talking about "Degree Days Freezing" which means that only temperatures below zero count. I.e. while "-10C" adds 10 to the cumulative total, "+2C" leaves the total unchanged.

On Neven's Sea Ice Graph Page, there is also a "Degree Days Thawing" (and its associate anomaly), in which all negative temperatures have been replaced with 0.

jdallen_wa

Regarding FDD's... you are generally correct. However, from discussions with Jim Hunt, I discovered the NSIDC uses -1.8C as their reference point, as the typical freezing point of sea water. I believe that is the basis for the graphs Mr. Slater has provided us.

Bill Fothergill

In the comment above, jdallen is perfectly correct in pointing out that the baseline for calculating FDDs is -1.8 degC.

Here is the text used by the NSIDC to describe usage...

"... The freezing temperature of ocean (saline) water is typically -1.8 degrees Celsius (28.7 degrees Fahrenheit). If the average daily temperature was -5.8 degrees Celsius (21.6 degrees Fahrenheit), this would be -4 degrees Celsius (24.8 degrees Fahrenheit) for one day..."

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

What seems to be causing further confusion amongst some is the fact that Dr Slater's graph has positive and negative values. The trick is to carefully read the title of the chart. In particular, one needs to take note of the last three words, which read "Anomaly from Median".

Bill Fothergill

Whilst writing the above post, I was summoned by "she who must be obeyed" and obviously had to comply instantly.

I had also meant to point out Dr Slater's use of the word "median", rather than the more familiar term, "mean". (Or, to be more precise, arithmetic mean.)

If you have a sample of size N, to get the arithmetic mean you simply add up the numeric values of interest, and divide this by N. This is exactly what most of us mean (sorry) when we, rather imprecisely, use the word "average".

To calculate the median however, the N samples are arranged in size order, and the value occupying the middle position in the ordered list is the median. (If there is an even number of samples, the median is taken as the arithmetic mean of the two central values.)

The median is considered to be a more robust measure when dealing with data that does not tend to be adequately described by the normal* distribution. (* Look it up yourselves.)

The primary reason for this "robustness" is that outliers are automatically rejected when determining the median. Of course, if all the outliers are on the same side, you are then beginning to reject valuable information.

me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-

There's a good page on this at NSIDC:
http://nsidc.org/cryosphere/seaice/processes/thermodynamic_growth.html

It describes the growth of seaice as a function of FDD, there's even an equation. The relationship is approximately the square root of FDD so with a substantial reduction in FDD over the season then the thermodynamic component of ice thickness growth will be less.
To assess this component it would be good to have a graph of the absolute FDD value.

Phil.

wayne

Phil,

That formula does not work too well, but gives a rough approximation.


Jim,

Mark 2 days ago the beginning of heat injection from the much warmer sea ice, I expect a noticeable surface temperature boost.
75 North The snow surface structure has now small ice covering at night, and it appears more expanded, breaking open at noon. 23 days in a row of mostly sunny days, yes it is indeed a desert in the Arctic.

Bill Fothergill

@ Phil

The NSIDC page you linked to was the same as the link I gave 2 comments earlier. Glad to see that you liked it, as, in a minor way, I helped update that page a couple of years ago.

@ Wayne

As stated on that page, The Lebedev formula given is but one of several empirical descriptions for ice formation. The presence of snow provides insulation which shields the ice from the worst of the freezing air temperatures, and thus inhibits growth. (As you know.)

The Lebedev formula could therefore be expected to over-estimate the growth of ice when there is snow on the surface. Would that assessment generally agree with your experience of ice growth?

I must confess that I'm surprised that NSIDC didn't use a more recent formulation. However, as with so many other areas, they have limited funding available, and even getting the time for one person to bring this more up to date is proving problematical.

Greg Charles

Thanks, all! I think I mostly understand it now. FDD is in fact the sum of the daily difference (absolute value) between freezing temperature and the actual average temperature, starting from July 1, and throwing out any days where the temperature is above freezing. That means the lowest possible value of FDD is 0. However, the above chart is showing FDD anomalies from a median. I'm still not clear if that's a median of all years' FDD values, or just some subset. In any case, the current value of -900 means this year has had some combo of fewer freezing days and warmer temperatures on the days that did freeze, and by quite a bit compared to whatever time period the median represents. This year's FDD is above 0, but 900 day-degrees lower than that median.

I don't quite get why that's a more useful number than just comparing temperature anomalies for the same time period. I don't grok why days above freezing would be thrown out. Wouldn't a day 10 degrees above freezing affect sea ice thickness more than a day 2 degrees above freezing? What's the advantage of counting them both the same?

Bill Fothergill

@ Greg
"I don't grok [sic] why days above freezing would be thrown out"

Neither do I. There is a bit about the melt part of the annual melt/freeze cycle on the "Cycle" tab, but it does not go into the detail in any way.

If one was trying to discuss this really accurately, then surely days above "zero" (i.e. above -1.8 degC) during the September - March part of the cycle should serve to "unwind the clock" in terms of cumulative FDDs.

Unfortunately, the non-linear relationship makes it unrealistic to do a simple book-keeping exercise, and neatly subtract the difference between the freeze and melt components. The timing of such occurrences is critical, and really needs to be represented by some continuously updating integration, rather than simply resolving differences at the end of the freeze cycle.

Kris

Back again!

The polinia in front of Barrow is back, and even bigger as before. And confirmed by the looks of the UNI-Bremen chart.

Albeit polinia do have strange habitudes, it never happened there at this time of the year (February --> early May) since Arctic monitoring began. Indicating the coastal ice is utterly thin and fragile indeed.

Greg Charles

@Bill

OK, interesting observations. Out of curiosity, why the [sic] on grok? Usually that's to indicate a typo or non-standard spelling in quoted text. Kudos for putting sic in brackets though. A lot of people don't do that right.

wayne

Last few days was the greatest heat injection from the Arctic ocean ever observed by the new horizon refraction method. It was observed by the horizon lowered for many more hours than previous seasons. The reason is highly likely the snow layer gaining some air by its sublimation, in other words, the snow layer is warming up with warmer air, especially the much thinner ice below and also relentless sunshine,
I was also quite surprised by the steep gain in temperature just aloft as well. On top of that the models are forecasting big surface temperatures gains remaining steady for at least a week.

http://www.weather.gc.ca/forecast/canada/index_e.html?id=NU

good model! look at the incredible warming everywhere. They must rely on Long wave radiation output.

Bill,

Would love to "put to the test" the other formulas.

Bill Fothergill

@ Greg Re: "grok [sic]"

The [sic] was there because I've never seen the term "grok" until now. I had a look in the Oxford Concise that lives next to my keyboard, and then took the almost unprecedented step of standing up and reaching for the Oxford Reference that lives among my physics books. All to no avail.

I therefore didn't know if it was...

a) an esoteric word from the far-corners of the former empire, or
b) a word recently introduced into the vernacular, or
c) a typo

Perhaps I should have signalled my confusion (something that's growing on a daily basis) by the use of (?) instead of [sic].

As regards the non-linearity of the effects of any surface melt, the factors involved are seriously varied.

# if the meltwater can drain away through cracks/moulins or slop over the edges, then it's gone, and the cumulative FDD clock really should rewind by an equivalent amount. (Except that this drainage can lead to local freshening of the surrounding sea water, hence raising its freezing point slightly.)

# if the meltwater stays in situ, it will refreeze more easily as its freezing point is 0 degC, rather than the -1.8 degC of the salt water in the ocean.

# whilst this meltwater is in the liquid phase, energy can pass more quickly from the relatively warm underlying ocean to the distinctly chilly atmosphere above. This, if anything, can help to enhance ice growth.

# however, if the melting occurs at a latitude where the sun has already started to warm things up, then the meltwater will act as albedo reducing melt ponds, and the melt season is off to a flying start.

All bloody complex

@ Wayne

If you get the chance (or get the time) to assess alternative empiricals, I'd love to hear your thoughts.

me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-

Hi Bill, I don't know what grok means either!
I thought the explanation on the NSIDC was fairly clear, I took it that the equation given was just an example and was more interested in the form of the dependence (~sq rt), than the exact terms.

Wayne Kernochan

Hopefully this post actually gets through.

Grok was introduced in Heinlein's Stranger in a Strange Land in the late 1960s, meaning (more or less) "to understand deeply and comprehensively." It was then adopted by hippie culture, and from thence moved into computer programming (hacker, in the old, good sense) jargon. It's good to see it again :)

Bill Fothergill

"Stranger in a Strange Land"

Many moons have passed since I read that. Perhaps it'll be next on the list when I finish re-reading Time Enough for Love.

Cheers Wayne

Jim Hunt

Winter in the Beaufort Sea looks to have turned into spring at the very least. The camera on O-Buoy 13 has defrosted as a consequence:


(Click the image for a larger version)

Note the co-located SIMB 2015J and ITP 88 buoys.

Susan Anderson

This refers to a few days back; here's Earth Observatory "OMG: Is the Ocean Melting the Ice?"
http://earthobservatory.nasa.gov/IOTD/view.php?id=87813

Funny that y'all would know OMG but not grok. But I think I'd put it less precisely, as absorbing meaning (comprehending at a gut level, understanding by or with feeling. (Could phrase that better, but time is short.)

Speaking of which the EO is rather a grok-y title ...

Runway troubles reminds me of that oil truck that sank. Too bad nature is punishing stupidity at such a rapid rate, given our collective degradation these days (hard to be from the US these days).

Mike

I also find it funny that such a group of intelligent people were ignorant of 'grok', maybe it's a word of a cooler era ;-). Oxford reference is not everything, always try the urban dictionary https://www.urbandictionary.com/define.php?term=grok for those difficult moments of need. Keep up the good work people. Stay Cool.

Bill Fothergill

It would appear that my command of the language of Shakespeare is doubleplusungood.

;-)

Sifright

Hi Neven,

I was wondering if I could have permission to use your ensemble graph http://neven1.typepad.com/.a/6a0133f03a1e37970b01b8d1b7816e970c-pi

in a forum post I'm writing else where?

Neven

Sure, go ahead.

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