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ORH_wxman

Arctic Sea Ice Extent, Area, and Volume

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5 hours ago, bdgwx said:

Sea ice area continues to decline though. This means the ice is spreading out. As noted above this typically means extent is poised for a significant drop.

he'll disappear in about a week

ecmwf-ens_T850aMean_nhem_6.png

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7 hours ago, Weatherdude88 said:

NSIDC sea ice extent is now the 7th lowest value for 6.17, with a value of 10.696 millions of kilometers squared. 2019 has greater sea ice extent for the date, than 2010, 2011, 2012, 2016, 2017, and 2018.

 

The ice has gotten battered due to a very unfavorable May/June, and the pattern is only projected to get worse as renewed blocking develops. 

I expect a cliff dive in sea ice next couple weeks. 

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21 hours ago, forkyfork said:

he'll disappear in about a week

ecmwf-ens_T850aMean_nhem_6.png

Yeah, some of these ensemble and OP runs are pretty monstrous with the heat in a few days.

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ASMR2 CAB sea ice area is once again one of the highest values in the post 2012 data set. Area losses basin wide have also been below average for the last 2 days.

 

gpOWpZk.png

 

MRJ3s05.png

 

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piomas updated for mid june. from the sea ice forum: 
 

index.php?action=dlattach;topic=119.0;attach=123702;image

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Have to say that the data strongly suggests a declining trend for arctic ice.

Possibly this is a cyclical phenomenon, which will reverse at some future date. Historical records from the 1920s suggest a similar warm cycle has been seen before.

Nevertheless, absent any identifiable mechanism to reverse the current warming, it seems reasonable to expect the 2012 lows will be broken, possibly this year.

Forkyfork makes a very strong argument that the recent increase in extent reflects fragmentation of previously solid ice pack, which sets the stage for enhanced melting of the shattered ice.

With the maximum melt still more than 2 months away, the odds are shifting towards a new record low imho.

 

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Area is currently about 300k behind 2012 right now. Still within striking distance but it needs to close the gap soon as 2012 goes cliff-diving again soon.

We're running about 100k ahead of 2007 and nearly tied with 2016. So this year is definitely in that top 3-ish zone right now. I'm a bit skeptical of it keeping pace with 2012 looking at the medium range forecast...but the long range euro tries to go nuclear, so if that happened, then we'd have a chance. But I try and not get sucked into anything beyond D5-6 in the Arctic. 

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Here's the current breakdown of how other years compare to 2019 right now......i.e, 2018 had 370k sq km more ice than 2019 at this point.

2018: +370k

2017: +300k

2016:  -20k

2015: +170k

2014: +390k

2013: +350k

2012: -280k

2011: +70k

2010: +50k

2009: +1.1 million

2008: +450k

2007: -20k

 

What sticks out here is how closely bunched 2019 is with 2016, 2011, 2010, and 2007 (and how much more ice 2009 had at this point than the others). Those are big melt years, so this one is on track for a big year. But we're still clearly lagging 2012 and that gap probably will need to be closed significantly before the end of the month to have a chance at a new record. 2012 loses about 1.2 million sq km of area between now and 6/30, so we're gonna need to lose more than that....which is hard to do. Only 2010 and 2007 lost more between 6/19 and the end of the month than 2012 did.

 

The pattern beyond D6-7 on the euro shows a very hostile setup for the ice....I think we'll need this to verify in order to keep within striking distance of 2012.

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The Pacific sector continues to experience the most hostile conditions for the sea ice.

https://mobile.twitter.com/alaskawx?lang=en

BREAKING CLIMATE: Utqiaġvik (Barrow) has been up to 73F (22.8C) through 7pm AKDT Thursday. This is a new all-time record high for the month of June. Previous record 72F (22.2C) on June 18, 1996. Climate obs since 1920

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Looking at the raw daily data, 2019 NSIDC sea ice area is still the third lowest value in the data set. For 6.20, the daily value is 8,039,945 kilometers squared. There was a loss of 67,579 kilometers squared from the previous date.

2019 now has 142,879 kilometers squared more of sea ice area than 2007, and 264,543 kilometers squared more than 2012. Losses continue to be below average.

The next closest year is 2016, which has a 66,540 kilometers squared lead.

NSIDC sea ice extent is now the 5th lowest for 6.20, with a value of 10.427 millions of kilometers squared. 2019 has greater sea ice extent for the date, than 2010,2011,2012, and 2016.

Jaxa sea ice extent is now the 6th lowest value for 6.20.

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The Chukchi-Laptev sector has been under withering fire for some time now. If this keeps up, there won't be an ESS "arm" of ice to be recirculated this year. About the only spot that's in halfway decent shape appears to be right near the pole. Some ponding there, but not too much -- yet. Ponding isn't quite as widespread as 2012 overall, but the open water fronts are generally in a more retreated position, with the open front from the Beaufort-Chukchi being opened very early and the Laptev bite being especially large and the fast ice and poleward pack ice in an advanced state of decay already. The Atlantic sector is in better shape than 2012 at this point and I think that's where most of the extra area/extent is located right now.

 

This year has a legit shot of seeing full open water at the pole, if nothing else due to the advanced state of the Laptev Bite.

One thing that does concern me considerably (for this year and future ones) is the amount of heat being pumped into the Chukchi. It is running extremely warm (4-8C SSTs already) and that water tends to be pumped under the halocline where it is stored from year to year. Once temps reach ~12C though, surface density drops below the fresher water at the top of the halocline, allowing it to be disrupted. It doesn't take a full disruption though. A weakened stability gradient is enough to cause some significant changes. So the heat pump that is running in overdrive this year will only serve to hasten the demise of the summertime Pacific sector in the future.

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1 hour ago, SnoSki14 said:

The upcoming pattern is an absolute ice destroyer, massive blocking high over the Arctic. 

Extent will plummet late June into July. 

https://www.esrl.noaa.gov/psd/forecasts/reforecast2/teleconn/forecast.html

Some of the area flatline is due to cooler weather, but some of it is also due to melt pond draining as water-covered ice tends to be (incorrectly) counted as open water by the sensor. There tends to be a big drop initially as widespread melt ponding sets in, it rebounds somewhat as those ponds drain and then drops again as the ice breaks up.

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My hunch is the AMO peaked for Summer-time SST warmth around 2012, and we'll continue to not beat the lows achieved that September. The periods near the prior AMO shifts tend to have stories like this if you look back in newspaper archives from the 1800s and 1900s. During the prior peak of the AMO warmth in the 1950s, there were reports that Summer sea ice extent was around 5 million square kilometers at peak melt. Other than 2012, that's not dramatically different than now. There were also reports earlier in 2019 of volcanic ash reaching near 50,000 feet above sea level, before the final data was corrected lower - eventually there will be a big volcanic eruption in the tropics, it's coming up on 30 years now since Pinatubo. Severe cold in the West & Plains, ala 2016-17 or 2018-19 during winter also tends to occur near AMO shifts historically. Look at 1932-33, 1935-36, or the winters around 1960.

2019_06_03_03_08_34-down.png

2019-06-20025642_shadow.jpg

https://trove.nla.gov.au/newspaper/article/58314725

ByshVZ4CAAEsXis_shadow.png

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Record low volume was 2016 (a near tie). Please tell me I'm misreading this and you're not trying to go down this "it's mostly natural variability" road.

That coffin has so many nails in it there's virtually no more room to fit another.

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http://www.realclimate.org/index.php/archives/2019/06/unforced-variations-vs-forced-responses/

 

Quote

Until recently, the hypothesis that there are significant natural (unforced) ocean cycles with an approximate periodicity of 60-70 years had been widely accepted. The so-called Atlantic Multidecadal Variability index (AMV, sometimes called the AMO instead), but also the Pacific Decadal Variability index (PDV) have been touted as major factors in observed multidecadal GMST fluctuations (for instance, here). Due to the strong co-variability between AMV and GMST, both, the Early 20th Century Warming (1915-1945) and the Mid-Century Cooling (1950-1980) have been attributed to low-frequency AMV variability, associated to a varying degree with changes in the Atlantic Meridional Overturning Circulation (AMOC). In particular, the uncertainty in quantifying the human-induced warming fraction in the early 20th Century was still substantial.

In contrast to those earlier studies, we were able to reproduce effectively all the observed multidecadal temperature evolution, including the Early Warming and the Mid-Century cooling, using known external forcing factors (solar activity, volcanic eruptions, greenhouse gases, pollution aerosol particles). Adding an El Niño signal, we virtually explain the entire observed record (Figure 1). Further, we were able to reproduce the temperature evolution separately over land and ocean, and between Northern and Southern Hemispheres (NH/SH). We found equally high fractions of explained variability associated with anthropogenic and natural radiative forcing changes in each case. Attributing 90% of the Early Warming to external forcings (50% of which is due to natural forcing from volcanoes and solar) is – in our view – a key leap forward. To date, no more than 50% had been attributed to external forcing (Hegerl et al. 2018). While there is less controversy about the drivers of the Mid-Century cooling, our response model results strongly support the idea that the trend was caused by increased levels of sulphate aerosols which temporarily offset greenhouse gas-induced warming.

 

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9 minutes ago, bluewave said:

The CPOM melt pond based outlook is going for a 2nd or 3rd place finish.

https://www.arcus.org/sipn/sea-ice-outlook/2019/june

https://www.arcus.org/files/sio/29427/cpom_david_schroederpan-arctic.pdf

We predict the September 2019 ice extent will be 4.3 +/- 0.5 million km2. This means there is a 68% likehood it will be among the lowest 3, 50% among the lowest 2, and 6% it will be a new mininum record. May 2019 has been the warmest and sunniest May in the Arctic since 2012 leading to melt pond fraction above average.
Brief explanation of Outlook method (using 300 words or less).
This is a statistical prediction based on the correlation between the ice area covered by melt-ponds in May and ice extent in September. The melt pond area is derived from a simulation with the sea ice model CICE in which we incorporated a physically based melt-pond model1. See our publication in Nature Climate Change http://www.nature.com/nclimate/journal/v4/n5/full/nclimate2203.html for details2.

 

This is in line with area numbers...which is a proxy for melt ponds. 

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1 hour ago, ORH_wxman said:

This is in line with area numbers...which is a proxy for melt ponds. 

This is the lowest that CPOM has gone since they began issuing outlooks back around 2014. While their forecasts usually finish within the error bars, they are often a little too high. 

CPOM June forecast compared September average NSIDC extent verification

Standard Deviations
+/- 0.5 mill. km2

2018...F...5.30....V...4.71

2017...F...5.00.....V..4.80

2016...F...4.50......V..4.70

2015...F...5.10......V..4.63

2014..F....5.40.......V..5.30

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51 minutes ago, bluewave said:

This is the lowest that CPOM has gone since they began issuing outlooks back around 2014. While their forecasts usually finish within the error bars, they are often a little too high. 

CPOM June forecast compared September average NSIDC extent verification

Standard Deviations
+/- 0.5 mill. km2

2018...F...5.30....V...4.71

2017...F...5.00.....V..4.80

2016...F...4.50......V..4.70

2015...F...5.10......V..4.63

2014..F....5.40.......V..5.30

Area is basically in a dead heat with 2016 right now. We'll see if it can pull ahead before the end of the month.

Extent is harder to predict. It's a lot easier to predict final area. Extent obviously has the nuances of compaction...take 2015 vs 2010 for example. 2015 finished with greater area but far less extent since 2015 had an epic compaction occur in August/early September. That's probably why they missed the extent prediction the most of any of their forecasts. They correctly saw that there would likely be more ice area than some other years at the minimum but had no way of knowing how compacted it would be. 

 

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I do think a lot of variability is still natural, how much is an open question. The Arctic is surely, what, half a degree to a degree warmer than in 2012 given that it is warming faster than the temperate zones? Something is counteracting that to change the patterns. Some of that is upper air patterns, but some of it is ocean temperature changes too. The AMO is not dramatically warmer anymore than it was in the prior peak of the AMO warm cycle.

https://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.mean.data

 1958   19.239   18.935   19.068   19.493   20.215   21.454   22.626   23.350   23.292   22.442   21.380   20.313
 1959   19.293   18.863   18.700   19.146   20.024   21.176   22.433   23.203   23.208   22.405   21.248   20.206
 1960   19.372   18.968   18.818   19.249   20.322   21.557   22.738   23.529   23.296   22.591   21.450   20.236

The prior peak produced AMO values in the 23.5-23.6C range in late Summer. We now get up to 23.8C, but the frequency of hitting 23.8C has been falling off in Aug/Sept since 2012, so I don't think I'm being too extreme in saying the AMO is holding back record low sea ice to some extent. The (black) ash landing on the highly reflective ice after the Arctic volcanic eruptions in 2011 couldn't have helped either.

 2017   19.579   19.135   19.055   19.593   20.491   21.704   22.927   23.661   23.593   22.886   21.709   20.620
 2018   19.529   18.974   19.022   19.376   20.179   21.387   22.645   23.467   23.408   22.599   21.240   20.199
 2019   19.344   18.995   19.014   19.439   20.270  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990  -99.990

Presumably, we'll melt less ice if this coming in 3-5 years?

 1963   19.361   18.925   18.871   19.264   19.942   21.199   22.439   23.128   22.891   22.231   21.150   20.046
 1964   19.131   18.783   18.779   19.017   20.070   21.252   22.334   22.970   22.876   22.034   21.044   19.988
 1965   19.011   18.587   18.665   19.069   19.934   21.124   22.292   22.997   22.876   22.060   20.937   19.98

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The AMO has become more amplified as the climate warmed. So even natural variability is impacted by climate change.

https://www.nature.com/articles/srep40861

Amplification of the Atlantic Multidecadal Oscillation associated with the onset of the industrial-era warming

North Atlantic sea surface temperatures experience variability with a periodicity of 60–80 years that is known as the Atlantic Multidecadal Oscillation (AMO). It has a profound imprint on the global climate system that results in a number of high value societal impacts. However the industrial period, i.e. the middle of the 19th century onwards, contains only two full cycles of the AMO making it difficult to fully characterize this oscillation and its impact on the climate system. As a result, there is a clear need to identify paleoclimate records extending into the pre-industrial period that contain an expression of the AMO. This is especially true for extratropical marine paleoclimate proxies where such expressions are currently unavailable. Here we present an annually resolved coralline algal time series from the northwest Atlantic Ocean that exhibits multidecadal variability extending back six centuries. The time series contains a statistically significant trend towards higher values, i.e. warmer conditions, beginning in the 19th century that coincided with an increase in the time series’ multidecadal power. We argue that these changes are associated with a regional climate reorganization involving an amplification of the AMO that coincided with onset of the industrial-era warming.

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both area and extent are in first place on AMSR2 data

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4 hours ago, forkyfork said:

both area and extent are in first place on AMSR2 data

UH AMSR2 extent is clearly not the lowest value in the data set.

WWOE5NL.png

UH AMSR2 CAB area shows significantly more high latitude sea ice than 2012 and 2016. It should also be noted that the UH ASMR2 data set started in 2012. 

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Perhaps the difference reflects definitional parameters?   One is Arctic Basin only, the other possibly the AMSR2 total area?  Hard to discuss when the data is inconsistent.

Just seems that Arctic ice is a topic where every detail has to be agreed, is it area, is it extent, is it volume, what coverage percent is included, are the land masks constant etc etc.

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7 hours ago, forkyfork said:

too bad so sad

 

 

You make a statement saying 'arctic extent is in first place' then you post a graph that shows arctic basin extent. 

These are not the same thing. If you look at UH AMSR2 high latitude sea ice area and extent within the arctic basin, there is significantly more ice at high latitudes within the arctic basin than the highest melt years. This data set also only goes back to 2012. Your above post is a classic example of 'cherry picking' to fit an agenda. 

 

UH AMSR2 CAB extent

HGDPjsm.png

 

UH AMSR2 CAB area

ubisZOO.png

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Looking at the raw daily data, 2019 NSIDC sea ice area is now the fifth lowest value in the data set. For 6.23, the daily value is 7,787,023 kilometers squared. There was a loss of 102,855 kilometers squared from the previous date.

2019 now has 9,356 kilometers squared more sea ice area than 2007, 236,390 kilometers squared more than 2012, 32,029 kilometers squared more than 2010, and 8,144 more than 2016.

edit: For the years before 2008, I should of been adding 310,000 kilometers squared to the value for a pole hole adjustment. I added 310,000 square kilometers to 2007, which would give 2019 9,356 kilometers squared of sea ice area than 2007.

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I'd caution your confidence over this matter esp when dealing with a measuring system that takes a 3.5km grid square and calls it 'fully ice covered' when 15% covered?

The system in use by NSIDC and others was invented to better capture the 'ice edge' and not to best capture the type of central basin ice we have seen evolve since 2012?

The reality ( for those who can be bothered to look ) is visible on any of the visible satellite platforms with vast areas nothing more than 'slush puppy' rubble studded with small floes.

We have been heading to this point over half a decade with the numbers showing a very 'stable picture' of sea ice come ice min whereas a combination of winter conditioning and ever less ice has placed us at a point where high heat at max insolation will drive both melt and ocean warming leaving a very precarious 'bottom melt' 1/3rd of the season with isolated floes and warm 'kill zones' where the ocean has been under full sun since ice max?

The apparent disappearance of the 'June cliff' should tell folks something surely? This year again we saw 'gains' over a few days in June. Do folk really think this was 'real' new ice or a fragmenting ,spreading ,pack triggering the 15% or more rule for empty peripheral squares?

When floes fall below 100m the 'side melt' becomes greater than the bottom melt so floes go 'poof' real quick.

We'd better hope that ice rubble isn't just that eh?

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34 minutes ago, Gray-Wolf said:

I'd caution your confidence over this matter esp when dealing with a measuring system that takes a 3.5km grid square and calls it 'fully ice covered' when 15% covered?

The system in use by NSIDC and others was invented to better capture the 'ice edge' and not to best capture the type of central basin ice we have seen evolve since 2012?

The reality ( for those who can be bothered to look ) is visible on any of the visible satellite platforms with vast areas nothing more than 'slush puppy' rubble studded with small floes.

We have been heading to this point over half a decade with the numbers showing a very 'stable picture' of sea ice come ice min whereas a combination of winter conditioning and ever less ice has placed us at a point where high heat at max insolation will drive both melt and ocean warming leaving a very precarious 'bottom melt' 1/3rd of the season with isolated floes and warm 'kill zones' where the ocean has been under full sun since ice max?

The apparent disappearance of the 'June cliff' should tell folks something surely? This year again we saw 'gains' over a few days in June. Do folk really think this was 'real' new ice or a fragmenting ,spreading ,pack triggering the 15% or more rule for empty peripheral squares?

When floes fall below 100m the 'side melt' becomes greater than the bottom melt so floes go 'poof' real quick.

We'd better hope that ice rubble isn't just that eh?

The thing is....NSIDC area is measured by SSMI/S and that particular satellite gets "tricked" by melt ponds into thinking it is water. It's been measuring like this for decades so we have a consistent database. So if we are a few hundred thousand sq km behind 2012 on this measurement, it's likely because we have less melt ponding than that year. Since melt ponding in June is the best predictor of final extent/area, we closely monitor the SSMI/S area numbers. 

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I think that , since the first Feb crackopalypse event in 2013, the large floes that used to hold extensive melt ponding have gone in favour of smaller individual floes that drain readily into the ocean.

No sooner had we sorted out a way of using the melt pond extent we lose it due to further changes in the basin!

 But yes , melt ponds and certain low level cloud type will fool sensors into seeing ice ( as will 'overwash' during choppy weather) but this 15% or more measure really does give scope for 'misdirection' from some who demand no real change to the basin since 2013.

All you can do is direct folk to sat imagery and ask them to compare shots for the same date of the year with the 'numbers' that are meant to capture that moment.

 

If you think that in year 1 the grid square could be 99% ice covered and so = 'ice covered'

Year 2 could be 75% ice covered and still ='ice covered'

Year 3 could be 40% ice covered yet still ='ice covered'

Year 4 could be 20% ice covered yet still= 'ice covered'

Year 5 could be 16% ice covered yet still ='ice covered'

Only on year 6 when ice cover goes below 15% do we see change as the grid square will then show 'ice free'

You can see that year 1 is very different to year 5 but to the algorithm they equate as 'equal'

With both the year on year degradation of the pack overall and this years extreme conditions some folk could be in for a big shock in late July/early Aug as the ice starting around 2m thick blinks out en masse

 

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