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    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    19 hours ago, ORH_wxman said:

    It is definitely weird that we saw an abrupt flip. I wish we knew what caused it. It seems to coincide with the formation of the deep cold pool anomaly in the North Atlantic sometime in spring of 2013 when the deep blocking from early that spring broke down. But I'm not sure what is cause and what is effect and also what is just reinforcing feedback. Probably some combo but interesting nonetheless. 

    The hadgem model from Hadley center seemed to predict this on some level after 2012...which is a nice score by that model. 

    Yeah, the HadGEM1 did a great job.

    https://www.the-cryosphere.net/7/555/2013/

    Mechanisms causing reduced Arctic sea ice loss in a coupled climate model
    A. E. West, A. B. Keen, and H. T. HewittMet Office Hadley Centre, Exeter, UK
    Received: 09 May 2012 – Discussion started: 18 Jul 2012
    Revised: 04 Feb 2013 – Accepted: 18 Feb 2013 – Published: 26 Mar 2013
     
    Abstract. The fully coupled climate model HadGEM1 produces one of the most accurate simulations of the historical record of Arctic sea ice seen in the IPCC AR4 multi-model ensemble. In this study, we examine projections of sea ice decline out to 2030, produced by two ensembles of HadGEM1 with natural and anthropogenic forcings included. These ensembles project a significant slowing of the rate of ice loss to occur after 2010, with some integrations even simulating a small increase in ice area. We use an energy budget of the Arctic to examine the causes of this slowdown. A negative feedback effect by which rapid reductions in ice thickness north of Greenland reduce ice export is found to play a major role. A slight reduction in ocean-to-ice heat flux in the relevant period, caused by changes in the meridional overturning circulation (MOC) and subpolar gyre in some integrations, as well as freshening of the mixed layer driven by causes other than ice melt, is also found to play a part. Finally, we assess the likelihood of a slowdown occurring in the real world due to these causes.
     
    • Like 2

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    1 hour ago, ORH_wxman said:

    Yeah if you read the Arctic sea ice forums, most of them are convinced every season is going to be a record low. There's a select few posters on there that do a good job and are pretty objective about the data but you can ignore the other 90% of them. As skier said, most of them just post anecdotes...pictures of buoy webcams or zoomed-in visible satellite pics that show ice "rubble" and then claim that means it has to melt out this year. 

    There's no doubt that this year started off really bad coming out of winter...likely worst on record...but it's clear now that we didn't carry that momentum into spring and summer. It will still be a pretty low ice year because of how bad we started, but I don't think we will get near any records. Maybe volume can still be close if we get some hostile weather in August. 

    I think some people are coming into each season thinking that it will be a continuation of the 2007-2012 mega dipole pattern. But outside July 2015, the summer Arctic pattern did a complete reversal following that 2012 record breaking summer. It was like the 2012 extremes of low sea ice extent and Greenland melt flipped a switch over to a new regime. Maybe some type of mini summer Arctic D-O event?

     

    500.png.21d8928a895e878bd55da5a29ddcbdea.png

    SST.png.d0045a395d5f68678db917c747f70455.png

     

     

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    17 hours ago, ORH_wxman said:

    PIOMAS had a mid-month update....2017 is still lower than 2012 by a very slim margin. It is 150 km^3 lower than 2012...it was 180 km^3 lower on July 1st update so basically no change. However, the difference in the CAB has shrunk to almost zero...compared to July 1st which had quite a bit more CAB volume in 2012 versus 2017. So I think it is only a matter of time before 2012 runs away from this year...but we will see. Until the total number diverges, it is still a race.

    This seems to be supported by the area numbers too (NSIDC area as measured by SSMI/S)...after starting off the month with some big drops as noted earlier in this thread....we've come to a screeching halt in area loss. We are sitting at 5.62 million sq km for area right now which is more than 800,000 sq km above 2012 at this point (with the big August cyclone still looming in 2012). We are actually ahead of 2013 and 2014 right now as well, but I do not believe we will stay there because both of those years went into big pauses later this month.

    I agree. The coming cooldown across the CAB should keep 2017 behind the 2012 extent over the next  the next 10 days. 2012 will probably run away from 2017 in early August when the steep 2012 drop occurred. With the exception of July 2015, a cooler polar vortex has dominated the Arctic summers from 2013-2017.

     

    ecmwf-ens_T850aMean_nhem_1.thumb.png.daeb78c9033bed4148cb1c22d51d47e9.png

    ecmwf-ens_T850aMean_nhem_6.thumb.png.4f6f09a03bd052468e66b85a8626c817.png

     

     

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    20 minutes ago, ORH_wxman said:

    Yeah I'm not sure what he is seeing that indicates we will go lower than 2012...there's still an outside chance we go lower on volume only because the very thick ice near Greenland and the CAA is quite a bit thinner than 2012...but the rest of the pack is in superior shape than 2012 was at this point, so it is hard to see how the area and extent get anywhere near it. Volume will be a task...it will require probably very hostile weather from here on out. We entered July nearly tied with 2012 for volume and so far this July has been significantly colder than 2012. We had a decent chance to beat 2012 on extent/area coming into May, but the weather since then has all but eliminated that chance now...never say never, but I'd put the odds probably below 10%. Maybe if we get a 2007-esque pattern later this month and right through all of August, we will make up ground.

     

    Yeah, and how much colder this summer is in Greenland compared to 2012.

    http://polarportal.dk/en/nyheder/arkiv/nyheder/bringing-harmonie-to-the-greenland-ice-sheet/

     

    Martin Stendel, Polar Portal leader, agrees. “This year has been extremely unusual, with a snowy winter and then a cool period at the start of this month. It’s extremely important we get the surface mass balance right.”

    The period from the 27th June to the 5th July saw days with close to zero or even slightly positive SMB (a net gain in mass) as well as a record low temperature recorded at the DMI weather station at Summit  -33.0 °C. This weather along with the snowfall in early June, and following from the heavy snow in the Autumn, has led to a relatively high surface mass balance for the time of year and an unusually bright and reflective ice sheet, as shown in the albedo anomaly map on the Polar Portal (and below). Professor Jason Box of GEUS explains “when we see cold snowy conditions like this in the summer time it brings melt to a halt. The fresh snow is bright and reflects sunlight whereas in normal years dark bare glacier ice is usually exposed at this time of year and so melt rates are strong. This is why we track the albedo through the year to see how much melt we can expect”.

    So far this summer there has been less melt than usual. As DMI weather forecaster Jesper Rosberg explains, “we have seen a persistent positive North Atlantic Oscillation this summer and the jet stream has been very far south of Greenland with very cold air over the ice sheet, so the precipitation falling this summer has mostly been snow, rather rain. ” 

    The cold and snowy conditions have been hindering scientific fieldwork this summer. But there are still several weeks of the ablation season left and the weather for the rest of July and August will determine the surface mass balance of Greenland this year. As far as DMI scientists know this is the first time that the SMB of the Greenland ice sheet has been calculated with such a sophisticated model in near real-time and it’s all the more interesting since we have snowfall interfering with melt. 

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    8 hours ago, WidreMann said:

    Given the state of the ice, very thin and broken up, I don't see how we don't beat 2012 by a decent margin. While the pattern isn't terrible, it's not great either. We certainly will beat it on volume.

    On JAXA and NSIDC extent we probably missed to our chance to beat 2012 with the stronger PV pattern from June into early July. It even fell a little behind last year in recent days. 

     

    5964b893bfa67_Screenshot2017-07-11at7_27_49AM.png.efc41dfe6448ac56f8b96379cb1810bb.png

     

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    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    53 minutes ago, ORH_wxman said:

    Greenland is actually having a historically cold summer. Kind of weird obviously in the recent warm context but it's a reminder that natural variability still plays a large role. 

    Either natural variability or the early emergence of the CCSM4 summer pattern in response to climate change. The NH summer circulation since 2013 bears a strong similarity to the presentation below. 

    https://ams.confex.com/ams/94Annual/webprogram/Paper235210.html

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    2 hours ago, chubbs said:

    July often reverses the June 500 mb tendency in the arctic with 2009+2015 being recent high height years in July and 2010+2012 relatively low.

     

     After record breaking -AO and KB block last fall, the PV has mostly been in charge. While we had some transient Arctic blocking episodes, but the PV quickly makes a return.

     

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    DJ.png.8bc833de461d8025de3369ca09eb33e5.png

     

     

     

     

     

     

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    44 minutes ago, chubbs said:

    Hopefully not the sun.

    SolarIrrad+Sunspots.png

    It's funny how the pattern reversed right after the paper was published.

    http://onlinelibrary.wiley.com/store/10.1029/2012GL053268/asset/grl29604.pdf;jsessionid=F7950891CB18B3DB5580C02EC912A4A1.f01t03?v=1&t=j4ppf2qo&s=29436c163ab48e25e8f4989445de41091a8d6ccd&systemMessage=Wiley+Online+Library+'Journal+Subscribe+%2F+Renew'+page+will+be+down+on+Wednesday+05th+July+starting+at+08.00+EDT+%2F+13.00+BST+%2F+17.30+IST+for+up+to+75+minutes+due+to+essential+maintenance.

    Thus we can say that a six year run of near one standard deviation negative excursions (2007–2012) is unique in the 63 year record. To further test the significance of the 2007–2012 AD patterns we randomly generated 10,000 time series, each with 63 points to match the observed time series and with a normal distribution without autocorrelation. For this simple calculation, the chance for having five consecutive values with a negative AD of magnitude greater than 1.0 standard deviation units in a sample size of 63 is rare, less than 1 in a 1000.

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    26 minutes ago, chubbs said:

    Interesting charts. Highlights the difficulty in predicting sea ice, particularly a record low, with any lead time. Note though that the trend in 925 mb temps is upward so the dice are slowly being loaded.

    While the overall annual temperature  trend is an unmistakable up, it would be interesting to know what changed after the 2012 summer. To get a 6 year historic stretch of dipole patterns during the summer and then a reversal is pretty extreme 500 mb behavior.

     

    T.png.77ae7ed95d4e8f6394503425e47337db.png

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    17 hours ago, ORH_wxman said:

    Also, probably one of the more underrated events during the whole decline of sea ice in the past decade-plus is the winter of 2007-2008. 2007 might not have been a complete game-changer had the 2007-2008 winter not exported a ton of that compacted multiyear ice. While the summer of '07 melted out a lot of volume, even more was exported the following winter...the '07 summer pushed/compacted all the MYI leftover from the 2006 season (and previous seasons) toward Greenland/CAA and then a really hostile winter/spring pattern proceeded to export a lot of that ice...expediting the transition from a lot of MYI to mostly FYI.

    June officially continues the post 2012 pattern of a more active polar vortex and cooler temps.You can see the long range ensembles continuing this general pattern right into July.

     

    500.png.eeb436b37b8d01915aad209c1ea40eb9.png

    temp.png.decfb7d2f7a4c60d22bb96f784eb8e83.png

     

     

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    15 minutes ago, ORH_wxman said:

    2012 and 2011 were fairly different in volume by September though, 2012 was clearly lower...they were close in July. A much better example IMHO would be 2007...it had a much higher September volume than years like 2013 and barely lower than 2009...yet it had one of the lowest extents/areas at the minimum due to the extreme compaction (caused by the weather)....way lower than 2009/2013.

    You are right. That was probably the better example of Volume vs extent divergence. 2007 was the year of the mega dipole. Remarkable how a version of the summer pattern repeated much of the time until 2012 and then abruptly reversed.

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    21 hours ago, csnavywx said:

    PIOMAS actually stayed slightly below 2012 -- or a statistical tie, so it definitely hasn't lost much ground over the past 2 weeks. Most of the gap closing occurred early in the month.  Current anomaly is the lowest on record. As far as the state of the pack is concerned -- it's definitely weaker on the Pacific and ESS-Laptev front and definitely stronger on the Atlantic/Kara side.

    The dipole shuts down after D5 (as far as the OP runs are concerned) and a cool PV pattern is dominant on the ensembles. This year has waffled rapidly back and forth, so we'll see if that continues.

    It's interesting how big a difference the extents can vary with similar volume depending on weather conditions. We saw the divergence between 11 and 12 extents on similar volume due to the much more hostile weather pattern in 12.

     

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    1 minute ago, forkyfork said:

    it says a lot about the state of the ice that mundane melt weather could still bring a top 5 low finish

    IMHO the 2005-2007 period pretty much reset the whole Arctic background state. Arctic amplification really took off at that time when the September avg extents started regularly falling below 6 million sq km on NSIDC. We didn't even need a 2012 record minimum the last few years to set the extreme Arctic warmth records. 

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    50 minutes ago, ORH_wxman said:

    There's actually a pretty good dipole pattern that gets going later this week, but it doesn't look like it will last more than a few days....but I also recall that July 2015 didn't initially look like it was going to last, but it was able to for most of the month. We'll have to see.

    We would need a solid dipole pattern to lock in to have a chance of challenging 2012. Otherwise, it's going to be another year that the 2012 record holds.  Seems like the really extreme Arctic conditions for the most part since 2012 have been during the winters instead of the summers from 2007-2012. 

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    21 minutes ago, ORH_wxman said:

    The rapid regression of PIOMAS seems to suggest that it might have been a little low in May versus reality. Hard to say for sure. We'll see what it does in the next couple weeks.

    If this cooler pattern continues, then it might not really matter if we know the exact volume for sure. 2012 and 2011 weren't all that different on volume in August and September. But the 2012 record warmth with the weather pattern made all the difference between the two extent finishes in September. This June is continuing the post 2012 stronger polar vortex pattern vs the 2007-2012 raging dipole regime. We would need a July 2015 rapid reversal to really accelerate the melt. But that kind of reversal isn't showing up in the longer range guidance as of yet. Even Greenland is enjoying a below average melt compared to recent years.

     

    meanT_2017.png.a6c1ae747e6eb03cd4240cf19b8eddae.png

    greenland_melt_area_plot_tmb.png.3183d07f87ae91683e972202d23f3afc.png

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    More uncertainty about the actual thickness this year due to the divergence between PIOMAS and CryoSat. NSIDC mentioned it in a recent discussion.

    Data from the European Space Agency’s CryoSat-2 satellite indicate that this winter’s ice cover may be only slightly thinner than that observed at this time of year for the past four years. However, an ice-ocean model at the University of Washington (PIOMAS) that incorporates observed weather conditions suggests the volume of ice in the Arctic is unusually low.

    6a0133f03a1e37970b01bb09818900970d-800wi.png.850e4402699ef754c6811c09204a1509.png

     

     

    Arctic Sea Ice Extent, Area, and Volume

    in Climate Change

    Posted

    1 hour ago, csnavywx said:

    Yeah, the EPS is now pretty adamant that just about the entire basin goes cold. I'm beginning to think the current +PDO/warm ENSO stretch is inhibiting any lengthy dipole development. There have been a couple of papers hinting at this outcome recently. You had one a couple years back relating to this issue as well, I believe?

    Yeah, the flip occurred right around the record breaking March 2013 -3.185 AO. That's when the dominant blocking shifted from the Atlantic to Pacific sector. The +PDO recently set a record breaking 40 positive months in a row.Must be related to AGW, Arctic, tropics, Atlantic, Pacific ,and rossby wave linkages.

    A.png.3e33b33d909e316d1981d9afc5d9980b.png

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    Record Number Of Top 10 Warmest Months Since 2010

    in New York City Metro

    Posted

    Month...Year...Station...Rank

    3...2010...EWR...7...NYC...6...LGA...5...JFK...4...BDR...2...ISP...3

    4...2010...EWR...1...NYC...1...LGA...1...JFK...1...BDR...2...ISP...2

    5...2010...EWR...4...LGA...5...JFK....4...BDR...4...BDR...4...ISP...5

    6...2010...EWR...2...NYC...4...LGA...2...JFK...1...BDR...2...ISP...1

    7...2010...EWR...3...NYC...2...LGA...1...JFK...1...BDR...3...ISP...2

    8...2010...EWR...10...LGA...8...BDR...10

    9...2010...EWR...5...LGA...6...JFK...7...BDR...7...ISP...7

    ...............................................................................................

    4...2011...EWR...10

    6...2011...EWR...9

    7...2011...EWR...1...NYC...5...LGA...10...JFK...2...BDR...4...ISP...3

    9...2011...EWR...7..LGA...10...BDR...4....ISP...4

    11..2011..EWR..5...NYC...6...LGA...6...JFK...5...BDR...3...ISP...4

    12..2011..EWR...5...NYC...5..LGA...5....JFK...7...BDR...3...ISP...6

    ................................................................................................

    1...2012...BDR...8...ISP...7

    2...2012...EWR...3...NYC...2...LGA...2...JFK...1...BDR...1...ISP...2

    3...2012...EWR...1...NYC...2...LGA...1...JFK...1...BDR...1...ISP...2

    4...2012...LGA....4...JFK...4...BDR...3...ISP....4

    5...2012...EWR...7...JFK...3...BDR...3...ISP...3

    7...2012...EWR...5...JFK...6...BDR...7...ISP...7

    12..2012..EWR..10...LGA..8..JFK...10...BDR...7...ISP...5

    ................................................................................................

    7...2013...EWR...5...NYC...8...LGA...3...JFK...3...BDR...1...ISP...2

    ................................................................................................

    12..2014..BDR...10...ISP...9

    .................................................................................................

    5...2015...EWR...2...NYC...2...LGA...3...JFK...2...BDR...2...ISP...3

    8...2015...EWR...7....NYC...4...LGA...4...JFK...2...BDR...3...ISP...4

    9...2015...EWR...3...NYC...1...LGA...2...JFK...1....BDR...1...ISP...1

    11..2015..EWR...1...NYC...1...LGA...3...JFK...2...BDR...4...ISP...1

    12..2015...EWR..1...NYC...1...LGA...1...JFK...1...BDR...1...ISP...1

    .................................................................................................

    3...2016...EWR...3...NYC...4...LGA...3...JFK...3...BDR...3...ISP...2

    7...2016...EWR...9...LGA...4...JFK....5...BDR...5...ISP...5

    8...2016...EWR...2...NYC...3...LGA...1...JFK...1...BDR...1...ISP...2

    9...2016...EWR...3...NYC...5...LGA...3...JFK...5...BDR...2...ISP...5

    10..2016..BDR..9...ISP...8

    11..2016..EWR..9...LGA...5...JFK...7...BDR...10

    ...............................................................................................

    1...2017...EWR...10...LGA...6...JFK...6...BDR...1...ISP...6

    2...2017...EWR...1....NYC...2...LGA...1...JFK...1....BDR...2...ISP...3

    4...2017...EWR...4...NYC...2...LGA...2....JFK...2...BDR....2...ISP...1

    9...2017...EWR..10..LGA...8...JFK...7....BDR...8...ISP...4

    10..2017..EWR...1..NYC..1....LGA...1....JFK...2...BDR..1...ISP...1

    .....................................................................................................

    2...2018...EWR...2....NYC...1...LGA....2....JFK...3....BDR...3.....ISP....1

    5...2018...EWR...6....NYC...6...LGA....2....JFK...5....BDR...4.....ISP....4

    8...2018...EWR...5....NYC...9...LGA....2....JFK...5...BDR....2.....ISP....4

    9..2018....EWR...7....LGA...6...JFK.....8....BDR..6...ISP.....3

    ......................................................................................................

    4.....2019....EWR...10...NYC...8...LGA...10...JFK...10...BDR...9.....ISP...5

    7.....2019....EWR...7.....NYC..10...LGA...3....JFK....4....BDR...3.....ISP...2

    9.....2019....LGA...8

    10...2019....EWR...9...ISP...#7

    ....................................................................................................................

    1....2020...EWR...9...NYC...9...LGA....7...JFK...6...BDR...3....ISP...6

    2....2020...EWR...6...NYC...6...LGA....8...JFK...4...BDR...5....ISP...3

    3....2020...EWR...7...NYC...8...LGA....5....JFK...5...BDR...3...ISP...5

    6....2020...EWR..10..LGA...3...BDR...5.....ISP....5

    7....2020...EWR...5...NYC...7...LGA...1.....JFK...4...BDR....1...ISP....4

    8....2020...EWR...10..LGA...5...BDR...3...ISP....6

    11..2020...EWR....4...NYC...1....LGA....1...JFK...4...BDR...5....ISP....4

    .................................................................................................................

    3....2021...LGA.....9....JFK....10.....BDR....8

    6….2021….EWR…..2…..NYC….6……LGA……5…..BDR….ISP…..6

    8….2021….EWR…..2…..LGA…..6…..JFK……10…..BDR….3…..ISP….5

    9…2021…..EWR…..4…..LGA…..7…..JFK……7……..BDR…..5….ISP….4

    10..2021….EWR…..1…..NYC…..6…..LGA….3……..JFK……3….BDR…..3…..ISP….2

    ………………………………………………………………………………………………………………….
     

    7…..2022……EWR…..#2….LGA…..#6….JFK….#4…..BDR…#10….ISP….#7

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