17 hours ago, csnavywx said:

Yeah, pretty remarkable warming in that region.

 

Also see:

 

https://www.ncbi.nlm.nih.gov/pubmed/28386025

 

 

I'm trying to dig up some of the figures from that, but if I recall (from reading it earlier in the year) the shoaling magnitudes were pretty remarkable. On average, the water layer had shoaled halfway to the surface on the order of a decade or so and is steadily progressing eastward. It was part of the reason (along with the warm weather) why it took so long for that ice to freeze up last fall/winter.

Still looks like the paper is behind a paywall. But phys.org posted some of the key findings.

https://phys.org/news/2017-04-eastern-arctic-ocean-atlantification.html

(Phys.org)—An international team of researchers has found that the eastern part of the Arctic Ocean is undergoing what they describe as "Atlantification"—in which the ocean is becoming more like the Atlantic Ocean. In their paper published in the journal Science, the group describes how they tracked ocean temperatures over a 15-year period and the changes they found.

The Arctic Ocean has traditionally been different from the Atlantic or Pacific in a fundamental way—the water gets warmer as you go deeper (due to inflows from the Atlantic) rather than the other way around, as happens with the other two. But now, the researchers with this new effort have found that may be changing. They have been using tethered moorings to record ocean temperatures at different depths for approximately 15 years and have found that changes have taken place—sea ice is melting from below, not just from above due to warmer air temperatures.

In studying the data from the moorings, the researchers found that warm water from the Atlantic, which has traditionally been separated from melting ice because of the halocline layer—a barrier that exists between deep salty water and fresher water closer to the surface—has been penetrating the barrier, allowing ice to melt from below. It has also led to the water becoming less stratified, like the Atlantic. They describe the changes as a "massive shift" in the ocean that has occurred over an extremely short time frame. These new findings may explain why the extent of ice coverage has been shrinking so dramatically—at a rate of 13 percent per decade.

The result, the researchers report, is a feedback loop—as more ice melts due to warmer air, more vertical mixing occurs, allowing warmer water to move upwards, which causes melting from below. They also acknowledge that it is not yet clear what impact the change might have, but suggest it is likely to be substantial—from the biogeochemical to geophysical levels, basic components of the ocean will likely be altered, causing changes such as phytoplankton blooms in places where they have never been seen before. They also note that there is another factor to consider—the massive amounts of fresh water pouring into the ocean from rivers in Siberia as permafrost thaws.

11 hours ago, wxeyeNH said:

As a total side note when Gmail started I took out the name herbertsbox.  So my email address is [email protected]   After signing up I realized it should be  herbertbox not  herbertsbox.  People always ask me what herbertsbox means.  No one knows but a true tropcial weenie like me...  Okay, back to Maria....

Just a remarkable amount of intensity and activity in such a short time there. Almost like we are seeing some type of rebound effect after years of of dry air and suppression in that region. So we swing from one extreme to the other.

Gives new meaning to heavy wet snow.

0810 AM     HEAVY SNOW       2 SE MONTANA CITY       46.52N 111.90W
09/16/2017  M15.0 INCH       JEFFERSON          MT   TRAINED SPOTTER

            POWER IS OUT. LOST PART OF CHERRY TREE DO TO THE WEIGHT
            OF THE SNOW. 2.21 INCHES OF LIQUID EQUIVALENT

Looks like the first time in the satellite era that 3 hurricanes as intense as Irma, Jose, and Maria passed through the Hebert Box #1 in one month or a complete season.

http://climate.ncsu.edu/climateblog?id=91

1 hour ago, csnavywx said:

While I don't think we'll melt out before 2030, I really think it's unlikely we recover to pre-2007. Part of that is the consistent loss of ice in the Beaufort Gyre region, which has flipped from being a system which recirculates MYI from season to season to a system that effectively destroys it (this year included) due to melt before it can be recirculated. Another is the remarkable amount of shoaling of warmer Atlantic Water (AW) on the Eurasian side of the basin. The forcing from this oceanic input is substantial. These factors alone are enough to prevent a MYI recovery. Without a sustained recovery in MYI, a FYI dominated basin will always be susceptible to summer melt-out, even in somewhat cooler-than-average summers.

The downward trend in April volume (which has a fairly large correlation of about .4-.5 to Sept. volume) has not stopped or slowed down. Unless that changes, this signal will eventually overwhelm any temporary gains due to cooler summer weather in the long run.

Bottom line -- predicting imminent doom or recovery in the pack at this point kinda leaves the predictor as a hostage to fortune.

 

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0693.1

 Extreme warming in the Kara Sea and Barents Sea during the winter period 2000 to 2016

9 minutes ago, ORH_wxman said:

Yeah I'm skeptical we'd get there again...maybe if we got 3 flukish slow melt years and maybe one or two colder winters mixed in we'd see some much higher min...but even then I'm not sure. We had a lot of mulityear ice back then. We'd really need to replenish it over 4-6 years and that isn't easy in the current state. We started to do it after 2012 but we saw most of it get destroyed during the epic July 2015 pattern. 

 

Realistically, I think we would need another Pinatubo eruption to get back around 6 million sq km. We'd prob drop Arctic temps by about 1-2C for a couple years which might be enough for big temporary rebound. 

I am beginning to think that the key number for Arctic amplification was dropping below 6 million sq km. Crossing the technically ice free mark below 1 million sq km sometime in the future may not even be that significant an event.

31 minutes ago, nzucker said:

If we have a relatively -AO winter with limited Fram export, and another cold PV dominant summer following this relatively benign melt year (6th to 8th lowest extent), then we may have a chance to get back to pre-2007 conditions. It definitely appears the ice pack has stabilized somewhat.

And yes, Friv disappeared when the big melt years ceased. Interesting to see the bias of different posters on here.

It would probably take an extraordinary circumstance to ever see a September minimum extent above 6 million sq km after the damage that was done to the ice during the 2007-2012 era.

Tough to beat the 2012  extent record with such a strong summer polar vortex pattern since then. But 2007 will probably go down in history as the year that the Arctic permanently shifted to this warmer state with reduced sea ice. Even recent numerous more favorable summers haven't allowed  the sea ice recover to pre 2007 levels. Our best year now is still lower than anything that came before 2005-2007.

Coming up on the 7th anniversary. Just turn down those speakers.

1 hour ago, dWave said:

I was waiting for the Bronx one. It'll be interesting to compare to. I'm on the other side of the NYBG, just under 2 miles SE of Lehman. 

It will be great to get the rainfall and wind measurements which have been lacking for the Bronx.

New rooftop mesonet site for the Bronx. It's 189 feet up so the temps will be different than the surface. 

http://www.nysmesonet.org/mesonow#?stid=BRON

I got a chance to watch the new jetty building operation the other day when I was down in Long Beach. Pretty impressive job at beaches like Neptune where all the boulders are piled up on the beach by a stream of trucks. The beaches especially on the east sides of the new jetties have really gotten longer. It's becoming more of a walk from the boardwalk to the ocean than it used to be as the longshore current piles up the sand against the new jetties.

Typical post 2012 summer with stronger polar vortex conditions preventing a challenge to the 2012 record minimum extent. This summer was right down the middle between 2013-2014 and 2015-2016.

Update from NSIDC:

https://nsidc.org/arcticseaicenews/

Ice retreat from August 1 to August 21 averaged 73,000 square kilometers (28,000 square miles) per day. This was faster than the 1981 to 2010 average rates of ice loss of 57,300 square kilometers (22,000 square miles) per day, but slower than in 2012, which exhibited the fastest rate of ice loss compared to any other August in the passive microwave satellite data record. Normally the rate of ice retreat slows in August as the sun starts to dip lower in the sky. The rate of ice loss was more rapid at the beginning of August, slowing down considerably starting on August 17.

Air temperatures the first two weeks of August were 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit) cooler than the 1981 to 2010 average throughout the Arctic Ocean and over Greenland and the North Atlantic. The lowest air temperatures relative to the long-term average were found in coastal regions of the Kara and Barents Seas, continuing the pattern seen throughout much of this summer. Cooler than average conditions within the Central Arctic were a result of persistent cold-core cyclones. These cyclones have not been as large or as strong as the Great Arctic Cyclones of 2012 and 2016, despite the central pressure of one of these systems dropping down to 974 hPa on August 10. In addition, these cyclones are located closer towards the pole within the consolidated ice pack, where they are less likely to cause significant ice loss, as did the 2012 Great Arctic Cyclone in the Chukchi Sea.

While air temperatures start to drop in August, ice melt continues through the month as heat gained in the ocean mixed layer during summer continues to melt the ice from below and from the sides. Sea surface temperatures have been up to 5 degrees Celsius (9 degrees Fahrenheit) above average near the coastal regions, but generally near average or slightly below average along the ice edge in the Beaufort and Chukchi Seas

7 hours ago, PhillipS said:

Apologies if I'm splitting hairs, Bluewave, but August didn't see an increase in Arctic SIV, it saw a decrease in the anomaly.  Arctic SIV continued to drop, albeit at a slower rate.  

 

No problem. We may be able to further decline the anomaly if we can avoid the historic warmth that we saw last Oct-Dec. That may set the volume up to come into next summer a little better than we saw this year. The state of the sea ice next summer will then come down whether the less hostile 2013-2017 stronger polar vortex pattern can prevail another year. Or the 2007-2012 dipole pattern makes a return. Be interesting to see how many more years the 2012 can hold on. The reversal of the summer pattern in 2013 turned out to be a surprise that people didn't think was possible during the fall of 2012. But some studies came out in early 2013 that mentioned this possibility. Long term sea ice decline with increases or decreases in the short term rate.

One of the greatest early August anomaly decreases on the PIOMAS with the cool and stormy pattern in the Arctic. Also among the strongest polar vortex patterns for the first half of August.  

15 hours ago, chubbs said:

This year has been cool like 2013 so the volume and extent data are not inconsistent.

 

Much cooler summer regime since 2013 with low pressure dominating instead of high pressure.

Likely quite a bit of snow has fallen from this Arctic cyclone... Wish the polar bears could report obs [Map: esrl.noaa.gov/psd/people/amy…]pic.twitter.com/nrL6U5LplZ

1 hour ago, ORH_wxman said:

Yeah it's actually a pretty compact ice pack right now. I think the cyclone perhaps has just slowed the peripheral melting. 

Though bluewave is correct that typically cyclones over the CAB try and disperse the ice. But the concentration hasn't suffered even if it is doing that. 

Yeah, the record August 2012 storm seemed to be the exception to the rule. 

http://nsidc.org/arcticseaicenews/2012/08/a-summer-storm-in-the-arctic/

Low pressure systems over the Arctic Ocean tend to cause the ice to diverge or spread out and cover a larger area. These storms often bring cool conditions and even snowfall. In contrast, high pressure systems over the Arctic cause the sea ice to converge. Summers dominated by low pressure systems over the central Arctic Ocean tend to end up with greater ice extent than summers dominated by high pressure systems.

However, the effects of an individual strong storm, like that observed in early August, can be complex. While much of the region influenced by the August cyclone experienced a sudden drop in temperature, areas influenced by winds from the south experienced a rise in temperature. Coincident with the storm, a large area of low concentration ice in the East Siberian Sea (concentrations typically below 50%) rapidly melted out. On three consecutive days (August 7, 8, and 9), sea ice extent dropped by nearly 200,000 square kilometers (77,220 square miles). This could be due to mechanical break up of the ice and increased melting by strong winds and wave action during the storm. However, it may be simply a coincidence of timing, given that the low concentration ice in the region was already poised to rapidly melt out.

1 hour ago, chubbs said:

This year's low volume/high NSIDC area status is unusual. Looks like the mild winter is having some impact but is a weaker factor than a slow start to the Arctic Ocean melt season.

There may also be a higher degree of uncertainty in the PIOMAS data compared to other years. But we saw how the the PIOMAS and NSIDC extent widely diverged in 2013 compared to the 2007 season. Lower PIOMAS in 2013 vs 2007,but the cool 2013 summer resulted in a much higher higher September extent than 2007.

http://nsidc.org/arcticseaicenews/2017/03/

It was a very warm autumn and winter. Air temperatures at the 925 hPa level (about 2,500 feet above sea level) over the five months spanning October 2016 through February 2017 were more than 2.5 degrees Celsius (4.5 degrees Fahrenheit) above average over the entire Arctic Ocean, and greater than 5 degrees Celsius (9 degrees Fahrenheit) above average over large parts of the northern Chukchi and Barents Seas. These overall warm conditions were punctuated by a series of extreme heat waves over the Arctic Ocean.

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.

So far it looks like the Arctic storm has slightly slowed the decline rate as the pack appears to be spreading out a bit. The storm has brought an early freeze for the post 2005 Arctic. Right now the extent is tracking between 2007 and 2016 as 2012 pulls further out of reach. 

There has traditionally been a relationship between Arctic sea ice and the AMO as we have seen with the decline in the 20's and 30's. More specifically, the region south of Greenland seems to have the largest influence on September minimum extent. When those SST's were at their warmest from 2005 -2012, there were three new records set in 2005, 2007, and 2012. The reversal to cooler SST's in this region since 2013 has been accompanied by no new September extent records. You can see the 2005-2012 rate of decline was in a class by itself with nothing else coming close. While that area south of Greenland has cooled dramatically in recent years, the AMO has still remained positive.

Recent cooler temps and stronger polar vortex let 2017 fall a little behind 2007 over the last few days.

Early dip near freezing with the strong polar vortex similar to 2014 and 2013.

12 minutes ago, ORH_wxman said:

The cold pool in the North Atlantic also really expanded and intensified in 2013 which was right after the huge Greenland melt in 2012...so I wonder if that was at least partially related. 

It could also be related to why the Siberian October snow signal hasn't worked in recent winters with the stronger PV and more +AO/+NAO.

14 hours ago, WidreMann said:

I would trust the dynamical more than the statistical, because we are in uncharted territory here. Even so, it looks like the median of those models would still be above 2012.

We missed our chance to beat 2012  when the strong dipole pattern of 2007-2012 failed to emerge in June. So the 2012 extent record will remain safe another year. The HadGem model did a great job back in 2012 showing a slower rate of loss vs the extreme 2005-2012 loss rate.

I am wondering if the dramatic dipole reversal following the historic 2007-2012 rapid melt seasons is a result of the weaker AMOC?

http://nsidc.org/arcticseaicenews/

In the far northern Atlantic, warm water flowing northward from the tropics is cooled by the atmosphere, becomes denser, and eventually sinks to great depths. The descending water is key in driving a sub-surface and surface ocean circulation system called the Atlantic Meridional Overturning Circulation (AMOC), which is part of the global ocean conveyor belt of heat and salinity. Where the Atlantic water sinks has a very important effect on the climate of Northern Europe; the heat that the ocean loses to the atmosphere is what keeps Northern Europe quite warm relative to its latitude. For example, Amsterdam is at the same latitude as Winnipeg, Canada, but experiences much warmer winters.

Based on a recent modeling study, Florian Sévellec and colleagues propose that the ongoing loss of Arctic sea ice may disrupt the AMOC. The sea ice loss leads to a freshening of the northern North Atlantic and stronger heat absorption at the surface. This means that waters in the northern North Atlantic are less dense than they used to be, which has the effect of providing a cap, or lid, that may inhibit the northward flow of warm waters at the surface and the eventual sinking of these waters. The authors suggest that the Arctic sea ice decline may help to explain observations suggesting that the AMOC may be slowing down, and why there is a regional minimum in warming (sometimes called the Warming Hole) over the subpolar North Atlantic.