bluewave

It may also struggle under extreme blocking and dipole regimes like we are seeing this year. Its biggest miss or underestimation of melt from a June forecast was in 2015. July 2015 experienced the strongest blocking and dipole pattern during the 2013 to 2018 era. June 2015 CPOM forecast September average extent......5.10....Verification.......4.63 This was the most impressive piece of information from the statistical model that CPOM uses for their forecasts. The simulated melt pond fraction in June 2019 has been higher then in any June before.

12z Euro has record breaking 500mb heights and surface pressures over the CAB for this time of year.

Numerous 3.00+ amounts with Syosset near the top at 3.94. Syosset 3.94 856 AM 7/23 Co-Op Observer

Here’s a quote from Wipneus on the July 15th PIOMAS update: PIOMAS has updated the gridded thickness data to the 15th of this month. Volume calculated from this was 8.77 [1000km3]. That is the lowest for the day, with quite a margin.

The Arctic experienced a record May and June combination of warmth and high pressure. So we have been seeing steep declines this week even with more favorable conditions than the last few months.

Another big daily drop of 187K puts 2019 into 1st place on 7-19 for NSIDC extent. The early portion of August is when 2012 ran away with the lead during the record Arctic storm. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx 7-18-19....7.267 7-18-11....7.299 7-18-12....7.420 A few papers on the record breaking 2012 season: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/grl.5034 On the 2012 record low Arctic sea ice cover: Combined impact of preconditioning and an August storm https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/grl.50190 The impact of an intense summer cyclone on 2012 Arctic sea ice retreat

Continuing to see steep losses even with more a reverse dipole relative to the last few months. That tells you something about the current condition of the ice pack. NSIDC had a -164 K daily extent drop on July 17th. So very close to 2011 and 2012 on this date. Area losses continue to keep pace with 2012. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx 7-17-19.....7.454 7-17-12.....7.481 7-17-11.....7.444 Last 5 days

Updated for the 3.80 max in Canoe Brook, NJ. CANOE BROOK 3.80 800 AM 7/18 HADS

127K daily drop on NSIDC extent. Continuing to run very close to 2011 and 2012 as of July 15th. The area is around 2012 on this date. 7-15-19....7.676 7-15-12....7.705 7-15-11....7.609

https://mobile.twitter.com/mikarantane/status/1150489505419452417 20.5°C (69°F) only 800 km from the North Pole is something.

No problem. They keep a daily file on their site with the exact numbers. 2019 is still holding an area lead over the other years.

It’s right on the NSIDC site. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx We fell behind 2011 on the 13th. 7-13-11...7.765....#1 7-13-19...7.856....#2 7-13-12...7.917....#3

2019 maintains a narrow lead over 2012 and 2011 as of July 12th. More modest 70k daily drop as the dipole relaxes from near record recent levels. NSIDC extent 7-12-19....7.901 7-12-12....7.946 7-12-11....7.955

Finally got the slowdown in the rate of daily losses as the dipole pattern relaxes a bit. 2019 is holding on to a very small NSIDC extent lead over 2012. Area also very close to 2012. 7-12-19.....7.971 7-12-12.....8.032

Updated for 3.10 in Oakland, NJ. Oakland 3.10 800 PM 7/11 CWOP

5th consecutive NSIDC daily extent drop of 100k or greater. 2019 continues in first place on July 10th ahead of 2012. One of the most impressive weekly drops during the month of July. 7-10-19....7.996 7-10-12....8.130

2019 jumps into the extent lead over 2012 with a major 247k drop as of July 9th. 2019....8.098 2012....8.174

The blocking and high pressure relaxation is coming just as 2019 edges ahead of 2012 for extent. But the thing that separated 2012 from the rest of the pack was the big storm and record late season decline. 2019...8.345 2012...8.398

It will be interesting to see if 2019 can hold the area lead over 2012 if the models are correct about the polar blocking weakening. https://sites.google.com/site/cryospherecomputing/daily-data https://mobile.twitter.com/judah47/status/1147128282225287170

Yeah, probably 6-7 million sq km for September extents. But nothing close to the historic drop in recent times. https://www.carbonbrief.org/guest-post-piecing-together-arctic-sea-ice-history-1850 First, there is no point in the past 150 years where sea ice extent is as small as it has been in recent years. Second, the rate of sea ice retreat in recent years is also unprecedented in the historical record. And, third, the natural fluctuations in sea ice over multiple decades are generally smaller than the year-to-year variability. https://mobile.twitter.com/ZLabe/status/1146506078932230144?ref_src=twsrc^google|twcamp^serp|twgr^tweet New study in @AMSJCLi to model #Arctic sea ice volume since 1901: "The sea ice decline over the 1979-2010 period is pan-Arctic and 6 times larger than the net decline during the 1901-40 period."

The longer reconstructions further back in time make the last 40 years even more exceptional.

Ice has no agenda. It continues melt as the climate warms. The beauty of science is that you don’t have to believe in it for it to work.

2nd lowest June extent with the 2nd warmest Arctic temperatures. https://nsidc.org/arcticseaicenews/2019/07/melt-season-shifts-into-high-gear/ https://sites.uci.edu/zlabe/arctic-temperatures/

2019 continues to remain in the top 3 lowest extents right into early July. 7-2 2019....9.056 2012....8.971 2010....8.943

The record Chukchi SST warming has implications for the entire Arctic. https://www.newscientist.com/article/2178160-a-warm-water-time-bomb-could-spell-disaster-for-arctic-sea-ice/ The Arctic is in hot water, literally, following the discovery that heat has been accumulating rapidly in a salty layer of the Arctic Ocean 50 metres down. Currently, it’s being held at that depth by a less dense layer of freshwater overhead, but if the two layers start to mix it could melt all seasonal sea ice, accelerating the already-rapid loss of polar ice cover. Researchers discovered the heat time-bomb after analysing publicly available data on ice cover, and at different depths on sea temperature, heat content and saltiness over the past three decades. The data was gathered around the Canadian Basin, a major basin of the Arctic Ocean fed by waters from the North Chukchi Sea, just north of the Bering Strait between Alaska and Siberia. Over this timespan, the heat content of the salty layer doubled, from 200 to 400 million joules per square metre, enough to reduce overall Arctic ice thickness by 80 centimetres. The root cause is global warming, which has seen temperatures in the Arctic rise by 2 degrees from pre-industrial levels–twice the global average—leading to record-low sea ice coverage. The researchers found that with sea ice retreating, heat absorption by exposed surface waters has increased fivefold in 30 years, mainly from direct sunlight, which no longer gets reflected by ice. And with no ice in the way, strong northerly winds push these newly-warmed surface waters at the Arctic fringes down to the depths where they’re now accumulating under the Arctic. The fear is that the freshwater “lid” keeping them there could fall apart. “It could be lost through increased mechanical mixing of the water layers, especially driven by the winds,” says Mary-Louise Timmermans at Yale University and head of the team. “With continued sea-ice losses, we’d have more wind-driven mixing, and that would erode this natural barrier,” she says. Loss of a protective “freshwater” layer is already happening elsewhere around the Arctic in the Barents Sea north of Scandinavia, allowing warmer Atlantic waters to flow in and potentially destroy an entire Arctic ecosystem in the North Barents Sea within a decade.