BTV - Could do a version of the bar chart to show change from Sept Minimum to Minimum?
That would visualize the stats posted by Oren showing what an absolute beast 2007 was.
I think this is what you're after.
Thanks BFTV, uber Nice! That is even more informative than I expected. I was looking to see a visual representation of the strong melt year from Sept 2006 to Sept 2007 - which the chart definitely demonstrates. But it shows a lot more than that. One bonus is seeing just how dynamic Arctic sea ice change is from year to year.
The chart highlights some other major change years: 1990, 1993, and of course our favorite 2012. On the other side of the coin, it shows 2013 as a large rebound year.
Going out on a limb, I think the chart reflects the fact that 2007 was a "deep" melt year
, whereas 2012 was kind of a superficial melt year in that much of the melt was due to the release of subsurface ocean heat by the GAC 2012 that caused late summer melt, but the loss of that heat also contributed to the large rebound in 2013.
Pushing my ignorance one more step, I think that the chart shows that 2019, while a 2nd place (at the time) finisher to 2012, was more a "deep" melt year, i.e. the real deal, not some flash in the pan caused by a temporary cyclone stirring up the waters.
And finally, I expect that 2020 was another "deep" melt year. Yes the July cyclone in the Beaufort was a significant nudge, but it was not the driving factor behind the total melt, and did not release that heat bomb that lies at depth in the Beaufort Sea. When that heat eventually is released, it will be an ice Armageddon -- for a while at least. Such an event would likely be followed by a rebound year just like 2013 followed 2012. Then again, with the ASI getting weaker from year to year, such a body blow could push it over the edge into a new equlibrium from which it cannot recover even with relatively mild melt weather in the subsequent year(s).
If we look at each year as the first of a two-year pair to factor in the reboud effect, then 2007 really stands out as not only the biggest melt year, but a big melt year without a recovery the following year. While 2019 was an intermediate melt year, it is one of only three (the others being 1997-1998, and 2007-2008) with two melt years in succession. Both members of the 2019-2020 pair were stronger than the 1997-1998 pair. (Worth noting that 97-98 was strong El Nino. As was 2015-2016, which had back to back loss years, but much weaker.)
I suspct that in addtion to the summer weather, the strong 2020 melt in the Laptev (and possibly ESS and Kara as well) this year may reflect the weakening of the thermocline due to Atlantification. If so, it is likely to be a persistent feature from now on, not a single year anomaly.
And ominously, what drove the damage to the CAA-Greenland-North Pole triangle this year, including the north Greenland megacrack? If it was purely a weather issue (which seems very possible) then it is less likely recur next year, though with continued warming such a weather scenario (or one with similar impact) also becomes increasing likely. If the melting in the triangle was due to ocean forces, such as suspected for the Laptev, then it would be more likely to be a regular feature going forward. I can't even guess at that question. But the assault on the Atlantic-side ice edge during August and September 2020 has me suspecting that Atlantification contributed at least partically to the 2020 triangle melt.
All just guesswork. Interested in hearing what other folks think. I just wish this very interesting intellecual exercise was about something other than the disruption of the planetary climate we all depend on. I feel guilty enjoying watching the process unfold (and not the only one with those feelings I'm sure). I tell myself it is important to stay informed. Which is true. But a part of me just likes watching math unfold regardless of the horrendous implications.
I don't think the public really gets it that our entire civilization is built with reliance upon expectation of climatic norms for both levels and variaiblity around those norms, and upon dependable weather patterns like monsoons and other systems that drive agriculture and other endeavors. I hope that ASIF, besides being fun to watch and enjoyable as my first and only on-line community, serves a purpose at raising awarenss. When you vote, just remember: Creep Instability