My intuition says september minimum will be some 90%...105% of 2012's. I made this prediction yesterday elsewhere.
Interestingly, this nearly matches two answers of this poll taken together - because 90%...105% of 2012's september minimum equals 3,249...3,79 (assuming 3.61 for 2012). Since i can't vote for two answers here, though, i picked 3,25...3,5 one.
Interestingly, i am the 1st person to do so, in this poll.
Now, about why i think it'll be roughly 3,25...3,8 (apart from intuition, that is), based on my message which i made elsewhere yesterday.
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So i now think we'll indeed see "extremely fast ice melt later in August and in September". In part, both the current halt and the incoming extreme melt (which i predict here) - are and will be real; but, in other part, it's just a quirk of reporting systems. Quirk which is significant enough to explain in a bit of detail.
I mean, if, now, some relatively large areas of, say, 30%...50% ice concentration are reported as "ice covered", and then, if just 1/3 of _really_ existing ice surfaces in such areas melt away, - then any system which reports 30%-or-higher-ice-concentrations as "ice covered" - will "suddenly" report dramatic reduction of ice cover in such areas. Math for this is simple:
- minus-one-third to 30%...50% - equals 20%...33.3% remaining ice concentration, and then only a QUARTER of such areas will remain above 30% of sea ice concentration:
- 33.3% - 30% = 3.33% is the part which is above 30%,
- 33.3% - 20% = 13.3% is the whole thing,
- so 3.33% / 13.3% = 0.25 = 25%, i.e. one quarter remains above 30% ice concentration - the other 75% "suddenly" start to be said "no ice cover".
So, in this particular example, the process of melting of 33% of initially existing (at some point) _real_ ice surface - results in the loss of 75% of _reported_ ice cover. Impressive quirk, eh? *
* again, this is not about all ice area/extent monitoring systems, but only about those which assume 30% sea ice concentration still being "ice covered", and anything less - not being "ice covered"; however, same logic applies much to most systems, as there usually still is some lower limit below which pieces of the ocean "start" to be considered ice-free - for some it's 15% ice concentration, for some 25%, for some 30%, etc.
So, relatively small _real_ further ice loss can result in massive _reported_ ice extent (area) loss.
When and why can this happen? Obviously, when Arctic has large areas which at some point are having "just slightly above minimum ice concentrations to be reported as ice-covered". As for "why", i suspect that that massive cyclone which happened in late July spred alot of ice to a larger area, thus indeed creating large areas which have much-lower-than-100%-ice-concentration areas, which for _now_ are still being reported as "ice covered", thus creating conditions for above described "quirk" of reporting systems to become seriously significant.
I also have a guess why this sort of thing didn't happen before - not at such a dramatic scale, that is. I mean such a definite and long (~11 days) _halt_ of the process of early-august ice area declining, reported by some systems, such as Cryosphere Today.
Until quite few last years (~10), Arctic had much more ice during this time of the year; and in many places - for many thousands kilometers, - ice fields were actually still in contact with land (Eurasia and North America continental shores). The land prevents sea ice from spreading out, if there are air and/or ocean currents pushing it - and massive cyclones have very powerful air currents which do just that, especially for ice fields which are already below 100% concentration (created surface water waves and pushing, "sailing" ice packs a bit). So, in the past, with more land in contact with larger perimeters of ice fields, there were more cases of shores holding much of the ice, which occasional late-july cyclone was trying to "veer away". And in such "collision course" with lands, ice packs were opposing their own melt by getting pressed into higher ice concentrations, too.
Nowadays, with much more open water near polar shores, and large areas of open water next to them, late July / early August large-scale cyclone have much more free water to drive remaining ice fields to. And, when there is no land mass for ice packs to "stop" at, there is also no "putting ice together into close to 100% concentration" force - ice packs continue to "sail" open waters under strong cyclone's winds while still being much like "swiss cheese", i.e. having way lower than 100% ice concentration. Which, i guess, just happened (during last two weeks) on unprecedentally large scale. And to which existing systems of reporting sea ice area/extent are not exactly prepared for, it seems - the "quirk" i described above is probably not the only possible difficulty.
One might ask why this sort of _reported_ halt in early-august Arctic sea ice melting process - 10+ days of pretty much stable total sea ice area/extent, - did not happen during last few years, when there was much open water, late July, near Arctic shores. Well, i guess it was because no truly large cyclones which were pressing ice packs into large bodies of open water were developed in the Arctic at this particular time of the year - late July.
And, by the way, i believe that it's indeed late July when large-scale ice fields are already weakened much by summer melt, and can be readily separated on a large scale by cyclones, if pushed to large open water areas; but in the same time these ice fields are often still thick enough and large enough to not disappear right away under cyclonic conditions, - similar cyclone in late August would produce much more quick "result" in terms of additional and readily observable reduction of reported ice cover.
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All the above is an opinion of an amateur (me), which may be wrong in some parts (hopefully not entirely, though!
). I am happy to stand corrected, if/when i'd be wrong somewhere. Please do point out any mistakes you could see, but please do bring sound, rational arguments while doing so. Thanks!
P.S. While i predict september minimum ice extent near or slightly below 2012's, i also expect this year minimum ice volume to stay significantly above 2012 september minimum in the same time. We'll see.
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