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When will 2020 JAXA extent cross 2012?

Sept. 21-25
1 (2.9%)
Sept. 26-30
3 (8.6%)
Oct. 1-5
5 (14.3%)
Oct. 6-10
10 (28.6%)
After Oct. 10
15 (42.9%)
Not in 2020
1 (2.9%)

Total Members Voted: 32

Voting closed: September 20, 2020, 03:19:39 AM

Author Topic: When will 2020 JAXA extent cross 2012?  (Read 2314 times)

wdmn

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When will 2020 JAXA extent cross 2012?
« on: September 15, 2020, 03:19:39 AM »
How fast will refreeze start this year? When will JAXA extent for 2020 cross with 2012?


oren

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Re: When will 2020 JAXA extent cross 2012?
« Reply #1 on: September 15, 2020, 04:41:24 AM »
I suggest to add another option:
Will not cross by Dec 31st.

Though personally I think a Oct-Dec cross has good probability.

Tom_Mazanec

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Re: When will 2020 JAXA extent cross 2012?
« Reply #2 on: September 15, 2020, 01:09:38 PM »
I took Oct 6-10, eyeballing the lines.

Stephan

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Re: When will 2020 JAXA extent cross 2012?
« Reply #3 on: September 15, 2020, 08:33:39 PM »
I subracted 0.45 M kmĀ² from the 2019 extent and this line crosses the 2012 path on October 10, 2020. I think the refreeze will be delayed this year (as it was 2019) because of all the warm water masses around the actual ice edge. Therefore 2020 should roughly follow 2019, but at a slightly lower level.
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Positive retroaction

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Re: When will 2020 JAXA extent cross 2012?
« Reply #4 on: September 16, 2020, 02:14:48 AM »
From 6 to 10 october for me, because the laptev and ESS anomaly is really high
The freeze may start as in 2012 but quickly be slowed down and the 400,000 km 2 higher than 2012 could be lost
But it might be after October 10
Sorry, excuse my bad english

Paddy

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Re: When will 2020 JAXA extent cross 2012?
« Reply #5 on: September 16, 2020, 07:20:40 AM »
I've gone for "after Oct 10th", but really, any time in October seems plausible. Partly I went with this because it covers such a wide expanse of time.
« Last Edit: September 16, 2020, 08:56:17 PM by Paddy »

gerontocrat

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Re: When will 2020 JAXA extent cross 2012?
« Reply #6 on: September 16, 2020, 03:27:18 PM »
Here are a couple of graphs to enlighten / confuse the issue (delete as applicable).

As you can see, on Oct 13, as 2019 extent gain had slowed and 2012 extent gain had increased, 2109 become lowest,

And on Oct 27, as 2019 extent gain had suddenly increased while 2016 extent gain remained low, 2016 became lowest.

With all that ocean heat, apparently well beow the surface SSTs, a slow 2020 extent gain would look likely, but the last 2 days JAXA extent gains contradict that.
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Paddy

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Re: When will 2020 JAXA extent cross 2012?
« Reply #7 on: October 09, 2020, 02:36:06 PM »
Looks very likely to happen around October 9th to 11th at the moment. This one is coming down to the wire.

wdmn

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Re: When will 2020 JAXA extent cross 2012?
« Reply #8 on: October 11, 2020, 05:52:06 AM »
I could have designed this poll a bit better, but, as Paddy said, it came down to the wire.

JAXA extent on Oct. 10 is 4,547,527 km2, just 31,388 km2 more than 2012 for the date (4,516,139 km2).

A large gain on the 11th for 2012 all but guarantees the change between 1st and 2nd will happen on the 11th.

Congratulations to all who voted "after Oct. 10th."

wdmn

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Re: When will 2020 JAXA extent cross 2012?
« Reply #9 on: October 12, 2020, 06:52:09 AM »
Might as well make it official.

2020 crossed 2012 on Oct. 11, reaching 4,636,863 km2, 44,972 km2 lower than 2012.

I want to say those who voted Oct 6-10 were "right in spirit, if not in the letter."   ::)

Tom_Mazanec

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Re: When will 2020 JAXA extent cross 2012?
« Reply #10 on: October 12, 2020, 11:29:33 AM »
Well, I almost voted for after Oct 10 myself, but went with the earlier one.