Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

I was monitoring the ice extent every day during September of the years 2003 to 2009. All those years had at least a double minimums. The day of the first minimum in 2002 was 9th September, and it advanced each year by about 1 day until 2008 when the first minimum was the 9th again and the second minimum was 1 day later than the first minimum in 2007, ie on 17/8/2008 and 16/9/2007 repectively. The second minimums also advanced by roughly a day each year, and in 2008 there was a third minimum one day laterthan the 2nd min in 2007.

In 2009 the first min was on 13/9/2009 and the second on 16/09/2009 completely upsetting the pattern :-( I didn't monitor it after that.

This year seems to be an exception with only one minimum, but that may be because they are averaging over five days instead of recording each day.

If you want I can email the values displayed in an Excel spread sheet.

OTOH, here are the values if you want to play with them yourself

2009 2008 2007 2006 2005 2004 2003 2002
08/09/2009 5,330,469 4,715,469 4,413,438 5,935,781 5,642,656 5,839,219 6,103,750 5,649,688
09/09/2009 5,315,938 4,707,813 4,399,531 5,936,094 5,628,281 5,835,313 6,086,406 5,646,875
10/09/2009 5,295,313 4,729,688 4,367,188 5,926,094 5,599,844 5,825,000 6,060,469 5,655,156
11/09/2009 5,278,594 4,751,563 4,343,438 5,896,719 5,581,875 5,784,688 6,041,250 5,674,063
12/09/2009 5,259,375 4,745,156 4,327,969 5,864,219 5,545,000 5,806,719 6,105,625 n/a
13/09/2009 5,249,844 4,742,344 4,323,750 5,814,063 5,506,563 5,854,375 6,180,313 n/a
14/09/2009 5,276,563 4,747,188 4,291,250 5,781,719 5,522,344 5,901,094 6,146,563 n/a
15/09/2009 5,301,094 4,731,875 4,267,813 5,794,063 5,492,500 5,912,188 6,049,844 n/a
16/09/2009 5,291,094 4,726,250 4,267,656 5,806,094 5,447,656 5,882,813 6,041,875 n/a
17/09/2009 5,326,094 4,718,594 4,268,750 5,828,281 5,422,344 5,821,250 6,033,281 n/a
18/09/2009 5,348,438 4,736,406 4,281,406 5,874,063 5,385,156 5,809,688 6,032,031 n/a
19/09/2009 5,358,594 4,745,000 4,296,250 5,892,500 5,368,438 5,808,750 6,088,906 n/a
20/09/2009 5,383,594 4,752,500 4,310,313 5,846,875 5,345,156 5,818,906 6,122,656 n/a
21/09/2009 5,401,875 4,773,750 4,284,531 5,847,656 5,315,625 5,866,719 6,085,469 n/a
22/09/2009 5,432,813 4,809,219 4,276,719 5,851,406 5,315,156 5,925,625 6,047,031 5,985,781
23/09/2009 5,417,031 4,873,125 4,267,344 5,883,281 5,335,156 5,994,688 6,080,469 6,001,563
24/09/2009 5,408,281 4,878,750 4,254,531 5,972,188 5,377,969 6,107,188 6,101,719 6,047,969
25/09/2009 5,439,688 4,873,750 4,265,000 6,036,719 5,407,656 6,169,531 6,137,031 6,075,000
26/09/2009 5,480,781 4,945,313 4,297,813 6,039,844 5,460,781 6,204,375 6,152,813 6,148,281
27/09/2009 5,516,406 5,003,906 4,372,188 6,016,094 5,524,375 6,257,031 6,156,875 6,244,063


HTH, Alastair.

On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

There is a chart here where you can see the minimums, and by placing your cursor on the graph get the values.
http://nsidc.org/arcticseaicenews/ch...sea-ice-graph/

Although the refreeze began quickly thsi year it has now slowed down, and may set a record low for the day of the year in the near future. The "cause" may be this http://ocean.dmi.dk/arctic/plots/mea...meanT_2016.png . The Arctic is failing to cool.

On Wed, 12 Oct 2016 17:10:04 -0700 (PDT)
Alastair wrote:

On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area ,
if there is sustained elevasted temps and sustained storminess over
the Arctic? All I can find is decadal average plots, for earlier
records. Presumably any second minimum would not be so deep as the
initial one, but what effect would any such double minimum have on
ice recovery?

There is a chart here where you can see the minimums, and by placing
your cursor on the graph get the values.
http://nsidc.org/arcticseaicenews/ch...sea-ice-graph/

And another graph doing something vaguely similar:
https://ads.nipr.ac.jp/vishop/#/extent


Although the refreeze began quickly thsi year it has now slowed down,
and may set a record low for the day of the year in the near future.
The "cause" may be this
http://ocean.dmi.dk/arctic/plots/mea...meanT_2016.png . The
Arctic is failing to cool.

Saw an animated map a day or two ago, probably on Twitter, showing how
unusual warmth had been affecting the Arctic but that it is coming to
an end so the temperatures should soon drop somewhat closer to normal.


--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
My web-site: http://www.scarlet-jade.com/
Posted with Claws: http://www.claws-mail.org/

On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

Quite often.

As I've said many times and referred to NSIDC to support the view, short-term changes in ice extent are down to Arctic weather. If warmer conditions develop in an area of vulnerable ice mid-sept, the melt there will exceed the freezing overall and a 'double dip' will be observed. Really, there's only one minimum and the rest is down to the weather - with the caveat that Arctic Warning over time will drive the ice extent low down over time. That's a given, unless things change.

The minimum has little effect on the rate of ice recovery, as seen in many years. Even after a new record, freezing is swift. It's dark and cold in the Arctic and freezing will happen, whatever has happened in the melt season, some weeks previously.

On Thursday, 13 October 2016 00:52:17 UTC+1, Alastair wrote:

This year seems to be an exception with only one minimum, but that may be because they are averaging over five days instead of recording each day.

If you want I can email the values displayed in an Excel spread sheet.

Not wishing to seem pedantic but that is a pair of records isn't it?
Another one to post to the dawlish thread.

On Thursday, 13 October 2016 01:10:07 UTC+1, Alastair wrote:

Although the refreeze began quickly thsi year it has now slowed down, and may set a record low for the day of the year in the near future. The "cause" may be this http://ocean.dmi.dk/arctic/plots/mea...meanT_2016.png.. The Arctic is failing to cool.

Frickin ell how many's that?

On Thursday, 13 October 2016 08:05:03 UTC+1, wrote:
On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

Quit often?

Are you going to answer a question there is no answer to?
Nor question too unlesss you missed question two.

As I've said many times baa none.

Is that another record?

and referred to Ant'NSIDEC to support the view, of short-arsed changes in ice extent are down to 0.6 degrees. If warmer conditions develop in an area of vulnerable ice mid-sept, the melt there will exceed the freezing overall and a 'double dip' will be observed.

Bloody hell I was making a mockery of this post and I don't need to.

Really, there's only one minimum and the rest is down to the weather - with the caveat that Arctic Warning over time will drive the ice extent low down over time. That's a given, unless things change.

Someone is going to put rocks on the ice or what?

The minimum has little effect on the rate of ice recovery, as seen in many years. Even after a new record, freezing is swift. It's dark and cold in the Arctic and freezing will happen, whatever has happened in the melt season, some weeks previously.

Sliptumber you mean?
Octoblover perhaps?
Novunder?
Deepcember...
But since the heat content of an ocean the size of Antarctica has never been measured, temperatures can only be superficial indicators or has you glowballs got snowballs?

And what will the environmentits have to say about you placing weights on ice? Or is that wet sheep taking a metaphorphor a ride?

On 13/10/2016 01:10, Alastair wrote:
On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

There is a chart here where you can see the minimums, and by placing your cursor on the graph get the values.
http://nsidc.org/arcticseaicenews/ch...sea-ice-graph/

Although the refreeze began quickly thsi year it has now slowed down, and may set a record low for the day of the year in the near future. The "cause" may be this http://ocean.dmi.dk/arctic/plots/mea...meanT_2016.png . The Arctic is failing to cool.


A useful record and visualisation, that nsidc page.
Nothing stands out as more pronounced, extent and lack of gradient, than
the current situation, perhaps 1981 and 1997 and prolonged main minima
in 1994 and another 90s (cant read my own writing)

On Friday, 14 October 2016 11:54:23 UTC+1, N_Cook wrote:
On 13/10/2016 01:10, Alastair wrote:
On Wednesday, 12 October 2016 12:41:53 UTC+1, N_Cook wrote:
Has there ever been an observable double minima in the ice area , if
there is sustained elevasted temps and sustained storminess over the Arctic?
All I can find is decadal average plots, for earlier records.
Presumably any second minimum would not be so deep as the initial one,
but what effect would any such double minimum have on ice recovery?

There is a chart here where you can see the minimums, and by placing your cursor on the graph get the values.
http://nsidc.org/arcticseaicenews/ch...sea-ice-graph/

Although the refreeze began quickly thsi year it has now slowed down, and may set a record low for the day of the year in the near future. The "cause" may be this http://ocean.dmi.dk/arctic/plots/mea...meanT_2016.png . The Arctic is failing to cool.


A useful record and visualisation, that nsidc page.
Nothing stands out as more pronounced, extent and lack of gradient, than
the current situation, perhaps 1981 and 1997 and prolonged main minima
in 1994 and another 90s (cant read my own writing)

Interestingly, Graham's chart seems to show the extent bending upwards where as mine shows it continuing in a straight line. It will be interesting to see which is correct, and if my linear prediction of a new record min. on one or more days this autumn does happen.