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Messages - Iain

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1
Arctic sea ice / Re: The 2019/2020 freezing season
« on: December 02, 2019, 06:05:30 AM »
@charles_oil

LoL, yes, it is set at a level Joe Public would be able to follow.

The BBC charter includes a commitment to  " ...inform, educate..."

E.G the recent nature programmes highlighting plastic waste in the seas being ingested by marine life .

Significantly, many more of the public now realise their small action has a consequence.

< I'm drifting OT, last post on this >


2
Arctic sea ice / Re: The 2019/2020 freezing season
« on: December 01, 2019, 08:42:58 AM »
Ah, Now I get it.

A brief explainer on what a SSW is and possible effects:

https://www.bbc.co.uk/weather/feeds/20992173

3
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 11, 2019, 01:28:14 PM »
Also worth noting the linear trend of September minimums predicts BOEs will be common in 16 years from now.

Scary.

An excursion below the trend line such as seen in 2010, 11 or 12 reduces that to 4 or 5 years from now.

Very scary.

4
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 11, 2019, 01:24:12 PM »
Piomas now has the Oct data.

2019 is within a whisker of 2012 and 2016 for time of year.

5
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 23, 2019, 06:09:21 AM »
“How soon before BOE is a possibility?”

About 14 years, if the linear trend continues
That’s a seriously scary number and worth mentioning in conversation, where appropriate.
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAprSepCurrent.png

With the spiky nature of the data, more likely to be sooner than that than not.
Also have to consider the many competing +ve and –ve feedbacks, but the timescale is so short, less than half of the Piomas record, I think their effect is unlikely to deflect the trend.

6
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 09, 2019, 03:17:26 PM »
Oh, and I would like to make clear I have made many thousands of informative posts on this forum, it's just that my post count has been stuck at 62 since 1975.






 ;)

7
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 09, 2019, 03:15:27 PM »
Charctic puts 2019 in second lowest extent for day of year - 4.879 against 4.882 for 2007.

8
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 08, 2019, 03:46:39 PM »
...Like I said, it's a tease this year, 2019 extent graph almost intersecting 2007....

9
Arctic sea ice / Re: The 2019 melting season
« on: September 19, 2019, 03:20:20 PM »
Chartic puts 2019 at 4.153 Million km^2, 2nd place in the satellite record.


https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

10
Arctic sea ice / Re: The 2019 melting season
« on: September 18, 2019, 03:13:10 PM »
2019 on 4.220 Million km2

Next nearest minima are: 2016 4.165; 2007 4.163. 4.155

"Here's the throw, here's the play at the plate, Holy cow....."
[/quote

STOP RIGHT THERE!!! ........]

"Let me sleep on it...."

At 4.170 today

11
Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 04:35:15 PM »
@ Ossifrage. Good concise summary. Thanks

I believe the CAA will become a significant export route for the CAB in the years to come.

12
Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 03:07:23 PM »
2019 on 4.220 Million km2

Next nearest minima are: 2016 4.165; 2007 4.163.

"Here's the throw, here's the play at the plate, Holy cow....."

13
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 03:21:40 PM »
The extent graphs are a tease this year

14
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 03:52:18 PM »
...Also my post count is stuck again,  at 54 this time. I'll never get past being a crystal....
: )


15
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 03:49:53 PM »
2019 extent is back in 3rd place.

16
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 09:26:29 AM »
Cloud free image of the CAA from Worldview, I think I'll frame it and put it on the wall.

More importantly there has been no Southward movement of ice from the CAB into the clear blue water in the last couple of days, despite a Northerly wind.

Wind is forecast to continue to from the North and strengthen for the next couple of days, also the Ice can stay mobile into early October, so there is still time for the CAB to populate the channels with floes.

However, if not, there will only be salty 1st year ice there, ready for an early breakup next year.

17
Arctic sea ice / Re: The 2019 melting season
« on: August 21, 2019, 01:03:24 PM »
West end of the CAA: New cracking along the East coast of Victoria I and the adjacent bay. The storm coming on Fri/Sat  will shake things up.

18
Arctic sea ice / Re: The 2019 melting season
« on: August 19, 2019, 01:16:16 PM »
Southward movement has restarted in Nares and between some of the Islands of the CAA: Borden, Ellef Ringes, Meighen and Ellesmere, also the South end of Parry Channel
Map here:
https://en.wikipedia.org/wiki/Arctic_Archipelago

Wind has been light over the last few days (Gif is for 15th to 18th Aug) so this is this is mostly ocean current driven.

South of the floes is clear blue ocean, so the potential for export over the next 6 weeks (2 w past the expected minimum date) is high.

19
Arctic sea ice / Re: The 2019 melting season
« on: August 05, 2019, 12:47:47 AM »

My naive reaction is that those anomalies around the CAA suggest that a complete melt out is possible there.
[/quote]

The thickness in most of the CAA is already very low according to PIOMAS, so I agree.
[/quote]

The tidal flow is generally from North to South through the CAA, so the CAA gets filled with floes from the CAB. Recently the wind has been from the South, preventing the usual South going export, but it looks like that has restarted.

The breakup of the first channel from CAB to Parry Chanel occurred at the end of July, the earliest on a tie with 2012. The export flow has continued into October in the past.

20
Arctic sea ice / Re: The 2019 melting season
« on: July 29, 2019, 04:48:22 AM »
CAA - There is cracking in the landfast ice all the way to the CAB. That's early, but not unprecedented. As near as I can, visibility permitting, the same event happend on these dates in the recent past:

2018 Aug 15
2017 Aug 22
2016 Between July 30 and Aug 04 (thick cloud)
2015 Jul 31
2014 Sept 12
2013 between Aug 11 and Aug 22 (thick cloud)
2012 July 28

21
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 17, 2019, 05:31:41 PM »
Dispersal showing up as a left swerve on Chartic.

22
Greenland and Arctic Circle / Re: The 'Very Big Chunk' poll
« on: May 12, 2019, 09:01:09 PM »
Confirmed on Worldview. Shattered. I'm not optimistic Nares will block until winter.

23
Greenland and Arctic Circle / Re: The 'Very Big Chunk' poll
« on: May 06, 2019, 11:09:57 PM »
From what I've seen so far, very unlikely that the remaining FBCs (Fairly big.....: ) will block the channel.


24
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 06, 2019, 10:56:56 PM »
VBC has broken further with the rest of the FBCs (Fairly big....) separating from the arch. The grey infill looks like cloud, not refreeze - there is clear blue water in the strait

25
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 05, 2019, 10:18:31 AM »
VBC has split in half.

27
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: April 05, 2019, 11:11:39 AM »
Fracture of a slab of landfast ice at the narrow near Inglefield Land

28
Arctic sea ice / Re: The 2019 melting season
« on: March 11, 2019, 09:11:32 PM »
Not a serious objection, but shouldn't the extent uptick be discussed in the freezing thread rather than the melting thread?

More freez-ing happening than melt-ing (extent wise) is the reason for the uptick.



29
Arctic sea ice / Re: The 2018/2019 freezing season
« on: March 11, 2019, 04:00:12 PM »
Here's the throw,
Here's the play at the plate,
Holy cow.....

30
Greenland and Arctic Circle / Re: Old ice moving through Nares Strait
« on: March 10, 2019, 09:58:14 AM »
And there is still movement along the full length.

Potentially significant because:

The date has passed when it blocked last year
The sun is coming up
Though narrow, there is a fast current carrying the ice southwards. Only a strong South wind would halt or reverse the floes
There is an accumulation of thick ice nearby, against the N coast of Greenland and the CAA.
Much of that is fragmented

One to watch

31
Greenland and Arctic Circle / Re: Old ice moving through Nares Strait
« on: March 10, 2019, 09:47:11 AM »
Better view on Polar View

32
Greenland and Arctic Circle / Re: Old ice moving through Nares Strait
« on: March 10, 2019, 09:43:25 AM »
Look like new ice is entering from the North.

33
Greenland and Arctic Circle / Re: Old ice moving through Nares Strait
« on: March 04, 2019, 11:14:51 PM »
I think it would depend largely on Sea Surface Temperature, as Nares is the first left turn exit for the Atlantic drift,  but my goto source for day to day graphics has a snapshot archive for 2017 but not '18:

https://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticsst.html

Ignore the warning, advanced > allow exception

So I can't decide.

34
Arctic sea ice / Re: The 2018/2019 freezing season
« on: March 02, 2019, 10:28:36 AM »
Meanwhile, there is still movement in the Nares straight at both ends. This time last year it was static at the Southern end on March 8th. Cloud obscured the view in the preceding days, so it may have blocked earlier.

https://worldview.earthdata.nasa.gov

Oh, and my post count has  stuck on 34. Not bothered for myself but others may be affected.

35
Arctic sea ice / Re: The 2018/2019 freezing season
« on: March 02, 2019, 10:01:29 AM »
Oops, I should have cited the source - NSIDC.

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/


36
Arctic sea ice / Re: The 2018/2019 freezing season
« on: March 01, 2019, 03:16:04 PM »
I’m not calling the maximum, I’ll leave that to a more frequent poster, only that I think it is more likely than not the max is already past.

Because:

Mar 1st is the long term 1981 to 2010 peak
2019 would have to climb 0.113 M km2 to exceed the Feb 25th extent
DMI shows above average temperature for most of the arctic
The Climate re-analyser 3 day forecast shows above average temperature for most of the arctic, though not on the Atlantic periphery

37
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 26, 2018, 03:40:37 PM »
2018 growth has accelerated, 2016 is now the lowest extent for October 25th, 2018 2nd lowest.

Is there such a measure as extent days or volume days, or average extent/volume for a month or so either side of the max and min?

The PIOMAS page publishes a graph of summer minimum and winter maximum volumes with a linear trend of loss per decade.

Taking only the max and mins each year yields spikey data, the averages above I expect to be smoother, so the observed values would deviate less from a linear trend line.

38
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 25, 2018, 03:23:30 PM »
Extent for day of year now lowest since '79 on NSIDC.

Oct 24th 2018: 6.546 M km^2
Oct 24th 2016 (not shown for clarity) 6.622 M km^2

39
Arctic sea ice / Re: The 2018 melting season
« on: September 25, 2018, 03:15:12 PM »
It's not over yet, 2018 extent is still flatlining. It's now lower for the day of year than any year since 2000 except 07 and 12.

40
Arctic sea ice / Re: The 2018 melting season
« on: July 23, 2018, 01:42:54 PM »
Ice breakup in the CAA North of Cornwallis Island

About a week earlier than in 2017

There are still ice bridges intact at the southern end either side of CI and c. 200km of landfast ice to the north to the CAB

Winds are from the North for the next few days which will add pressure to the ice bridges

It’s one to watch. In the last few years the ice did not become mobile all the way to the CAB until late Sept / early Oct, so there was limited time for export of the thick CAB ice prior to refreeze. If it breaks up earlier, with the prevailing current from the north, there is potential for substantial export of the most resilient ice.

41
Arctic sea ice / Re: The 2018 melting season
« on: July 02, 2018, 07:09:33 AM »
Yearly comparison of HYCOM CICE thickness for July 1st (June 30th on 2017 for the nearest date with data). Click to animate.

<edit - oops, the above is a quote, the below is my comment>
Thanks for the animation. My main takeaway is the reduction of thick ice North of the CAA.

In recent years the CAA ice broke up late Sept/early Oct.

This year the breakup in Parry has progressed less far for the time of year than in 14-17, though it has been largely cooler than average so far. One to watch.

42
Arctic sea ice / Re: The 2018 melting season
« on: June 20, 2018, 07:05:50 AM »
Breakup in the Perry Channel. Clouds make it hard to see the extent. Polar view does not have an image of the area post breakup yet.

https://worldview.earthdata.nasa.gov


43
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 17, 2018, 01:18:48 PM »
Jim,

There was some discussion around FDDs this time last year in the 16/17 freezing thread.

From memory, the gist was that for any given temp difference between cold air and above-freezing seawater, the Ice thickness tends to a particular value.

The upshot was that the dT in the period immediately prior to onset of spring melting was the most important for thickness and summer survivability. FDDs at the onset of Autumn freezing made much less difference.

44
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 30, 2017, 11:56:00 AM »
bosbas,

It was updated at 03:00 today, but averaged from the last couple of days. From the site:

"Averaging period and the update timing of daily data : In general, sea-ice extent is defined as a temporal average of several days (e.g., five days) in order to eliminate calculation errors due to a lack of data (e.g., for traditional microwave sensors such as SMMR and SSM/I). However, we adopt the average of latest two days (day:N & day:N-1) to achieve rapid data release. Only for the processing of WindSat data (Oct. 4, 2011 to the present) the data of the day before yesterday (day:N-2) is also sometimes used to fill data gaps."

Charctic updates mid afternoon from memory:
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

45
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 30, 2017, 10:47:10 AM »

46
Arctic sea ice / Re: The 2017 melting season
« on: June 05, 2017, 11:01:14 PM »
Ice breakup at the SE end of Parry Channel

47
Arctic sea ice / Re: The 2017 melting season
« on: April 03, 2017, 01:53:19 PM »
Are the purple and mauve areas inside the 85 deg latitude, indicating 400 – 500 mm of thickness for real?

Or are they a false reading at the edge of the scan for some reason?

48
Arctic sea ice / Re: The 2017 melting season
« on: March 25, 2017, 01:39:29 PM »
Visual confirmation the ice is moving along the full length of Nares strait and Robeson channel, however the grain size of the ice in the CAB is still too large to enter.

Meanwhile Parry channel, a conduit for ice getting through the CAA to enter Baffin bay, is still blocked between Somerset and Devon islands by an arch of ice. In 2016 it didn't break until 2nd of July. One to watch.

49
Arctic sea ice / Re: The 2017 melting season
« on: March 21, 2017, 10:42:42 PM »
<no off-topic stuff in this thread, especially when related to Donnie Tiny Hands. Take it elsewhere; N.>

50
Arctic sea ice / Re: The 2016/2017 freezing season
« on: March 07, 2017, 01:05:00 PM »
@meddoc

Not sure what you mean.

NB: It's funded by Europe,  so safe from any Trumpheting.

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