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Messages - CameraMan

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1
Arctic sea ice / Re: Latest PIOMAS update (July 2019)
« on: July 22, 2019, 07:37:16 PM »
A few more regional charts.
With the CAB becoming the most important in the late season, a chart of all years since 2000, with 2019 showing a disturbing trend. And another chart of the volume for certain days of the year. Anyone who thinks the CAB has stabilized in recent years, check out the black line for day 196 (mid-July, the most recent data point) that set a new record low for the date.
The Barents volume, where 2019 trails 2012 by a huge margin, shows by proxy the state of the Atlantic side. A lot depends on the developments on that front in the next two months.
And the total for Kara, Laptev, ESS, Chukchi, Beaufort, CAB, CAA and Greenland Sea, the only regions expected to participate in the Sept. minimum. Eyeballing the chart shows there are only two options, new record or 2nd lowest, with the 2012 "Great Leap Forward" (days 217-220, the GAC) making things complicated.

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Arctic sea ice / Basic questions about melting physics
« on: May 28, 2019, 10:02:37 AM »
Further to one or two recent discussions, here is a place to discuss the basic physics of freezing and melting sea ice.

Here are my own helpful hints on that thorny topic (amongst other things):

http://GreatWhiteCon.info/resources/arctic-sea-ice-explanations/

3
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 26, 2018, 03:04:54 PM »
And finally the seas not in the Arctic Ocean (but connected one way or another through ocean currents and/or influence on weather)

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 26, 2018, 02:55:41 PM »
The Atlantic Front - For how long will they hold out ?

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 26, 2018, 02:47:55 PM »
These two seas are ahead of the game in freezing up.

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 26, 2018, 02:42:24 PM »
Here are the seas currently playing catch-up.

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Arctic sea ice / Re: Latest PIOMAS update (September)
« on: September 17, 2018, 10:45:15 PM »
Better late than never (+ a discussion of the end of this melting season):

PIOMAS September 2018

8
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 11, 2018, 05:04:35 PM »
Ultimately, volume is the single best metric. We should have a poll. This will be one more poll in which I will never participate
Huh! he said in reply. You want a poll to be designed and implemented but never to use it. Weel, weel. But I have bashed out a graph that will probably never be used, so may as well post it just the once.

Having the daily volume measurements and having done similar for JAXA extent, I made a graph of average volume for the previous 365 days over time and added a couple of trend lines for good luck.

9
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 06, 2018, 05:26:03 AM »
The "Inner+" regions have been decreasing over time, with a possible leveling-off since 2011 (the trend of day 135 makes this claim dubious). Losses have been on the rise in early season, rather steady in mid-season, with only a very slight decrease in late-season. While the difference between 2000 and 2018 is around 6-7 (1000 km3) in the beginning of the season, it is around 8 at the end of the season.
IMHO this high variability plus rising losses mean that low winter max volumes of recent years will eventually translate to new record minimum volumes.

10
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 06, 2018, 05:15:17 AM »
The outer regions starting volume is decreasing over time, while the end result is typically near-zero. Interestingly, the trends for volume loss are more or less constant in early and mid-season, with late-season losses shrinking due to the obvious fact that no volume is available to lose.
The main study of these regions should be the length of open season, as volume is reaching near-zero earlier.

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Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 06, 2018, 05:00:47 AM »
I'd be interested to see the piomas loss by month over time for the melting season.
I'd like to step in with some charts regarding this question. Volume has been declining over time, basically in all months but with a somewhat different shape of trend. Here are some charts for total PIOMAS volume in day 135 (mid-May) to day 212 (end-July) and day 260 (~Sep. minimum).
The second chart shows the half-month volume loss (for example the "day 135" volume loss shows the loss from day 120 to day 135). Some trends are obvious:
* early volume loss has been on the increase since ~2009
* mid-season loss has been on the increase since 2000, with a maximum reached in 2012
* late-season loss has been on the decrease since ~2009

It's interesting that early and mid season loss have been increasing despite having less volume to being with. Its only natural that late season losses are decreasing as less ice is available to melt.

More interesting insights can be gained by focusing in the next posts on different geographical regions:
* "Outer" regions, those that typically have zero volume at minimum. All regions excluding "Inner+".
* "Inner+" regions, those that typically participate in the minimum, including the CAB, Kara, Laptev, ESS, Chukchi, Beaufort, the CAA and the Greenland Sea.
* Only the CAB, the most protected and northerly region.

12
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 05, 2018, 10:55:39 PM »
Time to break out 2018's Arctic minimum running back chart (named after the way it will wiggle through a crowd of dots in a few weeks' time).

13
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 05, 2018, 09:31:56 PM »
NSIDC Total Area as at 3 August (5 day trailing average) =  4,537,926  km2
This is 208  241 251 255 k above the 2010-2017 average area


Total Area loss 55 K, Central Seas loss 48 k, Periphery loss 7 k, Other Seas loss 0 k  
Analysis of individual seas.

Pacific Side
- The Bering Sea - finished,
- Chukchi Sea loss 2 k, area is a still a bit below the 2010's average,
Atlantic Side
- Baffin Sea loss 2 k, area 47k - less than 5% of 1980's average maximum,
- Greenland Sea loss 4 k,
- Barents Sea - finished,
- The Kara Sea area loss 2 k, area is now at 44 k, just under 5% of 1980's average maximum.
- The Laptev Sea area loss 6 k.
CAB
- Beaufort Sea GAIN 1 k,
- The Central Arctic Sea LOSS 35 k,
- The Canadian Archipelago loss 3 k,
- East Siberian Sea loss 0 k .
Other seas
- St Lawrence -finished,
- Hudson Bay area loss 0 k, Area now 63 k andand being stubborn - it's that little enclosed bay right in the north that I always forget about that is retaining ice cover,
- The Okhotsk Sea - finished.

On average, this is when daily area loss declines sharply  This area loss of 57 k is circa 5k below this day's 2010's average.

Qu1. The question is - will above average area losses return in the last 40 days or so of the season ? Not on July 31 to August 4, that's for sure.

Qu2. How low will Greenland Sea Ice Area go ? If not for the complete oddity that was 2002, the Greenland sea would have been at a record low for 158 days out of the 217 days of the year to date.

14
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 05, 2018, 08:28:11 PM »
JAXA ARCTIC EXTENT 6,156,200 km2(August 4, 2018)

Posts will be erratic for a few days - things happening.

Just to add to Juan's post....
- Extent loss in the last 4 days was about the average or a bit below for this time of year,
- Extent is now 48 k km2  (0.8%) below the 2010's average extent on this date,
- and 114 k (1.8%) above 2017 (which had a late burst of melt before an even later series of low extent losses) ,
- Extent loss to date is now 420k 293 310 334 km2 (4.1 %) below the 2008-2017 average, with 81.0 % of the average melting season done.

Resulting minimum from average remaining melt is  4.26 million km2, (excluding 2012 from the average gives 4.34 million km2). Range of results from last ten years remaining melt is 3.55 to 4.59 million km2. For a minimum at 2nd lowest remaining melt needs to be about 10% above average, for a new record low 40%.

That 2017 feeling returns - extent losses are not catching up on the slow melt to date and NSIDC Area losses have slowed significantly. There is, on average, under 20 % (39 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss sharply reduce? Yes.

As a result of these persistent higher than average extent loss, a September minimum down one bin in the range of 4.25 to 4.75 million km2, and perhaps even another bin lower, now looks increasingly possible or even likely. But that is still possibly 0.5 0.4 0.3 million km2 above 2nd place and about 0.8 million km2 above the 2012 outlier.

ps: I won't be making a vote on the minimum until the last moment. Breathlessly awaited PIOMAS volume for July - tells me vote for the 210's average minimum, but I wait.

15
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 05, 2018, 05:53:01 AM »
[ADS-NIPR-JAXA] ASI Extent.

August 4th, 2018: 6,156,200 km2, a drop of -47,854 km2.
2018 is the fifth lowest on record.

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 04, 2018, 02:36:25 PM »
NSIDC Total Area as at 3 August (5 day trailing average) =  4,593,103 km2
This is 208  241 251 k above the 2010-2017 average area


Quote
Posted by: Thawing Thunder
« on: Today at 01:36:01 PM » Insert Quote
Quote
Quote from: gerontocrat on Today at 09:58:10 AM
I won't be making a vote on the minimum until the last moment. Breathlessly awaiting PIOMAS volume for July.
I suppose the June volume data didn't clarify much your doubts, Gero. To me at least it seems we're still sticking in a highly volatile, contradictory and uncertain season.

Too right, confusion reigns - up, down, sideways.
Area loss 3 Aug                                        57k,
Extent loss  2 Aug (5 day average)             91k,
Extent GAIN 2 Aug (daily) 14k, loss 3 Aug 115k

Total Area loss 57 K, Central Seas loss 47 k, Periphery loss 8 k, Other Seas loss 2 k  
Analysis of individual seas.

Pacific Side
- The Bering Sea - finished,
- Chukchi Sea loss 4 k, area is now well below the 2010's average,
Atlantic Side
- Baffin Sea loss 3 k, area 49k - less than 5% of 1980's average maximum,
- Greenland Sea loss 4 k,
- Barents Sea - finished,
- The Kara Sea area loss 4 k, area is now at 46 k, 5% of 1980's average maximum.
- The Laptev Sea area loss 5 k.
CAB
- Beaufort Sea loss 21 k,
- The Central Arctic Sea LOSS 13 k,
- The Canadian Archipelago loss 0 k,
- East Siberian Sea loss 0 k .
Other seas
- St Lawrence -finished,
- Hudson Bay area loss 2 k, Area now 63 k and just about at average.
- The Okhotsk Sea - finished.

On average, this is when daily area loss declines sharply  This area loss of 57 k is 10 k below this day's 2010's average. The  5 day trailing average extent loss in contrast averaged over 100k per day for the last five  days (5 day average eliminates most of the ups and downs of daily extent measures and the monthly adjustments). But daily extent rose by 14k on the 2nd August but fell by 115k on the 3 August. Extent losses are still catching up with area losses again.

Qu1. The question is - will above average area losses follow the big NSIDC daily extent losses ? Not on July 31 or August 1 & 2 & 3, that's for sure.

Qu2. How low will Greenland Sea Ice Area go ? If export of ice down the FRAM strait is finished for this season (see Wipneus fram strait animation on PIOMAS August thread) and that warmth keeps drifting up from the Atlantic (that blocking high from Western Europe across the Atlantic is liable to stay there for some time) then....

17
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 04, 2018, 09:58:10 AM »
JAXA ARCTIC EXTENT 6,204,054 km2(August 3, 2018)

Just to add to Juan's post....
- Extent loss in the last 3 days was about the average or a bit below for this time of year,
- Extent is now 79 k km2  (1.3%) below the 2010's average extent on this date,
- and just 24 k (0.4%) above 2017,
- Extent loss to date is now 420k 293 310k km2 (3.9 %) below the 2008-2017 average, with 80.3 % of the average melting season done.

Resulting minimum from average remaining melt is  4.24 million km2, (excluding 2012 from the average gives 4.32 million km2). Range of results from last ten years remaining melt is 3.47 to 4.58 million km2. For a minimum at 2nd lowest remaining melt needs to be about 9% above average, for a new record low 40%.

That 2017 feeling fades yet but still lingers on - extent losses are not still yet enough to catch up on the slow melt to date and NSIDC Area losses have slowed significantly. There is, on average, just under 20 % (40 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss sharply reduce? Yes.

As a result of these persistent higher than average extent loss, a September minimum down one bin in the range of 4.25 to 4.75 million km2, and perhaps even another bin lower, now looks increasingly possible or even likely. But that is still possibly 0.5 0.4 0.3 million km2 above 2nd place and about 0.8 million km2 above the 2012 outlier.

ps: I won't be making a vote on the minimum until the last moment. Breathlessly awaiting PIOMAS volume for July.

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