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sja45uk

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Re: 2019 sea ice area and extent data
« Reply #1950 on: August 01, 2019, 10:04:46 AM »

There are many different ways to look at change is sea ice. Each gives a different view. Examples attached are looking at open water percentages instead of sea ice area. Still under development.

Love these charts. It is interesting to see the jump up for the CAB in 2007 when so much MYI met its demise. The % of open sea has been higher since.

Chukchi as well.

Not sure what I am seeing here, running 30-day averages as it is clearly filtered?

psymmo7

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Re: 2019 sea ice area and extent data
« Reply #1951 on: August 01, 2019, 10:09:32 AM »
Hi Killian,
sorry you had a typo

"Daily Changes Needed to Exceed 2012 low on Oct. 10. (Related to effect of GAC and it's import vs. 2019's melt cycle.)"

Oct. 10 should almost certainly be Aug. 10.

You might want to edit your post.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1952 on: August 01, 2019, 10:17:14 AM »

There are many different ways to look at change is sea ice. Each gives a different view. Examples attached are looking at open water percentages instead of sea ice area. Still under development.

Love these charts. It is interesting to see the jump up for the CAB in 2007 when so much MYI met its demise. The % of open sea has been higher since.

Chukchi as well.

Not sure what I am seeing here, running 30-day averages as it is clearly filtered?
No filters.

If the label says it is for a month's period it is based on that month's average of daily sea ice area readings,
If the label says it is for a three month period it is based on those three month's average of daily sea ice area readings,

The formula is simply ...
open water percentage = (the physical area of that sea minus the average daily ice area in that period) divided by the the physical area of that sea as a %.
 
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Phil.

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Re: 2019 sea ice area and extent data
« Reply #1953 on: August 01, 2019, 12:45:07 PM »
Daily Change to Exceed 2012 Record Daily Lows

7/31/2019 = -40k
                = 5.96M km sq., a record low for the date.

8/01/2012 = 6.08M km sq.
7/31/2019 = Loss of < 120k km sq. required for a record low on this date.

Shouldn't that be a gain of < 120k km sq?

Ktb

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Re: 2019 sea ice area and extent data
« Reply #1954 on: August 01, 2019, 01:30:33 PM »
Semimonthly BOE evaluation

July 31 extent was 5,955,851 km^2. With on average 44 days to go until the end of the melt season on September 13th, we now require a daily drop of -112,633 km^2 for a BOE to occur. (See Attachment 1).

Total extent loss in July 2019 was -3,080,630 km^2. And total extent loss so far this season is -8,315,270 km^2. This has resulted in the current average daily drop of -58,974 km^2. For the period from maximum to July 31st, this is the 3rd fastest rate of melt for the same period for the years 2007-2019. Barely squeaking in behind 2012, and lagging well behind 2010. (See Attachment 2). 
Additionally, if the melt season ended today, -58,974 km^2 would place 2019 as 3rd out of 13 for the years 2007-2019, once again behind 2010, with 2012 in first place.

Looking only at the month of July, we have averaged -99,375 km^2 per day. This average daily drop places July 2019 as 2nd out of 13 (2007-2019) in average daily July melt. We needed a drop larger than 58k today to maintain 1st place in this category. (See Attachment 3).
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Ktb

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Re: 2019 sea ice area and extent data
« Reply #1955 on: August 01, 2019, 01:35:31 PM »
And for comparisons to other years:

The following attachment is for actual previous years daily average melt from August 1 to their respective minimums. From this point until the end of the melt season, only 3 years since 2007 have maintained greater than -60,000 km^2/day losses. (Attachment 1).

The following section is for what the previous years would have needed for a BOE to occur: From August 1st to each years respective minimum, our current BOE requirement is the 4th highest value, of which 2018 is the leader. Keep in mind that 2018's minimum was reached on September 21st. (See attachment 2).
« Last Edit: August 01, 2019, 03:26:14 PM by Ktb »
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Re: 2019 sea ice area and extent data
« Reply #1956 on: August 01, 2019, 02:18:49 PM »
NSIDC daily extent, 2019 and 2012

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1957 on: August 01, 2019, 03:30:33 PM »
NSIDC Total Area as at 31 July 2019 (5 day trailing average)  4,209,835 km2

Whoops #8

The turnaround continues for a second day?
Area loss well above average again after the 8 days slump in losses.
                        
Total Area         
 4,209,835    km2      
-372,631    km2   <   2010's average.
-489,044    km2   <   2018
-1,143,571    km2   <   2000's average.
         
Total Area Change   -72    k   loss
Peripheral Seas   -10    k   loss
Central Seas__   -60    k   loss
Other Seas___   -2    k   loss
         
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -0    k   loss
Greenland____   -9    k   loss
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____   -7    k   loss
CAA_________   -11    k   loss
East Siberian__   -18    k   loss
Central Arctic_   -14    k   loss
         
Kara_________   -5    k   loss
Laptev_______   -0    k   loss
Chukchi______   -5    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    0    k   gain
Hudson Bay___   -2    k   loss
- Area loss 72 k, 13 k MORE than the 2010's average loss of 59 k on this day.
- Total area 2nd Lowest, 63 k LESS than 2016, and 125 k MORE than 2012.

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On this day area loss perked up, but not as much as in 2016 and 2012.

Of note were:
- The Chukchi & the ESS continue to lose area at a good clip,
- The Beaufort is showing greater signs of ice melt,
- The CAA should be really warm all this week - and some rain. Also increasing daily melt.
- No Fram export - Greenland area loss accelerating.
- the CAB had an area loss for a 2nd day.

The final area outcome - ??
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1958 on: August 01, 2019, 03:42:12 PM »
Central Arctic Sea area graph attached.

Makes one think.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Rich

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Re: 2019 sea ice area and extent data
« Reply #1959 on: August 01, 2019, 04:07:36 PM »
Central Arctic Sea area graph attached.

Makes one think.

Interesting chart. Current CAB area is closer to the 1990's average than the 2010's average.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1960 on: August 01, 2019, 04:31:03 PM »
Daily Change to Exceed 2012 Record Daily Lows

7/31/2019 = -40k
                = 5.96M km sq., a record low for the date.

8/01/2012 = 6.08M km sq.
7/31/2019 = Loss of < 120k km sq. required for a record low on this date.

Shouldn't that be a gain of < 120k km sq?

Yup. Thanks. Irony: I love editing... others stuff. Hate editing my own.

oren

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Re: 2019 sea ice area and extent data
« Reply #1961 on: August 01, 2019, 06:19:42 PM »
Central Arctic Sea area graph attached.

Makes one think.
Makes one think that the only difference is the extra ice near Svalbard, ice that does not have CAB characteristics and is relatively easy to melt. Other differences in 2012's favor are Beaufort ice (will melt eventually), Laptev (will melt), and western CAA (this could be the important lead). In 2019's favor is the ESS/Chukchi, hard to melt ice, but it did melt in 2012 anyway.

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1962 on: August 01, 2019, 07:46:33 PM »
Central Arctic Sea area graph attached.

Makes one think.
Makes one think that the only difference is the extra ice near Svalbard, ice that does not have CAB characteristics and is relatively easy to melt. Other differences in 2012's favor are Beaufort ice (will melt eventually), Laptev (will melt), and western CAA (this could be the important lead). In 2019's favor is the ESS/Chukchi, hard to melt ice, but it did melt in 2012 anyway.
The ESS does not look hard to me, and there is alternate storm/compaction/storm in the next 15 days probably. It should not withstand.... No?

Steven

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Re: 2019 sea ice area and extent data
« Reply #1963 on: August 01, 2019, 08:10:53 PM »
Central Arctic Sea area graph attached.

Makes one think.
Makes one think that the only difference is the extra ice near Svalbard, ice that does not have CAB characteristics and is relatively easy to melt.

Gerontocrat was talking about area, not extent.  It's not just the extra ice near Svalbard.  Most of the CAB looks "whiter" in 2019 than in years like 2012 or 2016 for the NSIDC sea ice concentration images.  Comparison 2019 vs. 2012:


gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1964 on: August 01, 2019, 08:11:31 PM »
It made you think.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1965 on: August 02, 2019, 05:43:49 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 1st, 2019:
     5,905,215 km2, a drop of -50,636 km2.
     2019 is the lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1966 on: August 02, 2019, 06:38:07 AM »
7/31/2019 = -40k
                = 5.96M km sq., a record low for the date.

8/01/2019 = -51k
                = 5.91M km sq., a record low for the date.

Daily Change to Exceed 2012 Record Daily Lows

8/02/2012 = 6.03M km sq.
8/01/2019 = Gain of < 120k km sq. required for the record.

-----------------------------------

Daily Changes Needed to Exceed 2012 low on Aug. 10. (Related to effect of GAC and it's import vs. 2019's melt cycle.)
8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 107.78k km sq. for a record low on this post-GAC date. (9 days)

Daily Changes Needed to Exceed 2012 Record Low on Sept. 15. (Related to comparison of 2012 vs 2019's melt cycle.)
9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 60.67k km sq. for a record low on this date. (46 days)

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1967 on: August 02, 2019, 07:21:32 AM »
JAXA ARCTIC EXTENT :- 5,905,215 km2(August 1, 2019)

JAXA extent loss continues at a slow rate.

- Extent is lowest in the satellite record (45 days this year), extent is 177 k below 2012, 417 k below 2016.
- Extent loss on this day 51 k, 13 k LESS than the average loss on this day of 64 k.
- Extent loss from maximum 8,366 k, 552 k (7.1%) greater than the average of 7,814 k loss from maximum by this day,
- On average 79.1% of the melting season done, with 43 days to average date of minimum (13 September).

The Perils of Projections.
**Average remaining melt would give a minimum of 3.84 million km2, 2nd lowest in the satellite record, 0.66 million km2 above the 2012 low of 3.18 million km2 and 0.18 million below the 2nd lowest  in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually reduce until the minimum. 

Over the next 5 days Greenland, Baffin Bay and the CAA will still be warm, and at times hot. The CAA may well get some rain. And once again it looks like there will be little or no export of ice down the Fram into the Greenland Sea, though on the Russian side winds may tend to push ice into the Barents. Persistent but not strong easterlies across the north of Greenland and the CAA?
_____________________________________________________________
On the melting thread is talk about a small cyclone in the Beaufort. Parts of northern England have just found out what a small but active cyclone can do.
« Last Edit: August 02, 2019, 07:27:25 AM by gerontocrat »
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Re: 2019 sea ice area and extent data
« Reply #1968 on: August 02, 2019, 10:20:51 AM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 2007 with still 5-6 weeks to to go.

Here are the bottom 20 rankings:

NH Area
1 2012-09-12 2.228429
2 2016-09-06 2.463209
3 2011-09-05 2.916451
4 2007-09-07 2.954993
5 2017-09-11 3.000742
6 2010-09-07 3.071674
7 2008-09-08 3.079552
8 2015-09-07 3.139137
9 2018-09-09 3.235357
10 2009-09-08 3.547109
11 2014-09-09 3.576643
12 2013-09-08 3.607877
13 2019-07-31 4.026394
14 2006-09-22 4.082958
15 2002-09-05 4.098445
16 2005-09-03 4.134433
17 2003-09-05 4.155104
18 2000-09-03 4.235279
19 1999-09-16 4.318875
20 1998-09-11 4.346996

Extent is a bit less extreme: 2019 has not entered the bottom 20.

NH Extent
1 2012-09-16 3.339905
2 2016-09-07 4.144993
3 2007-09-14 4.146931
4 2011-09-08 4.332572
5 2015-09-08 4.387092
6 2008-09-18 4.548265
7 2010-09-19 4.589683
8 2018-09-21 4.630291
9 2017-09-13 4.634885
10 2014-09-16 4.988244
11 2013-09-13 5.039617
12 2009-09-12 5.046571
13 2005-09-20 5.314284
14 2002-09-18 5.625038
15 1999-09-12 5.676431
16 2006-09-14 5.746404
17 2004-09-18 5.770495
18 2000-09-11 5.942586
19 2003-09-17 5.969052
20 1990-09-21 6.010841
21 1995-09-04 6.012446
22 1993-09-13 6.161196
23 2019-07-31 6.192291
 
« Last Edit: August 02, 2019, 02:21:35 PM by Wipneus »

Rich

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Re: 2019 sea ice area and extent data
« Reply #1969 on: August 02, 2019, 11:28:02 AM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 200 with still 5-6 weeks to to go.

13 2019-07-31 4.026

Is this the same metric Gero is reporting every day, but the most recent daily # vs  his 5 day average?

Phil.

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Re: 2019 sea ice area and extent data
« Reply #1970 on: August 02, 2019, 12:27:04 PM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 200 with still 5-6 weeks to to go.


Below 2006?

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1971 on: August 02, 2019, 01:12:47 PM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 200 with still 5-6 weeks to to go.

13 2019-07-31 4.026

Is this the same metric Gero is reporting every day, but the most recent daily # vs  his 5 day average?
Nope, it's daily, hence lower.
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Re: 2019 sea ice area and extent data
« Reply #1972 on: August 02, 2019, 02:28:40 PM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 200 with still 5-6 weeks to to go.


Below 2006?

2007, I have no idea where I lost that "7".

I report daily data always as daily.

BTW, extent is now (1st August) 20th lowest. Only 1999 (rank #15) of the previous century is still lower.

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Re: 2019 sea ice area and extent data
« Reply #1973 on: August 02, 2019, 02:34:22 PM »
While at it, a near double century extent drop today. Here is the latest diff map to answer the question "where?".

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1974 on: August 02, 2019, 03:11:45 PM »
NSIDC Total Area as at 1 August 2019 (5 day trailing average)  4,120,028 km2

The turnaround continues for a third day?
Area loss well above average again.
                        
Total Area         
 4,120,028    km2      
-391,146    km2   <   2010's average.
-491,216    km2   <   2018
-1,161,327    km2   <   2000's average.
         
Total Area Change   -90    k   loss
Peripheral Seas   -10    k   loss
Central Seas__   -78    k   loss
Other Seas___   -1    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -2    k   loss
Greenland____   -6    k   loss
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____   -6    k   loss
CAA_________   -14    k   loss
East Siberian__   -20    k   loss
Central Arctic_   -26    k   loss
         
Kara_________   -6    k   loss
Laptev_______   -0    k   loss
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -1    k   loss
- Area loss 90 k, 24 k MORE than the 2010's average loss of 66 k on this day.
- Total area 2nd Lowest, 38 k LESS than 2016, and 150 k MORE than 2012.

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On this day area loss perked up again, but not as much as in 2016 and 2012.

Of note were:
- The Chukchi & the ESS continue to lose area at a good clip,
- The Beaufort is showing greater signs of ice melt,
- The CAA should be really warm all this week - and some rain. Also increasing daily melt.
- No Fram export - Greenland area loss being maintained.
- the CAB had an area loss for a 3rd day.

The final area outcome - ??
________________________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1975 on: August 02, 2019, 06:23:59 PM »
NSIDC daily extent

AmbiValent

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Re: 2019 sea ice area and extent data
« Reply #1976 on: August 02, 2019, 06:39:54 PM »
That would be rank #20 in Wipneus' list in #1968, jumping 3 ranks in one day.
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

Rich

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Re: 2019 sea ice area and extent data
« Reply #1977 on: August 02, 2019, 07:49:40 PM »

Central Arctic_   -26    k   loss
         
- the CAB had an area loss for a 3rd day.


That's a big CAB loss. How quickly mometum ignites when nature turns the heat back on.

Even a ho-hum finish from here gets to top 3 and a place on the medal stand. Some work still to do for gold or silver.

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Re: 2019 sea ice area and extent data
« Reply #1978 on: August 02, 2019, 08:05:14 PM »
While at it, a near double century extent drop today. Here is the latest diff map to answer the question "where?".
Also shows where the mask change on 1 Aug dumped the artefacts?
Mind you, looking at previous years 1 daily extent changes suggests a strong real drop as well?
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

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Re: 2019 sea ice area and extent data
« Reply #1979 on: August 03, 2019, 05:48:31 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 2nd, 2019:
     5,852,665 km2, a drop of -52,550 km2.
     2019 is the lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1980 on: August 03, 2019, 07:14:50 AM »
JAXA ARCTIC EXTENT :- 5,852,665 km2(August 2, 2019)

JAXA extent loss continues at a slow rate.

- Extent is lowest in the satellite record (45 days this year), extent is 181 k below 2012, 348 k below 2016.
- Extent loss on this day 53 k, 18 k LESS than the average loss on this day of 71 k.
- Extent loss from maximum 8,418 k, 534 k (6.8%) greater than the average of 7,885 k loss from maximum by this day,
- On average 79.8% of the melting season done, with 42 days to average date of minimum (13 September).

The Perils of Projections.
**Average remaining melt would give a minimum of 3.86 million km2, 2nd lowest in the satellite record, 0.68 million km2 above the 2012 low of 3.18 million km2 and 0.16 million below the 2nd lowest  in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually reduce until the minimum. 

On the Russian side winds may continue tend to push ice into the Barents, while central Siberia looks very warm.
Over the next 5 days Greenland, Baffin Bay and the CAA will still be warm, and at times hot. The CAA may well get some rain.
And once again it looks like there will be little or no export of ice down the Fram into the Greenland Sea.
Persistent but not strong southerly winds pushing north from Greenland and the CAA
On the melting thread is talk about a small cyclone(s) in the Beaufort.
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Killian

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Re: 2019 sea ice area and extent data
« Reply #1981 on: August 03, 2019, 11:41:31 AM »
7/31/2019 = -40k
                = 5.96M km sq., a record low for the date.

Now being posted in the 2012 vs 2019 thread.

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1982 on: August 03, 2019, 02:49:06 PM »
NSIDC daily extent

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1983 on: August 03, 2019, 03:30:10 PM »
NSIDC Total Area as at 2 August 2019 (5 day trailing average)  4,015,799 km2

The turnaround continues for a fourth day.
Area loss well above average.
                        
Total Area         
 4,015,799    km2      
-424,220    km2   <   2010's average.
-495,990    km2   <   2018
-1,191,581    km2   <   2000's average.
         
Total Area Change   -104    k   loss
Peripheral Seas   -5    k   loss
Central Seas__   -98    k   loss
Other Seas___   -1    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -1    k   loss
Greenland____   -2    k   loss
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____   -12    k   loss
CAA_________   -17    k   loss
East Siberian__   -20    k   loss
Central Arctic_   -34    k   loss
         
Kara_________   -5    k   loss
Laptev_______   -4    k   loss
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -1    k   loss
- Area loss 104 k, 33 k MORE than the 2010's average loss of 71 k on this day.
- Total area 2nd Lowest, 70 k LESS than 2016, and 154 k MORE than 2012.

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On this day area loss perked up again, more than in 2016 but not as much as in 2012 on thid day.

Of note were:
- The Chukchi & the ESS continue to lose area at a good clip,
- The Beaufort is showing increased ice melt,
- The CAA should be really warm all this week - and some rain. Also increasing daily melt.
- No Fram export - but Greenland area loss slowed.
- the CAB had a much larger area loss for a 3rd day.

________________________________________________________________________
NSIDC area & extent much above average daily loss, JAXA extent loss below average on this day.
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Re: 2019 sea ice area and extent data
« Reply #1984 on: August 03, 2019, 03:54:31 PM »
1st, 2nd or 3rd...

be cause

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Re: 2019 sea ice area and extent data
« Reply #1985 on: August 04, 2019, 02:54:59 AM »
Impressive turnaround in the Central Arctic in the last 5 days ! 
 
Am I really to believe that Okhotsk of all seas increased while every other sea fell .. 2 days running ? :)
 
Whatever Okhotsk does , we are heading under 4 million sqkm today , already below the 2000's average minimum and still on track for 1st .. b.c.

ps .. again thanks for your dedication and delivery , Gerontocrat et al !
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1986 on: August 04, 2019, 05:44:00 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 3rd, 2019:
     5,785,444 km2, a drop of -67,221 km2.
     2019 is the lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1987 on: August 04, 2019, 05:47:27 AM »
 
Am I really to believe that Okhotsk of all seas increased while every other sea fell .. 2 days running ? :)
 
Artefacts - mere illusions undecipherable by the sensors - no AI on board.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1988 on: August 04, 2019, 06:00:18 AM »
JAXA ARCTIC EXTENT :- 5,785,444 km2(August 3, 2019)

JAXA extent loss continues at a slowly increasing rate.

- Extent is lowest in the satellite record (47 days this year),
- extent is 125 k below 2012, 299 k below 2016.
- Extent loss on this day 67 k, 16 k LESS than the average loss on this day of 83 k.
- Extent loss from maximum 8,486 k, 518 k (6.5%) greater than the average of 7,968 k loss from maximum by this day,
- On average 80.6% of the melting season done, with 41 days to average date of minimum (13 September).

The Perils of Projections.
**Average remaining melt would give a minimum of 3.87 million km2, 2nd lowest in the satellite record, 0.69 million km2 above the 2012 low of 3.18 million km2 and 0.15 million below the 2nd lowest  in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually reduce until the minimum. 

Little change in the 5 day weather outlook maps from GFS...
On the Russian side winds may continue tend to push ice into the Barents, while central Siberia looks very warm.
Greenland, Baffin Bay and the CAA will still be warm. The CAA may well get some rain.
And once again it looks like there will be little or no export of ice down the Fram into the Greenland Sea.
"Para a Causa do Povo a Luta Continua!"
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"Damn, I wanted to see what happened next" (Epitaph)

Killian

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Re: 2019 sea ice area and extent data
« Reply #1989 on: August 04, 2019, 06:59:47 AM »
Whatever Okhotsk does , we are heading under 4 million sqkm today , already below the 2000's average minimum and still on track for 1st

Not really. I'm betting 2019 ASIE is higher than 2012 ASIE by the 7th (JAXA). If that happens, '19 will have a very hard time catching 2012 again and staying ahead. Average melt is just too low as the season progresses.

The key is whether, as some are forecasting, there's a big melt out of all that mush at the perimeter westerly and northerly of the central area of the basin.

Stephan

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Re: 2019 sea ice area and extent data
« Reply #1990 on: August 04, 2019, 08:29:33 AM »
I just had a look at geronotcrat's 31.07.2018 values of these three seas that do not have any ice left:
4.796 km² Okhotsk, 2.514 km² St. Lawrence, 2.595 km² Bering.
Obviously there is no ice any more, but the sensors seem to identify some. With around 4 M km² ice area, it is way less than 1%, so it does not matter in the whole picture.
It is too late just to be concerned about Climate Change

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Re: 2019 sea ice area and extent data
« Reply #1991 on: August 04, 2019, 01:49:52 PM »
NSIDC daily area is currently second lowest for the date, behind 2012.  There were strong losses this week.



(Note: data from Wipneus.  He uses leap year corrections for the anomaly data.)

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1992 on: August 04, 2019, 02:41:29 PM »
I just had a look at geronotcrat's 31.07.2018 values of these three seas that do not have any ice left:
4.796 km² Okhotsk, 2.514 km² St. Lawrence, 2.595 km² Bering.
Obviously there is no ice any more, but the sensors seem to identify some. With around 4 M km² ice area, it is way less than 1%, so it does not matter in the whole picture.
Sometimes the sensors get fooled, usually at similar places, especially on the shoreline.

But sometimes even the AMSR2 sensor (much sharper than the NSIDC sensor) gets caught out with new virtual ice. Observe the Aug 2 & Aug 3 image extracted from Univ Bremen attached.
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1993 on: August 04, 2019, 03:32:59 PM »
NSIDC Total Area as at 3 August 2019 (5 day trailing average)  3,911,453 km2

The turnaround continues for a fifth day.
Area loss well above average.
                        
Total Area         
 3,911,453    km2      
-461,254    km2   <   2010's average.
-507,736    km2   <   2018
-1,226,126    km2   <   2000's average.
         
Total Area Change   -104    k   loss
Peripheral Seas   -3    k   loss
Central Seas__   -101    k   loss
Other Seas___    0    k   gain
         
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -1    k   loss
Greenland____   -1    k   loss
Barents ______   -1    k   loss
         
CAB Seas         
Beaufort_____   -13    k   loss
CAA_________   -13    k   loss
East Siberian__   -17    k   loss
Central Arctic_   -42    k   loss
         
Kara_________   -5    k   loss
Laptev_______   -5    k   loss
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___    0    k   gain
- Area loss 104 k, 33 k MORE than the 2010's average loss of 71 k on this day.
- Total area 2nd Lowest, 105 k LESS than 2016, and 152 k MORE than 2012.

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On this day area loss perked up again, more than in 2016 and as much as in 2012 on this day.

Of note is:
- All the seven seas of the High Arctic are losing seas ice area at above average daily rates.
- The Chukchi & the ESS continue to lose area at a good clip,
- The Beaufort is showing increased ice melt,
- The CAA should be really warm all this week - and some rain. Also increasing daily melt.
- No Fram export - but Greenland area loss slowed.
- the CAB had a much larger area loss for a 4th day.

Area continues 'twixt 2012 and 2016.
________________________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

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Re: 2019 sea ice area and extent data
« Reply #1994 on: August 04, 2019, 03:54:48 PM »


Not really. I'm betting 2019 ASIE is higher than 2012 ASIE by the 7th (JAXA).

Going out on the limb there.  ::)

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Re: 2019 sea ice area and extent data
« Reply #1995 on: August 04, 2019, 04:12:30 PM »
NSIDC Total Area as at 3 August 2019 (5 day trailing average)  3,911,453 km2

Herewith an analysis of NSIDC 5 day area using same basis as the JAXA extent analysis.

NSIDC sea ice area loss continues at a well above average rate.

- Extent is 2nd lowest in the satellite record,
- Extent loss from maximum 9,212 k, 514 k (5.9%) greater than the average of 8,697 k loss from maximum by this day,
- On average 86.8% of sea ice area loss done, with 41 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 2.59 million km2, 3rd lowest in the satellite record, 0.34 million km2 above the 2012 low of 2.25 million km2 and 0.14 million above the 2nd lowest  in 2016 of 2.45 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily area loss will gradually reduce until the minimum. 

Little change in the 5 day weather outlook maps from GFS...
On the Russian side winds may continue tend to push ice into the Barents, while central Siberia looks very warm.
Greenland, Baffin Bay and the CAA will still be warm. The CAA may well get some rain.
And once again it looks like there will be little or no export of ice down the Fram into the Greenland Sea.
______________________________________________________
Average = average of last 10 years
_________________________________________________
ps: Graph of total arctic sea ice area already posted earlier, so here is the 365 day trailing average graph since 1990. Still some way to go to get to new lows - blame 2018.
"Para a Causa do Povo a Luta Continua!"
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Re: 2019 sea ice area and extent data
« Reply #1996 on: August 04, 2019, 04:47:25 PM »
NSIDC daily extent

Killian

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Re: 2019 sea ice area and extent data
« Reply #1997 on: August 05, 2019, 12:08:00 AM »


Not really. I'm betting 2019 ASIE is higher than 2012 ASIE by the 7th (JAXA).

Going out on the limb there.  ::)

With all the slush and the cyclones blowing through, I think so. We could easily see multiple days of 100k drops... or one huge drop... or the ice just sort of keep hanging on as it has. Not easy call, is it? After all, wouldn't everyone be doing it?

;-)

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Re: 2019 sea ice area and extent data
« Reply #1998 on: August 05, 2019, 05:41:31 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 4th, 2019:
     5,719,542 km2, a drop of -65,902 km2.
     2019 is the lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Jontenoy

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Re: 2019 sea ice area and extent data
« Reply #1999 on: August 05, 2019, 09:31:09 AM »
Extent is 5.72 M sq km and area 3.90 M sq km. Therefore 1.82 is the water area of the 5.72
This represents 32 % of the 5.72 M sq km and so could be a measure of the slushiness of the total ice pack