2019 sea ice area and extent data

[Killian]

7/28/2019 stands at 6.19M km sq. 2019 needs an increase of < 10k km sq. for a record low on this date.

7/29/2012 stood at 6.20M km sq. on this date , a drop of 80k.
7/29/2019 stands at 6.08M km sq., a record low for this date, after a drop of over 110k.

7/30/2012 stood at 6.13M km sq. on this date , a drop of 70k.
7/29/2019 stands at 6.08M km sq. 2019 needs an increase of < 50k km sq. for a record low on this date.

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

8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 94.67k km sq. for a record low on this post-GAC date. (12 days)

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 60.03k km sq. for a record low on this date. (48 days)

[bbr2314]

There is so much sh*t ice in the ESS, Beaufort, and Laptev that will drop below the 15% extent threshold by 8/10. It is actually a bit disturbing to consider that 2019 could potentially beat 2012's decrease over this period due to this fact, even WITHOUT a GAC -- in my possibly incorrect opinion.

[Killian]

It is actually a bit disturbing to consider that 2019 could potentially beat 2012's decrease over this period due to this fact, even WITHOUT a GAC

I'm cautiously optimistic given 95k sustained over 12 days is a big ask. I've felt for a month or so the trend line suggested '12 crossing '19 between the 5th & 10th. Prematire call, though.

[weatherdude88]

The NSIDC sea ice extent value for 7.29, is 6.318 millions of square kilometers. This is a decrease of 87,000 square kilometers.

NSIDC sea ice extent is currently the lowest on record for the date. 2019 now has a 160,000 square kilometers lead on 2012.

[weatherdude88]

The NSIDC sea ice area value for 7.29, is 4,324,853 square kilometers. This is a decrease of 51,042 square kilometers.

NSIDC sea ice area is currently the second lowest on record for the date. If the current rate of losses (average for the last week) continue, 2019 will fall to the third lowest NSIDC area value on 8.1 (2016 and 2012).

[gerontocrat]

NSIDC Total Area as at 29 July 2019 (5 day trailing average)  4,353,853 km2

Whoops #8
Area loss staying at  below average. 8 days really does mean reaching the place called significant.

Total Area           4,353,853    km2       -353,730    km2   <   2010's average. -431,404    km2   <   2018 -1,127,051    km2   <   2000's average.           Total Area Change   -51    k   loss Peripheral Seas   -10    k   loss Central Seas__   -36    k   loss Other Seas___   -5    k   loss           Peripheral Seas          Bering _______   -0    k   loss Baffin  Bay____   -1    k   loss Greenland____   -9    k   loss Barents ______   -0    k   loss           CAB Seas          Beaufort_____   -7    k   loss CAA_________   -8    k   loss East Siberian__   -18    k   loss Central Arctic_    11    k   gain           Kara_________   -3    k   loss Laptev_______   -3    k   loss Chukchi______   -8    k   loss           Other Seas          Okhotsk______    0    k   gain St Lawrence___   -0    k   loss Hudson Bay___   -5    k   loss

- Area loss 51 k, 2 k LESS than the 2010's average loss of 53 k on this day.
- Total area 2nd Lowest, 126 k LESS than 2016, and 65 k MORE than 2012.

Area loss remains slightly below average.

Outlook
We are in the period of maximum daily area loss that is already sliding down a bit faster. Area losses in the last week currently trending very much downwards. It definitely was a steep downward slope that has now greatly eased to below average losses. Each day now represents just over 2 percent of remaining average time available. 8 days of slow area losses increases the absolute and percentage deviation from the average required for a result such as a record low.

But note the exceptions:
- The Chukchi & the ESS.
- The Beaufort is showing signs of ice melt greater than ice import.
- The CAA should be really warm this week - and some rain. Also increasing melt.
- No Fram export - Greenland area loss accelerating.
________________________________________________________________________

[gerontocrat]

NSIDC Extent continues to tell a different story - still in pole position by a significant amount.

The contrast is shown by the collapse in dispersion (increase in concentration) over the last week or more.

An odd end to the melting season in development a la 2012 again?

[Rich]

After 11 days in the 2.6 - 2.7M km2 range, CAB area finally breaks through and goes back above 2.7M.

The anticipation of the July PIOMAS #'s is going to be sky high. 2D is very strong. What's going on in the 3D CAB?

[Alphabet Hotel]

NSIDC daily extent

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 30^th, 2019:
     5,997,752 km², a drop of -78,250 km².
     2019 is the lowest on record.
     (2012 highlighted).

[gregcharles]

2019 has now beaten every year through 1998, with 40-some melting days still to go.

[gerontocrat]

JAXA ARCTIC EXTENT :- 5,997,752 km2（July 30, 2019）

On average, over 3/4 of extent loss completed.

- Extent is lowest in the satellite record (43 days this year), extent is 134 k below 2012, 537 k below 2016.
- Extent loss on this day 78 k, 10 k more than the average loss on this day of 68 k.
- Extent loss from maximum 8,273 k, 587 k (7.6%) greater than the average of 7,686 k loss from maximum by this day,
- On average 77.8% of the melting season done, with 45 days to average date of minimum (13 September).

The Perils of Projections.
**Average remaining melt would give a minimum of 3.80 million km2, 2nd lowest in the satellite record, 0.62 million km2 above the 2012 low of 3.18 million km2 and 0.22 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 initially slowly reduce, this reduction in daily loss gradually accelerating on the approach to minimum. 

Over the next 5 days Greenland, Baffin Bay and the CAA will still still be warm, and at times hot. The CAA may well get some rain.
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,

In the last 14 days the average extent loss per day has been just over 100k. The June volume data persuaded me to drop my guesstimate for the minimum  to below 4 million km2 from exactly 4 million km2. So far this seems to have been a sensible decision. Indeed, my June guess of 3.75 to 4.25 million km2 may be at risk, i.e. too high.

There is even a possibility that my July guess of 3.5 to 4 million km2 is also too high. However, this would require remaining melt to follow the pattern of 2016 at something like 15% above average.
______________________________________________________________

[DrTskoul]

Trouble sleepin Gero? Thank you for the update!!! Momentum is still strong..

[gerontocrat]

For those who like to predict the unpredictable (all of us?) ...

- here is a graph showing the projections of the 2019 JAXA extent minimum using previous years daily changes,

- who is curious about when the 365 day trailing average will reach a new low?  At current rates that is in late 2019 or early 2020.

[DrTskoul]

So anywhere between 3 - 3.75...

The second graph looks like forced ratcheting downwards ...heat forcing with negative feedback for 4-5 years ...

[Phil42]

Interesting to note that 30^th July 2019 is the first ever day in July where JAXA extent falls below 6M km². Before, the earliest date was 3^rd August 2012. So this record has been beaten by an impressive amount of 4 days.

[DrTskoul]

This is an interesting graph from the late Andrew Slater's webpage:



I wonder if somebody here can update it to 2019.

[Killian]

For those who like to predict the unpredictable (all of us?) ...

- here is a graph showing the projections of the 2019 JAXA extent minimum using previous years daily changes

Unexpectedly, 2002 is the closest match I could find to 2019's curve. (See image.)

- who is curious about when the 365 day trailing average will reach a new low?  At current rates that is in late 2019 or early 2020.

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

[DrTskoul]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

State of the cryosphere...an average obscure measure  that gives us a simple numerical picture...

[Paddy]

- who is curious about when the 365 day trailing average will reach a new low?  At current rates that is in late 2019 or early 2020.

I wouldn't like to guess at the exact date, but given how low the last four months have been, I wouldn't be at all surprised by a new trailing average minimum sometime in the next 200 to 300 days. Particularly not if it happens next spring, once 2019's relatively high January to March extent is no longer part of the average.

EDIT: Although I wouldn't want to predict the date at which we first get a new lowest trailing average, I would guesstimate that we may hit the bottom of the next trough around march 31st next year.

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

State of the cryosphere...an average obscure measure  that gives us a simple numerical picture...

I'd say that it gives a more complete picture of the current trend in sea ice extent than just tracking the minimum from year to year. Especially as the minimum point reached in a given year may be more subject to random noise than the average over the course of a year.

[gerontocrat]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

State of the cryosphere...an average obscure measure  that gives us a simple numerical picture...

I'd say that it gives a more complete picture of the current trend in sea ice extent than just tracking the minimum from year to year. Especially as the minimum point reached in a given year may be more subject to random noise than the average over the course of a year.

I think you can see that comparing 2016 with 2012.

2016 sea ice was low all year.
2012 was very much an extreme event at the end of the season followed by a strong recovery.

Hence the AWP anomaly for the total Arctic was much higher in 2016 than for 2012.
2019 is showing much more of a 2016 pattern than 2012.

Hence the climatic effect for the year is likely to be higher when low extent / area is maintained than a flash in the pan such as 2012?
____________________________________________________________
"Flash in the Pan" might raise some hackles

Ditto for Greenland ice sheet melt - this year it has gone on and on without a break. Greater impact?

[Stephan]

This is an interesting graph from the late Andrew Slater's webpage:

I just wondered that the E/SE part of the Hudson Bay must have been ice-free over winter/spring at least once.

[Rich]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

This is an amusing question coming from you Killian. You don't seem too concerned with function in your own posts. What's the utility of your guessing extent losses every day?

Note...your posts don't bother me at all. They're harmless and a source of amusement. But there is irony in your questioning the value of more interesting data.

[Rich]

IMO, the data which would best represent what is going on in the Arctic is a 5 or 10 year rolling average.

Individual summers bring a lot of weather volatility which will swing the 365 day average around a lot.

The mob awaits the spectacle of the mythical event that suddenly transforms us from ok to calamity. But AGW isn't a lion attack. It's a constrictor. Slowly and steadily tightening it's grip and suffocating us.

[Paddy]

Good point Rich with regards to individual summers.

I will now leave commenting on this thread to those with actual data to present rather than discuss further, however.

[gerontocrat]

NSIDC Total Area as at 29 July 2019 (5 day trailing average)  4,282,355 km2

Whoops #8

The turnaround starts here?
Area loss well above average after the 8 days slump in losses.

Total Area           4,282,355    km2       -366,173    km2   <   2010's average. -475,417    km2   <   2018 -1,139,131    km2   <   2000's average.           Total Area Change   -71    k   loss Peripheral Seas   -11    k   loss Central Seas__   -59    k   loss Other Seas___   -1    k   loss           Peripheral Seas          Bering _______   -0    k   loss Baffin  Bay____   -1    k   loss Greenland____   -9    k   loss Barents ______   -1    k   loss           CAB Seas          Beaufort_____   -8    k   loss CAA_________   -10    k   loss East Siberian__   -18    k   loss Central Arctic_   -11    k   loss           Kara_________   -6    k   loss Laptev_______   -1    k   loss Chukchi______   -5    k   loss           Other Seas          Okhotsk______   -0    k   loss St Lawrence___    0    k   gain Hudson Bay___   -1    k   loss

- Area loss 71 k, 25 k MORE than the 2010's average loss of 46 k on this day.
- Total area 2nd Lowest, 96 k LESS than 2016, and 86 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.

Of note were:
- The Chukchi & the ESS and the Laptev
- The Beaufort is showing signs of ice melt greater than ice import.
- 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

I will neither predict nor project the final area outcome.
________________________________________________________________________

[TeaPotty]

The mob awaits the spectacle of the mythical event that suddenly transforms us from ok to calamity. But AGW isn't a lion attack. It's a constrictor. Slowly and steadily tightening it's grip and suffocating us.

Can you keep your nonsense out of the data threads?

[Killian]

7/30/2012 stood at 6.13M km sq. on this date , a drop of 70k.
7/29/2019 stands at 6.08M km sq., a record low for the date. 2019 needs an increase of < 50k km sq. for a record low on this date.

7/30/2019 sdrops 80k km sq to 6.00M km sq., a record low for the date.

7/31/2012 stood at 6.10M km sq. on this date , a drop of 30k.
7/30/2019 stands at 6.00M km sq. 2019 needs an increase of < 100k km sq. for a record low on this date.

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

8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 96.36k km sq. for a record low on this post-GAC date. (11 days)

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 60.00k km sq. for a record low on this date. (47 days)

[stjuuv]

IMO, the data which would best represent what is going on in the Arctic is a 5 or 10 year rolling average.

Indeed, it's a lot easier to stick a linear trend on the 5-year average extent (for now) - however since I can only start the full 5-year average from July 2007, the low extents from there are already masking the steeper extent losses in the early 2000s.

[Killian]

The mob awaits the spectacle of the mythical event that suddenly transforms us from ok to calamity. But AGW isn't a lion attack. It's a constrictor. Slowly and steadily tightening it's grip and suffocating us.

Can you keep your nonsense out of the data threads?

Particularly the Ad Hom nonsense:

This is an amusing question coming from you Killian. You don't seem too concerned with function in your own posts. What's the utility of your guessing extent losses every day?

Note...your posts don't bother me at all. They're harmless and a source of amusement. But there is irony in your questioning the value of more interesting data.

[Killian]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

State of the cryosphere...an average obscure measure

I'd say that it gives a more complete picture of the current trend in sea ice extent... as the minimum point reached in a given year may be more subject to random noise...

I think you can see that comparing 2016 with 2012.

2016 sea ice was low all year.
2012 was very much an extreme event at the end of the season followed by a strong recovery.

Thanks.

[gerontocrat]

I just wondered that the E/SE part of the Hudson Bay must have been ice-free over winter/spring at least once.

Dec 25 2018 attached.
By March 2019 totally frozen up

[DrTskoul]

IMO, the data which would best represent what is going on in the Arctic is a 5 or 10 year rolling average.

Indeed, it's a lot easier to stick a linear trend on the 5-year average extent (for now), although it will definitely miss the eventual cliff.

Yeah but it misses phenomena like the rebound years

[Tom_Mazanec]

The mob awaits the spectacle of the mythical event that suddenly transforms us from ok to calamity. But AGW isn't a lion attack. It's a constrictor. Slowly and steadily tightening it's grip and suffocating us.

Can you keep your nonsense out of the data threads?

Why is this nonsense? There is nothing in the quoted passage that I find "nonsensical".

[DrTskoul]

This thread is for DATA and for slight data commentary only.

[Tom_Mazanec]

The mob awaits the spectacle of the mythical event that suddenly transforms us from ok to calamity. But AGW isn't a lion attack. It's a constrictor. Slowly and steadily tightening it's grip and suffocating us.

Can you keep your nonsense out of the data threads?

OK, that is not exactly polite, but it is less than I have frequently seen on this forum.
Particularly the Ad Hom nonsense:

This is an amusing question coming from you Killian. You don't seem too concerned with function in your own posts. What's the utility of your guessing extent losses every day?

Note...your posts don't bother me at all. They're harmless and a source of amusement. But there is irony in your questioning the value of more interesting data.

[Tom_Mazanec]

This thread is for DATA and for slight data commentary only.

"slight data commentary" is a slippery slope. Either be data exclusively, or we will be arguing over what commentary is "slight".

[petm]

Personally, I would prefer it if it was those who contributed the data who were the ones to make (slight) comments about it. We already have one thread that is overrun with content-less screeds. And as one who has not contributed value to this thread, I will now shut up.

[DrTskoul]

This thread is for DATA and for slight data commentary only.

"slight data commentary" is a slippery slope. Either be data exclusively, or we will be arguing over what commentary is "slight".

Yes you can ask somebody to explain the data product if you misunderstand it or you want it plotted a different way... you cannot post tables numbers and nothing more...

[gerontocrat]

IMO, the data which would best represent what is going on in the Arctic is a 5 or 10 year rolling average.

Indeed, it's a lot easier to stick a linear trend on the 5-year average extent (for now) - however since I can only start the full 5-year average from July 2007, the low extents from there are already masking the steeper extent losses in the early 2000s.

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.

[Alphabet Hotel]

NSIDC daily extent

[Stephan]

Evaluation of the individual seas' area "relative area wise" July 17-30.
The highest loss was found in Hudson (81%)
Losses between 52 and 46% happened in Chukchi, Kara, Baffin, and Barents.
Around a third of ice area was lost in Grønland Sea and ESS.
Between 25 and 17% loss was measured in Laptev, Beaufort and CAA.
A very minor loss (< 1%) occurred in the largest sea (CAB)

Seas with almost no ice were not analysed.

[Shared Humanity]

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.

[Neven]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

This is an amusing question coming from you Killian. You don't seem too concerned with function in your own posts. What's the utility of your guessing extent losses every day?

Note...your posts don't bother me at all. They're harmless and a source of amusement. But there is irony in your questioning the value of more interesting data.

Rich, from the moment you have registered as a member here, you've been causing frictions. Going into August (a very important one), I'd appreciate it if you could refrain from behaviour that distracts from the topics at hand. Killian asked a perfectly sensible question.

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 31^st, 2019:
     5,955,851 km², a drop of -41,901 km².
     2019 is the lowest on record.
     (2012 highlighted).

[Wherestheice]

In order to really beat 2012 this year, the ice is gonna need to melt like crazy. I could very well be wrong, but I am getting the feeling this year will beat out 2016, not 2012.

[Juan C. García]

In order to really beat 2012 this year, the ice is gonna need to melt like crazy. I could very well be wrong, but I am getting the feeling this year will beat out 2016, not 2012.

I invite everyone to vote and post on the new "JAXA 2019 Arctic SIE September daily minimum: August Poll" (and also on the "NSIDC 2019 Arctic SIE September average: August poll"):

JAXA:
https://forum.arctic-sea-ice.net/index.php/topic,2845.0.html
NSIDC:
https://forum.arctic-sea-ice.net/index.php/topic,2846.0.html

P.S. Neven: Can you stick the polls on the "Arctic sea ice" top topics? Thanks. 

[etienne]

Excuse my ignorance, but what is the function or use of a 1-year trailing average?

State of the cryosphere...an average obscure measure

I'd say that it gives a more complete picture of the current trend in sea ice extent... as the minimum point reached in a given year may be more subject to random noise...

I think you can see that comparing 2016 with 2012.

2016 sea ice was low all year.
2012 was very much an extreme event at the end of the season followed by a strong recovery.

Thanks.

One year trailing average is very useful to follow non linear datasets. I have been using it a lot in a facility management context and have written a small article about it. Just that i used "running average" instead of "trailing average". I still hsve to correct this. https://bayenet.jimdo.com/running-calculation-methodology/

[Killian]

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 = Gain of < 120k km sq. required for a record low on this date.
Thanks, Phil.
(Another complaint, another change. Those of you who like these posts, better? Answer via PM *only*, please.

Those of you who don't like them: Shush. Scroll.)

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

Daily Changes Needed to Exceed 2012 low on Aug. 10. (Related to effect of GAC and it's import vs. 2019's melt cycle.) (Thx to Psymmo.)
8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 102.00k km sq. for a record low on this post-GAC date. (10 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 > 60.43k km sq. for a record low on this date. (46 days)

[gerontocrat]

JAXA ARCTIC EXTENT :- 5,955,851 km2（July 31, 2019）

Whoops #1
As NSIDC area loss suddenly begins to accelerate, JAXA extent loss suddenly slows down.

- Extent is lowest in the satellite record (43 days this year), extent is 131 k below 2012, 482 k below 2016.
- Extent loss on this day 42 k, 23 k LESS than the average loss on this day of 65 k.
- Extent loss from maximum 8,315 k, 565 k (7.3%) greater than the average of 7,751 k loss from maximum by this day,
- On average 78.4% of the melting season done, with 44 days to average date of minimum (13 September).

The Perils of Projections.
**Average remaining melt would give a minimum of 3.83 million km2, 2nd lowest in the satellite record, 0.65 million km2 above the 2012 low of 3.18 million km2 and 0.19 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 initially slowly reduce, this reduction in daily loss gradually accelerating on the approach to 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. Even sea ice drift seems pretty minimal.

In other words, nothing seems to have changed to account for the sudden drop in extent loss on this day. But it is just one day.

I will seek enlightenment on the melting thread. Wish me luck.