2018 sea ice area and extent data

[gerontocrat]

JAXA Extent 10,585,063 km2（June 5, 2018）

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.31 million km2, down to 40k below the average for the last 10 years. Consistently slightly slower than or at average daily melt.
- 2017 was a slow year also, hence 2018 extent is still 346k (3.0%) below 2017,
- 2012 extent was 682k km2 more than 2018 on this date and yet still ended up with a record low by a bit more than 800,000 km2. We are swiftly approaching the time (2nd week of June) when 2012 extent loss started to accelerate.
- 2007 has a similar story - extent 637k more than 2018 on this date but melt accelerated starting very soon,
- on average 34% of the melting is done for this season - still a long way to go, on average 100 days.

I have added a line on the first table to show the effect of removing 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.13 million km2 as opposed to 3.97 million km2. The range of outcomes from the last 10 years remaining melt is 2.5 to 4.4 million km2.

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will get a dose of real warmth increasing from today onwards.

BUT - I am increasingly surprised that the effect on extent data is still not obvious yet. Perhaps the effect on the seas in the CAB is more a case of thinning, fracturing and opening of leads rather than larger areas of open water at less than 15% ice covered appearing.

[Wipneus]

That interdecile range doesn't look right. I count what looks like a quintile ( rather than a decile (4) worth of data lines below it on some dates.

The percentiles are computed from the 1981-2010 period (WMO preferred climate standard, similar to what NSIDC uses). I will fix the legend next time.

[Hautbois]

Days in the bottom 3, cumulative, from January 1 to May 31.

By the end of May, 2018 had only had 6 days that weren't. And had also just overtaken 2012's total for the year.

[magnamentis]

Days in the bottom 3, cumulative, from January 1 to May 31.

By the end of May, 2018 had only had 6 days that weren't. And had also just overtaken 2012's total for the year.

that's it, the big picture that i like so much, can safe many petty discussion about daily and weekly ups and downs and ranks because they're absolutely irrelevant.

last but not least, this trend is so obvious and so strong, one could easily get afraid of what's gonna happen if that speed of development will keep up or even accelerate?

thanks of this especially for the idea.

[gerontocrat]

NSIDC has done the May analysis (http://nsidc.org/arcticseaicenews/)

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 6^th, 2018:  10,518,855 km², a drop of -66,208 km².
2018 is the second lowest on record.
2018 has 185,748 km² more than 2016 and 70,481 km² less than 2015.

[bbr2314]

[ADS-NIPR-JAXA] ASI Extent.

June 6^th, 2018:  10,518,855 km², a drop of -66,208 km².
2018 is the second lowest on record.
2018 has 185,748 km² more than 2016 and 70,481 km² less than 2015.

Looks like 2018 should go crashing through 2016 in the next few days as the cyclone accelerates this year past that year's June stall.

[ArcticMelt1]

According ice extent in the Central Basin, June 2018 it stably comes first, with a big gap from the rest of the years since 2006.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 7^th, 2018: 10,482,795 km², a drop of -36,060 km².
2018 is the second lowest on record.
2018 has 184,983 km² more than 2016 and 106,089 km² less than 2015.

[gerontocrat]

JAXA Extent 10,482,795 km2（June 7, 2018）

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. I am increasingly surprised that the effect on extent data is still not obvious yet. Perhaps the effect on the seas in the CAB is more a case of thinning, fracturing and opening of leads rather than larger areas of open water.

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.41 million km2, 60k below the average for the last 10 years. Consistently slightly slower than or at average daily melt.
- 2017 was a slow year also, hence 2018 extent is still 314k (3.0%) below 2017,
- 2012 extent was 544k km2 more than 2018 on this date and yet still ended up with a record low by a bit more than 800,000 km2. We are now in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 647k more than 2018 on this date but melt accelerated starting very soon,
- on average 35% of the melting is done for this season - still a long way to go, on average 97 days.

I have added a line on the first table to show the effect of removing 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.14 million km2 as opposed to 3.99 million km2. The range of outcomes from the last 10 years remaining melt is 2.6 to 4.4 million km2.

[gerontocrat]

NSIDC Total Area as at 7th June (5 day trailing average)   9,552,410 km2

Area loss at around 60k per day for the last 5 days, now mostly in the Central Seas
Pacific Side
- The Okhotsk Sea area is down to 16 k km2, well under 5% of historical average maximum, daily loss <1k and is more or less irrelevant.
- The Bering Sea area is 1k, and is irrelevant (except to see for how long the vestiges of ice will persist).
- Chukchi and Beaufort Sea losses are modest but consistent. - Pacific warmth surely must hit these seas over the next few days.
Atlantic Side
- Area loss in the Baffin, Greenland, and Barents Seas in range 15 to 25 k per day.
- The Laptev Sea los increased to 19 k .
- The Kara Sea is lost 65 k area in the last 3 days  .
- Other Central Seas area loss has stalled.
Other seas
- St Lawrence has at last lost about all remaining ice in the last 5 days, area is <1k,
- Hudson Bay area loss is more than occasional days of gain.

GFS from cci-reanalyzer.org still shows  there is a believable significant influx of warm air from Eastern Russia and the Pacific Ocean happening now and in the next few days, and warmth looks as if it will continue to hit the southern half of Hudson Bay as well. We are having had this big cyclone - Kara Sea seems to be the place where it has a significant effect so far.

[gerontocrat]

The St Lawrence is interesting. No matter that area in winter is declining substantially over the years, the final collapse seems to be the first week in June regardless. The start of winter area gain seems also the same no matter what.

[lanevn]

The St Lawrence is interesting. No matter that area in winter is declining substantially over the years, the final collapse seems to be the first week in June regardless. The start of winter area gain seems also the same no matter what.

It's alwayse "false ice" near shores detectes and 1 June is probably day when they remove that region from calculations at all.

[gerontocrat]

The St Lawrence is interesting. No matter that area in winter is declining substantially over the years, the final collapse seems to be the first week in June regardless. The start of winter area gain seems also the same no matter what.

It's alwayse "false ice" near shores detectes and 1 June is probably day when they remove that region from calculations at all.

Nope

Date    Area km2 May   31    14,515 June   1    12,839 June   2    11,008 June   3    6,079 June   4    3,644 June   5    1,880 June   6    1,720 June   7    936

[RoxTheGeologist]

JAXA Extent 10,482,795 km2（June 7, 2018）

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. I am increasingly surprised that the effect on extent data is still not obvious yet. Perhaps the effect on the seas in the CAB is more a case of thinning, fracturing and opening of leads rather than larger areas of open water.

83 cm of rain at 1C to will melt 1 cm of ice, and the melting ice buffers the temperature of the water, and, that water at 0C, is fresh and floats. The latent heat of fusion of water soaks up an enormous amount of energy. The ice in the middle of the pack will thin and warm, but not lose extent. this is what Neven calls "Pre-conditioning" it accelerates the July and August extent losses.

Sea ice melts from the edges of the pack. The water at the edges of the pack is dark and heats up quickly, throughout the photic zone, and across a wide area. It is mixed with the ice at the edge of the pack, by wind or wave action, and by some night/day convection as the surface cools and sinks at night. I imagine the best conditions for ice to melt are sunny days with the ice being blown towards open water. I think understanding the mechanism of melt, that heat energy over a wide are of ocean is transferred to the point of melting is critical to understanding the rate of extent loss.

On the Atlantic side, I think A team has made a very good case that the boundary of the sea ice is determined by the bathymetry. The position is relatively stable. The relatively thick cold ice meets the warm dense Atlantic waters, There is enough warm water to melt the ice, and the melting ice cools the water, causing it to sink, a mechanism that tracks the shelf edge. Only when there isn't enough ice to cool the incoming waters will this boundary progress further into the Basin.

[gerontocrat]

Thanks for the explanation, Rox the Geologist.

So the question is, will the warmth, cyclones  (if they persist) lead to an unusually large extent/area loss later in the season ? Or is this still in the lap of the gods.

[Sciguy]

83 cm of rain at 1C to will melt 1 cm of ice

That would be a huge amount of rain anywhere (well, maybe not India during the monsoon season), much less the Arctic.  Here are some facts about the Arctic climate:

https://en.wikipedia.org/wiki/Climate_of_the_Arctic

The Arctic Basin is one of the driest parts of the Arctic. Most of the Basin receives less than 250 mm (9.8 in) of precipitation per year, qualifying it as a desert. Smaller regions of the Arctic Basin just north of Svalbard and the Taymyr Peninsula receive up to about 400 mm (16 in) per year (Serreze and Hurst 2000).

Monthly precipitation totals over most of the Arctic Basin average about 15 mm (0.59 in) from November through May, and rise to 20 to 30 mm (0.79 to 1.18 in) in July, August, and September (Serreze and Hurst 2000).

[Sciguy]

Here's a letter from Environmental Research Letters in 2014 discussing the climate of Svalbard, which is wetter than most of the Arctic:

http://iopscience.iop.org/article/10.1088/1748-9326/9/11/114021/pdf

Daily amount of precipitation (measured once or twice
daily (at 0600/1800 h) and covering the previous 12/24 h
period) has been recorded continuously for multiple decades
at three manned weather stations in Spitsbergen (the largest
island on Svalbard, Stations 1–3, figure 1(a)): the small
research settlement Ny-Ålesund (population ∼30 year-round;
Norwegian Meteorological Institute, data available at http://
eklima.no), the Russian settlement of Barentsburg (population
∼435; data available at www.tutiempo.net/en/Climate/
BARENCBURG/07-1973/201070.htm), and Svalbard Airport.
At all three weather stations, several heavy rainfalls were
associated with the two-week warm spell (figure 1(c),
table 1). The most striking event was recorded in Ny-Ålesund
on January 30th when 98 mm rain fell (Tmax = 4.3 °C), which
had (prior to this event) a return period of >500 years following
the Norwegian manual for calculation of probable
extreme daily precipitation values (Førland 1992),

Note that the letter refers to 98mm as being a 500 year event.  That's about 1/10th of what someone asserted fell in this cyclone in a drier part of the Arctic.

[oren]

Off-Topic alert.  Reminding this is the extent and area thread.

[Neven]

Off-Topic alert.  Reminding this is the extent and area thread.

Thanks, oren.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 8^th, 2018: 10,457,617 km², a drop of -25,178 km².
2018 is the second lowest on record.
2018 has 178,906 km² more than 2016 and 132,929 km² less than 2015.

[gerontocrat]

JAXA Extent 10,457,617 km2（June 8, 2018）

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. I am even more surprised that the effect on extent data is still not obvious yet. Perhaps the effect on the seas in the CAB is more a case of thinning, fracturing and opening of leads rather than larger areas of open water. But when will all this apparently amazing weather show up in the extent data ? Perhaps it will not.

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.41 million km2, 60k below the average for the last 10 years. Consistently slightly slower than or at average daily melt, a very low 36k and 25k in the last 2 days.
- 2017 was a slow year also, but 2018 extent is a much reduced 261k (3.0%) below 2017,
- 2012 extent has dropped from 544k to 350k km2 more than 2018 on this date. We are now truly in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 650k more than 2018 on this date but melt accelerated later than 2012,
- on average 35% of the melting is done for this season - still a long way to go, on average 96 days.

I have added a line on the first table to show the effect of removing 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.16 million km2 as opposed to 4.02 million km2. The range of outcomes from the last 10 years remaining melt is 2.8 to 4.4 million km2.

[Wipneus]

The storm has initiated the drop in area known as the "June cliff".

[gerontocrat]

NSIDC Total Area as at 8th June (5 day trailing average)  9,475,797 km2

Area loss 77k, 57k in the Central Seas

Pacific Side
- The Okhotsk Sea area is 18 k.
- The Bering Sea area is 1k.
- Chukchi Sea - k, Beaufort Sea +1k.
Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas 21k.
- The Laptev Sea area loss increased to 24 k .
- The Kara Sea area loss 16k.

- The Central Arctic Sea loss 20k.

Other seas
- St Lawrencearea is <1k,
- Hudson Bay area loss is more than occasional days of gain.

GFS from cci-reanalyzer.org still shows  there is a believable significant influx of warm air from Eastern Russia and the Pacific Ocean happening now and in the next few days, and warmth looks as if it will continue to hit the southern half of Hudson Bay as well.

See Wipneus graphs above re start of the June cliff

[ArcticMelt1]

Over the past two days, the gap between 2018 and the remaining years has only increased.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 9^th, 2018: 10,412,759 km², a drop of -44,858 km².
2018 is the second lowest on record.
2018 has 175,390 km² more than 2016 and 175,459 km² less than 2015.

[gerontocrat]

JAXA Extent 10,412,759 km2（June 9, 2018）

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. I am even more surprised that the effect on extent data is still not obvious yet. The effect is showing in area data, especially in the Central Seas.

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.48 million km2, 110k below the average for the last 10 years. Consistently slightly slower than or at average daily melt, a very low 36k and 25k and 44k in the last 3 days.
- 2017 was a slow year also, but 2018 extent is a much reduced 231k (2.2%) below 2017,
- 2012 extent has dropped from 350k to 279k km2 more than 2018 on this date. We are now truly in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 686k more than 2018 on this date but melt accelerated later than 2012,
- on average 36% of the melting is done for this season - still a long way to go, on average 96 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.16 million km2 as opposed to 4.03 million km2. The range of outcomes from the last 10 years remaining melt is 2.9 to 4.4 million km2.

[gerontocrat]

NSIDC Total Area as at 9th June (5 day trailing average)   9,411,713 km2

Area loss 64k, 41k in the Central Seas

Pacific Side
- The Okhotsk Sea area is 18 k.
- The Bering Sea area is 2k.
- Chukchi Sea -7 k, Beaufort Sea +3k.
Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas 23k.
- The Laptev Sea area loss 23 k .
- The Kara Sea area loss 9k.

- The Central Arctic Sea loss down from 20k to 2k.

Other seas
- St Lawrence area is <2k,
- Hudson Bay area loss is more than occasional days of gain.

No drama, really.

[FishOutofWater]

Cyclones cause dispersion of ice. Stormy Junes are generally good for ice. Because this storm hit its max intensity over open water in the Barents sea it advected a warm sector over the Laptev sea causing warm offshore winds and melting so it doesn't fit the general mold of June storms. It very likely caused a large amount of melting. However, the dispersion it caused offset the drop in sea ice extent in the Laptev sea.

Any time there's a large shift in wind direction in the Arctic's melt season  the rate of decline in extent slows down.

Because of dispersion this warm storm caused a volume drop but not an extent drop.

[Pagophilus]

Several on the melting season thread (oren, subgeometer etc.) strongly agree with you.  Winds from the cyclone pushed mobile ice from the northern/eastern Kara into the Barents over the past few days, increasing extent while simultaneously making the ice more vulnerable to melting.  And subgeometer shows images of huge tendrils of melting ice north of Svalbard billowing out into the ocean, which probably also increase measured extent. 

So the extent data are somewhat deceptive right now, but of course still wholly valid for broad year-on-year comparisons.  If I had to bet on this, then I would say that extent is probably going to drop steeply in the near future, putting this year in 'first' place at some point in June.  I hope I am wrong, and who knows what will happen past that ... I certainly don't.

Cyclones cause dispersion of ice. Stormy Junes are generally good for ice. Because this storm hit its max intensity over open water in the Barents sea it advected a warm sector over the Laptev sea causing warm offshore winds and melting so it doesn't fit the general mold of June storms. It very likely caused a large amount of melting. However, the dispersion it caused offset the drop in sea ice extent in the Laptev sea.

Any time there's a large shift in wind direction in the Arctic's melt season  the rate of decline in extent slows down.

Because of dispersion this warm storm caused a volume drop but not an extent drop.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 10^th, 2018: 10,389,973 km², a drop of -22,786 km².
2018 is the second lowest on record.
2018 has 199,592 km² more than 2016 and 152,322 km² less than 2015.

[gerontocrat]

JAXA Extent 10,389,973 km2（June 10, 2018）

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.50 million km2, 150k below the average for the last 10 years. Consistently slightly slower than or at average daily melt, a very low 36k and 25k and 44k and 23k in the last 4 days.
- 2017 was a slow year also, but 2018 extent is a much reduced 172k (1.6%) below 2017,
- 2012 extent has dropped from 279k to 177k km2 more than 2018 on this date. We are now truly in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 696k more than 2018 on this date but melt accelerated later than in 2012,
- on average 37% of the melting is done for this season - still a long way to go, on average 96 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.19 million km2 as opposed to 4.07 million km2. The range of outcomes from the last 10 years remaining melt is 3.0 to 4.4 million km2.

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. Meanwhile extent loss for the last 4 days has been very much below average.

[gerontocrat]

NSIDC Total Area as at 10th June (5 day trailing average) = 9,349,082 km2

Area loss 63k, 42k in the Central Seas

Pacific Side
- The Okhotsk Sea area is 18 k.
- The Bering Sea area is 3k.
- Chukchi Sea -1 k, Beaufort Sea +1 k.
Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas 17k.
- The Laptev Sea area loss 27 k .
- The Kara Sea area loss 4 k.

- The Central Arctic Sea loss 3k.
- The Canadian Archipelago - first significant loss of the season - 8k

Other seas
- St Lawrence area is <2k,
- Hudson Bay area loss is more than occasional days of gain.

No drama, really. But of note is -
- that area loss far exceeds extent loss in the Central Seas, while the opposite sometimes happens in the peripheral seas. In total, area loss is still consistently ahead of extent area loss. Whoops.

- the Laptev Sea Ice is disappearing fast.

[Phil.]

<em> In total, area loss is still consistently ahead of area loss.</em>??

[gerontocrat]

Ok, clever-clogs.

<em> In total, area loss is still consistently ahead of extent area loss.</em>??

[Hyperion]

With warm and moist air flooding in off all continental coasts and strong winds flowing out into Atlantic and Pacific side kill zones the pack is sprawling outwards and big extent losses will no doubt shortly follow the big volume losses that are no doubt already in progress.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 11^th, 2018: 10,375,064 km², a drop of -14,909 km².
2018 is the second lowest on record.
2018 has 220,120 km² more than 2016 and 90,032 km² less than 2012 (Which appears for the first time).

[gerontocrat]

JAXA Extent 10,375,064 km2（June 11, 2018）

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.52 million km2, 180k below the average for the last 10 years. That is a significant amount. Consistently slightly slower than or at average daily melt, a very low 36k and 25k and 44k and 23k and now just 15kin the last 5 days.
- 2017 was a slow year also, but 2018 extent is a much reduced 127k (1.6%) below 2017,
- 2012 extent has dropped from 177k to just 90k km2 more than 2018 on this date. We are now truly in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 684k more than 2018 on this date but melt accelerated later than in 2012,
- on average 37% of the melting is done for this season - still a long way to go, on average 96 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.22 million km2 as opposed to 4.11 million km2. The range of outcomes from the last 10 years remaining melt is 3.1 to 4.5 million km2.

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth. Meanwhile extent loss for the last 5 days has been very very much below average.

Indeed, if one look at this extent data only for a view of the September minimum one would be thinking more like 4.5 million rather than circa 4.0 million km2 a week or two ago.

[DavidR]

[ADS-NIPR-JAXA] ASI Extent.
2018 has 220,120 km² more than 2016 and 90,032 km² less than 2012 (Which appears for the first time).

That's the first  time this year 2012 has appeared in the lowest three for the day. It currently has a total of 150 days in the lowest three compared to 2018's 154. 2018 can only increase its number from here while 2012 is likely to drop a few. 2018 currently has the third highest number in the top 3 behind 2016 (276) and 2017 (186).  2018 could catch 2017 (with 174 each) on July 1st.  2012 has only two century breaks left in this run before dropping back to an average rate of decline for the remainder of the month.  2018 needs to lose 152K in the next two days to retain second lowest place but we have seen it kick off when threatened before.

Still it is what happens in September that counts.

[gerontocrat]

An illustration of why for the Central Seas of the CAB especially area is so much better as an indicator of the reality.

I will be posting more on area later today - but wait small, biznis to do first. (Why is retirement so bloody busy?)

[Pagophilus]

Terrific graph.  Shows as clearly as any other chart I have seen why looking at extent right now is not so useful.  The digression in trends since June 7 is quite dramatic.

Also, while that extent trend appears linear over this period, the area trend has an ominously exponential look to it... 
 

 

An illustration of why for the Central Seas of the CAB especially area is so much better as an indicator of the reality.

I will be posting more on area later today - but wait small, biznis to do first. (Why is retirement so bloody busy?)

[gerontocrat]

NSIDC Total Area as at 11th June (5 day trailing average) =  9,257,434 km2

Area loss 92k, 61k in the Central Seas Wow?
Pacific Side
- The Okhotsk Sea area is 18 k.
- The Bering Sea area is 3k.
- Chukchi Sea +2 k, Beaufort Sea 0 k.
Pacific side stalled...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas 12k.
- The Laptev Sea area loss 27 k again  .
- The Kara Sea area loss 11 k.

- The Central Arctic Sea loss 13k.
- The Canadian Archipelago - 2nd significant loss of the season - 10k

Other seas
- St Lawrence area is <2k,
- Hudson Bay area loss 19k, but still well behind 2010's average area.

But of note is -
- that area loss far exceeds extent loss in the Central Seas (see above posting), while the opposite sometimes happens in the peripheral seas. In total, area loss is still consistently ahead of extent loss. .

- the Laptev Sea Ice is disappearing really fast.

[gerontocrat]

Time to rest the eyes from all those numbers a bit. Some area graphs.

Examples of leaders and laggards this melting season.

[Stephan]

Maybe that enhanced area loss will soon become an enhanced extent loss when all these smaller ice packs along the border between open seas and the more or less compact CAB ice will melt out due to a higher surface to volume ratio?
I think the next two weeks should decide whether we will have another "slower" year as 2017 was or whether the whole thing speeds up and becomes more like 2016, 2007 or even 2012...

[Buddy]

FYI ..... ending Arctic sea ice EXTENT 1984 vs 2012..... and where we are NOW in CONCENTRATION (I know.... extent is NOT concentration).  The concentration shows a better highlight of where the ice will melt NEXT (the light blue areas show up as "white" on the extent).

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

June 12^th, 2018: 10,378,230 km², a small increase of 3,166 km².
2018 is the third lowest on record and very close to the fourth lowest.

Lowest      Year         Extent       Difference
1st.         2016       10,130,495    -247,735
2nd.        2012       10,342,187      -36,043
4th.         2017       10,382,216         3,986

[gerontocrat]

JAXA Extent 10,378,230 km2（June 12, 2018）

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.51 million km2, 250k below the average for the last 10 years. That is a significant amount. Consistently slightly slower than or at average daily melt, a very low 36k, 25k, 44k, 23k and 15k in the last 5 days, and now an increase of 3k.
- 2017 was a slow year also, but 2018 extent now just 4k (0.0%) below 2017,
- 2012 extent has changed from 90k km2 to juts 36kmore than 2018 to on this date. We are now truly in the time (2nd week of June) when 2012 extent loss accelerated.
- 2007 has a similar story - extent 647k more than 2018 on this date but melt accelerated later in the season than in 2012,
- on average 38% of the melting is done for this season - still a long way to go, on average 96 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.28 million km2 as opposed to 4.18 million km2. The range of outcomes from the last 10 years remaining melt is 3.2 to 4.5 million km2.

All is confusion ?:- (I am confused, anyway)

On 11th June NSIDC daily area loss was 90k. I expect (ha-ha)something like that again for the 12th.

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth.

Meanwhile extent loss for the last 5 days has been very, very much below average. Indeed, if one look at this extent data only for a view of the September minimum one would be thinking more like 4.5 million rather than circa 4.0 million km2 a week or two ago.

I recommend readers have a good long read of the melting season thread over the last few days - melting ponds / surface water confusing the area data? Ice spread out confusing the extent data?

Time will make things clearer but I think my choices for the June poll for the September minimum requires "Mystic Meg's" assistance urgently.

[Brigantine]

- Extent loss for the melting season to date is, at 3.51 million km2, 250k below the average for the last 10 years. That is a significant amount.

A whole bin!

[Alexander555]

Maybe there is an explanation for the Jaxa data, that's about that 15 % cover. There is less ice than normal on the Bering side, and on the Atlantic side. The ice at the siberian side is thicker than normal. And the ice on the Greenland side is backed by a big chunk of ice. So that should be the last to go. And first you had that cyclon. And now the last few days the wind is blowing the ice further into the open ocean.

[gerontocrat]

AREA VS EXTENT

More than one post today as this area and extent variation is getting really interesting.

NSIDC Total Area      as at 12th June (5 day trailing average) =  9,167,062 km2
NSIDC Total EXTENT as at 12th June (5 day trailing average) = 10,959,702 km2


AREA     total loss 90k, 63k  loss in the Central Seas,  9 k loss in the periphery
EXTENT total loss 30k,   4k  gain in the Central Seas, 36 k loss in the periphery

See the graphs and the tables for a bit more history.

Extent loss is playing catch up in the peripheral seas.
Is Area loss in the Central Seas an exaggeration due to melt ponds?
Is Extent loss in the Central Seas under-recorded due to the 15% rule?

Lots of discussion in the melting season thread.
Perhaps Wipneus with the AMRS2 data will shed some light.

But this is the NSIDC data. Make of it what you will.