2018 sea ice area and extent data

[gerontocrat]

Yeah, the leap day problem is a pesky one. To solve it for CT SIA, I had to convert all the dates to metric time. And still you get one line too many for complete uniform graphing for the data. I just split the difference over the whole year... But to be very accurate, technically, you'd need to start to number the datapoints of a year at six hour intervals on Metric time over the four year period. Thus you'd get staggered points of datevalues on graphs of several years. I figured that as I did not know the exact times of data acquisition, though the satellites orbit is very regular, this didn't matter. Anyway the fixed year+date/365 or date/366 made for prettier graphs at least with some illusion i knew what i was doing. And please don't ask me what to do about year 2100 which doesn't fit to the Julian calendar system.

FAR TOO DIFFICULT for my Pooh-Bear Brain. Mind you, I got caught on March 1 when doing my semi-automatic transfer  from the NSIDC spreadsheets to my copies - NSIDC does, of course have the Feb 29 line in all their data.

[Pmt111500]

FAR TOO DIFFICULT

(clip)

Yeah, I dropped the line too on some versions of the spreadsheet and worked it out as a puzzle to solve. The calendar system isn't too user friendly on science. Pmt on the evening of the day that ends at 12018.169863 (year.metric) of Holocene Era.

[gerontocrat]

FAR TOO DIFFICULT

(clip)

Yeah, I dropped the line too on some versions of the spreadsheet and worked it out as a puzzle to solve. The calendar system isn't too user friendly on science. Pmt on the evening of the day that ends at 12018.169863 (metric) of Holocene Era.

It could be worse - just think if we were changing from the Julian to the Gregorian Calendar.

The Julian Calendar in Modern Society. Although the Gregorian calendar has become the international civil calendar, the Julian calendar was still used by some countries into the early 1900s. Some Orthodox churches still use it today to calculate the dates of moveable feasts, such as the Orthodox Church in Russia.

[Dharma Rupa]

Seems to me if you wanted a rational dating scheme for the datatypes involved you'd want to tie it to the solar cycle (solstices, equinoxes, and the like) and completely ignore the Gregorian calendar -- but unfortunately, converting all the datasets to start on December 21 is beyond my pay grade.
 

[gerontocrat]

Seems to me if you wanted a rational dating scheme for the datatypes involved you'd want to tie it to the solar cycle (solstices, equinoxes, and the like) and completely ignore the Gregorian calendar -- but unfortunately, converting all the datasets to start on December 21 is beyond my pay grade.

But the Equinox doesn't ALWAYS happen on December 21.

Better stop this, I feel the approach of Neven with his snipper.

[Neven]

I wish I could snip February 29th once and for all. 

But yes, a bit more on-topic, s'il vous plait.

[gerontocrat]

I wish I could snip February 29th once and for all. 

But yes, a bit more on-topic, s'il vous plait.

Oui M'sieur, c'est on-topic

JAXA DATA as at 3rd March, extent 13,729,800 km2, down 7k.

Baffin (including Newfoundland) region still very warm ? cci-reanalyzer says so (but not for long), especially around Newfoundland, and above zero temperatures well up into the Barents Sea. NSIDC regional data may confirm.

Extent is 150k less than the 2017 maximum on 6th March, and 84k less than 2017 on the 3rd March. On average (last 10 years), 12 days, 1.1% and 0.11 million of extent gain to go, leading to a maximum of 13.84 million km2, 40k less than 2017's record low maximum.
BUT the strong NAO which even I can see is in play, may extend the freezing season as the Arctic becomes a lot colder.

2018 extent still in its lonely furrow, 84k less than 2017, but only 9k less than 2015 which lost extent over the next few days.So likely to be second to 2015 for a bit very soon - like today March 4th.

PIOMAS update - "Wherefore Art Thou, PIOMAS".

[gerontocrat]

NSIDC Data as at 3rd March 2018.

Extent 14.227 million km2, down 74k, that's down 130k in 2 days
and 179k less than 2017 on that date
and 220k less than the 2017 maximum on 5th March

Regional Sea extent
Baffin down 25 k, Greenland up 23k, others not a lot of change, so where was the extent loss?

[Steven]

Regional Sea extent
Baffin down 25 k, Greenland up 23k, others not a lot of change, so where was the extent loss?

The regional numbers that you posted are based on 5-day running averages.

Wipneus has some regional data for the 1-day (unfiltered) NSIDC extent.  This shows that in the last two days there have been extent gains in the Central Arctic Basin and Greenland Sea,  and extent losses in the Baffin/Labrador, Okhotsk and Bering Sea.



Data: https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_arc_nt_detail.txt
Graph: https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc-nt-regional-extent-overview.png

[gerontocrat]

The regional numbers that you posted are based on 5-day running averages.

MEA CULPA

I import the data from the NISIDc Sea Ice Tools page entitled:-
Daily sea ice extent, by region (Sea_Ice_Index_Regional_Daily_Data_G02135_v3.0.xlsx)

It said daily, so I assumed daily, as the overall data file has both daily and 5-day in it.

But now I have read the detailed documentation - oh dear. I was wrong. It's a pity as the Arctic is now in such a mobile state that 5-day trailing averages may mask abrupt change.

Ho hum. will have to add that proviso to the postings.

[gerontocrat]

JAXA DATA as at 4th March, extent  13,690,835 km2, down 39k.

Extent is down by just under 70k in the last three days. The possibility that March 1 was the maximum extent at 13,759,813 km2 cannot be discounted. BUT the strong NAO which even I can see is in play, may extend the freezing season.

2018 extent is now 2k greater than 2015, i.e. no longer is 2018 extent in its lonely furrow. Extent is 139k less than 2017 on the 4th March. On average (last 10 years), 11 days, 1.1% and 0.11 million of extent gain to go, leading to a maximum of 13.80 million km2, 80k less than 2017's record low maximum.

March is when Arctic ice extent dithers, so March 1 max? Extended freezing season? You pay yer money and you takes yer choice.

ps: This is the time of year when the table produces the odd impossible result.


URGENT : PIOMAS update - "Wherefore Art Thou, PIOMAS".

[gerontocrat]

JAXA Regional Data (peripheral seas)
N.B. 5 day trailing average

Baffin extent loss 101k in 6 days.
Greenland Sea extent gain 95k in 6 days.

perfect switch round from previous days.

[Gray-Wolf]

When I see ice enter Greenland I always say 'Tara!'

The same is true for Baffin ( it ain't running back up Nares and into the basin!)

The ragging peripheral areas has been seeing must lead to an amount of 'collapse and spread' before that ice thins to less than 15% cover and blinks out.

There is also the mixing of the waters at the ice edge as swells and waves do their work feeding a constant supply of warmer, saltier water to work on the ice now liberated?

Okhotsk, Baffin,Greenland and Barentsz are all one way tickets to oblivion for the ice.

We may see cold air over the central basin and that may lead to some thickening of the ice there but the peripheral areas will still be plagued by LP systems and ever warmer background temps.

We may see a very slow start to melt season though as , over past years, it was peripheral areas that made up initial losses? This year we are low on peripheral ice ( apart from Baffin/Okhotsk) so losses will be slow until the main basin melt kicks in?

[magnamentis]

When I see ice enter Greenland I always say 'Tara!'

The same is true for Baffin ( it ain't running back up Nares and into the basin!)

The ragging peripheral areas has been seeing must lead to an amount of 'collapse and spread' before that ice thins to less than 15% cover and blinks out.

There is also the mixing of the waters at the ice edge as swells and waves do their work feeding a constant supply of warmer, saltier water to work on the ice now liberated?

Okhotsk, Baffin,Greenland and Barentsz are all one way tickets to oblivion for the ice.

We may see cold air over the central basin and that may lead to some thickening of the ice there but the peripheral areas will still be plagued by LP systems and ever warmer background temps.

We may see a very slow start to melt season though as , over past years, it was peripheral areas that made up initial losses? This year we are low on peripheral ice ( apart from Baffin/Okhotsk) so losses will be slow until the main basin melt kicks in?

about as you say which will result in an ever longer "quasi-plateau"  lasting from about now till ever later. if it were not for ice once could easily project what happens to an ever flattening curve with an ever longer plateau

[gregcharles]

PIOMAS update - "Wherefore Art Thou, PIOMAS".

PIOMAS =  Pan-Arctic Ice Ocean Modeling and Assimilation System, so that's why (aka wherefore) PIOMAS, but, "What's in a name?" A rose by any other name would have the same total ice volume.   

Or did you mean "where"? 

[gerontocrat]

PIOMAS update - "Wherefore Art Thou, PIOMAS".

PIOMAS =  Pan-Arctic Ice Ocean Modeling and Assimilation System, so that's why (aka wherefore) PIOMAS, but, "What's in a name?" A rose by any other name would have the same total ice volume.   

Or did you mean "where"? 

I was being lazy, using it when knowing that it is a common misconception of the meaning. Unfair of you to pick me up on it, so "Lay off, MacDuff!"

[gerontocrat]

JAXA DATA as at 5th March, extent   13,629,925 km2, down 61k.

Extent is down by 130 k in the last four days. The possibility that March 1 was the maximum extent at 13,759,813 km2 is moving from possibility to probability. One more day of extent drops would be it ? It is a classic transition, the CAB getting colder i.e. additional freezing, with peripheral seas warming and melting.

2018 extent is back down to 35k less than 2015, i.e. back in in its lonely furrow. Extent is 229k less than 2017 on the 5th March. It is difficult to see extent gain from now greater than that.

On average (last 10 years), 10 days, 1.0% and 0.10 million of extent gain to go, leading to 13.73 million km2, 30k less than the 2018 current maximum of 13.76 million km2 on March 1st..

ps: 2018 extent is currently just over 1 million km2 LESS than 2012, and yet 2012 ended up with the record lowest minimum extent to date.

[DavidR]

Nothing is off the cards for the next  few weeks. 2014 dropped 240K over the next few days then rose  440K to  set its winter maximum. Weather is a massive factor over the remainder of the month.We won't be sure of the maximum for a few weeks yet.

This year has been so unusual that anything  could happen. Having said that  2018  does seem determined to hang on to  first  place and definitely  not fall  below 2nd lowest.

[gerontocrat]

JAXA Regional Data (peripheral seas) as at 5th March
N.B. 5 day trailing average

Baffin extent loss 125k in 6 days.
Greenland Sea extent gain 1055k in 6 days.

perfect switch round from previous days continues. Bering and Okhotsk also going down

NISIDC Arctic daily extent  14.169 million km2, down 58k on the 5th and down 188k in the last four days.

[gerontocrat]

ESSENTIAL READING.

NSIDC HAS POSTED THE FEBRUARY ANALYSIS

https://nsidc.org/arcticseaicenews/

[gregcharles]

I was being lazy, using it when knowing that it is a common misconception of the meaning. Unfair of you to pick me up on it, so "Lay off, MacDuff!"

Yes, I guessed that already.

"Just", Measure for Measure, II, 2
"giving", As You Like It, III, 5
"you", Comedy of Errors, I, 2
"a hard", Merchant of Venice, II, 2
"time.",  All's Well That Ends Well, I, 1

By the way, thanks for all you do in this thread. It's the first place I look every morning!

[Juan C. García]

March 6^th: JAXA drop of 17,592 km².
Now 147,480 km² lower than March 1^st.
And 2018 is the lowest on record.   

[gerontocrat]

JAXA DATA AS AT 6TH MARCH Extent  13,612,333 km2

Extent is down by 147 k in the last five days. The possibility that March 1 was the maximum extent at 13,759,813 km2 has moved from possibility to probability.

2018 extent is now 48k less than 2015, i.e. staying in its lonely furrow. Extent is 266k less than 2017 on the 6th March, the day of the 2017 maximum. It is difficult to see extent gain from now greater than that, i.e. 2018 maximum will be a record low. The only question is by how much? 120k if March 1 was the minimum, less if extent increases by more than 147k from now.

On average (last 10 years), 9 days, 0.8% and just 73,000 km2 of extent gain to go, leading to 13.69 million km2, 70k less than the 2018 current maximum of 13.76 million km2 on March 1st..

The second table attached is a look forward to the 2018 minimum. Using the last 10 years data that minimum would range from 2.1 to 4.2 million km2, and with average melt 3.76 million, a clear 2nd lowest behind 2012. 2018 extent is currently 1.05 million km2 LESS than 2012, and yet 2012 ended up with the record lowest minimum extent to date.

Is the ice in good condition to meet the melting season compared with 2017? Extent says no, volume says yes. Damage to the ice especially during February says no. I expect an outpouring of hypotheses when Neven lets the genie out of the bottle by opening the 2018 melting thread.

[oren]

Gerontocrat, in calculating potential rises for the table, are you also looking at years that went up somewhat but have not reached a new maximum? I am specifically asking about the yellow line of 2015.

[gerontocrat]

Gerontocrat, in calculating potential rises for the table, are you also looking at years that went up somewhat but have not reached a new maximum? I am specifically asking about the yellow line of 2015.

I have commented before on my postings that the spreadsheet can produce odd results when we are at the time when some years have reached maximum (or minimum) and some have not. The spreadsheet simply looks at the difference between extent on the day and extent at the maximum (minimum) to produce the additional extent gain (or loss) to come. No problem until the season is in transition .

If extent gain to maximum is +ve (i.e. max not reached yet), the spreadsheet uses that figure. If maximum has been reached, the spreadsheet says extent gain to come is zero. (The reverse for the minimum in September)

This has the effect of overestimating average gain as extent loss from years already beyond maximum is excluded. I was content with that, as it is a small error on the side of a conservative view. But the same methodology underestimates potential gain from an oddity like 2015 (maximum on 16th Feb and 29 days later extent loss just 41 k but a huge dip in the middle.

What to do about such oddities? Change the spreadsheet or admit the limitation. Methinks I should have highlighted 2015 as one of those years where standard operating procedures do not apply.

[oren]

Thanks for the clarification. 2015 was indeed peculiar in its behavior.
Looking at its numbers and assuming a repeat performance, this year could surpass its Mar 1 maximum, and even reach/surpass just about the 2017 maximum. We'll see, though I'd be very surprised if it actually happens.

[gerontocrat]

JAXA Regional Data (peripheral seas) as at 6th March
N.B. 5 day trailing average

The table below has changed a bit, and ordered by peripheral sea West to East, i.e. Okhotsk & Bering, Baffin and St. Lawrence, Greenland and Barents. Chukchi is out (CAB sea) and St. Lawrence in (peripheral sea). Will need a second table soon for the CAB seas.

(Sorry Sleepy, the Baltic didn't get an invite).

Bering down 52k in four days, Okhotsk down 32k also in four days.
Baffin extent loss 144k in 8 days plus St Lawrence 32k in 4 days.
Greenland Sea extent gain 112k in 8 days, Barents up 34k in 3 days.

perfect switch round from previous days continues.

NISIDC Arctic daily extent  14.152 million km2, down 17k on the 6th and down 205k in the last five days.

[oren]

I still can't get over the early and low max in the Bering.

[charles_oil]

Just looking at Chartic .. .2010, 12, 13, 14, 15, 16 I was surprised to see that all had "bounces" in area after a significant drop as we have seen in the last few days. 2011 & 17 were the only ones that didn't.

[Juan C. García]

JAXA March 7^th:

Now ASI at 13,609,296 km².
A small drop of -3,037 km².
But another day has passed.
In my opinion, the recovery is not likely to happen now, so the maximum was on March 1^st.
2018 continues to be the lowest on record.

Edit:

According to Hautbois analysis, it could still be possible... 
March 7^th = day 66, according to JAXA (Jan 1^st=Day 0, February has 29 days)

Beware the false Max!!

Just for laughs I thought I'd look over the last 10 years to see how often there was a 'cheeky peak' that might have got people thinking 'we've hit maximum', followed by a dip, and then followed by another peak that turned out to be the real maximum.

There were 5 that did that, and a sixth that nearly did, but not quite.

2008: 14.75m sq.km on day 62, lost 76k, then gained 100k.
2010: 14.651 on day 68, then lost 180k, then gained 217k
2011: 14.108 on day 67, then lost 181k, then gained 200k
2013: 14.513 on day 60 (March 1st, people), then lost 207k, then gained 217k.
2014: 14.255 on day 65, then lost 240k, then gained 433k as if to say 'haha just messin' with ya'

The 'not quite' year was 2012 - it dropped 199k, then gained 183k, so peak 2 wasn't quite the max in the end.

The 10 years before that were less tricksy. There were only three false max years; 1999 and 2003 stand out, overturning drops  of 307k and 258k respectively from an initial false max.



(Now, what was I meant to be doing....)

[gerontocrat]

As Juan C. García has noted above, JAXA extent on March 7th is 13,609,296 km2, a small drop of 3k. But it is still a drop, it is a day later in the year, reducing the chances of a late large extent increase.

But as Hautbois has pointed out, extent can go up and down and then up again by fairly large amounts at this time of year. I look at it more like waves - that happen all year, perhaps reflecting waves of weather flowing over the Arctic.

So is Arctic extent due to go up for a bit, and if so, by how much ?

And as I have noted before , once it is the time of year when in some years the maximum is done, but in other years not, the projections I post become somewhat meaningless. So I am  posting the projections for the September minimum instead, but without comment.


Meanwhile, extent at 7th March 2018 is 50k less than 2015, 249k less than 2016, and 257k less than 2017 extent on that date.

[gerontocrat]

WHOOPS !!! NSIDC Regional Data (peripheral seas) as at 7th March
N.B. 5 day trailing average

Bering down 61k in fivedays, Okhotsk going back up (4k).
Baffin extent loss 157k in 9 days plus St Lawrence down 52k in 5 days.
Greenland Sea extent gain 115k in 9 days, Barents up 48k in 4 days.

perfect switch round from previous days continues.

NISIDC Arctic daily extent  14.204 million km2, up 52k.  A second max starts to form?

[Buddy]

Bering down 61k in fivedays,

The condition of the Bering this year has to have a negative effect on the CAB.

[oren]

Gerontocrat, I am suddenly not sure... Is your regional data from JAXA, NSIDC, or a combination?

[gerontocrat]

Gerontocrat, I am suddenly not sure... Is your regional data from JAXA, NSIDC, or a combination?

Blast and damn. No sleep last night and brain wiring shorted. My rule is NEVER mix NSIDC and JAXA data in one post. It was NSIDC data. Post corrected.

Thanks for spotting it.

[Juan C. García]

JAXA March 8^th:

After 6 consecutives drops on March, for the first time there is an increase in ASI, of 18,984 km². JAXA SIE now at 13,628,280 km².
2018 has to increase more than 131,533 km², in order to have a new max.

2018 is still first of record, now 21,589 km² below 2015. But 2015 had drops of -20,672 and -5,429 km² on March 9th and 10th. So maybe 2018 will be second lowest on record tomorrow or the day after.

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 8th March
N.B. 5 day trailing average

Bering down 61k in five days, Okhotsk going back up (25k).
Baffin extent loss 166k in 10 days plus St Lawrence down 71k in 6 days.
Greenland Sea extent gain 113k in 9 days, Barents up 63k in 5 days.

perfect switch round from previous days continues.

NISIDC Arctic daily extent  14.289 million km2, up 86k (8 mar) + 51k (7 mar).  A second max starts to form?

Interesting times

[gerontocrat]

JAXA extent on March 8th is  13,628,280 km2, an increase of 19k. But March 1 is still the current max, it is a day later in the year, reducing the chances of a late large extent increase.

But as Hautbois has pointed out, extent can go up and down and then up again by fairly large amounts at this time of year. We looked at 2015. I should have looked at March 2014 as well.

(Note:NSIDC daily extent up 137k in two days)

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 9th March
N.B. 5 day trailing average

Activity in extent in decline - and only exists in the peripheral seas. Net increase 21 k.

NISIDC Arctic daily extent  14.319 million km2, up 30 k (9 March), 86k (8 mar) + 51k (7 mar).  A second max starts to form or is the increase running out of steam?

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 10th March
N.B. 5 day trailing average

Activity in extent increases   (partly effect of using 5 day trailing average ?)- and only exists in the peripheral seas. (CAB continues to get colder).  Net increase in periphery 32 k, mainly in Bering and Okhotsk

NISIDC Arctic daily extent  14.303 million km2, down 16 k (10th March) after going up 30 k (9 March), 86k (8 mar) + 51k (7 mar).  Now 54 k less than its maximum to date on 5th March.

A second max starts to form or is the increase running out of steam? What a tease.

ps: Note the blob of warmth between NE Greenland and Svalbard on the map- that is a persistent feature.

(Jaxa continues its little holiday - back to tomorrow?)

[gerontocrat]

JAXA extent on March 11th is  13,780,135 km2, A new maximum for the year by 20 k. Typical that JAXA was off-line when a big change happens.
 
In the last three days extent increased by 32k ( 9 Mar ),  80k (10 March) and  40k (11th March), very high for this time of year. As a result 2018 extent is now 132 k greater than 2015 and only just below 2017 as at 11th March.

The table still shows a probability of a record low maximum (just). The average extent gain is totally distorted by just one year, 2014 where extent grew by 330k from 11th March to its maximum on 19th March. Given the current chilly outlook in the Arctic this is a real possibility. (see image for the equinox below)

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 11th March
N.B. 5 day trailing average

Activity in extent increases   (partly effect of using 5 day trailing average ?)- and only exists in the peripheral seas. (CAB continues to get colder).  Net increase in periphery 26 k, entirely due to Bering + 31k, and Okhotsk +8k. All other seas extent down.

NISIDC Arctic daily extent 14.289 million km2, down 14k, (11th March), down 16 k (10th March) after going up 30 k (9 March), 86k (8 mar) + 51k (7 mar). 

Now 68 k less than its maximum to date on 1st March. 
Very different from JAXA, but the poll was the date of the JAXA maximum.

A second max continues to form or is the increase running out of steam? What a tease.

[gerontocrat]

JAXA extent on March 13th is  13,837,866 km2, yet another  new maximum for the year . Typical that JAXA keeps going off-line when big changes happen.
 
In the last two days extent increased by 27k ( 12 Mar ),  and  31k (12th March),  high for this time of year. As a result 2018 extent is now 150 k greater than 2015 and greater than 2017 by 22k on this date.

The table now shows a probability of amaximum of 13.89k, not quite a record low. The average extent gain is totally distorted by just one year, 2014 where extent grew by 150k from 13th March to its maximum on 19th March. Given the current chilly outlook in the Arctic this is a real possibility. (see image for the equinox below)
On the other hand, as regards extent it is what will happen in the peripheral seas that matter at this time of year.

[Neven]

What are the chances of JAXA SIE going over 14 million km2?

[gerontocrat]

What are the chances of JAXA SIE going over 14 million km2?

All about the peripheral seas - at the moment the Bering Sea.

NSIDC Regional Sea Data - 5 day trailing average
Data as at 13th March

Bering Sea extent up by  30,991 km2 (12th March) and 33,081  km2(13th March).
Total increase (all peripheral seas)  36,715 km2 (12th March) and 34,398 km2 (13th March).
 
Extent gain (all other seas) 2,235 km2

And tomorrow ??????????????
 

[gerontocrat]

JAXA extent on March 14th is  13,853,284 km2, yet another  new maximum for the year . Extent is fourth lowest for the day, greater than 2015 by 167k, 2016 by16k , and 2017 by 18k.

Extent increased by 15k, less than half the previous 6 days average gain of  38k. Perhaps the tide is turning to extent reductions?

The table now shows a a maximum of 13.90k, not quite a record low. In 6 out of the last 10 years maximum had been reached, i.e. extent loss was now happening. In 4 years, significant extent gain was still to occur.

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 14th March
N.B. 5 day trailing average

Activity in extent increases  - and still only exists in the peripheral seas. .  Net increase in periphery 43 k, entirely due to Bering + 31k, and Barents + 18k. Bering Sea extent up by 149 k in just 5 days.

NISIDC Arctic daily extent  14,504,000 km2, up 51,000 jm2. (Up 215,000 km2 in just 3 days. Extent is now 57 k greater than the record low maximum in 2017 on the 5th March.

[gerontocrat]

JAXA extent on March 15th is  13,875,677 km2, yet another  new maximum for the year . Extent is fourth lowest for the day, greater than 2015 by 151k, 2016 by just 1k , and 2017 by 58k.

Extent increased by 22k, making 2017 extent just 2,610 km2 less than the record low maximum of 2017. The table now shows a a maximum of 13.91k, not quite a record low. In 6 out of the last 10 years maximum had been reached, i.e. extent loss was now happening. In 4 years, significant extent gain was still to occur.

The vagaries of the weather in the peripheral seas will determine the final result.

[Juan C. García]

JAXA extent on March 15th is  13,875,677 km2, yet another  new maximum for the year . Extent is fourth lowest for the day, greater than 2015 by 151k, 2016 by just 1k , and 2017 by 58k.

No that it is very important, but on March 15^th, the year 2018 is the fifth lowest. 2006 is also below 2018.

                  March 15         vs. 2018
2018        13,875,677   
2006        13,874,040          -1,637
2015        13,724,438      -151,239
2016        13,874,820             -857
2017        13,818,067        -57,610

P.S. And there is still some anomaly cold weather on the following days... 

[gerontocrat]

NSIDC Regional Data (peripheral seas) as at 15th March
N.B. 5 day trailing average

Activity in extent stays high  - and still only exists in the peripheral seas. .  Net increase in periphery 41 k, due to Bering + 16k, Okhotsk + 12k,  and Barents + 15k. Bering Sea extent up by 165 k in just 6 days. Extent gain in CAB seas a mind-boggling 132 km2 (which is, I suspect, not statistically significant.)

SNOW
It is being said by some commentators that loads of snow in N. America, especially Quebec Province, will slow down melt. It is obviously logical. However, the two peripheral seas with the most significant and persistent melt in March to date are The St. Lawrence, over half extent gone (down 131 k to just 97k) and Baffin (mainly southern end down 170 k or 12% ). Hudson Bay concentration does not look so good in parts as well.


NISIDC Arctic daily extent  14,502,000 km2, DOWN A WHOLE 2k. The contrast with regional data must be because regional data is  five-day-trailing average.