2018 sea ice area and extent data

[jdallen]

ADS NIPR JAXA, ASI Extent.

April 24^th, 2018: 12,794,137 km², a drop of -9,060 km².
2018 is the second lowest on record.
2018 is 160,465 km² above 2016 and 38,713 km² under 2017.

Interesting how both 2017 and 2018 are currently running in parallel.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

Well, the drop increased today. 

April 25^th, 2018: 12,761,033 km², a drop of -33,104 km².
2018 is the second lowest on record.

2018 is 165,215 km² above 2016 and 65,325 km² under 2017.

[gerontocrat]

JAXA DATA - Extent 12,761,033 km2（April 25, 2018）

Nothing to add to Juan's posting except the tables.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

The drop is getting bigger:

April 26^th, 2018: 12,708,674 km², a drop of -52,359 km².
2018 is the second lowest on record.

2018 is 138,269 km² above 2016 and 101,601 km² under 2017.

[gerontocrat]

JAXA Extent 12,708,674 km2（April 26, 2018）

Nothing to add to Juan's posting except the tables.

[gerontocrat]

NSIDC Arctic Total Extent (daily extent) at 26 April 13.443 million km2.
The contrast with JAXA data is pronounced.

Extent is up by 50k km2 from 4 days before, i.e. extent loss has stalled.

NSIDC AREA DATA (5 day trailing average) AS AT 26 APRIL

Overall area loss has also slowed to about 8k on the 26th. Excluding the Hudson and Okhotsk Seas (often considered as physically separate from the Arctic Ocean) area loss has morphed into area gain.

Total Area  without Hudson and Okhotsk    Date   Area change Km2 18-Apr   -24251 19-Apr   -29493 20-Apr   -24356 21-Apr   76 22-Apr   2531 23-Apr   -190 24-Apr   12677 25-Apr   10548 26-Apr   5304 On any measure of extent or area NSIDC says the Arctic Ocean is having a mini(?)-break from the melting season.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

April 27^th, 2018: 12,679,541 km², a drop of -29,133 km².
2018 is the second lowest on record.
2018 is 180,543 km² above 2016 and 120,798 km² under 2017

[Thomas Barlow]

Is someone still doing the Arctic Ocean extent graph, year to year comparison?
ie. N. Hemisphere sea-ice, but with all peripheral seas and fjords taken out? - eg. Hudson Bay, Greenland Sea, CAA, Baffin Bay, Nares, taken out (only because I think the Arctic Ocean itself, without all that other stuff, is the best way to get an idea of the real state of the Arctic Ocean icepack )

[oren]

Wipneus has nice charts of Arctic Basin (as he defines it) area and extent on his website,  I can post the link tomorrow if you can't find it.
Note at this time of year it's not very useful, it becomes much more interesting during summer.

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

April 28^th, 2018: 12,641,635 km², a drop of -37,906 km².
2018 is the second lowest on record.
2018 is 227,801 km² above 2016 and 116,518 km² under 2017

[oren]

Wipneus has nice charts of Arctic Basin (as he defines it) area and extent on his website,  I can post the link tomorrow if you can't find it.
Note at this time of year it's not very useful, it becomes much more interesting during summer.

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/basin-area-multiprod.png
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/basin-extent-multiprod.png
Note the charts are still not updated for 2018.

[Wipneus]

Note the charts are still not updated for 2018.

Fixed 

[gerontocrat]

JAXA EXTENT 12,641,635 km2（April 28, 2018）

Extent loss continues to dawdle as it has over the last week or so - below average but greater than 2017 so far.

[gerontocrat]

NSIDC Arctic Total Extent (daily extent) at 28 April 13.443 million km2.

Extent is down by 129k km2 from 2days before, i.e. extent loss has resumed. This is not showing in the 5-day area data YET.

NSIDC AREA DATA (5 day trailing average) AS AT 28 APRIL

Overall area loss is a modest 13k on the 28th. Excluding the Hudson and Okhotsk Seas (often considered as physically separate from the Arctic Ocean) area loss has morphed into area gain.

Total Area without Hudson and Okhotsk    Date   Area change Km2 19-Apr   -29493 20-Apr   -24356 21-Apr   76 22-Apr   2531 23-Apr   -190 24-Apr   12677 25-Apr   10548 26-Apr   5304 27-Apr   2900 28-Apr   3416 On any measure of extent or area NSIDC says Arctic Ocean Area is having a mini(?)-break from the melting season at the moment.

Individual Seas
The Okhotsk Sea area loss was 21k (7% of remaining area).
Bering Sea area loss is now less than 2k per day, but that is still around 7% of remaining area er day. The Chukchi is now losing area again, the Beaufort has just started.
Other seas show marginal change.

[Wherestheice]

With all this stalling melt, a big drop seems likely right?

[Juan C. García]

With all this stalling melt, a big drop seems likely right?

Hi, Wherestheice.

In my opinión, 2018 has not stall. 2016 was terrible on April and specially on May. So, it is pretty bad to be the second lowest on record.

Anyway, it is getting late for me and the JAXA data has not being updated yet. So, if anybody gets the information updated, please feel free to post it.
The link is: https://ads.nipr.ac.jp/vishop/#/extent

Thanks!

[oren]

As I have dealings with the Japanese stock market, I happen to know that today is a holiday in Japan, so quite possibly there will be no data release today.
The same could happen on Thursday/Friday/Saturday this week, as all of these are national holidays as well.

[Wherestheice]

With all this stalling melt, a big drop seems likely right?

Hi, Wherestheice.

In my opinión, 2018 has not stall. 2016 was terrible on April and specially on May. So, it is pretty bad to be the second lowest on record.

Anyway, it is getting late for me and the JAXA data has not being updated yet. So, if anybody gets the information updated, please feel free to post it.
The link is: https://ads.nipr.ac.jp/vishop/#/extent

Thanks!

Yes that makes sense. Thanks for reply!

[gerontocrat]

NSIDC Daily Extent dropped by 2k km2 on 29th April

[Daniel B.]

With all this stalling melt, a big drop seems likely right?

Hi, Wherestheice.

In my opinión, 2018 has not stall. 2016 was terrible on April and specially on May. So, it is pretty bad to be the second lowest on record.

Anyway, it is getting late for me and the JAXA data has not being updated yet. So, if anybody gets the information updated, please feel free to post it.
The link is: https://ads.nipr.ac.jp/vishop/#/extent

Thanks!

Yes that makes sense. Thanks for reply!

The melt has stalled if you examine the last week only.  For the season, the total melt is slightly less than average.  However, the lower melt may be entirely due to the lower starting sea ice.  If you plot the melt compared to the maximum, 2018 falls squarely on the trend line.  The largest melts on this date occurred in 1989, 1990, and 1983.  The lowest occurred in 2009, 1999, and 2011.  April melt does not portend anything with regards to the September minimum.

[Juan C. García]

As I have dealings with the Japanese stock market, I happen to know that today is a holiday in Japan, so quite possibly there will be no data release today.
The same could happen on Thursday/Friday/Saturday this week, as all of these are national holidays as well.

Thank you for your answer, Oren.

Again, it is late for me and the JAXA data has not being updated. So, I appreciate if someone else brings the updated information.

The link is: https://ads.nipr.ac.jp/vishop/#/extent
Good night or good morning!

[Kica68]

Hi. Just checked ADS_NIPR on Twitter and found this tweet:

ADS_NIPR‏ @ADS_NIPR · 5h5 hours ago 
5月1日から2日までメンテナンスを実施するためADSのサービスは停止いたします。
ADS services is stopped to do H/W maintenance from May 1st to 2nd.

https://twitter.com/ads_nipr

[gerontocrat]

Hi. Just checked ADS_NIPR on Twitter and found this tweet:

ADS_NIPR‏ @ADS_NIPR · 5h5 hours ago 
5月1日から2日までメンテナンスを実施するためADSのサービスは停止いたします。
ADS services is stopped to do H/W maintenance from May 1st to 2nd.

https://twitter.com/ads_nipr

I hope it is more to do Japan's Golden Week of holidays and they've gone to the beach or the park or.....

Dedication to duty can be overdone.

[gerontocrat]

It is May 1st and I am not out there protesting against something. Shame.

Before I start the notes of where NSIDC area data is at 30th April, Robertscribbler.com says "Major Arctic Warming Event Predicted For the Coming Week". Interestingly, he uses a cci-renalyzer image of the maximum temperatures over the next five days to make his point (maximum temperatures matter more than average temperatures  -says Gerontocrat).

NSIDC Total Area as at 30th April.(5 day trailing average)

The first table attached shows how area loss has increased to 40k on the 30th from less than 20k per day over the last two days. When Hudson Bay and the Okhotsk Sea are excluded, this goes down to a modest 18k.

Pacific Side
The Okhotsk has been losing area at 20k a day for nearly 10 days now, and is at a bit above 25% of its 1980's average maximum. (Graph attached below).
The Bering Sea is now at less than 5% of its average maximum and is now more or less irrelevant.
Instead the Chukchi Sea has lost area at a still modest but significant rate - on the 30th an area loss of 6k.
The Beaufort sea changes are minimal.

Atlantic Side
Baffin Bay has lost modest amounts.

Both the Greenland and Barents seas have gained area.
The Laptev and Kara seas have lost and gained area over the last 10 days.
The Central Arctic has gained area.

If it was not for the 20k a day area loss of ice in the Okhotsk, Arctic Sea Ice area would have increased over the last 10 days. I do call that a stall.

The question is what will the effect be of the major temperature increase on the Atlantic side over the next week ?

[Thomas Barlow]

Note the charts are still not updated for 2018.

Fixed 

Thanks, Wipneus and Oren.
This is great !
To me this is what really counts. The state of the Arctic Ocean.
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/basin-extent-multiprod.png

[Dharma Rupa]

It is May 1st and I am not out there protesting against something. Shame.

I know this is off-topic, but, it is May 1st and I am going to have my yearly shave -- head and beard.

[DavidR]

Reviewing April it seems to  be the worst predictor for summer extent. The attached graph shows the rankings (1 = Lowest) for the past 15 years based on the 31 year NSIDC record since they switched to daily reporting.  As can be seen some years ranked as high as 24.  Up until late March none of these years had ranked above 19. From the end of May only 2004 will rank higher than 18 until the end of September.

As an aside extent drops on May 1st have been around 200K for the last few years  for technical reasons so  we should expect a big drop tomorrow. 2017 dropped 259K between April 30 and May 1st.

[gerontocrat]

Hi. Just checked ADS_NIPR on Twitter and found this tweet:

ADS_NIPR‏ @ADS_NIPR · 5h5 hours ago 
5月1日から2日までメンテナンスを実施するためADSのサービスは停止いたします。
ADS services is stopped to do H/W maintenance from May 1st to 2nd.

https://twitter.com/ads_nipr

I hope it is more to do Japan's Golden Week of holidays and they've gone to the beach or the park or.....

Dedication to duty can be overdone.

Jaxa is on holiday but they have just put up data for the 29th April. Extent down by a slightly below average 39k.

Perhaps they will put Apr 30 and May 1 during the next few hours?

[Juan C. García]

[ADS-NIPR-JAXA] ASI Extent.

Date             2006            2016              2017             2018        Drop 2018
April 28   12,782,805    12,413,834    12,758,153    12,641,635    
April 29   12,730,348    12,347,980    12,713,247    12,602,757    -38,878
April 30   12,661,451    12,293,447    12,674,471    12,574,787    -27,970
May   1    12,558,242    12,195,413    12,648,560    12,556,176    -18,611
May   2    12,444,466    12,164,312    12,585,016    12,521,612    -34,564


May 2^nd, 2018: 12,521,612 km².
2018 is the third lowest on record.
On May 2^nd, the year 2018 is 357,300 km² above 2016, 77,146 km² above 2006 and 63,404 km² under 2017.

[Juan C. García]

The northern hemisphere sea-ice extent (or volume) doesn't matter.
Only the Arctic Ocean sea-ice extent matters.

With the heat, specially on the Atlantic, I believe that we will see some drops on Okhotsk, Hudson, Baffin, Greenland Sea and Barentsz, so I think that 2018 will be the second lowest on record in a couple of weeks.

[gerontocrat]

The northern hemisphere sea-ice extent (or volume) doesn't matter.
Only the Arctic Ocean sea-ice extent matters.

There is 1.4 million km2 of open ocean on May 2 receiving a strong dose of solar radiation where in the 1980's there was ice-covered ocean. (In 2016 it was 1.8 million km2.) This is a positive feedback mechanism for increase in ocean heat content.

While the peripheral seas are ice-covered this inhibits the transfer of heat into and the effect of wind/wave action on the CAB.

Sea ice extent in the periphery certainly matters to polar bars and walruses, whales, orcas, etc who are moving into regions that were ice-covered.

Sea ice extent in the periphery certainly matters to the humans watching their shores eroded and their livelihood changed forever due to earlier sea-ice melt.

So I, for one, will continue to take a keen interest in changes to extent, area, and volume for the Arctic as a whole and individual seas within it (including the timing and extent of sea-ice loss in the central seas of the Arctic Basin as a whole and individually).

[gerontocrat]

JAXA has returned from holiday - Extent 12,521,612 km2（May 2, 2018）

Only to add to Juan's post that:
- the graph shows extent loss remains below average,
- the possibility of a minimum below 4 million km2 diminsihes,
BUT:
- only 15% of the melting season has passed,
- the data does not yet reflect the intensifying heat moving northwards into very high latitudes on the Atlantic side for the next week or so (that may even impact on the CAB seas).

[gerontocrat]

NSIDC Total Area as at 2nd AprilMAY.(5 day trailing average)
Another whoops

The first table attached shows how area loss has increased to 70k per day over the last two days. When Hudson Bay and the Okhotsk Sea are excluded, this is still 40k per day.
The 2nd of May saw area loss in all seas - a first for this melting season.

Pacific Side
The Okhotsk is still losing area at 20k a day.
The Bering Sea is now at 15k area (less than 5% of its average maximum) and is now more or less irrelevant. At this rate area will be zero in about two weeks
Instead the Chukchi Sea has lost area at a still modest but significant rate - on 2 May an area loss of 4k.
The Beaufort sea changes are still minimal.

Atlantic Side
Baffin Bay has lost modest amounts.

The Greenland has lost 20k of area in the last two days. The Barents area loss is small..
The Laptev Sea has lost 9k over the last two days. The Kara Sea losses of area are minimal.
The Central Arctic has gained area.

In the last two days area loss overall has increased strongly.

The question still is what will the effect of the major temperature increase on the Atlantic side be over the next week ?

[Phil.]

"NSIDC Total Area as at 2nd April.(5 day trailing average)"

Don't you mean May?

[Thomas Barlow]

The northern hemisphere sea-ice extent (or volume) doesn't matter.
Only the Arctic Ocean sea-ice extent matters.

There is 1.4 million km2 of open ocean on May 2 receiving a strong dose of solar radiation where in the 1980's there was ice-covered ocean. (In 2016 it was 1.8 million km2.) This is a positive feedback mechanism for increase in ocean heat content.

While the peripheral seas are ice-covered this inhibits the transfer of heat into and the effect of wind/wave action on the CAB.

Sea ice extent in the periphery certainly matters to polar bars and walruses, whales, orcas, etc who are moving into regions that were ice-covered.

Sea ice extent in the periphery certainly matters to the humans watching their shores eroded and their livelihood changed forever due to earlier sea-ice melt.

So I, for one, will continue to take a keen interest in changes to extent, area, and volume for the Arctic as a whole and individual seas within it (including the timing and extent of sea-ice loss in the central seas of the Arctic Basin as a whole and individually).

There could still be ice in Baffin Bay, CAA, and others, when the Arctic Ocean starts to warm up due to loss of albedo. A lot of talk is about 'lowest' or '2nd lowest'. So the lowest Arctic Ocean extent may be telling us something that the northern hemisphere extent is not. I'm talking about the overall picture of ice extent, not animals and people. That is a different topic. I'm asking the question, could a disaster unfold in the Arctic Ocean extent, even if the northern hemisphere extent is in 2nd or 4th place for the time of year? If blue ocean extends even a little more than usual in the Arctic Ocean, I'm hoping that the heating effect does not come to a tipping point in the ocean, or something more like exponential heating.
It would be interesting to compare the lowest northern hemisphere extents over the years in September, with the lowest Arctic Ocean extents over the years in September. I wonder if it would show correlations or very little precise correlation between northern hemisphere sea ice extent and Arctic Ocean sea ice extent. That could tell a lot about what is happening overall.

[Neven]

The topic is 2018 sea ice area and extent data. Let's stay on it and take the more complex discussions elsewhere. Thank you.

[gerontocrat]

"NSIDC Total Area as at 2nd April.(5 day trailing average)"

Don't you mean May?

Whoops! Thanks - methinks I had better slow down - or stop.

[gerontocrat]

JAXA's on holiday - so so am I

[Stephan]

Just a little proposal to move "Hudson Bay" into the peripherical seas table so both tables have the same number of columns, and Hudson Bay is quite far away from CAB.

[gerontocrat]

Just a little proposal to move "Hudson Bay" into the peripherical seas table so both tables have the same number of columns, and Hudson Bay is quite far away from CAB.

I am thinking of parking both Hudson Bay and the Okhotsk Sea to one side as they are so physically separate from the main Arctic Ocean.

But my brain hurts - even my computer is protesting at all the data lugged around dealing with all the NSIDC data linked to all my analyses. (I always work indirectly with the NSIDC spreadsheets to ensure they are never altered by me inside my machine)

[Pmt111500]

Just a little proposal to move "Hudson Bay" into the peripherical seas table so both tables have the same number of columns, and Hudson Bay is quite far away from CAB.

I am thinking of parking both Hudson Bay and the Okhotsk Sea to one side as they are so physically separate from the main Arctic Ocean.

Add Bering, as it is functionally just a buffer that prevents early melt in the Arctic Proper... But your human health first, of course. These are hard times with people talking of f.e. healthy economy as if economy could have diseases.

[gerontocrat]

Just a little proposal to move "Hudson Bay" into the peripherical seas table so both tables have the same number of columns, and Hudson Bay is quite far away from CAB.

I am thinking of parking both Hudson Bay and the Okhotsk Sea to one side as they are so physically separate from the main Arctic Ocean.

Add Bering, as it is functionally just a buffer that prevents early melt in the Arctic Proper... But your human health first, of course. These are hard times with people talking of f.e. healthy economy as if economy could have diseases.

The Bering Sea is important - being the plug inhibiting warmth, waves etc entering the main Arctic Ocean. How quickly that plug is removed matters, which is why it needs to stay.

Incidentally, the Bering Sea is currently demonstrating that abrupt sea-ice loss can happen. (The Pacific end of the Arctic, especially the Bering and Chukchi areas, apparently have had the largest increase in air temperature within the Arctic over the last few years).

[gerontocrat]

But then again, abrupt sea ice loss can turn around into abrupt sea ice gain.

[gerontocrat]

NSIDC produced their April analysis on May 3rd. http://nsidc.org/arcticseaicenews/

[gerontocrat]

NSIDC Total Area as at 4 May (5 day trailing average)

The first table attached shows how area loss has increased to 70k per day over the last 4 days. When Hudson Bay and the Okhotsk Sea are excluded, this is still over 50k per day.

Pacific Side
The Okhotsk is still losing area at 20k a day.
The Bering Sea is now at 15k area (less than 5% of its average maximum) and is now more or less irrelevant. At this rate area will be zero in about two weeks
Chukchi Sea area loss slowed to standstill.
The Beaufort sea changes are still minimal.

Atlantic Side

The question was what will the effect of the major temperature increase on the Atlantic side be over the next week ?
The answer so far is - significant. Except for Baffin Bay - increasing in area.

In contrast :
- The Greenland has lost 40k of area in the last two days.
- The Barents area loss has suddenly grown to 15k
- The Laptev and Kara Sea losses of area are small but measurable
- The Central Arctic has lost 10k per day for the last two days.

[Shared Humanity]

There is something very striking about the conversation here tracking the beginning of the melt season. When I 1st came here, the conversation was about cloudless high pressure, insolation and melt ponds. We now talk about warm weather intrusions and 2m temperature anomalies.

I don't know that this is a good thing.

[Neven]

There is something very striking about the conversation here tracking the beginning of the melt season. When I 1st came here, the conversation was about cloudless high pressure, insolation and melt ponds. We now talk about warm weather intrusions and 2m temperature anomalies.

I don't know that this is a good thing.

Not to go too far off-topic, but warm weather intrusions, inevitably coupled with cloudy conditions at this time of year, are important for melt onset, ie snow melting on top of the ice. This snow often refreezes, but is then more vulnerable to solar radiation. That's when the high pressure comes in and gets preconditioning through melt ponds on the road.

Both are important, depending on the timing.

[jdallen]

But then again, abrupt sea ice loss can turn around into abrupt sea ice gain.

Gain at this point in the Barentzs isn't necessarily a good thing, as probability indicates, it will all be gone by the end of the melt season.

[Csnavywx]

There is something very striking about the conversation here tracking the beginning of the melt season. When I 1st came here, the conversation was about cloudless high pressure, insolation and melt ponds. We now talk about warm weather intrusions and 2m temperature anomalies.

I don't know that this is a good thing.

Probably because we understand a bit more since the 2012 season.

Cloudless high pressure doesn't do nearly as much if it occurs on fresh, unbroken snowfall. Strong warm air advection followed by clear skies does significant damage, especially if there's some decent inversion-weakening or breaking wind to go with it.

There's a reason Chinook winds are called "snow-eaters".

The CAB had virtually no WAA events before July last year and as a result survived mostly intact.

[gerontocrat]

NSIDC Total Area as at 5 May (5 day trailing average)

The first table attached shows how area loss has increased to 70k per day over the last 5 days. When Hudson Bay, the Okhotsk Sea and the St. Lawrence are excluded, this is still over 50k per day.

Pacific Side
The Okhotsk is still losing area at 20k a day.
The Bering Sea at this rate area will be zero in about two weeks.

Chukchi Sea area loss slowed to standstill.
The Beaufort Sea is gainingb area.

Atlantic Side

The question was and still is what will the effect of the major temperature increase on the Atlantic side be over the next week ? The answer so far is - significant. Except for Baffin Bay - increasing in area.

In contrast :
- The Greenland has lost 58k of area in the last three days.
- The Barents area loss has grown to 23k on 5 May
- The Laptev and Kara Sea losses of area are small but measurable
- The Central Arctic has lost 40k per day over the last three days.