Tag Archives: Extent

The 2020 Maximum Arctic Sea Ice Extent

Extent, , , , , , , , ,

As Zack Labe has recently pointed out, in 2015 the Arctic sea ice maximum extent based on the JAXA numbers had already occurred on February 15th:

Perhaps it’s time we started paying attention this year! However the National Snow and Ice Data Center reported a significantly later date in 2015:

On February 25, 2015, Arctic sea ice extent appeared to have reached its annual maximum extent, marking the beginning of the sea ice melt season. This year’s maximum extent not only occurred early; it is also the lowest in the satellite record. However, a late season surge in ice growth is still possible.

Each year we keep track of the assorted Arctic sea ice metrics over the next month or so, and they rarely agree on the date of maximum extent, and never agree on the sea ice extent on that date! The reason for that is explained in a 2017 paper entitled “Variability and trends in the Arctic Sea ice cover: Results from different techniques“:

Reports on the sea ice cover have been provided by different institutions using basically the same set of satellite data but different techniques for estimating key parameters such as ice concentration, ice extent, and ice area. In this study, a comparison of results from four different techniques that are frequently used shows significant disagreements in the characterization of the distribution of the sea ice cover primarily in areas that have a large fraction of new ice cover or significant amount of surface melt.

In due course we’ll look at the metrics from a variety of different institutions, but let’s start with JAXA, comparing 2020 with 2015 and the 2010s average:

Extent is clearly increasing just at the moment! Will the next peak prove to be the maximum for the year or will we have to wait another month or more to find out that value, as suggested by the average?

Compare and contrast JAXA extent with Wipneus’ high resolution AMSR2 extent and area:

Perhaps the 2020 maximum area has already been reached?

[Edit – February 25th]

Or perhaps not! We’re playing mix and match this morning, since Wipneus’s new numbers haven’t been released yet. Here UH AMSR2 high resolution Arctic sea ice area from February 23rd:

Plus JAXA extent for the 24th:

[Edit – February 27th]

Tony Heller’s latest sea ice themed article claims “Normal Sea Ice Extent At Both Poles”. Hence today’s JAXA extent graph includes the averages for previous decades:

Extent is evidently increasing once again, and is even more evidently well below what passed for “normal” in the twentieth century!

Let’s also compare the Pacific periphery:

with the Atlantic side of the Arctic Ocean:

The Bering and Okhotsk Seas will be sea ice free by the time September 2020 arrives. How about the Kara, Barents and particularly Greenland Seas though?

[Edit – February 29th]

Arctic sea ice maximum volume usually occurs in April, but nonetheless let’s keep an eye on the metric that most nearly measure the “amount” of sea ice left in the Arctic in 2020. Here’s our “measured” CryoSat-2/SMOS volume metric, using reanalysed data up to February 12th:

PIOMAS “modelled” volume for February should be released soon, but getting back to extent the JAXA flavour has been setting new highs over recent days:

whereas the NSIDC’s Charctic 5 day averaged extent has not!

[Edit – March 6th]

Here’s the February PIOMAS gridded Arctic sea ice thickness map, courtesy of Wipneus on the Arctic Sea Ice Forum:

plus the traditional modelled volume graph:

As angech has pointed out elsewhere, according to the PIOMAS team:

CryoSat-2 data show total volume for February 2020 substantially lower than PIOMAS with 2020 Febuary near record low levels over the 2011-2020 period

[Edit – March 19th]

The March mid month PIOMAS numbers have been crunched by Wipneus. Here’s how things look at the moment:

For comparison purposes here’s the current CryoSat-2/SMOS Arctic sea ice thickness map:

[Edit – March 20th]

After flatlining for a long time JAXA extent has posted significant declines for two days running. There’s been no official announcement from the NSIDC as yet, but it now seems safe to conclude that there won’t be a late surge in extent similar to 2010. Here’s the current JAXA graph:

plus NSIDC’s 5 day averaged extent:

Hence the (still provisional!) maximum numbers for 2020 are:

JAXA/VISHOP AMSR2 – 14.45 million square kilometres on March 3rd
NSIDC 5 day SSMIS – 15.05 million square kilometres on March 5th

The University of Hamburg’s JAXA AMSR2 concentration data seems to have suffered an outage over the crucial period. Hopefully the gaps will be filled in due course. However more recent regional graphs  reveal the following:

The recent declines in overall extent are evidently driven by declines on the Pacific periphery.

Facts About the Arctic in October 2019

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Whilst we await the PIOMAS volume numbers which generally arrive around the 5th of each month, and before we look at graphs of extent, with the refreeze well under way some “measured” thickness maps are coming back! Here’s the first SMOS map this autumn:

Then of course there’s our usual Arctic wide high resolution AMSR2 area and extent graphs:

They reveal both metrics currently still second lowest (in the brief AMSR2 record) after 2012. It looks as though that may well change soon, particularly area.

The MOSAiC Expedition has started in earnest, with Polarstern and Akademik Fedorov in amongst the sea ice at long last:

However:

[Edit – October 3rd]

The near real time NSIDC monthly extent for September is 4.32 million km². Here’s the graph:

We’re eagerly awaiting the first ice mass balance buoy “near real time” data, but for now the 2019 PIOMAS minimum volume is expected to be revealed real soon now, so:

[Edit – October 5th]

As previously perfectly predicted, the PIOMAS numbers have arrived over at the ASIF. Here’s the thickness map for the end of September:

and the volume graph:

Since I’m involved is a heated “debate” about Arctic sea ice trends over at ex Prof. Judy’s, here’s an added bonus this month. The September volume trend:

[Edit – October 6th]

A marginally off topic excursion down under. The NSIDC 5 day average Antarctic sea extent looks to have peaked at 18.40 million km² on September 30th:

[Edit – October 7th]

The first of the MOSAiC Expedition’s Ice Mass Balance buoys has been installed, presumably on the ice floe Polarstern is moored to. It reveals sea ice that is currently just over 1 meter thick with a sprinkling of snow on top:

P.S MOSAiC IMB buoy #3 has gone live today too:

There’s currently only 0.5 meters of ice under this one.

[Edit – October 9th]

Here’s the latest annual PIOMAS “ice cube” animation from Andy Lee Robinson:

[Edit – October 10th]

Here’s the latest DMI “high Arctic” temperature graph:

Needless to say that means the DMI Freezing Degrees Days graph is tracking the lowest readings in the DMI’s records:

[Edit – October 11th]

MOSAiC IMB buoy #2 has now been installed and is beaming back data:

The sea ice at this location is decidedly on the thin side at present. A mere 20 cm or thereabouts!

[Edit – October 12th]

The JAXA ViSHOP web site is down at the moment, so by way of a change here is the University of Bremen’s AMSR2 based extent graph instead:

2019 Arctic sea ice is extent is now once again “lowest for the date” (since AMSRx satellite records began).

[Edit – October 14th]

The JAXA/ADS/ViSHOP web site is back online after being down over the weekend, presumably due to the effects of Typhoon Hagibis:

Sure enough the Japanese flavour of AMSR2 based extent is also now “lowest for the date”.

Plus a stunning image from Mike Horn and Borge Ousland as they attempt to “walk” to the North Pole then on towards Svalbard:

Mike and Borge’s current position was reported yesterday as: 89°35′51″N 140°30′32″E

[Edit – October 15th]

The latest SMOS Arctic sea ice “thinness” map shows sea ice starting to form on the shores of the Laptev Sea:

[Edit – October 16th]

The Centre for Polar Observation and Monitoring (CPOM) have just published the first CryoSat-2 Arctic sea ice thickness map of the 2019/20 freezing season:

Note in particular the dark blue area north of the Canadian Arctic Archipelago.

[Edit – October 20th]

Wipneus has just crunched the October mid month PIOMAS numbers. Here are the results. Not only the modelled Arctic sea ice thickness map:

but also the Arctic sea ice volume graph:

[Edit – October 21st]

Over on Twitter Judah Cohen suggests that:

Here’s the evidence:

I have been trying to bring the implications of this to the attention of the denizens of Judith Curry’s “Climate Etc.” blog, thus far with remarkably little success! This is the gist of my argument:

See:

“Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins” Mary-Louise Timmermans, John Toole, Richard Krishfield (2018)

“Summer solar heat absorption by the surface waters has increased fivefold over the same time period, chiefly because of reduced sea ice coverage.”

“The effects of an efficient local ice-albedo feedback are thus not confined to the surface ocean/sea ice heat budget but, in addition, lead to increased heat accumulation in the ocean interior that has consequences far beyond the summer season.”

“In the coming years, however, excess Beaufort Gyre halocline heat will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth.”

Watch this space!

The 2019 Arctic Sea Ice Metric Minima

Extent, , , , , , , , , ,

September is here once again, so the assorted minima of a variety of Arctic sea ice metrics will be reached soon, if they haven’t happened already!

In the latter category let’s first take a look at the NSIDC’s 5 day averaged SSMIS based Arctic sea ice extent:

It looks entirely feasible that the current minimum of  4.29 million square kilometres on September 7th will hold for the rest of the calendar year. The daily NSIDC number is currently 4.24 million km² on September 4th.

By way of contrast the JAXA/ViSHOP AMSR2 based extent hit a new low of  4.11 million  km² yesterday:

And what of our much beloved high resolution AMSR2 metrics derived by “Wipneus” from the University of Hamburg’s AMSR2 concentration data? Area certainly looks to be past the minimum for this year, whereas extent is still conceivably capable of another push lower:

The provisional minimum extent for 2019 is 3.80 million km² on September 3rd.

The minimum Arctic sea ice volume generally occurs slightly later than area or extent. The data certainly arrives later! Here’s the PIOMAS graph up to August 31st:

and here’s the associated thickness map:

Note that Arctic wide modelled volume is only slightly higher than in 2012 at the same time of year, but there is a noticeably greater percentage gap in extent. That implies that average ice thickness across the Arctic is lower in 2019 than in 2012.

Note also that the thickest ice is no longer located along the north coasts of Greenland and the Canadian Arctic Archipelago. Here are the equivalent maps for previous years for comparison purposes:

Perhaps JAXA extent will head still lower over the next few days? Perhaps PIOMAS volume will sneak below 2012 before the peripheral refreeze begins?

[Edit – September 13th]

JAXA Arctic sea ice extent has reached a new minimum of 4.09 million km².

NSIDC daily extent is currently 4.28 million km², still just above the September 4th minimum.

[Edit – September 14th]

JAXA Arctic sea ice extent has reached a new minimum of 4.05 million km², which now puts it below the 2007 minimum that occurred somewhat later in September:

[Edit – September 14th PM]

NSIDC 5 day averaged extent has also (by a whisker!) reached a new minimum for the year of 4.285 million km²:

The daily number fell to 4.21 million km².

[Edit – September 15th]

I have somewhat belatedly discovered that in the build up to the forthcoming MOSAiC Expedition the Alfred Wegener Institute recently announced  that:

The sea-ice extent in the Arctic is nearing its annual minimum at the end of the melt season in September. Only circa 3.9 million square kilometres of the Arctic Ocean are covered by sea ice any more, according to researchers from the Alfred Wegener Institute and the University of Bremen. This is only the second time that the annual minimum has dropped below four million square kilometres since satellite measurements began in 1979.

[Edit – September 16th]

JAXA/ViSHOP extent has dropped below the 2016 minimum, and now measures 4.01 million km²:

Only 2012 left to beat!

Wipneus’ high resolution AMSR2 extent has also posted a new low for the year, but still has a little way to go before passing 2016:

Area is also currently declining, but is still well away from a new minimum for 2019:

[Edit – September 19th]

After some more modest declines JAXA/ViSHOP extent has just increased marginally from the previous day, and now measures 3.98 million km²:

That puts the (very!) tentative minimum for 2019 at 3.96 million km² on September 17th.

[Edit – September 20th]

The mid month PIOMAS gridded thickness and volume numbers have been released:

As anticipated given recent extent values, the volume difference from 2012 has increased somewhat over the last two weeks.

[Edit – September 23rd]

The National Snow and Ice Data Center have called the 2019 minimum in their latest edition of Arctic Sea Ice News:

On September 18, 2019, sea ice extent dropped to 4.15 million square kilometers (1.60 million square miles), effectively tied for the second lowest minimum in the satellite record along with 2007 and 2016. This appears to be the lowest extent of the year. In response to the setting sun and falling temperatures, ice extent will begin increasing through autumn and winter. However, a shift in wind patterns or a period of late season melt could still push the ice extent lower.

[Edit – September 24th]

To summarise the assorted minimum extent metrics for 2019:

University of Bremen – 3.77 million km² on September 18th, 2nd lowest behind 2012.
JAXA/ViSHOP – 3.96 million km² on September 17th, “Statistical tie” with 2016 for 2nd lowest.
NSIDC 1 day – 4.10 million km² on September 17th, “Statistical tie” with 2016 for 2nd lowest.
NSIDC 5 day – 4.15 million km² on September 18th, 2nd lowest behind 2012.

[Edit – October 1st]

Two sides of the same coin? Sea ice area on the Pacific side of the Arctic has been at historic lows for most of the melting season:

whereas on the Atlantic side:

[Edit – October 7th]
The September monthly numbers have arrived from the NSIDC, together with some intriguing annotations by Walt Meier:

Watch this space. Just in case!

The 2019 Maximum Arctic Sea Ice Extent

Extent, , , , , , , , , , , , , , , ,

March 2019 has arrived, which in recent years has proved to be by far the likeliest month to contain the maximum extent of Arctic sea ice for the year. To begin with, here’s our favourite high resolution extent graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:

Hopefully you can plainly see the pronounced sharp peak towards the end of February 2019? The current maximum Arctic sea ice extent for 2019 is 13.83 million square kilometers on February 22nd. Here’s Arctic sea ice area for good measure:

The current maximum area for 2019 is 13.10 million square kilometers, also on February 22nd. Here too is the NSIDC’s 5 day averaged extent:

charctic-20170221

This reveals a current maximum extent for 2019 of 14.705 million square kilometers on February 24th.

At this juncture you may well be wondering what the cause of that sudden sharp peak might be? Here’s your starter for ten:

Whilst overall Arctic sea ice area is unremarkable for the current decade, sea ice area in the Bering Sea is remarkable low for the time of year! What’s more much like last year the Chukchi Sea is not currently full to overflowing with sea ice, and is also lowest for the date in the AMSR2 satellite records:

I’ve also been experimenting with the new gridded CryoSat-2/SMOS thickness data from the Finnish Meteorological Institute, which reveals this:

That’s a weekly overview dated February 24th, but it does perhaps explain how such a large area of sea ice could melt so swiftly?

As luck would have it the skies are reasonably clear over the Bering Strait this morning (UTC). Here’s Terra’s view from on high of the current situation:

Terra's view of the Bering Strait on March 1st 2019
Terra’s view of the Bering Strait on March 1st 2019

 
[Edit – March 1st PM]

The “low resolution” version of JAXA extent has fallen once again today:

Do you suppose that the current maximum of 14.19 million square kilometers on February 22nd will hold until All Fools’ Day and beyond?

 
[Edit – March 2nd]

An animation of recent movements of sea ice in the Bering and Chukchi Seas:


 

Note the recent spread of open water across the southern Chukchi Sea.

 
[Edit – March 3rd]

Another angle on the Chukchi Sea, plus significant areas of open water now becoming evident in the Beaufort Sea:

 

[Edit – March 5th]

Some alternative views on Arctic sea ice thickness:

PIOMAS via Wipneus:

Blended CryoSat-2/SMOS:

plus close ups of the Bering/Chukchi area:

and the Atlantic periphery:

Please note the change of scale.

 

[Edit – March 6th]

Arctic sea ice extent is currently rebounding:

although not in all the peripheral seas:

 

[Edit – March 7th]

High resolution AMSR2 area and extent both declined today:

Long distance swells are already reaching the Bering Sea, with much more to come:

 

[Edit – March 9th]

Wipneus’ trusty Raspberry Pi hasn’t crunched the high res AMSR2 numbers yet, so let’s take a look at some other extent metrics.

Here’s JAXA’s “low res” AMSR2 numbers:

Here too is the NSIDC’s 5 day average:

By special request from Michael Ohere for the first time is the DMI’s take on Arctic sea ice extent:

In addition, here is the underlying sea ice concentration data from the OSI-SAF:

Since Michael is also asserting that there currently exists “the greatest February Arctic sea ice extent (according to DMI) in your blog’s history”, here’s Arctic sea ice area excluding the extremely peripheral Okhotsk and St. Lawrence regions:

P.S. Wipneus’ Pi has processed the AMSR2 data now, and area shows another, more modest, decline today:

In addition, here is the underlying sea ice concentration data from the University of Hamburg:

 

[Edit – March 10th]

Both area and extent increased today:

including increases on both the Atlantic:

and Pacific sides of the Arctic:

 

[Edit – March 11th]

Both area and extent are still moving inexorably upwards:

The late February maximum still holds, on the high resolution numbers at least. The JAXA/VISHOP web site is down at the moment, so we’ll have to wait for an update to that particular metric, as well as a post weekend update to the NSIDC’s Charctic chart.

P.S. Jaxa is still down this afternoon, but here’s the latest from the NSIDC:

 

[Edit – March 13th]

Arctic wide area and extent have blasted past their respective late February maxima:

However Arctic sea ice area excluding the Okhotsk and St. Lawrence peripheral regions has still not exceeded the maximum formed on January 25th:

 

[Edit – March 14th]

This morning’s data reveal the first decline in extent for several days:

The (extremely!) tentative new maximum Arctic sea ice extent for 2019 is 13.89 million square kilometers on March 12th.

 

[Edit – March 15th]

JAXA is back!

UH AMSR2 confirms that extent is still declining:

 

[Edit – March 16th]

Arctic sea ice extent continues to decline, whilst area is still flatlining:

Meanwhile a look at freezing degree days based on the DMI’s dubiously weighted data for north of 80 degrees reveals the story of the freezing season. A historically warm start, but now back in amongst the pack of the 2010s:

 

[Edit – March 17th]

It looks as though there’ll be no going back from this. Arctic sea ice area is finally following extent’s decline in no uncertain terms:

Barring exceedingly unforeseen circumstances after this year’s “double top” that leaves the 2019 Arctic sea ice maximum extent numbers as follows:

UH/Wipneus AMSR2 – 13.89 million square kilometers on March 12th
JAXA/VISHOP AMSR2 – 14.27 million square kilometers on March 12th
NSIDC 5 day SSMIS – 14.78 million square kilometers on March 13th

 

[Edit – March 19th]

Arctic sea ice area has fallen off the proverbial cliff over the last few days. There can now be no doubt that the 2019 maximum extent has been reached:

That being the case, all other Arctic sea ice discussion for the month of March can now take place over at:

Facts About the Arctic in March 2019

 

[Edit – March 21st]

The NSIDC have provisionally confirmed this year’s maximum extent:

On March 13, 2019, Arctic sea ice likely reached its maximum extent for the year, at 14.78 million square kilometers (5.71 million square miles), the seventh lowest in the 40-year satellite record, tying with 2007. This year’s maximum extent is 860,000 square kilometers (332,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles) and 370,000 square kilometers (143,000 square miles) above the lowest maximum of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017. Prior to 2019, the four lowest maximum extents occurred from 2015 to 2018.

The date of the maximum this year, March 13, was very close to the 1981 to 2010 median date of March 12.

Please note this is a preliminary announcement of the sea ice maximum. At the beginning of April, NSIDC scientists will release a full analysis of winter conditions in the Arctic, along with monthly data for March.

Facts About the Arctic in October 2018

Volume, , , , , , , , , , , , ,

A somewhat belated start to our October 2018 coverage, but firstly please take a look at this graph:

VISHOP_Extent_20181020

Following a remarkably sluggish refreeze this year JAXA extent is currently the lowest for the date since their records began. Meanwhile Wipneus has just released his mid month PIOMAS volume update on the Arctic Sea Ice Forum:

piomas-trnd4-2018-10-20

That graph reveals that Arctic sea ice volume has been increasing much more slowly than usual during October. The fact that the DMI freezing degree days graph is currently below all previous years in their records no doubt has something to do with that:

DMI-FDD-2018-10-20

Wipneus has also updated the mid month PIOMAS gridded thickness map:

PIOMAS-20181015

That’s the output of a model of course, but here too is the CPOM version of CryoSat-2 “measured” thickness:

Both sources agree that there’s a remarkable lack of thick ice in the Wandel Sea off north east Greenland this Autumn.

For a handle on the areas of thinner ice where refreezing is taking place around the periphery of the pack, here’s the latest SMOS map:

Finally, for the moment at least, here’s our favourite high resolution AMSR2 area and extent metrics based on JAXA data processed by the University of Hamburg to produced gridded concentration which is then used to derive area and extent by the inimitable Wipneus once again:

UH-Arctic-Area-2018-10-20

UH-Arctic-Extent-2018-10-20

 

[Edit – October 28th]

Here’s the latest thickness maps from SMOS:

and CryoSat-2:

There’s been a recent rapid refreeze, leaving large areas of thin ice around the edges of the central pack:

The 2018 Arctic Sea Ice Metric Minima

Extent, , , , , , , , , ,

September is upon us once again, the month in which the assorted Arctic sea ice area and extent metrics (almost) always reach their respective annual minima. Now we are free to start speculating about what the assorted minima will be, and on what date.

To begin with let’s take a look at our much beloved high resolution AMSR2 metrics derived by “Wipneus” from the University of Hamburg’s AMSR2 concentration data:

Arctic-Area-2018-09-01

Arctic-Extent-2018-09-01

There’s currently some divergence between the area and extent graphs. Area is declining rapidly for the time of year, whilst extent seems to almost have come to a standstill!

Next here’s the prediction of the late, great Andrew Slater’s Probabilistic Ice Extent algorithm:

SPIE-extent-20180901

Before looking at some of the other metrics we’ll wait for the effect of the assorted storms currently circling the Arctic to play out. Here’s how the AMSR2 concentration map looks at the moment:

Arc_20180901_res3.125

whilst here’s the University of Bremen’s summer SMOS sea ice “thinness” map:

SMOS-20180901

 

[Edit – September 3rd]

UH AMSR2 area and extent both increased yesterday, so we have a (very!) provisional minimum extent of 4.35 million square kilometres on September 1st.

 

[Edit – September 4th]

Area and extent have both increased again:

Arctic-Area-2018-09-03

Arctic-Extent-2018-09-03

Is the minimum already in, or will the storms still circulating around the Arctic Ocean reverse that trend over the next few days?

 

[Edit – September 6th]

High resolution area and extent both posted marginal new lows for the year yesterday:

Arctic-Area-2018-09-05

Arctic-Extent-2018-09-05

 

[Edit – September 29th]

According to the latest edition of the NSIDC’s Arctic Sea Ice News:

On September 19 and 23, Arctic sea ice appeared to have reached its seasonal minimum extent for the year, at 4.59 million square kilometers (1.77 million square miles). This ties 2018 with 2008 and 2010 for the sixth lowest minimum extent in the nearly 40-year satellite record.

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

Figure2_09232018

The NSIDC numbers are based on a 5 day average, whereas the one day high resolution AMSR2 extent reached a minimum of 4.195 million square kilometers on September 17th:

Arctic-Extent-2018-09-28

The AMSR2 area minimum occurred significantly earlier. 3.737 million square kilometers on September 9th:

Arctic-Area-2018-09-28

Facts About the Arctic in April 2018

Volume, , , , , , ,

First of all Wipneus has been very quick off the mark this month with his PIOMAS gridded thickness map. Here is what it reveals for the last day of March:

PIOMAS-20180331

Here too is the latest PIOMAS volume graph:

PIOMAS-volume-20180331

together with the associated anomaly graph:

PIOMAS-anomaly-20180331

They show 2018 still in second lowest position, albeit much closer to third place than last year’s line, which is currently leading the pack by a considerable margin.

By way of comparison here are the current Arctic sea ice thickness maps from SMOS:

SMOS-thkness-20180402

and CryoSat-2:

CryoSat-20180330

All eyes are still on the Bering and Chukchi Seas, where significant extent declines look likely over the coming days.

 

[Edit – April 4th]

The official PIOMAS graph including March 2018 is now available:

BPIOMASIceVolumeAnomalyCurrentV2.1_20180331

Meanwhile, according to NIPR/JAXA, Arctic sea ice extent is once again lowest for the date since their records began:

VISHOP_Ext_20180404

 

[Edit – April 6th]

The NSIDC 5 day averaged extent is now in “lowest in our records” territory:

Charctic-20180406

Meanwhile “JAXA” extent has just edged above 2016!

 

[Edit – April 11th]

The focus has been on the Bering and Chukchi Seas until now. However there were clear skies over the Mackenzie Delta yesterday, revealing some open(ish) areas in the Beaufort Sea:

NASA Worldview “true-color” image of the Beaufort Sea on April 10th 2018, derived from the MODIS sensor on the Terra satellite
NASA Worldview “true-color” image of the Beaufort Sea on April 10th 2018, derived from the MODIS sensor on the Terra satellite

There’s only the merest hint of a blip on the area graph so far though:

UH-Beaufort-Area-2018-04-10

It will be interesting to see if the decline in Beaufort Sea area continues from here, or whether this year’s “flatline” resumes and continues for a while longer.

 

[Edit – April 19th]

It’s not so apparent on the other extent metrics, but as the periphery melts the high resolution AMSR2 version looks to be heading into virgin territory on the downside:

UH-Arctic-Extent-2018-04-18

The 2018 Maximum Arctic Sea Ice Extent

Extent, , , , , , , , , , , ,

According to the latest edition of the National Snow and Ice Data Center’s “Arctic Sea Ice News”

On March 17, 2018, Arctic sea ice likely reached its maximum extent for the year, at 14.48 million square kilometers (5.59 million square miles), the second lowest in the 39-year satellite record, falling just behind 2017. This year’s maximum extent is 1.16 million square kilometers (448,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles).

The four lowest seasonal maxima have all occurred during the last four years. The 2018 maximum is 60,000 square kilometers (23,200 square miles) above the record low maximum that occurred on March 7, 2017.

Here’s a close up view of recent maxima via the NSIDC’s Charctic interactive sea ice graph:

Charctic-20180323

Next let’s take a look at extent data from the Japanese National Institute of Polar Research, colloquially referred to as “JAXA extent”

VISHOP_Extent-20180323

In this case the maximum was 13.89 million square kilometers, also on March 17th.

Here too are the extent and area graphs based on Wipneus’ processing of the University of Hamburg’s AMSR2 based concentration data:

UH-Arctic-Extent-2018-03-23

UH-Arctic-Area-2018-03-23

They highlight the surge in Arctic sea ice area in the middle of March due to the sudden “cold snap”:

meanT_2018-03-24
Looking at the third Arctic dimension, here’s the latest SMOS thickness map from the University of Bremen:

SMOS-20180323

and here’s the latest CryoSat-2 thickness map:

CS2-thk_28-2018-03-21

They reveal large areas of relatively thin sea ice in the Okhotsk and Barents Seas where the ice can now be expected to melt as quickly as it formed. There is also remarkably little sea ice in the Bering Sea for the time of year:

UH-Bering-Extent-2018-03-23

Facts About the Arctic in February 2018

Volume, , , , , , , , ,

Whilst the official PIOMAS volume figures for January have yet to be released Wipneus has worked his usual magic on the gridded thickness numbers to reveal:

PIOMAS-thkness-20180131

not to mention the calculated volume:

PIOMAS-volume-20180131

and the volume anomaly:

PIOMAS-anomaly-20180131

As Wipneus puts it:

Estimated from the thickness data, the latest value is from 31st of January: 17.57 [1000 km3], which is the second lowest value for that day, 2017 is lowest by a rather large margin at 16.16 [1000 km3].

Here are the “measured” thickness maps from SMOS:

SMOS-20180131

and CryoSat-2:

CS2-thk_28-2018-01-29

Here are the end of January Arctic wide high resolution AMSR2 graphs based on University of Hamburg data:

UH-Arctic-Area-2018-01-31

UH-Arctic-Extent-2018-01-31

In addition, since it’s that time of year, here too is Wipneus’ NSIDC global sea ice extent:

nsidc_global_extent_20180202

The minimum thus far is very slightly above last year’s value, but perhaps like last year there will be a “double dip”?

Getting back to the Arctic, here is the DMI >80N temperature plot for January:

DMI-meanT_20180201

together with the associated freezing degree days graph:

2018-02-01-DMI-FDD

Here’s a video showing the effect of the mid January cyclones on the sea ice in the Fram Strait and north of Svalbard:

Finally, for the moment at least, here is the current Fram Strait surf forecast for 12:00 UTC on February 5th:

Significant_height_of_combined_w in multi_1.glo_30mext.20180203_00021

Mean_period_of_wind_waves_surfac in multi_1.glo_30mext.20180203_00021

Those maps shows 10 meter high, 15 second period waves heading straight for the ice edge north of Svalbard.

 

[Edit – February 7th]

The latest edition of Arctic Sea Ice News has been published. As the NSIDC put it:

January of 2018 began and ended with satellite-era record lows in Arctic sea ice extent, resulting in a new record low for the month. Combined with low ice extent in the Antarctic, global sea ice extent is also at a record low.

monthly_ice_01_NH_v3.0

Air temperatures at the 925 hPa level (about 2,500 feet above sea level) remained unusually high over the Arctic Ocean. Nearly all of the region was at least 3 degrees Celsius (5 degrees Fahrenheit) or more above average. The largest departures from average of more than 9 degrees Celsius (16 degrees Fahrenheit) were over the Kara and Barents Seas, centered near Svalbard. On the Pacific side, air temperatures were about 5 degrees Celsius (9 degrees Fahrenheit) above average. By contrast, 925 hPa temperatures over Siberia were up to 4 degrees Celsius (7 degrees Fahrenheit) below average. The warmth over the Arctic Ocean appears to result partly from a pattern of atmospheric circulation bringing in southerly air, and partly from the release of heat into the atmosphere from open water areas.

airtemp-201801

 

[Edit – February 10th]

The University of Hamburg’s high resolution AMSR2 derived area is bouncing back after the recent cyclone, but extent is currently still declining:

UH-Arctic-Area-2018-02-09

UH-Arctic-Extent-2018-02-09

The recent drop in Arctic sea ice extent has pushed the NSIDC global extent to a new all time (satellite era!) low:

nsidc_global_extent_20180209

The 2017 Arctic Sea Ice Metric Minima

Extent, , , , , , , , , ,

September has arrived once again, the month in which the assorted Arctic area and extent metrics (almost) always reach their respective annual minima. Now we can start to speculate about what the assorted minima will be, and on what date.

First of all let’s take a look at “Snow White’s” favourite high resolution AMSR2 metrics derived by “Wipneus” from University of Hamburg AMSR2 concentration data:

UH-Arctic-Area-2017-09-02

UH-Arctic-Extent-2017-09-02

As you can see, today’s values are both higher than yesterday’s. Hence we already have potential minima to consider! In this case:

UH AMSR2 Area – 3.65 million km² on September 1st
UH AMSR2 Extent – 4.30 million km² on September 1st

Personally I don’t think those numbers will last long, and here’s one reason why. The “surf forecast” for the far North Atlantic for midday on September 6th:

Significant_height_of_combined_w in multi_1.glo_30mext.20170903_00029

Mean_period_of_swell_waves_order in multi_1.glo_30mext.20170903_00029

Some significant swells are currently forecast to batter the ice edge on the Atlantic side of the Arctic over the next few days.

 

[Edit – September 3rd PM]

Shock news! Tony Heller has made a prediction about this year’s minimum!! Unlike last year, this year the NSIDC 5 day average extent seems to be his Arctic metric of choice:

Charctic-20170902

Tony tells his faithful flock:

The Arctic sea ice minimum this year is very likely going to be be larger than 2016, 2015, 2012, 2011 and 2007.

It is also likely that the minimum extent will be higher than 2010 and 2008.

Instead of reporting the huge gain in ice and massive failure of their forecasts, climate alarmists will report that extent was “8th lowest on record.”

All those years are on the graph above. We shall see.

 

[Edit – September 15th]

Our normal Arctic sea ice extent 2017 minimum service will be restored as soon as possible. Meanwhile here is the test card:

That comes to you via the Daily Express of all places!

On the way the cruise’s resident naturalist and Smithsonian lecturer, Michael Scott, risked the wrath of Trump supporters by pointing to some of the changes Greenland is undergoing.

A Nasa map based on data between 2004 and 2014 revealed that the ice is melting across most of Greenland – an area nine times the size of the UK.

Pulling together several papers, Michael said Greenland’s summer melt season now lasts 70 days longer than in the early 1970s.

This melting is unfreezing the fringes of the permafrost, which may explain why Nasa satellites are picking up fires raging where the ice has retreated.

 

[Edit – September 16th]

It is of course still to early to be 100% certain about this. However:

UH-Arctic-Extent-2017-09-15

It certainly looks as though the bottom is in for the University of Hamburg AMSR2 extent: 4.25 million km² on September 11th.

It’s much the same story for JAXA extent:

VISHOP_Extent-20170915

4.47 million km² on September 9th and 10th.

 

[Edit – September 19th]

The NSIDC have followed in Snow White’s glass slippered footsteps and tentatively called the minimum:

On September 13, Arctic sea ice appears to have reached its seasonal minimum extent of 4.64 million square kilometers (1.79 million square miles), the eighth lowest in the 38-year satellite record. The overall rate of ice loss this summer was slowed by a persistent pattern of low sea level pressure focused over the central Arctic Ocean.

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

The ever industrious Wipneus has also called the PIOMAS minimum volume for 2017:

Minimum volume was reached at 11th September: 4.542 103km3, which is fourth lowest after 2012, 2011 and 2016 (resp 3.673, 4.302, 4.402) and just below 2010 (4.582).

piomas_gridded_thickness_20170911

 

[Edit – September 23rd]

Here’s the 2017 edition of our annual NSIDC daily max/min extent graph:

NSIDC-NH-MaxMin-2017

The maximum extent was the lowest in the satellite record, and the minimum was just fractionally above the trend line. For those that concern themselves with “statistical significance”, the PIOMAS minimum volume was a “statistical tie” for second place:

PIOMAS-20170915

Watch this space!