Tag Archives: Area

Facts About the Arctic in December 2021

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Christmas is coming. Santa’s secret summer swimming pool has frozen over. The time has come for a new monthly Arctic update.

The JAXA/ADS/ViSHOP web site is undergoing maintenance for a week, so let’s start the festive season with a look at high resolution AMSR2 area and extent:

After a brief hiatus in early November both metrics are once again tracking within, but near the upper bound of the last 10 years.

Next let’s take a look at the latest AWI CryoSat-2/SMOS thickness map:

together with the anomaly map from the Finnish Meteorological Institute:

Still thinner than usual in the so called “last ice area” north of Greenland and Ellesmere Island, and thicker than usual on the Siberian side of the Arctic, particularly in the Chukchi Sea.

Finally, for the moment at least, here’s the latest CryoSat-2/SMOS volume graph:

Unlike the previous metrics, this particular one is close to the middle of the pack.

[Edit – December 5th]

The National Snow and Ice Data Center issued their latest monthly Arctic Sea Ice News update earlier than usual this month:

Sea ice extent increased at a faster than average pace through November and by the end of the month, extent was just within the interdecile range. Extent was above average in the Bering Sea, but Hudson Bay remained unusually ice free through the month.

The November 2021 monthly average extent was 9.77 million square kilometers (3.77 million square miles), which ranked tenth lowest in the satellite record. The 2021 extent was 930,000 million square kilometers (359,000 million square miles) below the 1981 to 2010 long-term average. Extent was higher than average in the Bering Sea, but is extremely low in Hudson Bay.

Air temperatures at the 925 millibar level (about 2,500 feet above the surface) were well above average north of the Canadian Archipelago, by as much as 6 degrees Celsius. Conversely, temperatures over southwest Alaska and the eastern sector of the Bering Sea were as much as 6 degrees Celsius below average:

The sea level pressure pattern for November featured widespread low pressure over the Atlantic side of the Arctic and extending into the Barents and Kara Seas, paired with a moderately strong Beaufort Sea High. Strong low pressure over the Gulf of Alaska resulted in a circulation pattern in the eastern Bering Sea that brought cold air from the north. This pattern was favorable for sea ice growth, and can explain the above average ice extent in the region:

[Edit – December 7th]

Since the start of December high resolution AMSR2 extent has been flatlining:

Sea ice area has even declined slightly over the past few days:

Here too is an animation created by Uniquorn on the Arctic Sea Ice Forum using AWI ASMR2 data to reveal ice movement through the Nares Strait during December:

[Edit – December 9th]

The JAXA/ADS/ViSHOP web site is down again, so let’s take another look at high resolution AMSR2 area and extent:

It seems that the “brief hiatus” is over, and extent is now in a “statistical tie” with 2018/19 at 4th lowest for the date amongst recent year.

[Edit – December 13th]

The PIOMAS Arctic sea ice volume data for November 2021 has been released:

Average Arctic sea ice volume in November 2021 was 7,830 km3. This value is the 7th lowest on record for November,  about  1600 km3 above the  record set in 2016.   Monthly  ice volume was 61% below the maximum in 1979 and 45% below the mean value for 1979-2020. Average November 2021 ice volume was about one sigma above the 1979-2020 trend line. October saw relative rapid ice growth  for recent years bringing the mean ice thickness  (above 15 cm thickness) above the recent low values: 

The ice thickness anomaly map for November 2021 relative to 2011-2020 continues to show anomalies divided into positive and a negative halves with areas of positive anomalies increasing since the two prior months. Negative anomalies stretching from North of Greenland and along the Canadian Archipelago across the Eastern Arctic into the Barents Sea. Areas North of Greenland again feature very low ice thickness as in prior years (see our recent paper).  Positive anomalies are notable in the Beaufort and Chukchi seas due to advection of thicker older ice into the areas during the previous winter (See recent paper on this). The Alaskan summer has also been relatively cold contributing to unusually thick ice in this area:

CryoSat-2 ice thickness shows a similar picture sea ice thickness anomalies but with the maxima slightly displaced which maybe due to temporal sampling of the composite:

The JAXA web site is still down, so here’s another set of high resolution AMSR2 graphs:

[Edit – December 14th]

NOAA have just released their 2021 Arctic Report Card. Here’s the introductory video:

and here is the report itself:

[Edit – December 18th]

Ice hardened LNG tanker Vladimir Vize is about to enter the Vilkitsky Strait on the Northern Sea Route:

Meanwhile Science.org reports that “The Arctic is warming four times faster than the rest of the world“:

“Everybody knows [the Arctic] is a canary when it comes to climate change,” says Peter Jacobs, a climate scientist at NASA’s Goddard Space Flight Center, who presented the work on 13 December at a meeting of the American Geophysical Union. “Yet we’re misreporting it by a factor of two. Which is just bananas.”

Jacob’s co-authors include researchers who oversee several influential global temperature records, and they noted the faster Arctic warming as they prepared to release the global temperature average for 2020. NASA’s internal peer reviewer challenged the higher figure, suggesting the scientific literature didn’t support it. But the researchers have found the four times ratio holds in record sets from both NASA (3.9) and the United Kingdom’s Met Office (4.1), and they hope to soon include the Berkeley Earth record. (Their work also has company: In July, a team at the Finnish Meteorological Institute posted a preprint also arguing for the four times figure.)

The researchers found Arctic warming has been underestimated for a couple of reasons. One is climate scientists’ tendency to chop each hemisphere into thirds and label the area above 60°N as the “Arctic”—an area that would include, for example, most of Scandinavia. But the true definition of the Arctic is defined by Earth’s tilt. And, as has been known for centuries, the Arctic Circle is a line starting at 66.6°N. When researchers lump in the lower latitudes, “you’re diluting the amount of Arctic warming you’re getting,” Jacobs says. “That is not a trivial thing.”

The other difference is the choice of time periods over which the warming rate is calculated. Jacobs and his colleagues focused on the past 30 years, when a linear warming trend emerged for the Arctic. Analyses that look at longer term trends see less divergence between the Arctic and the world.

[Edit – December 23rd]

Here is the latest CryoSat-2/SMOS volume graph, now including some reanalysed data which seems to have come in slightly higher than the earlier “near real time” numbers:

Plus the AWI thickness map:

Further discussion of the divergence between volume and extent continues in the new New Year 2022 thread:

Facts About the Arctic in November 2021

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It’s not November until tomorrow, but Andy Lee Robinson has just published the 2021 edition of his long running “Arctic ice cube” video series, based on the PIOMAS volume data. Here it is for your edification:

You may also wish to keep tabs on our deep dive into CERES top of the atmosphere energy flux data. Here’s a sneak preview:

[Edit – November 3rd]

In stark contrast to other recent years, northern hemisphere snow cover is very low at the moment:

Continue reading Facts About the Arctic in November 2021 →

Facts About the Arctic in July 2021

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The JAXA ViSHOP web site was down for maintenance over the weekend. It is now back in action, to reveal Arctic sea ice extent at the lowest for the date in the AMSR2 record:

[Edit – July 6th]

High resolution AMSR2 area is also now lowest for the date:

as indeed is extent:

[Edit – July 13th]

According to the Canadian Meteorological Centre the current cyclone has bottomed out with a central mean surface level pressure of 971 hPa:

Continue reading Facts About the Arctic in July 2021 →

Facts About the Arctic in June 2021

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Let’s begin the month with a “true colour” image from the Terra satellite of the Laptev Sea and thereabouts:

The blueish tinge indicates the appearance of melt ponds almost everywhere over the land-fast ice currently covering the majority of the Laptev Sea.

Let’s also take a look at the high resolution AMSR2 metrics for the end of May 2021:

Thanks to the recent “brief hiatus” in areal decline, Arctic wide compaction is no longer in record territory:

Finally, for the moment at least, here is the Danish Meteorological Institute’s high Arctic temperature data in the form of a graph of freezing degree days:

For some reason the data file still doesn’t include data to the end of May, but things won’t change much by then. Over the winter as a whole only 2016/17 was significantly warmer.

Let the 2021 Arctic sea ice summer melting season officially begin!

[Edit – June 4th]

Perhaps unsurprisingly the GFS forecast from four days ago hasn’t quite worked out as predicted. The Arctic as a whole is certainly on the warm side, with a +2 C anomaly at this moment:

However the 966 hPa MSLP cyclone predicted for Monday is now forecast to be a mere 978 hPa:

With 3 days to go there is a reasonable chance of it verifying in the “New Arctic” of 2021. As you can see from the map above a large area of the Central Arctic has now lost its snow cover. This is confirmed by the Rutgers Snow Lab northern hemisphere data for May:

A new Sentinel 3 melt pond fraction product from the University of Bremen confirms that on the fast ice in the Laptev & East Siberian Seas snow cover has departed and melt ponds have arrived:

In other news Wipneus has released the latest PIOMAS gridded thickness and volume data on the Arctic Sea Ice Forum:

For some strange reason 2021 volume at the end of May is almost identical to 2012 and 2020! Plus of course there’s the modelled volume export from the Central Arctic via the Fram Strait:

[Edit – June 6th]

This “false colour” image reveals that there’s virtually no snow cover left on land, and this “false colour” image reveals that the land-fast ice in the East Siberian Sea is now awash with melt ponds:

[Edit – June 8th]

The forecast low pressure area appears to have bottomed out near the Severnaya Zemlya islands with a 978 hPa MSLP:

High resolution AMSR2 Arctic sea ice area is now 2nd lowest for the date after 2016:

Laptev sea ice area is still lowest for the data, and looks as though it will retain that position for a while:

[Edit – June 9th]

The effect of the recent heat and wind on the remaining sea ice in the Laptev Sea is now all too apparent:

It’s also evident in the DMI >80N temperature graph, which has now reached sea ice “melting point” ahead of the climatology:

Note that the blue line is actually above the “freezing point” of salty Arctic sea water.

[Edit – June 13th]

Fairly clear skies over the Laptev Sea and the western East Siberian Sea, revealing wall to wall melt ponds and the land-fast ice starting to break up near the coast as well as on the edge of the now open ocean:

Plus yesterday’s view of the Beaufort Sea, revealing fast ice breaking up in the western entrance to the McClure Strait:

[Edit – June 18th]

A clearish view of the Laptev Sea today, revealing assorted cracks in a variety of locations:

[Edit – June 20th]

The latest mid-month PIOMAS thickness/volume numbers have been released:

[Edit – June 23rd]

The skies over the Vilkitsky Strait have been cloudy for a few days. However a fairly clear view yesterday reveals that breakup is well under way in what is usually one the last areas along the Northern Sea Route to become navigable:

[Edit – June 26th]

The land-fast ice in the East Siberian Sea has started to disintegrate en masse:

Data from ice mass balance buoy 441910, currently located at 76.1 N, 151.1 W in the Beaufort Sea, reveals the onset of both surface and bottom melt:

Watch this space!

The 2020 Arctic Sea Ice Minimum Extent

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I’ve been waiting for the results of the ARCUS SIPN August call, but despite the timetable specifying “26 August 2020 (Wednesday)” they’ve still not been published and I can wait no longer!

Hopefully the August “predictions” will be available soon, but for the moment let’s take a look at the July 2020 Sea Ice Outlook instead:

For the Arctic, the median July Outlook for September 2020 average sea-ice extent is 4.36 million square kilometers, essentially identical to the median prediction in the June report, with quartiles of 4.1 and 4.6 million square kilometers. For comparison, the historical record September low over the period of satellite observations was set in 2012 at 3.57 million square kilometers, and the second lowest record was 4.27 million square kilometers set in 2007. This year’s projection is close to the 2019 observed September sea-ice extent of 4.32 million square kilometers. As was also the case for the June report, only two of the outlooks project September sea-ice extent below the 2012 record. The consensus judgement against a new record low September sea-ice extent hence remains unchanged. Interestingly, as of this report, observed extent stands at a record low for this time of year.

Note that those numbers represent “September 2020 average sea-ice extent” and not the daily minimum. Let’s now take a look at the assorted different flavours of “Arctic sea ice extent” metric. Firstly here’s the NSIDC’s “Charctic” 5 day average extent:

Next here’s JAXA/ViSHOP extent, generally assumed to be a “2 day average”:

Next here’s the DMI version, which neglects to include 2012:

Continue reading The 2020 Arctic Sea Ice Minimum Extent →

Facts About the Arctic in July 2020

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The new month starts with JAXA extent “lowest for the date in the satellite record” by a whisker:

The high resolution Arctic sea ice area and extent graphs based on the University of Hamburg’s AMSR2 concentration data are also in “statistical ties” for that honour, in records going back to 2013:

The 2020 melting season currently seems to be a game of two (geographical) halves. The sea ice on the Siberian side of the Arctic is currently at record lows:

Whereas the Beaufort Sea is near a record high:

Currently the tell tale signs of surface melt are visible across most of the central Arctic, as are the large number of wildfires across Arctic Siberia:

NASA Worldview “false-color” image of the Arctic on July 1st 2020, derived from the MODIS sensor on the Terra satellite

[Edit – July 4th]

The June 30th PIOMAS gridded thickness numbers have been released, and here are the results of Wipneus’s number crunching:

This month including a visualisation of the increasing negative anomaly:

[Edit – July 6th]

A break in the clouds over the North Pole reveals the onset of surface melt:

NASA Worldview “false-color” image of the North Pole on July 6th 2020, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the North Pole on July 6th 2020, derived from the MODIS sensor on the Terra satellite

[Edit – July 8th]

After a brief hiatus there are once again some ice mass balance buoys installed at assorted locations across the Arctic. Some have ceased to function, but one of the buoys installed as part of the MOSAiC expedition is still sending back data as it heads towards the Fram Strait. Buoy 387850 is currently located at 81.66 N, 4.19 E. Here’s its ice mass balance plot:

As you can see, both surface and bottom melt are well under way, with just over a meter of ice still remaining.

Now let’s take a look at buoy 386840, currently located at 74.30 N, 132.60 W in the Beaufort Sea:

It looks as though the ice thickness has increased, but surely that can’t be right at this time of year? To try and find out I downloaded the raw data and plotted the temperature readings from the buoy’s thermistor string:

It looks to me as though the ice floe carrying the buoy is currently floating on some warm fresh water from a recently drained melt pond, which is confusing the sensor designed to measure the position of the bottom of the ice. There certainly seems to be far less than the claimed “1.653 m snow and ice thickness” still remaining to be melted!

[Edit – July 15th]

A very unusual image. Hardly a cloud in the sky over the North Pole yesterday:

NASA Worldview “false-color” image of the North Pole on July 14th 2020, derived from the MODIS sensor on the Terra satellite

The July 2020 extent “plummet” shows no signs of ending just yet. Here’s the JAXA/ViSHOP version:

[Edit – July 17th]

JAXA AMSR2 extent is now below 7 million km², and the high resolution version is lower still:

As the “Laptev Bite” and the Atlantic periphery of open water extends further towards the North Pole, Central Arctic Basin extent is now also at record lows for the date in the AMSR2 record:

[Edit – July 19th]

Wipneus has crunched the mid month PIOMAS gridded thickness numbers, and here are the results:

Extent is currently lowest in the satellite era by a long way, but modelled volume is only fourth lowest!

Watch this space!

[Edit – July 21th]

At long last there’s a sub 1000 hPa MSLP low pressure area slowly wending its way across the central Arctic:

It seems to have bottomed out at 997 hPa. Perhaps this will inhibit the ongoing “plummet” in extent? JAXA extent fell by 114,342 km2 yesterday.

[Edit – July 23rd]

The Northern Sea Route has opened unusually early this year:

Based on the AMSR2 concentration maps from the University of Hamburg that happened on July 13th. The final choke point, as is so often the case, was the Vilkitsky Strait. According to the charts from the Russian Arctic and Antarctic Research Institute, by the 14th there was a narrow way through occupied by no more than 3/10 concentration ice:

[Edit – July 25th]

A mere three days away, and the GFS and ECMWF forecasts are in agreement, so there is a decent chance this setup will materialise in the real world:

Graphics via Tropical Tidbits

A 972(ish) hPa MSLP cyclone sitting over the ice Beaufort Sea by 12Z on Tuesday.

[Edit – July 27th]

The Sea Ice Prediction Network July forecast for this year’s September minimum extent have been released. Here’s the graphical overview:

This year’s median projected value from the July forecasts of 4.3 million square kilometers is essentially identical to the median from the June forecasts. Quartiles are 4.1 and 4.6 million square kilometers. As was also the case for June, only two projections, both by dynamic models, are for a new record low, below the mark of 3.57 million square kilometers set in 2012. One dynamical model predicts the September sea-ice extent above 5.0 million square kilometers, compared to two in the June report.

Note that the numbers quoted are for the average NSIDC extent across the month of September, not the lowest daily JAXA extent, which I suggested earlier would be “below 4 million km²” this year.

Meanwhile over on Twitter this evening (UTC):

[Edit – July 28th]

The MSLP of the (Great?) Arctic cyclone sank below 970 hPa overnight:

Here’s an early false colour snapshot of how (s)he looks from on high this afternoon (UTC), courtesy of the MODIS instrument on the Terra satellite:

[Edit – July 29th]

First up today we have a more complete “true colour” image of the cyclone doing its worst yesterday, including a fairly clear view in the bottom left corner of the initial damage to the sea ice covering the eastern Beaufort Sea. This one is from the Aqua satellite:

Watch this space!

Facts About the Arctic in June 2020

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As is our current habit this month’s report begins with the high resolution Arctic sea ice area and extent graphs based on the University of Hamburg’s AMSR2 concentration maps:

Area and extent are currently vying for second place with 2019 on the “lowest for the date” leader board, a little behind 2016 at this point in the 2020 melting season.

However following the extremely warm spring in Siberia, the sea ice area along the assorted sea that comprise the Northern Sea Route is well below all previous years in the AMSR2 record:

Another effect of the sweltering Siberian spring is evident in the melt ponds visible below the clouds across the southernmost parts of the Laptev Sea:

NASA Worldview “false-color” image of the Laptev Sea on June 1st 2020, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Laptev Sea on June 1st 2020, derived from the MODIS sensor on the Aqua satellite

plus the East Siberian Sea and Chaunskaya Bay:

NASA Worldview “false-color” image of the East Siberian Sea on June 1st 2020, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the East Siberian Sea on June 1st 2020, derived from the MODIS sensor on the Terra satellite

[Edit – June 4th]

The May 31st PIOMAS gridded thickness numbers have been released, and Wipneus has crunched the numbers:

Here too is the latest volume graph:

According to the Polar Science Center’s May 2020 update:

Average Arctic sea ice volume in May 2020 was 21,500 km3. This value is 1700 km3 above the record minimum value of 19,800 km3 set in 2017, making it the sixth lowest on record. Monthly ice volume was 39% below the maximum in 1979 and 25% below the mean value for 1979-2019. May 2020 ice volume falls 0.8 standard deviations above the trend line. Daily volume anomalies for May progressed at a fairly normal pace for recent years. Average ice thickness is in the middle of the pack for the more recent years. Ice thickness anomalies for May 2020 relative to 2011-2018 continue the April pattern and show relatively thin ice along the Russian Coast and thicker than normal sea ice in the Barents sea. There are some fairly strong positive anomalies in the eastern Beaufort and north of Greenland. This anomaly pattern is likely due to the very strong positive Arctic-Oscillation index pattern that occurred during the Winter of 2020.

There looks to be a lot of anomalously thick ice waiting to melt out on the Atlantic periphery, and it will be interesting to see how the thicker ice in the eastern Beaufort Sea fares as the melting season progresses.

As also suggested by the area graph above, the Northern Sea Route is going to be open early in 2020. In fact a ice hardened tanker has already begun its journey through, unsupported by an icebreaker:

It was the “Christophe de Margerie” that on the 19th May kickstarted this year’s shipping season across the eastern part of the Northern Sea Route. The vessel owned and operated by Russian shipping company Sovcomflot loaded up liquefied natural gas in Sabetta and is due to arrive in the Chinese port of Jingtang on the 11th June. It was the earliest east-bound shipment on the route ever for this kind of vessel.

Shipments in the Northern Sea Route 27th May 2020. Map by MarineTraffic
Shipments in the Northern Sea Route 27th May 2020. Map by MarineTraffic

By 27th May, the ship had made it almost to Wrangel Island, information from ship tracker service MarineTraffic shows. The “Christophe de Margerie” is accompanied by nuclear powered icebreaker “Yamal”.

In the wake of the almost 300 meter long vessel now follows the “Vladimir Voronin”, a vessel that is operated by company Teekay. The “Vladimir Voronin” on the 25th May left Sabetta and was on May 27th located in the Vilkitsky Strait north of the Taymyr Peninsula.

The ”Vladimir Voronin” is not accompanied by icebreaker. The “50 Let Pobedy” that escorted the ship out of Sabetta and eastwards towards the Vilkitsky Strait has now returned and appears to be on its way back to Sabetta.

[Edit – June 17th]

The mid month PIOMAS gridded thickness numbers have just been released. Here’s the thickness map:

and the volume graph:

In addition JAXA extent is now in a “statistical tie” with 2019 in the “lowest for the date” competition:

Watch this space!

Facts About the Arctic in May 2020

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Let us begin this month’s report from the far north with the high resolution Arctic sea ice area and extent graphs based on the University of Hamburg’s AMSR2 concentration maps:

Area is currently lowest for the date in the AMSR2 record. After briefly occupying that position extent has increased over the last few days of April due to winds causing sea ice to move in the direction of the far North Atlantic:



The Alfred Wegener Institute has now finished reanalysing their CryoSat-2/SMOS thickness data, and the resulting volume graph looks like this:

“Measured” Arctic sea ice volume is the lowest in the CryoSat-2 era as we head towards the main 2020 melting season, which in my calendar at least begins on June 1st. The PIOMAS modelled volume numbers should be released shortly.

[Edit – May 5th]

The April 30th PIOMAS gridded thickness numbers have been released, and Wipneus has worked his usual magic. By way of comparison with the AWI metric:

Obviously differing from CryoSat-2/SMOS, PIOMAS has 2020 volume a long way above 2017, in amongst a gaggle of other years.

[Edit – May 13th]

The middle of May is rapidly approaching, so let’s start to set the scene for the forthcoming melting season. First off here are the hi res AMSR2 area and extent graphs:

Extent is currently significantly above 2016 due to the recent “dispersion” mentioned above, but area is very close to an all time low for the date.

Next take a look at the current northern hemisphere snow cover anomalies from the Rutgers University Snow Lab:

Whilst there is a positive anomaly near Hudson Bay, there are significant negative anomalies across Siberia and Alaska. This does not augur well for sea ice retention along both the Northern Sea Route and Northwest Passage by September 2020.

Watch this space!

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

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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!