Category Archives: News

Facts About the Arctic in April 2021

April 8, 2021NewsASIF, Extent, Fram Strait, Greenland Sea, JAXA, MSLP, Volume, WipneusJim Hunt

As part of his March PIOMAS gridded sea ice thickness update Wipneus also produced this graph of sea ice export from the central Arctic via the Fram Strait:

So far this winter export has been remarkably subdued, but that has now changed. A persistent dipole with high pressure over Greenland and low pressure over the Barents Sea is generating strong northerly winds in the Fram Strait, and even bringing some April snow showers to South West England:

Wondering why it's so #cold? We're still sat in Arctic air across the UK today

A change to milder #weather arrives tonight for Thursday and Friday, bringing temperatures much closer to average

But it doesn't last long as by the #weekend another Arctic plunge is likely pic.twitter.com/LUa5C3Y84O

— Met Office (@metoffice) April 7, 2021

Precisely how high the pressure has been over Greenland is the subject of much debate. See for example this discussion on the Arctic Sea Ice Forum about whether a new world high pressure record has just been set. Different weather forecasting models have come to very different conclusions about the mean sea level pressure of a high pressure area situated over the Greenland ice sheet, which reaches an altitude of over 3,000 metres. Here’s GFS for example, showing 1097 hPa at 06Z on April 4th:

whereas the Canadian Meteorological Centre synopsis for the same time shows a mere 1070 hPa:

At least all the assorted models agree that the isobars are closely packed over the Fram Strait, and hence some of the thickest sea ice remaining in the Arctic is currently heading towards oblivion in the far north Atlantic Ocean:

Here’s the US Navy’s sea ice drift forecast for Saturday 10th:

Facts About the Arctic in November 2020

November 3, 2020NewsAMSR2, CryoSat-2, Extent, JAXA, NSIDC, PIOMAS, SMOS, Thickness, VolumeJim Hunt

Arctic sea ice volume is of course far more important in the grand scheme of things. However sea extent is easier to measure, and the JAXA AMSR2 flavour thereof has now nudged into second place for the date above 2016:

[Edit – November 4th]

The PIOMAS gridded thickness numbers have been released, to reveal this end of October thickness map:

and these calculated volume graphs:

These show Arctic sea ice volume to be lowest for the date, even if extent has slipped into 2nd place.

For comparison purposes here too is the latest AWI CryoSat-2/SMOS merged thickness map:

Facts About the Arctic in October 2020

October 25, 2020NewsAMSR2, Arktika, AWI, CryoSat-2, NSR, Oleg Shchapin, PIOMAS, Rosatomflot, SMOS, Vilkitsky Strait, VolumeJim Hunt

Let’s start this somewhat belated article by looking at Arctic sea ice volume. The mid month PIOMAS gridded thickness numbers have been released to reveal these volume graphs:

Minimum volume for 2021 was 4.03 thousand km³ on September 17th, 2nd lowest in the PSC record.

Modelled volume is now in a “statistical tie” with 2012 for lowest on record for mid October. Here too is the PIOMAS thickness map:

Meanwhile for comparison purposes here is the first merged Cryosat-2/SMOS thickness map of the 2020/21 freezing season, hot off the presses at the Alfred Wegener Institute:

Facts About the Arctic in September 2020

September 3, 2020NewsCAA, CIS, PIOMAS, SoD, Thickness, VolumeJim Hunt

A detailed dissection of the 2020 minimum of various Arctic sea ice extent metrics can be found on a dedicated thread. All other Arctic news in September will be found below. As is usually the case, let’s set the ball rolling by taking a look at Wipneus’s visualisations of the August PIOMAS gridded thickness data:

together with the computed volume:

and anomaly graphs:

PIOMAS volume at the end of August was still firmly in 3rd place behind 2012 and 2019.

The 2020 Arctic Sea Ice Minimum Extent

August 27, 2020NewsAMSR2, Area, AWI, DMI, Extent, JAXA, NSIDC, SIPNJim Hunt

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:

Past Evidence Supports Complete Loss of Arctic Sea-ice by 2035

August 11, 2020NewsAnthony Watts, BAS, Charles Rotter, CICE, HadGEM3, Hadley Centre, Julienne Strove, Melt Ponds, NSIDC, UKMO, WUWTJim Hunt

Our title today is shamelessly plagiarised from the “Watts Up With That” blog of our old friend Anthony Watts. However daring to be different we have redacted the initial word “Claim -“.

The WUWT blog post is bylined “Charles Rotter”, and refers to a new paper in the journal Nature Climate Change entitled “Sea-ice-free Arctic during the Last Interglacial supports fast future loss“. Here’s an extract from the abstract:

The Last Interglacial (LIG), a warmer period 130,000–116,000 years before present, is a potential analogue for future climate change. Stronger LIG summertime insolation at high northern latitudes drove Arctic land summer temperatures 4–5 °C higher than in the pre-industrial era. Climate model simulations have previously failed to capture these elevated temperatures, possibly because they were unable to correctly capture LIG sea-ice changes. Here, we show that the latest version of the fully coupled UK Hadley Center climate model (HadGEM3) simulates a more accurate Arctic LIG climate, including elevated temperatures. Improved model physics, including a sophisticated sea-ice melt-pond scheme, result in a complete simulated loss of Arctic sea ice in summer during the LIG, which has yet to be simulated in past generations of models. This ice-free Arctic yields a compelling solution to the long-standing puzzle of what drove LIG Arctic warmth and supports a fast retreat of future Arctic summer sea ice.

There’s no mention of “2035” in there, so let’s look instead at yesterday’s press release from the British Antarctic Survey:

Facts About the Arctic in August 2020

August 1, 2020NewsAMSR2, Andrew Slater, Cyclone, Fram Strait, JAXA, MODIS, PIOMAS, Polarstern, SPIE, Suomi, Thickness, Thomas Wunderlich, VolumeJim Hunt

A new month begins today, and at the moment it looks as though it’s going to be the most interesting one since August 2012. Here once again is the satellite image of the enormous cyclone that was spinning over the Beaufort/Chukchi Seas just a few days ago:

Facts About the Arctic in July 2020

July 3, 2020NewsAMSR2, Area, Beaufort Sea, Cyclone, Extent, Fram Strait, IMB Buoys, MODIS, MOSAiC, MSLP, NSR, SIPN, Terra, Vilkitsky StraitJim Hunt

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:

Facts About the Arctic in June 2020

June 1, 2020NewsAMSR2, Area, Chaunskaya Bay, East Siberian Sea, Extent, Laptev Sea, PIOMAS, Volume, WipneusJim Hunt

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.

Facts About the Arctic in May 2020

May 2, 2020NewsAMSR2, Area, CryoSat-2, Extent, Hamburg Uni, NSR, NWP, Rutgers, SMOS, VolumeJim Hunt

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 Great White Con

Putting the Arctic sea ice record straight