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:
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 2021By way of a change we start this month’s look at all things Arctic with some sea ice statistical analysis. Anthony Watts’ Arctic porky pie production line has been speeding up recently, and I am not the only one who has noticed. As part of his takedown of the latest “skeptical” allegations against the United Kingdom Met Office Tamino has been looking at trends in Arctic sea ice extent over at his “Open Mind” blog:
First and foremost, the yearly minimum is only one day out of the year. We have sea ice extent data throughout the year, and what happens during the rest of the year counts. Instead of using the annual minimum, let’s use the annual average. To avoid losing the most recent data, I’ll compute the yearly average for October through the following September rather than the usual (but arbitrary) January through December. I’ll also omit October 1978 through September 1979 because that year is incomplete. I get this:
Continue reading Facts About the Arctic in October 2021The annual averages show much less fluctuation than the annual minima, so we can estimate things like rates of change with greater precision. I find that there is statistical evidence that the rate changed over time. One model of such changes uses three straight-line segments with their changes chosen to best-fit the data, like this:
A detailed dissection of the 2021 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.
Let’s start with a map of sea ice age at the beginning of August:
Firstly notice the absence of 3+ year old ice off the coast of north east Greenland. Also visible is a band of 4+ year old ice across the Pacific side of the Arctic Basin, which has slowed melting in the region and explains the following regional sea ice area graphs:
Next here’s the current AMSR2 concentration map:
There is currently a large area of open water in the Wandel Sea to the north of Greenland. There is also an arm of old ice across the Beaufort and Chukchi Seas which is still clearly visible, but also visible is the recent reduction in sea ice concentration in the region. By way of explanation, here’s another look at the thickness of an ice floe currently situated to the north of the Chukchi at 74.84 N, 164.29 W, as measured by an ice mass balance buoy:
As the 2021 melting season draws towards its conclusion the floe is experiencing rapid bottom melt. How much longer will this floe and others like it last? Will it survive to become an “old ice” dot on next year’s ice age maps?
[Edit – September 6th]As Wipneus puts it on the Arctic Sea Ice Forum, “PIOMAS has updated the gridded thickness data up to the 31st of August”. Here’s the latest modelled thickness map, which shows the thickest remaining ice located north of the Canadian Arctic Archipelago rather than north of Greenland:
The accompanying volume graph shows 2021 in 7th lowest position, at 4.7 thousand km3:
Here too are the current PIOMAS volume trends for each month of the year:
The Swedish icebreaker Oden has recently been exploring the area between northern Greenland and the North Pole as part of the Synoptic Arctic Survey expedition:
Here are the measurements of water temperature it has recorded over the past few days:
Ranging between -0.4 °C and -1.0 °C it doesn’t look as though the 2021 refreeze will be starting in the Wandel Sea just yet.
[Edit – September 10th]A picture of the sea ice at the North Pole from Ponant’s Le Commandant Charcot on September 6th:
Here’s the latest NSIDC sea ice age map:
That shows plenty of old ice still left in the Beaufort Sea. However ice mass balance buoy 52460 now appears to floating free of its ice floe at 75.56 N, 165.99 W:
“New ice” has started to appear in previously open water on the Canadian Ice Service charts. See area E south east of Resolute:
In answer to Frozen Earth’s metaphorical prayer, Wipneus has just released the mid September PIOMAS gridded thickness numbers on the Arctic Sea Ice Forum. First of all the thickness map:
followed by the volume graph:
and the monthly volume trends:
Volume calculated from the thickness data currently show that 2021’s minimum was reached on September 7th at 4.64 thousand km3, which is the 8th lowest value in the Polar Science Center’s record.
[Edit – September 23rd]NASA have just announced a new paper about clouds in the Arctic. Highly relevant given their recent overview of the 2021 melting season!
Clouds are one of the biggest wildcards in predictions of how much and how fast the Arctic will continue to warm in the future. Depending on the time of the year and the changing environment in which they form and exist, clouds can both act to warm and cool the surface below them.
For decades, scientists have assumed that losses in Arctic sea ice cover allow for the formation of more clouds near the ocean’s surface. Now, new NASA research shows that by releasing heat and moisture through a large hole in sea ice known as a polynya, the exposed ocean fuels the formation of more clouds that trap heat in the atmosphere and hinder the refreezing of new sea ice.
The findings come from a study over a section of northern Baffin Bay between Greenland and Canada known as the North Water Polynya. The research is among the first to probe the interactions between the polynya and clouds with active sensors on satellites, which allowed scientists to analyze clouds vertically at lower and higher levels in the atmosphere.
The approach allowed scientists to more accurately spot how cloud formation changed near the ocean’s surface over the polynya and the surrounding sea ice.
Watch this space!
Let’s first of all take a look at JAXA’s flavour of Arctic sea ice extent:
After reaching lowest extent for the date in early July, the weather in the Arctic Basin was stormy, cloudy and cool compared to other recent years until the last few days of the month:
Here’s the same period in 2020 for comparison purposes:
Consequently the rate of extent loss in the second half of July was significantly less than last year.
Next let’s take a look at AMSR2 concentration:
Continue reading Facts About the Arctic in August 2021Let’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:
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:
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:
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:
The latest mid-month PIOMAS thickness/volume numbers have been released:
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:
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!
It’s May Day 2021, and just for a change we’re going to start the month off with a pretty picture!
Parts of the Laptev Sea are starting to look distinctly “warm” in the infra-red. Here’s a “false colour” image taken by the Terra satellite during a gap in the clouds:
We have reached the time of year when the SMOS “thin ice thickness” readings start being affected by surface melt, but let’s take a look anyway:
That area of the Laptev certainly appears to be either thin or melting.
Meanwhile on the Canadian side of the Arctic the fast ice off the Mackenzie Delta is starting to get damp, even though the river itself still looks to be fairly well frozen:
It will also be interesting to follow the progress of this large floe as it heads towards oblivion through the Fram Strait:
Continue reading Facts About the Arctic in May 2021If the 2021 maximum Arctic sea ice extent is more your thing then please see the previous article:
“The 2021 Maximum Arctic Sea Ice Extent“
Maximum volume is still several weeks away, but let’s first of all take a look at the PIOMAS modelled volume numbers for February. They are not yet available via the University of Washington’s Polar Science Center web site, but Wipneus has once again crunched the gridded thickness numbers which are already available. Here is what they reveal:
As you can see, it will be a big surprise if the 2021 volume maximum occurs in March rather than April, and 2021 is currently 3rd lowest for the date, behind 2017 and 2018. For completeness here too is the PIOMAS thickness map for the end of February:
This does contain some surprises, such as an area of thick ice along the shore of the East Siberian Sea, but no such thing along the north coast of Greenland, the traditional bastion of “the thickest ice in the Arctic Ocean”.
The “measured” Arctic sea ice volume calculated from CryoSat-2 and SMOS thickness data has also updated to February 28th:
Note that the “near real time” figures graphed in blue will almost certainly be revised upwards when the “reanalysed” data is released in a couple of weeks. Equally certainly they will be “lowest for the date” in the 11 year record.
Here also is the CS2/SMOS thickness map for February 28th for comparison purposes:
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:
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:
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:
Continue reading Facts About the Arctic in October 2020A 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.
Continue reading Facts About the Arctic in September 2020