Arctic Sea Ice

June 2019, one hell of a month

Before the latest PIOMAS data are published, somewhere next week, I wanted to present an overview of all the things that have been happening in the Arctic these past couple of weeks, and what they may mean for the outcome of the 2019 melting season. You've guessed it, I'm going to be talking about melting momentum (for those not familiar with the concept, here's the archive). 

But I want to start off with something else. Almost every melting season is marked by some spectacular event nowadays. From the Great Arctic Cyclone of 2012, the huge cracking event of February 2013, the possibility to sail beyond 85N in September 2014, to the almost circumnavigation of Greenland in August last year. This year, another event has really stood out so far.

Every melting season, the entire North American coast clears of ice at some point, making it possible to sail from Bering Strait to M'Clure Strait (western exit/entrance of the Northwest Passage central route). Back in 2016, there was a chance of this happening record early, but it didn't pan out. This year it did, four weeks earlier than any other year in the Concentration Maps section of the ASIG. The event was reported by Rick Thoman (ACCAP) and Lars Kaleschke (University of Hamburg), both providing some great graphs and animations (see here).

Here's an animation of Uni Bremen Sea Ice Concentration maps showing how it all came about (we even had a great poll on the ASIF to speculate about the date when there would be open water all the way):

But just one event does not a record melting season make. What does make a record melting season, is melting momentum. Here follows a barrage of maps and graphs, with short commentary, to give you an idea of how the 2019 melting season stacks up so far (click on the images for larger versions).

PIOMAS June 2019

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

As you can see, 2019 has moved into second place on the PIOMAS volume graph. The drop of 3234 km3 for May was third highest on record (after 2010 and 2012 which dropped 3523 and 3508 km3 respectively) and well above the average May decrease of 2621 km3. Last month, 2019 was on a par with 2011, 2016 and 2018 for second place, but now there is no question who is second. And 2017's lead has been reduced further from 1665 to 1015 km3.

Here's how the differences with previous years have evolved from last month:

Wipneus' version of the PIOMAS graph also shows the minuscule lead over all the other years, except 2017, which is about to end its extraordinary excursion:

PIOMAS May 2019

Another month (and a half) has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

The flatline that started in the second half of March, continued for a while longer during April, shot up a tiny bit towards this year's maximum, and then essentially flatlined again, with a small dip towards the end of the month. This year's maximum of 22,490 km3 is the third lowest on record, 116 and 1,708 km3 behind 2018 and 2017 respectively (yes, the three lowest maximums on record have all occurred in the last three years).

This year's monthly change for April was +127 km3, just 8 km3 above the average of +119 km3. Just like last month, 2019 is still fourth lowest, but the difference with 2011 and 2018, 63 and 44 km3 respectively, has become so small that you could say that they're sharing the second position (together with 2016 that is just 13 km3 behind 2019). The difference with leader 2017 is still large at 1665 km3, but the largest gap was a whopping 2550 km3 on February 14th.

Here's how the differences with previous years have evolved from last month:

Wipneus' version of the PIOMAS graph shows that 2016 dropped very fast during May, also in extent (more on that below):

PIOMAS April 2019

Apologies for not posting an update last month (busy).

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Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Look at the red line in the graph above. Do you see it essentially flatline towards the end of March? That's the primary cause for 2019 smashing the record for lowest March volume increase in the 2007-2019 period (and probably before that as well). The March average for that period was 1869 km3, the record was 1557 km3 (March 2015), and this year's March came in at 1339 km3. 2019 went from 7th to 4th place in the rankings, with 2011 just 89 km3 lower and a gap with leader 2017 that went down from 2279 km3 to 1834 km3.

Here's how the differences with previous years have evolved from last month:

Wipneus' version of the PIOMAS graph shows that 2019 still has some ways to go to catch up with 2017 (that went extremely low because of a horror winter, but luckily bounced up again during spring and early summer):

PIOMAS February 2019

It was a long wait, what with the US government shutdown and a new year requiring spreadsheet updates, but here is the first PIOMAS update of 2019.

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Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Good news! So far, the winter has been good for Arctic sea ice. The past three months have been relatively cool, especially when compared to the previous three winters, which broke all temperature records for the Arctic (see Zack Labe's excellent graph here). Of course, PIOMAS has responded in kind. With 3456 km3, January was well above the 3179 km3 average for the 2007-2018 period. And so, 2019 starts out as 7th lowest on record, a whopping 2500 km3 behind ranking leader 2017, almost doubling the gap since the end of November.

Here's how the differences with previous years have evolved from last month:

Wipneus hasn't updated his version of the PIOMAS graph yet, so we move on to the anomaly graph. Here too, it's clear that things are going relatively well for the ice, with the trend line venturing into 2 standard deviation territory:

PIOMAS December 2018

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

November has been an excellent month for Arctic sea ice. With 4226 km3, it recorded the highest volume increase for November in the 2007-2018 period, well above the average of 3491 km3. The reasons for this are obvious: rapid growth in ice extent and relatively low temperatures (more on that below). This means that 2018 has dropped from 4th lowest to 6th lowest, and the gap with leader 2016 has grown by a whopping 1322 km3!

Here's how the differences with previous years have evolved from last month:

Because all the trend lines go up fast around this time of year, I'm posting another Wipneus graph that visualises PIOMAS volume anomaly, showing 2018's massive increase more clearly:

PIOMAS November 2018

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

October has seen a continuation of the trend that set in right after the September minimum (see last month's update), where 2018 went from 6th lowest at the minimum to 5th lowest at the end of the September, and now it's 4th at the end of October, practically on a par with 2011. The increase of 2115 km3, well below the 2367 km3 average, was actually 3rd lowest in the 2007-2018 record, with only 2007 and 2016 having an even lower increase (1637 and 1648 km3 respectively). That means that 2018 has crept closer to the years below it, and moved away further from the years above it, overtaking 2017 for the first time this year.

Here's how the differences with previous years have evolved from last month:

Wipneus' version of the PIOMAS graph shows how this year's trend line blocks out that of 2011, that's how close together they have been for a couple of weeks now:

PIOMAS October 2018

I was ready to write about this 10 days ago, but the data wasn't out yet. And then life got in the way, as it always does. On the bright side, Wipneus has just updated his PIOMAS graphs to mid-October. More on that below, but first I'll discuss the minimum.

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Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

As always, the minimum was reached in September. This year, the lowest amount of sea ice volume, according to PIOMAS, was reached on September 15th, and ended up 6th lowest on record, after 2010, 2011, 2012, 2016 and 2017. And thus, because the maximum was second lowest on record, total melt was 9th lowest on record:

If we look at the data for the end of September, 2018 has already crept to 5th lowest on record, almost on a par with 2017. Where most years gain a bit of volume during September, 2018 actually lost 119 km3, thus reducing the gap with all years that were lower at the end of August (dipping below 2010), as can be seen on this table showing how the differences with previous years have evolved from last month:

If we then look at Wipneus' most recent graph with data up to mid-October, we see that 2018 has gone down even further in the ranking and is now in 3rd place:

Freezing season has started, or has it?

We tend to focus on the end of the melting season, also known as the minimum, because that's when the ice covers the least amount of water. That's all fine and dandy, but of course, it's just an arbitrary measuring point. For instance, this year's minimum for the JAXA sea ice extent data set was 6th lowest on record, but flash forward to the first week of October and this year's trend line is third lowest on record and could soon be second lowest on record:

This, as always, had to do with the weather, which has been pretty crazy the past two weeks. First, fierce winds pushed back against the ice edge in most of the Arctic Ocean, delaying the ice pack's expansion, while at the same time continuing to melt that last, stubborn sliver of ice extending towards the East Siberian Sea. The result has been a continuing decline of sea ice extent in the Arctic Basin, and to a lesser extent in the East Siberian Sea, where, normally, the trend line should have been going up already (image courtesy of Wipneus, ASIG Regional graphs):

Another factor that has come into play these past few days, is heat. It's mostly coming from the Pacific, where sea surface temperatures are running quite hot again, as can be seen on these DMI sea surface temperature anomaly maps, comparing this year's start of October with those of 2016 and 2017:

2018 Arctic sea ice minimum

Another great video, this time from NASA Goddard: