Excellent melting season summary

It was posted on Mongabay yesterday and written by Gloria Dickie.

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At 2017 minimum, scientists ask:
Is Arctic entering the Thin Ice Age?

The sun reflects over thin sea ice and a few floating icebergs near the Denmark Strait off of eastern Greenland, as seen from NASA’s P-3B aircraft on April 14, 2012 — the record year for Arctic ice melt, so far. Photo by Jefferson Beck / NASA

• The decline of Arctic ice didn’t set a record this year, with sea ice extent coming in eigth after record-setting 2012. On September 13, at the summer minimum, sea ice covered 4.64 million square kilometers; that’s 1.25 million square kilometers more than 2012.
• However, that fact was overshadowed by another: experts say what matters most in the Arctic is the total volume of ice — a combination of thickness and extent. 2017 saw summer volumes among the lowest ever recorded.
• The Arctic set still another record that concerns scientists: no other 12-month period (September 2016 to August 2017) has had such persistently low sea ice extent.
• The Arctic ice is therefore showing no signs of recovery, scientists say, and its decline is likely continuing to impact the Earth’s weather in unpredictable and destabilizing ways.

After 16 months of consecutive record and near-record lows in late 2016 and early 2017, sea ice extent in the Arctic held fast over the summer thanks to more moderate weather and cooler temperatures. As of September 13, sea ice covered some 4.64 million square kilometers (1.79 million square miles) at its minimum, roughly 1.25 million square kilometers (482,000 square miles) more than record-setting year 2012.

Still, while 2017’s summer melt season didn’t break the record, it falls far below the 1981 to 2010 median extent by over 1.58 million square kilometers (610,000 square miles). Moreover, surface cover isn’t everything when it comes to the state of the Arctic — what experts say matters most is the total volume of ice — a combination of thickness and extent, and 2017 saw summer volumes among the lowest ever recorded.

Some scientists are now saying colloquially that the Arctic Ocean has in recent decades entered the “Thin Ice Age.” Since 1980, the average ice thickness come July has decreased by an estimated 120 centimeters (47 inches).

Notably this July, the average sea ice thickness in the Arctic was equivalent to the lowest on record.

Global sea ice area (Arctic and Antarctic) 1978 to 2017. Graphic by Kevin Pluck

So in spite of a slight rebound in summer extent, the average Arctic sea ice volume was still 47 percent below the 1979 to 2016 mean. That is not only likely bad news for the future of Arctic ice and polar ecosystems, but also for a stable global climate, which is highly influenced, and possibly unbalanced by events up North. Climatologists, for example, postulate that jet stream blocking, an effect hypothetically caused by a warming Arctic, could have stalled Hurricane Harvey over Houston.

This year’s thinner, slushier ice is more vulnerable than the past’s thick, multi-year ice, and it melts out rapidly during a spike in temperature or intense cyclonic activity. That’s why, even at the end of August, scientists at the National Snow and Ice Data Center weren’t quite ready to call how 2017 would shake out compared to previous summers. Last year, they noted, took a sudden nose dive around the same time.

“It was pretty unique going into the [2017] melt season, that we had had so many record low sea ice extents and thickness estimates all suggested we had quite thin ice and low ice volume,” says Julienne Stroeve, senior research scientist with the National Snow and Ice Data Center. “You would tend to think that maybe we’d have another record low, but what this summer has shown is that’s not enough to just have thin ice.”

Indeed, summer weather conditions have a larger impact on summer sea ice cover than the extent of the winter maximum going into the season. At least, that is the case, so far, with the ice record.

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There's more. Read the entire article here.

Comments

[Stewecar]

I think that the domino effect is starting badly..
No way to recover old thicker ice and thin ice that will became normal weak ice, ready to disappear once the freezing season will end up..
Thanks for the post, Neven.

[Wonderpilletal]

Stewecar, https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=119.0;attach=53247;image this graph seems to make it all crystal clear!

[Aksel Gasbjerg]

Excuse being off topic but i have a pressing question.

Assumptions in a thought example:
The air today contains 400 ppm CO2
We will emit 40 gt CO2 in the coming year, of which 20 gt ends in the air and 20 gt ends in the ocean/land.
The emissions result in an increase of 2 ppm to 402 ppm CO2 in a year.

With these assumptions (and of course, Ceteris Paribus) I have the following questions:
If tomorrow we cut CO2 emissions from 40 to 20 gt, what are ppm in a year?
If we stop total CO2 emissions tomorrow, what are ppm in a year?

[D_C_S]

Aksel Gasbkerg,

If the CO2 emission rate were to halve tomorrow then the increase in atmospheric CO2 concentration over the next year would be about half of what it would have been if the CO2 emission rate had remained the same. If CO2 emissions were to stop tomorrow then the atmospheric CO2 concentration in a year would about the same as it is now.

This topic has been debated on here though, and not everyone agrees.

[D-Penquin]

Aksel Gasbjerg

The August 2017 figure for atmospheric CO2 is 405.07ppm and this compares with the August 2016 figure of 402.45ppm.
https://www.co2.earth/

From 2012 to the present time emissions have been on a slightly downward trend but CO2 levels continue to rise at an increasing rate.

It is stating the obvious saying that CO2 emissions should be reduced as quickly as possible but on the evidence to-date it appears that reduced CO2 emissions do not lead to reduced atmospheric CO2ppm.

As commented by D_C_S...much debate on this issue and not everyone agreed.

[Neven]

There are some excellent discussions in this segment of the Arctic Sea Ice Forum.

[Andy Lee Robinson]

I've just made a new ice cube video for 2017.
With record low volumes earlier this year, we were considering the possibility we could be see a complete melt-out if the exceptional melt continued.
Fortunately melt-rate decelerated substantially over the summer and pulled back from the brink.
However, this year's minimum volume is virtually unchanged from last year.

Arctic Sea Ice Minimum Volumes 1979-2017
https://youtu.be/Xh3oakgxZ9w

Notes: Tweaked camera motion a little, increased framerate from 25 to 30 fps and added more pause at the end.
I use perl to make povray scripts, and am currently rendering a 4k version (3840x2160) which will take about a week for all the slaves to complete!

[AnotherJourneybyTrain]

Almost as scary as this: http://nsidc.org/arcticseaicenews/files/1954/10/figure4b.png

Was that Philip Glass in the soundtrack, btw?

[Andy Lee Robinson]

Yup, that's also pretty scary...
The soundtrack is me just improvising on the piano for this clip, but I appreciate your comparison!
Took hundreds of hours to write the rendering/scheduling code, 48+ hours to do the render across 8 Linux servers, and then 30 secs to play the music for it!

[AnotherJourneybyTrain]

Whoah!

You should know your work is appreciated and the Internet will always have it. Good job!

[John Christensen]

I just came across this explanation from Phys.org and Claire Parkinson, Sr Climate Scientist, NASA, for lowest summer Arctic SIE that I found puzzling ( https://phys.org/news/2017-09-end-of-summer-arctic-sea-ice-extent.html ):

"The three years with the lowest Arctic ice extents on record —2012, 2016 and 2007— experienced strong summer storms that hammered the ice cover and sped up its melt. "In all of those cases, the weather conditions contributed to the reduced ice coverage. But if the exact same weather system had occurred three decades ago, it is very unlikely that it would have caused as much damage to the sea ice cover, because back then the ice was thicker and it more completely covered the region, hence making it more able to withstand storms," Parkinson said."

The low summer SIE in 2007, unless my memory fails me entirely, was caused primarily by a strong Beaufort gyre, extraordinary export via Fram and unprecedented in-situ melting in Beaufort due to rapid SST increase and strong bottom-melt.

Also, wouldn't really agree that strong summer storms were the main differentiators of 2012 and 2016 compared to other recent summers - rather the contrary..

[Andy Lee Robinson]

Thanks, that means a lot - I often wonder if it's worth the effort and personal sacrifice.
Positive feedback and recognition helps to motivate me to continue, especially if I know it is helping to move the needle in world opinion.

When I started making this in 2013, I thought naively that it might go viral, and that if everyone could see it, they might just realize how much we are damaging the habitability of our world and want to do something about it.

Of course, there are a lot of people that really really do not want people to see it, and lots of people that really can't, don't, or don't want to understand its significance or feel that it is worth sharing, so it circulates in our bubble of activists and doesn't break out to where it needs to be shown.

However, it has had some success and I have a list of sites that have published it such as The Guardian, Washington Post, Slate, Think Progress, New York Times, but still nowhere near the level I think it deserves!

Few other visualizations communicate our dire situation more explicitly and effectively, and I really tried my best with the skills I have to make it interesting and appealing.

[P-maker]

Hi Andy

Just played it in the office. My colleagues thought it was my phone ringing, and they really liked the pleasant tune. Maybe a downloadable version for smart phones may do the trick you are asking for.

Cheers P