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John Christensen

Thank you for another great PIOMAS update Neven!

Given the weather with some storm activity in the CAB in Sept, I was surprised to see that volume went up as much and suspect that to some degree a new snow layer and snow-filled ponds on the ice have been measured as sea ice increase.

That said, the ecmwf forecast is now showing a high to remain in the CAB for the next week, which will slow down winds and cool down temps, so that more actual sea ice growth will be possible.

This summer IMO seems to have been an exemplary example of how the atmospheric conditions are changing in a warming Arctic:
- Winters are relatively warm and humid at/near the CAB due to later cover of sea ice.
- The Beaufort gyre is reduced, since high pressure areas increasingly tend to be based over land areas - both summer and winter (See e.g.:
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/piomas_ice_motion_anomaly_JanMarch2017.png )
- Winter-time low pressure areas above the sea ice will increase precipitation, which in addition to higher temps will insulate the ice and reduce sea ice formation, but at the same time should reduce sea ice export via the Fram Strait.
- Reversely, the well-known pattern of summertime low pressure areas in the CAB is further strengthened, lowering temps, increasing cloud cover and thereby reducing sea ice melting.

It seems clear to me that this is where we are heading, and the IPCC prediction models therefore seem to be reasonably accurate, as it could take a few more decades to reach an ice-free Arctic at Sept. minimum.

Consequently, I cannot agree with scientists such as Prof. Peter Wadham, who still in 2016 predicted an ice-free Arctic in 2017 or 2018:
https://www.theguardian.com/environment/2016/aug/21/arctic-will-be-ice-free-in-summer-next-year

The only really interesting feature that I am considering is the relationship between Greenland and the CAB: For years such as 2007, 2012, 2013, and 2017 we have seen a strong correlation between average air pressure over the CAB and the air pressure over the Greenland ice cap.
Especially in the fall of 2016, where tremendous storms rolled across Greenland with high levels of precipitation in October, the storms kept entering also the CAB.
This year, the air pressure over Greenland has gradually increased and been fairly high and stable over the past couple of months. It will be interesting to see if this helps blocking storms from entering the CAB also..

AnotherJourneybyTrain

I predict a third freak winter owing to the stagnating state of multi year sea ice, as outlined at NSIDC, and the return to lagging dmi temps.

John Christensen

Wow - not a huge crowd here these days..

Just wanted to note that the forecast remains for a good start to the Arctic winter: High pressure in the CAB with lows circulating in the northern parts of the continents, providing early extension of NH snow cover, while cooling down the Arctic waters.

And then, for my old discussion with wayne about the relationship between the AO index and Arctic cold or sea ice: The current setup seems near ideal for a cold NH winter and for expanding sea ice, yet the AO index is currently positive, meaning that the overall air pressure above 60N is slightly below average.

I was therefore not correct that a negative AO index (Above normal air pressure) would overall be positive for Arctic sea ice, as the distribution of high and lows seems to be much more important than the average air pressure.

AnotherJourneybyTrain

So, John, are you looking forward to a 'third freak winter' and why or why not?

(Do you agree with my amateur assessment?)

John Christensen

As mentioned in my first post, I would say we are generally moving to a regime of less-frigid Arctic winters and cool summers, so yes; in all likehood another freak warm winter.

That said, the current weather is somewhat anomalous for recent years, and I am curious how this will shape temps and wind in the CAB for the coming 1-2 weeks.

gkoehler

All of the trend lines in Wipneus Arctic Sea ice Sept. minimum volume graph show it at, or below, 1 million km3 in 2018. Given average thickness approaching 1 meter, this can be seen as analog of the 1 km2 sea ice extent threshold for an essentially open Arctic Ocean.

Crossing that line would not be the first year of "ice free summer Arctic Ocean" as the value is September minimum, not monthly averages for Aug-Sept-Oct. But the observations show those monthly averages only trailing the minimum by a few years.

With the trend line reaching these threshold levels in the next few years, the Arctic situation may soon a provide an intuitively relatable marker to enhance public perception and attention to global climate change that even deniers will have a hard time distorting, though I am sure they will find a way.

Comparing the color-coded chart of monthly Arctic temperatures to the volume and extent trends suggests that the next warm Arctic summer will take us into new territory. Low volume and extent values in 2007 and 2012 match warm summer months in those years.

Thanks to Neven for keeping the site going. I find the comprehensive monthly analysis more informative than the official sites at NSIDC and PIOMAS, though I certainly appreciate them also.

The Wipneus chart I am referring to is at https://tinyurl.com/wipneus1MKm3Trend
(you will be asked to download the chart)

Full URL for direct link is:
https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/piomas/grf/piomas-trnd1.png?attachauth=ANoY7cqMF2lquuSsV9jF4_Qgdt3pke8A1CTKoHtApeanyqCJgf_KYRoQkVY2-gklvr-X8AtEBwHTm0vmFRu57jQ2KKlnrOFR0xSBXOyOwcYuTacDUzEjaAxxz6xqYg4bhyvPWJVuIkAD8Dei7NNVgC317o6vz4570h1ER0x_fHrjz0ZtwhkjXCcushSlgMEwPUTdUkdaexEPi45iWSJQKsKZ6HxIC0k4OCXHQply_Rb7TxiOrcOjV8CtR-9-p4d8p6P-GjTzfYYf&attredirects=0

iceman

Just catching up on developments, wanted to add my note of appreciation to Neven as well as the commenters.
Any thoughts on providing context for the max-min graph? maybe show alongside min-max for the previous freezing season?

Neven

Chances are high that I will be covering next year's melting season, so traffic will probably pick up then.

Any thoughts on providing context for the max-min graph?

I had already renamed 'max-min' to 'total melt' (as it's much clearer), but somehow uploaded the old version to this blog post. Fixed now.

Here's the total freeze bar graph (posted earlier in April):

Wonderpilletal

gkoehler,

"Crossing that line would not be the first year of "ice free summer Arctic Ocean" as the value is September minimum, not monthly averages for Aug-Sept-Oct. But the observations show those monthly averages only trailing the minimum by a few years."
I find that a most interesting sentence. That, to me, shows the absolute reality of disintegration of the sea ice in the Arctic.


gkoehler

ooops, embarassing public brain fart...
The Wipneus graph shows all 5 extrapolations near or below THREE million km3 in 2018, not 1 million. Three of the five trend lines do cross 1 million in 2021.

The conclusions, albeit weakened, still stand.

1) Next few years, and next warm Arctic summer, likely to deliver a new record low Arctic Sea Ice volume, and probably Extent also.
Seems too soon to presume Arctic has entered a new state that would prevents next warm summer.

2) Adding my own presumption: The 2007 and 2012 dips were two years after El Nino year. With big El Nino in 2016, 2018 could be another dip year. Robert Scribbler blog mentioned that La Nina phase brings warmer water to Arctic, but I don't know what he based that on. Current ENSO forecast is for weak La Nina for this fall and winter. Even without an ENSO effect, another winter with low freezing units would precondition the ice for a decline in 2018. DMI chart for temps north of 80N following that pattern again so far this fall, but it is still early.

3) Arctic sea ice is one climate change manifestation people can relate to, vs. the more abstract nature of ppm CO2, watts per m2 forcing, etc. So it might increase recognition of our predicament.

4) Anecdotal tidbit. My son lived in Inuit village in Alaska this summer. I asked him what the natives had to say about climate change. He said that even the 20 year olds talked about how much things have changed "since they were kids" (i.e. within last 10 years or so). One example is willow trees now growing on what used to be flat tundra.

Wonderpilletal

DMI temps look very interesting.

FDD, https://drive.google.com/uc?id=0B1HTR0ONiUmEMFZiLWwxUW15QUk&export=download , is therefore worth keeping an eye on!

AnotherJourneybyTrain

Using this, http://sites.uci.edu/zlabe/arctic-sea-ice-volumethickness/ , and noting that 1996 is the first time volume goes below the '81-'10 avg. I could suppose with 'some' logic that:

The marketplace would have to acknowledge a 30 year average from '96-'26.

Seeing that would most likely deliver very bad numbers for the planet I would be expecting early movers to be well established in the new paradigm of energy use well before then.

I therefore see major changes to the American economy very soon. They will embrace this extremely well documented technological need for change.

I also expect Trump will change, to win his second term, but I've said that before.

John Christensen

Slightly OT, but wanted to let all know that DMI has launched an Arctic weather overview page with wind, temp, temp. anomaly, and precipitation anomaly:

http://polarportal.dk/en/weather/

You already can find the other DMI measures here such as SIE, ice volume estimate, sea ice temp, the DMI 80N temp, satellite images, etc.

Neven

Nice expansion of what they already had there. Thanks, John.

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