ASI 2015 update 5: late momentum

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2014 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

July 30th 2015

My apologies for being a week late with this update. In my defence: things have been remarkably stable in the past three weeks, or all month really, both weather conditions and trend lines on graphs. To make up, here's a guest blog I've written, that was posted by John Abraham on the Guardian website today.

The article describes the melting season so far, starting out with more sea ice volume than previous years, because of the rebound in volume after the 2012 mega-record melting season. This year the ice pack underwent little preconditioning during May and June, perhaps slightly more than 2013 and 2014, but much less than big melt years such as 2007 and 2012.

This order of play led to the early conclusion that 2015 wouldn't break any records, and could very well end up near the previous two rebound years. However, subsequent weather conditions during all of July have broadened the range of possibilities (see the previous ASI update). I'll be going into the details in the July analysis that will be posted in 10 days or so, but I can tell you that July 2015 was exceptionally sunny and warm.

And that brings us to this melting season's main theme: Will the rebound remain intact, or will it be reversed, and perhaps even wiped out?

Let's first have a look at what has happened in these past 3 weeks.

Sea ice area (SIA)

Here's the latest Cryosphere Today SIA chart, to which I've added preliminary data as calculated by Wipneus:

Despite almost perfect weather conditions this moth so far the 2015 trend line hasn't fallen off a cliff, but that's only logical, given the lack of preconditioning during June. What's remarkable, though, is how those stable weather conditions have been accompanied by an almost monotonous decrease that is now slowly tapering off, but well below 2013 and 2014, and not too far from the top 3 years.

Sea ice extent (SIE)

The same steady decrease can be seen on the SIE graph (based on data reported by the Japanese Arctic Data archive System):

The 2015 trend line has come a long way from being almost highest after the first week of the month, but is now also slowing down and still close to 2013.

Cryosphere Today area per IJIS extent (CAPIE)

With area dropping relatively fast, and extent less fast, compactness will also drop fast. In these updates I refer to compactness as CAPIE, meaning Cryosphere Today area divided by IJIS extent numbers, a measure that was invented collectively back in 2010, when the Arctic Sea Ice blog first got underway (read the CAPIE segment in ASI 2014 update 2 for a thorough explanation of what CAPIE actually is and what it tells us).

Here's the current situation:

The 2015 trend line has continued the precipitous drop that started towards the end of the June, and is now among the lowest on record. This, of course, has to do with 1) dispersal of the pack's ice floes, especially on the American side of the Arctic, and 2) massive melt ponding. July has made up for the lack of momentum being built up during June. We now have to wait whether this late momentum can still influence this melting season's final outcome, and if so, by how much. I eagerly await more data on melt ponds and volume.

Regional SIE and SIA

For the past few weeks I've been mainly focussing on the thicker multi-year ice in the Canadian Archipelago, Beaufort and Chukchi Seas, but in the past few weeks the melting season has been making lots of headway on the Siberian side of the Arctic as well. The Northern Sea Route has opened really early this year, as shown by yet another excellent video made by Jim Hunt from the Great White Con blog:

Most of the action has been taking place in the East Siberian Sea, where the ice is disappearing even faster than in 2012:

Wipneus has sent me another custom-made regional map that shows the changes that took place in this region during the past two weeks (red = less ice than two weeks ago, blue = more ice than two weeks ago):

That's a lot of red!

At the same time Baffin and Hudson Bay still refuse to melt out, meaning there is still almost 400K of ice that hasn't shown up yet on the graphs:

But, of course, there still has been plenty of melting in the past two weeks:

Weather conditions

With all that talk about those perfect melting conditions the past couple of weeks, it's high time we look at what the weather has done and will do, starting, as always, with sea level pressure (SLP) as displayed in this three-week animation of Danish Meteorological Institute SLP images:

I have not often seen this combination of big size and persistent stability in a high pressure area during summer (remember how I said it would be HUGE in the last ASI update?). The only things missing to make these weather conditions truly perfect, are compaction and transport. For that you need some lower pressure on the Siberian side of the Arctic, creating the winds that get everything on the move.

But still, an area from Greenland all the way to Alaska has been bombarded with sunshine the past three weeks, with the Canadian Arctic Archipelago at the very heart of it. No wonder the fast ice in the Northwest Passage's main channel has completely shattered in the past week:

Towards the end of the DMI SLP animation the high pressure is seen to be moving towards Siberia with a cyclone emerging over the Beaufort Sea, and so it's interesting to see what's going to happen in the coming 6 days, according to the ECMWF model (click for a larger version, and go to the ASIG Forecasts page for daily forecasts):

Wow, this is interesting, and I'm not sure what to make of it really. The cyclone is going to remain weak and remain in place, surrounded by high pressure from all sides, with two intense epicentres near the Atlantic-Siberian side of the Arctic and Greenland. The ice in that part of the Central Arctic Basin, and the adjacent ice left in the Laptev and Kara Seas - which should be relatively thin by now, as it didn't really get thick there over winter - is going to get tanned in the coming week.

At the same time that cloudy cyclone is offering some shade to the thicker multi-year ice in the Beaufort Sea that has been under siege by the Sun for a large part of this melting season, but the risk is that those dispersed floes get pushed into warmer water by the winds the cyclone will produce. I'm expecting a continuation of the slowdown that appeared on the SIE and SIA chart in the past few days, but things will probably not completely stall like we saw the last two years.

This also depends on temperatures, of course. The DMI 80N temperature graph shows that the trend line has been hovering around (and even above at times) the average and has only been going down since a week or so:

This is also corroborated by this NOAA/ESRL Physical Sciences Division map showing how warm much of the Central Arctic and especially the Canadian Arctic Archipelago has been from July 7th to 27th:

What can we expect for the coming 7 days? This is what the GFS temperature anomaly forecast maps provided by the excellent Climate Reanalyzer website are showing:

A couple of days of anomalous warmth for the ice off the coast of West Siberia, and a relentless heat wave continuing over the Canadian Arctic Archipelago. I don't see how the Northwest Passage can withstand so much heat and sunshine, and so it looks like yet again both passages will be open this year.

Unless sea surface temperatures are really cool, which they aren't:

Things continue to heat up everywhere, although I expected much more heat on the Pacific side of the Arctic, given the situation two weeks ago when SST anomaly was off the scale in that part of the Arctic. Still, it's comparable to the situation on July 28th 2012, August 4th 2014 (ie one week from now), and much, much warmer than July 26th 2014:

Conclusion

A warm and sunny July is making up for the lack of preconditioning during June, which means that it isn't likely that 2015 will end up as another rebound year. But if this year is proving anything, it's that you can't have a record without serious preconditioning of the ice pack during May and June, and subsequent melting momentum that keeps working at the ice until it can no longer hold out in August and September.

Perhaps 2015 can still make the top 3, but it will require a continuation of weather conditions that are conducive to melting, compaction and transport all the way to the minimum. Either way, the rebound (or 'recovery', as some called it prematurely) is in danger of getting wiped out, which brings us back to square -10, meaning that Arctic sea ice loss is still progressing much too fast.

We now await the latest PIOMAS update to see what has been happening volume-wise and whether the Arctic sea ice pack returns to the post-2010 position from where it could go really low, perhaps all the way to essentially ice-free conditions. All it takes is the preconditioning of 2010 or 2012, followed by a July like the one that is almost behind us, and then 2007-style compaction and transport through Fram Strait. I'm really convinced of that. The question is not if, but when.

Enjoy the Arctic sea ice, it's the only Arctic sea ice you've got.

Comments

[Neven]

Also be sure to read RobertScribbler's latest blog post on the current situation and forecast.

[wanderer]

I think it's important to include these graphs by Wipneus:
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/basin-extent-multiprod.png
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/basin-area-multiprod.png

As you said, Baffin and Hudson have still almost 400k of ice that WILL melt out, so we should concentrate on extent and area in the basin.

[Remko Kampen]

"surrounded by high pressure from all sides" - the circumpolar band about 65 tot 70° N. A completely new phenomenon, I've seen it first during Hurricane Sandy which by it made a unique and devastating track.
It's something that didn't occur before (eat your heart on an archive like this: http://www.wetterzentrale.de/topkarten/fsreaeur.html ). It is no normal blocking situation because it is essentially a zonal pattern.
It has dumped a quarter century of North Atlantic meteorological experience for me. I have to contend with completely new weather charts exhibiting completely new dynamics.
It is part of the 'Stuck Pattern Syndrome', the stall of planetary waves described by e.g. Jennifer Francis, caused by Arctic Amplification. The six EC charts Neven posted show this pathological freeze-up of summer circulation.

[navegante]

But if this year is proving anything, it's that you can't have a record without serious preconditioning of the ice pack during May and June, and subsequent melting momentum<\i>

There was no text-book preconditioning as you understand it, but temperatures in key peripheral regions were high since second half of May; not all at the same time, but when heat was not hitting one coast, it was hitting the other. Second half of June was really bad for ice contrary to what many people think. Temperatures went up and compactness dipped so much, despite cloudiness and slowdown of extent losses. The melting momentum shifted from the American side to the Eurasian side. The loss of compactness could make a difference now.
If you see the current state of the main pack, a GAC now would lead to similar 2012 losses. That won't probably happen.

CAA has more ice this year, after all it had much more ice after Winter to start with. See how it is resisting despite the persistent temperature anomalies.

Baffin and Hudson don't even count anymore.

[Remko Kampen]

Another new phenomenon: http://arctic-news.blogspot.nl/2015/07/thick-sea-ice-dislodged.html

[Neven]

The 'last thick ice' in a model that has problems:

The issue was spurious "SST" observations from the VIIRS satellite under sea ice, due to a new cloud detection scheme at NAVOCEANO that allowed more sun-glint areas (to get more SST observations) but which failed to reject sea ice regions in summer. The model "believes" the data and so SST and sea ice concentration were fighting each other, leading to massive ice melt. The bad SSTs started late in May, so we are going to rerun without VIIRS from May 1st to the present. This is going to take a while to complete.

Why do people keep using and linking to this model, when it's obvious it doesn't represent reality for a minute?

The open water to the north of the CAA is interesting, but no more than that. That's what you get when winds blow a certain way for weeks on end. When the wind turns, the ice crashes against the CAA again.

Now, maybe if this keeps up for another month, we get to see something really interesting.

[NeilT]

It's already beginning to close. We see something like this each year and each year it gets bigger and stays longer.

The story is not the open water but the pattern which is producing more of it.

[Andy Lee Robinson]

Momeltum :-)

[philiponfire]

A one day drop on MASIE of 279,000 km2 does not look like a slow down to me.

[VoteWhalen]

Been a while since I've posted (previously as nlpatents).

The stalled weather patterns extend to a low in the North Atlantic between Iceland, Ireland and my Newfoundland. Has made for a horrible summer and plenty of bad global warming jokes.

I don't think we can count out a record yet. The cool down shown on the Danish temperature charts appear over partial melt area where the sea ice floats in now exposed subzero water. I suspect that water will heat up in the sun. Area of relatively concentrated ice are above zero.

The question whether (weather) July made up for a lack of preconditioning is a good one. What do the melt ponds look like now?

[D]

Neven: The Navy model has a thickness discontinuity in the 30 day run which appears to have a sudden recent correction. The model may still be screwed up but it looks like recent maps don't have the error you just mentioned.

I look at those maps to see trends. I know that the absolute values are not to be taken literally.

The pulling away from the coast of the thick ice causes upwelling from below. This upwelling might be bringing up warmer saltier water which will increase melting. We'll see.

-George aka FishOutofWater

[Neven]

The question whether (weather) July made up for a lack of preconditioning is a good one. What do the melt ponds look like now?

Well, like it says in the update CAPIE is relatively low, but there's a lot of dispersal in the Beaufort and Chukchi, so it's not just melt ponds. But 2012 als had quite a lot of dispersal, ie open water between floes, on the Siberian side of the Arctic by now (and then the cyclone came).

In fact, Wipneus' compactness graph (which in principle is much more accurate, because it uses area and extent from the same sources) has 2015 as lowest in all three measures: NSIDC SSMIS 25km, JAXA AMSR-2 10 km, and Uni Hamburg AMSR-2 3.125 km.

And then there's this, a map produced by the Japanese Arctic Data archive System, based on JAXA AMSR-2 data:

I don't know how reliable that map is, but it's interesting and can be compared to data from previous years.

Plenty of melting potential.

[Neven]

Neven: The Navy model has a thickness discontinuity in the 30 day run which appears to have a sudden recent correction. The model may still be screwed up but it looks like recent maps don't have the error you just mentioned.

I've always found those thickness maps somewhat unreliable or unrealistic, even without parameter problems. And I still think there's something wrong with the current, given all that yellow/green right up to 80N.

I look at those maps to see trends. I know that the absolute values are not to be taken literally.

Yes, that's always a good thing to do. I use a comparison of these maps too for my winter analyses.

The pulling away from the coast of the thick ice causes upwelling from below. This upwelling might be bringing up warmer saltier water which will increase melting. We'll see.

It's definitely interesting, also because the fast ice in the CAA has just started to break up now, and with these winds will drift into the gap.

[John Christensen]

Thank you for the update Neven!

Regarding the DMI SST images: It appears DMI is having problems with their sensors or how the data is translated, which you will notice in the Bay of Bengal, in a couple of places of the eastern Pacific and possibly in the northern Pacific:
http://ocean.dmi.dk/satellite/index.uk.php
With these errors it is difficult to tell if the temp indication errors are one-sided, or if hot areas are exaggerated as well.

Remko said:

""surrounded by high pressure from all sides" - the circumpolar band about 65 tot 70° N. A completely new phenomenon, I've seen it first during Hurricane Sandy which by it made a unique and devastating track.
It's something that didn't occur before..
I have to contend with completely new weather charts exhibiting completely new dynamics."

Not quite Remko; please read the excellent blog entry by Neven "On persistent cyclones", where references point out that it is not unusual for a cyclone to persist in the Arctic Basin during the summer period, surrounded by high pressure areas on the northern continents. This phenomenon is caused mainly by the difference in temperature between the cold Arctic Ocean surface temps compared to surrounding continental areas.

You also mentioned:
"It is part of the 'Stuck Pattern Syndrome', the stall of planetary waves described by e.g. Jennifer Francis, caused by Arctic Amplification."

Dr. Jennifer Francis has a peculiar theory, which IMO seems to ignore conventional atmospheric physics.

Conventional theory would argue that the pattern and strength of the jet stream is tightly related to the relative strength of high and low pressure in the Arctic region:
NSIDC:
http://nsidc.org/icelights/2012/02/02/the-arctic-oscillation-winter-storms-and-sea-ice/
J.M.Wallace:
http://research.jisao.washington.edu/wallace/ncar_notes/#4Signatures
And even Wikipedia (which has the best graphical illustration):
https://en.wikipedia.org/wiki/Arctic_oscillation

In short, with negative AO we will experience more blocking patterns and a wavier jet stream, while a positive AO (low pressures in the Arctic) will cause the jet stream to strengthen and move further North.
Dr. Jennifer Francis argues that the 'waviness' of the jet stream is an indication that it is weakening due to Arctic amplification.
When you look at the DJFM AO index
(https://en.wikipedia.org/wiki/Arctic_oscillation#/media/File:Arctic_Oscillation.svg)
you will note that it was anomalously high (positive) from around 1990, which resulted in a strong, more northerly and less wavy jet stream in general for the past 20 years.
However, now the AO index is fluctuating and could possibly be turning to a primarily negative regime for the next 20-30 years, which according to conventional theory would cause the jet stream to weaken, move further south and become more wavy.
Therefore, it is correct that the jet stream has become weaker and more wavy since 1990, but in order to have some scientific validity, Dr. Jennifer Francis would need to show that the weakening and waviness of the jet stream could not have been a result of the change in the AO index, and secondly that the current jet stream is weaker and wavier than it was in the 1940s – 1980s, when the AO index also was primarily negative.

Personally, I think it will be interesting if we indeed are moving to a more negative AO regime and look forward to see, how that may impact – reduce or accelerate – the warming of the Arctic region.

[Remko Kampen]

John - 'Stuck Pattern Syndrome' is not at all about waviness, but about progression of planetary (Rossby) waves.
Think of the 'Ridiculously Resilient Ridge', for just one instance of the demiglobal phenomenon.

"... where references point out that it is not unusual for a cyclone to persist in the Arctic Basin during the summer period"

Show me a persistent cyclone in that region, please. You know, just show me the Arctic circumpolar vortex... http://www.wetterzentrale.de/topkarten/fsavnnh.html .

"... the weakening and waviness of the jet stream could not have been a result of the change in the AO index"
Of course not. The AO index is a number, not a 'cause' of anything. To paraphrase your remark, Francis would have to show that the waviness of the circumpolar jet is caused by its waviness, say.

"please read the excellent blog entry by Neven "On persistent cyclones"
....
Please read a comment of mine below that article, also move back some articles on that matter and find some comments. This to say, let's say, I'm quite with y'all on the matter. But quite!

Now this is not unusual (took a date from Neven's "On persistent cyclones") -
http://www.wetterzentrale.de/pics/archive/ra/2013/Rrea00120130605.gif

Just a normal Scandi blocking, in fact.

But this, e.g. today, is NEW, it is NOT a blocking AND it is NOT a west-circulation so wtf is it; and it is pathological, because it is no longer a transient circulation but something that as of Sandy is seen to be quite fixed for ever more days/weeks per year: http://www.wetterzentrale.de/pics/Rtavn241.html .

Like the EN/SO the AO is completely irrelevant to general trends of global temp or Arctic ice destruction.

"Conventional theory would argue that the pattern and strength of the jet stream is tightly related to the relative strength of high and low pressure in the Arctic region"

They are so tightly related as to be effectively the exact same phenomenon (this would be: conventional meteorology).
The point is both, or rather simply the whole, is governed by temperature differences below and aloft between tropic and Arctic.
There a simple lab experiments that can also be done in your kitchen where you can test 'Arctic Amplification' etc galore.

[John Christensen]

On the RRR:
If extraordinary weather patterns was a new phenomenon in California, then the RRR would be a great example of the climate being based on new mechanics/principles.
However, looking at precipitation history for California including the three wettest and driest years this seems to be unfounded:
1898: 2. driest year
1909: 2. wettest year
1929: 3. driest year
1983: 1. wettest year
1998: 3. wettest year
2013: 1. driest year
http://www.weatherwest.com/wp-content/uploads/2013/12/ytd_anom.png

When you look at other climate records on NOAA you will also see that deviations from average temperature at a US state-wide level have not increased in the past couple of decades - deviations which are typically caused by ridges getting stuck..
http://www.ncdc.noaa.gov/temp-and-precip/state-temps/
If you can show any reference to research using actual climate records, NOAA, Met-office, etc., indicating that temperature deviations (Cold or hot spells by quarter or year) are getting more frequent or more pronounced, then please share.

[wayne]

…. And the AO, however big region it covers is positive because _____________________ and negative because ______________________.

Feel free to explain this overstated , overused not always useful and nebulous oscillation John.

[Remko Kampen]

"If extraordinary weather patterns was a new phenomenon in California" - which I never said.

"... then the RRR would be a great example of the climate being based on new mechanics/principle"

Why? You wouldn't be suggesting that either:
- Classical mechanics dictate the dynamics of planetary waves is independent from things like Arctic Amplication or
- Arctic Amplification doesn't exist?

Seriously, what physics re propagation of planetary waves is challenged here? I saw 'Stuck Pattern Syndrom' happening in my own lab experiments as a beginning student in 1990, and measured their tempgradient dependence, and also - different parameter - dependencies of wave number on both abs temp and temp gradient!

Your list contains single years. But if you are looking for a 'Stuck' like the RRR, you will have to finds groups of like years, e.g. 2011 until and including 2015. So: was 1898 just a single very dry year, or was it member of a stretch of 3-5 years that each were (almost) as dry? Was 1909 just a single wet year, or a member of 3-5 years in a row that each were (almost) as wet?

Primer is the 2011 Hansen/Sato/Ruedy paper linked to here (pdf): http://earlywarn.blogspot.nl/2012/01/lots-more-killer-summers-on-way.html .

More on this: http://earlywarn.blogspot.nl/2012/04/slowing-rossby-waves-leading-to-extreme.html .

In this article the 2007 example (incidentally the warmest winter for Western Europe sinds the alfabet or before) is long surpassed by recent winters, of which the one flooding Somerset is the starkest example. But last winter was, though weatherwise 'flatter', even more stuck. Both winters featured two circulation patterns instead of one of two dozen... Atlantic hard west into Russia, or Atlantic hard west against a Scandi high made for an incredibly boring winter, mild but never far from average, no extremes. That regime ran over the entire spring as well ('coincidentally' just like the RRR mostly did). This shows that a stuck pattern may not at all give rise to any extreme at all, but just to an extremely prolonged period of same weather.

The 'Somerset' winter was #2 tempwise since or before the alfabet and also showed a strangely flat temperature curve. Not so on the other side of the Ocean of course, what with the RRR and its companion falsely dubbed the 'Polar Vortex'.

If you live at mid- or high latitude then you are an actual witness.

On increase of average duration of any circulationtype see pp 39 onwards in https://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CEQQFjAEahUKEwjuwq6Rz4XHAhXHz4AKHXk8Bjk&url=https%3A%2F%2Fwww.pik-potsdam.de%2Fresearch%2Fpublications%2Fpikreports%2F.files%2Fpr119.pdf&ei=Sou7Ve71JsefgwT5-JjIAw&usg=AFQjCNEFl_j963Rbxka_axCZiEVKYVVEyA&sig2=_qTexKNk0V0CvKTPdlmP0w&bvm=bv.99261572,d.ZGU . (pdf)

[Remko Kampen]

wayne, AO is kind of a magic number for some. While it is caused it is brought up as some first causer, as something of a driver or something. I've seen that thinking more often. Baffles me.
AO is an index, it is an aggregrate number/statistic that indicates the state of some aspects of something; it is the latter that should be studied, not the AO itself. That index could indicate there is something worth studying, that is just about all.
There are some drawbacks to the index too, firstly: it is but an extremely rough number for indicating pressure pattern, secondly it is a take of only a fairly small section of a hemispheric whole system.

In the end, diminishing Arctic ice, the great Greenland melt resulting in the cool pool south of Greenland are drivers that could influence the AO in special ways, or otoh they might not (if circumpolar does not exhibit changing wavenumber or -amplitude but only changing propagation velocity of waves, weather effects could be profound but the AO may show nothing special at all and presently that seems to be closest to the actual case).

[John Christensen]

@Remko,

Overall California saw very high precipitation levels in the period of 1904-1916, so something definitely had gotten stuck.
If we had been around on this blog it would surely had been labeled the Decade of Drenching - DOD.
The drought levels in 2011 and 2012 comparatively were very minor at 10-15% below average and only mattered, because;

A. They were followed by the extreme drought of 2013, and
B. Water consumption on the US west coast has sky-rocketed.

Seriously though, I will have a good look at the papers, thanks, and will probably not have any further response for a while.

[Martin Gisser]

Remko - "completely new phenomenon" ...
I'm a complete meteorology dummy, yet have been wondering for some time what the future of the NH polar plus mid-latitude cells will be. Particularly, are there any hints from climate models? Will the atmospheric circulation cells switch to an asymmetric pattern? Might it then possibly get slightly colder in Europe, when (if) polar and mid-latitude cells "merge"?

[John Christensen]

"the great Greenland melt resulting in the cool pool south of Greenland"

As a frequent observer of the Greenland ice sheet and DMI SST, I can assure you that the cool pool south of Greenland was present, while the accumulation of the Greenland ice sheet was above normal, which was until the last week of June.
I would blame the cool pool on the unusual cold temperatures across Greenland this spring.

http://polarportal.dk/en/groenlands-indlandsis/nbsp/isens-overflade/

[wayne]

Thanks Remko, I entirely agree with your assessment, although small compared worldwide, it is too large to have meaning in most instances. It is perhaps good for temperature fluctuations, but over all, I won't use it for pressure cycles because a large High over say elsewhere than over the Arctic basin in the AO zone affects the index. The NAO is very good. PDO has size problems, And ENSO is mostly good.

[Jenny E. Ross]

"Overall California saw very high precipitation levels in the period of 1904-1916, so something definitely had gotten stuck."

Apologies for the OT question, but: John C., since you seem to be very knowledgeable about this, can you recommend any scientific references regarding high precipitation levels in California, and the western U.S. more generally, during the first half of the 20th century? The issue is important for a major long-term documentary project I'm working on.

Thanks!
Jenny

[G man]

A little OT but it looks as though the Greenland melt is over. Very little melt at all happening now.

http://beta.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

[D]

The cool pool this spring and summer has been forced by the atmospheric circulation pattern. Cold relatively fresh water sank to below 1000m last winter. That water was driven out of the Canadian Arctic into the Labrador sea by the stormy winter in the Arctic ocean and the stronger than normal cold northwest flow across eastern Canada and the Labrador sea.

You can trace the relatively cold fresh water on Mercator Ocean or MyOcean.

[Robert S]

Although the southern and central CAA have a lot more ice this year than 2012, the breakup of the fast ice along the northern edge of the CAA didn't happen in 2012 the way it is this year. We're starting to see significant transport of big blocks of multi-year ice northward out of the CAA. This is not only accelerating the loss of ice in this area this year, but could also have long term consequences for future melt years, if we begin to see frequent young ice melt out and summer open water and fetch/wind effects along the northern coast of the CAA. This may not be as dramatic a year in terms of area or extent as 2012, but it looks to me like one of the last bastions is falling.

[Neven]

Okay, everyone, August polls are up on the Arctic Sea Ice Forum for:

NSIDC September average sea ice extent

and

CT daily sea ice area minimum

I want at least 100 votes for the NSIDC SIE poll, so don't let me down. :^)

[Chris Reynolds]

The Cool Pool....

http://www.realclimate.org/index.php/archives/2015/03/whats-going-on-in-the-north-atlantic/

and

http://www.realclimate.org/index.php/archives/2015/03/a-hypothesis-about-the-cold-winter-in-eastern-north-america/

The Atlantic meridional overturning circulation is shutting down, and the patch of cold anomaly is in the same place as in the articles above.

DMI global shows it.
http://ocean.dmi.dk/satellite/index.uk.php

And here is figure 1 from the first RC post.
http://www.realclimate.org/images//Rahmstorf_2015_1rc.jpg

[Hans Gunnstaddar]

http://www.iup.uni-bremen.de:8084/amsr2/

That link goes to the false color graphs. I watch those every day for changes. You'll see in the Beaufort some big areas of blue opening up. That region has been under a heavy melt assault for weeks and is just now starting to lose extent. Look for extent to dive when we get results for 8/1. Should send extent back into the 2012 range. How long it can hold there will be dependent on melt from here. Once this beaten up ice gives up the ghost, expect more assault on the CAB from that direction.

I tried to get sign in at the link for estimates to help raise the number to 100, but my typepad sign-in like I use to message here does not work. I don't remember having a different sign-in for this site so not sure what to do. Anyway, my guesstimate is 3.5 million square kilometers but it probably does not do any good here, right. Oh well.

[Tanada1945]

Okay this is probably a dumb question, but why doesn't everyone use a universal orientation for the Arctic on maps? I love maps and I figure them out, but for the casual viewer having some random location being at the top and bottom of each map depending on the publisher is just confusing. My suggestion would be to use 0 Longitude at center bottom and 180 Longitude at center top. These lines are internationally recognized for map use and would cause all polar maps to be displayed in the exact same orientation making comparison between visual data sets much much easier.

[NeilT]

Hi Hans,

When you failed to log in did you try the miniscle "lost your password" link at the bottom of the failed login dialog?

You should be able to use the email address you signed in with and it should send you the password change mail.

[Hans Gunnstaddar]

Yeah Neil, I tried that but never got an email. I'll try again. Thanks.

[Hans Gunnstaddar]

Tried receiving password email but no go, so just did a new registration and then went and posted vote of 4.25-4.5 Decided not to go with the lower estimate from my earlier post.

Neven, that makes 96 votes, so just 4 to go!

[Neven]

Thanks, Hans!

[Remko Kampen]

"B. Water consumption on the US west coast has sky-rocketed."
John Christensen, please realize this is irrelevent. It does not affect raw precipitation numbers.
Climate change is about those raw numbers.
It does, of course, aggravate existing water resources mismanagement but such aggravating is never a measure for CC itself.

[Remko Kampen]

"... wondering for some time what the future of the NH polar plus mid-latitude cells will be. Particularly, are there any hints from climate models? Will the atmospheric circulation cells switch to an asymmetric pattern? Might it then possibly get slightly colder in Europe, when (if) polar and mid-latitude cells "merge"?" (Martin Gisser 18:20 31st)

- Wondering, too. I thought of two changes based on recent years (as of summer 2006): a kind of spread of the northern part of the subtropical semipermanent high pressure zones to very high latitudes, leading to very large area's filled with very shallow high's and cool spots, not much general movement to them;
- Weakening of circumpolar jet leading to strange mergers with the subtropical jet _or_ strange, very northerly latitudes for other parts of that jet.

But I'm questioning all of this, moreover the recent AMOC behaviour w/ the cool spot south of Greenland is complicating everything again. This seems te (re-)create a strong jet at a remarkably low latitude, sending this summer some intense lows to the North Sea countries, or see the Somerset Flood pattern.

- Climate models, not that I know of they depict things like this that actually belong to meteorology.

- 'Assymetric pattern', you mean: a-zonal? With temp gradient tropics-arctic zonality will remain, but the normal chain of lows/highs circumventing the pole (at least over the oceans) seems to stall sometimes, leaving a kind of bubbly appearance to NH synopsis charts. Movement of all these systems sometimes seems to stall entirely.

Presently not the slightest of hints of any cooling anywhere in Europe. Contrary, vastly contrary.
If we could get a chronic 'Azores high' to lie west of Scotland in summer and over Scandinavia in winter time then we'd get a cool year. But CC has gone where circumstances really need perfection to get cooler than normal weeks (mid-August 2014 and spring 2013 be examples) while, by way of a saying, 'a day of more or less southerly winds has temps hang into record boundaries already' (in Europe at least). In fact by second half of this week another central European heatwave of non too perfect make-up will send temps up to near record values for the second time in six weeks.

[Bill Fothergill]

Re: Poll(s) on the forum

Edging closer to the 100 mark!

Went for 4.5-4.75 for NSIDC monthly, as I think 2008 is going to get nudged out of 4th lowest place.

However, things can change quickly in early August. Looking at the Charctic tool, the daily loss rate picked up in 2008, 2011 and 2012. On the other hand, the rate slowed noticeably in 2009, 2010, 2013 and 2014 over the same rough period.

On the CT daily, I think it will be pretty close to 3, but ended up selecting the 3-3.25 range.

Once again, things can change with great alacrity. Today (day 212), we've just seen a drop of 129k, but last year, between days 215 and 230, the corresponding drop was just 150k - an average of just 10k/day.

Consequently, a re-visitation of both values in about a week's time may well be necessitated.

On the Year-to-date metric I run on CT area, 2015 has just edged out 2006 into 3rd lowest as at day 212, behind 2011 (lowest) and 2007. (Obviously 2012 ended up lowest at the year end, but it had only just started to go ballistic by day 212.)

[John Christensen]

Sorry Neven; this will be the last OT comment on California precipitation:

Jenny,
I have not studied Western US or California precipitation patterns in particular and will recommend you check out data and possibly research projects on NOAAs website.
They have excellent searches on the 'Climate at a Glance' page for view and download
http://www.ncdc.noaa.gov/cag/time-series/us
and they have previously been helpful with providing particular data upon request.

Also, I unfortunately had used a graphic which missed December precipitation, which moved a few years around in ranking and also shows 2012 with above average precipitation - regarding that RRR..

wayne and Remko,

What is interesting about the AO is that it provides information about the degree to which the Arctic region has cloud cover or not, not the amounts or particular location of high or low pressures.

And why is clear skies in the Arctic important (= negative AO index)?

Because:
Mid-summer weeks: Clear skies increase the temperature and fraction of melt ponds at the center of the high pressure area.
Late summer/early fall, the balance will tip and clear skies will cause melt ponds to freeze over and shorten the period, before which sea ice starts rebuilding.
Winter-months: Clear skies deepen the Arctic freeze, builds ice quicker and reduces influx of warmer/moist air from mid-latitudes.

The AO index is just a reflection of weather patterns and shows just how important the weather patterns are for the Arctic ice, as observers of this blog can testament when comparing the past three melting seasons - especially the period of mid-May to mid-July where clear skies or cloud cover is crucial as factor in explaining what happens to the ice below.

Buildup for 2012 - Ideal ice-crushing AO scenario:
Very positive AO during 2011-12 winter(Strong low pressure areas during winter months, slowing down ice accumulation) and negative AO during 2012 summer (Clear skies, increased melting)

Buildup for the 2013 rebound year - Ideal ice-preserving AO scenario:
Negative AO during 2012-13 winter months (Increased ice accumulation) and positive AO during 2013 summer months with the lingering low pressure areas providing cloud cover, keeping temps down and melt pond fractions low).

If the AO index would obtain positive and negative values with no pattern or trend at all, then it would be just another weather pattern providing noise in the models.
However, that is not the case, as it has shown long-term trends, which NOAA tracks on another excellent page:
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/JFM_season_ao_index.shtml

If we are indeed moving to a regime of predominantly negative AO index, then the Arctic region will experience longer periods of clear skies, which I speculate could assist in preserving the ice to some degree, based on a hypothesis that clear skies will benefit the ice perhaps eight months of the year and be destructive to the ice for about four months. Pure speculation on these periods though, and I am following the DMI 80N temp and pressure maps closely these days to see, when the coin will flip..

[Jenny E. Ross]

Thanks, John. Apologies for OT, Neven.

[Neven]

No problem, Jenny.

[Hans Gunnstaddar]

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png

As of 8/3 false color arctic link above; look at how much open water is evident now in the Beaufort.

[wayne]

Hans, we see that, also NW passage has been open for a few days on East-West side of Peel Sound depending on the winds, NE passage equally open, the melt over Beaufort is not surprising at all with ice moving above on and off warmer water. The only thing which surprises me is that many people seem bored, expecting that this will be another year like 2013-14. But CT reports -1.589 million square km anomaly for the first time since 2012, 2015 should be in 3rd place JAXA wise tomorrow, and still there is some ice in Baffin Bay!

[NeilT]

The Bremen concentration maps are showing significant open water half way from the Beaufort to 85n.

The locations of the Obuoy's and what their camera's see seems to bear out what those maps are showing.

This is the most interesting year I've watched yet. We have at least 4 weeks if not 5 weeks of melt to go, depending on how the weather turns.

What will interest me most is what happens to that band of unmelted (thick?) ice which is now separated by mainly open water. Will it, as we saw in 2012, simply vanish under the bombardment of the heat and warming sea? Or will it remain to form a core of ice for the next season?

I did notice that the outlying arm of ice which reached the shore vanished in 3 days. It just melted out.

[Neven]

As of 8/3 false color arctic link above; look at how much open water is evident now in the Beaufort.

Yes, this is the second time (after 2012) that we see substantial portions of pack ice detach themselves from the core (there's another piece in the Laptev Sea that got abandoned last week). I'd love to see an update of the Fowler/Maslanik/Tschudi ice age distribution maps.

[Kris]

Don't forget to keep an eye onto the Helheim Glacier - in the past houres again quite a mass of ice has been calved off.

Actually, it now looks like more as a collapsing rather than a calving ...

[philiponfire]

and now the last of the large(50km)floes in the Beaufort has broken up. Still asking! If there is so much multi year ice in the Beaufort sea why is it breaking up so easily?
The ice in the centre of the NW passage is at least 2 years old and presumably also thicker than one year ice and yet here we are with the whole length of the NW passage broken up in spite of the fact that that ice was linked to land on both sides.

[philiponfire]

To me there seems to be a disconnect between the thickness/age models and the reality I am watching in the current observed images.

[Sam]

Phillip,

I couldn't agree more. It appears clear at this point that all of the ice thickness/volume models have become completely unreliable and frankly unusable. They don't agree with one another in huge ways. And as you note, they don't match observed reality.

But then the extent models aren't much better. The Danish effort is the worst. What looks like an up trend in ice is in reality the shattering of the sheet.

And this points out another huge issue, namely that of relying on metrics to be surrogates for reality and forgetting that they are simply metrics. The bases for the metrics can completely fall apart, as is happening with extent, and as a result be rendered not just of low utility, but as in the DMI plots, become downright misleading.

Sam

Sam

[Sam]

Stunning!

http://1.usa.gov/1P8yQze

I am reminded of 2001 A Space Odyssey and the character Dave Bowman's quote: "My God, It's full of stars!"

Looking at Wipneus' excellent plots, we appear on track to equal 2012. The tale will be told in late August when the central Arctic comes in (or not).

But looking at the ice yesterday on Aqua, where there should have been 4 meter ice, there is Swiss cheese instead. Looking at the Beaufort, there is an ice slushy or worse.

It's hard to image now how 2015 won't equal or beat 2012. It's equally hard for me to imagine a recovery this winter sifficient to prevent 2016 from being that first year of an essentially ice free arctic.

This is bolstered by the monster El Niño that just continues to build and build and build, with yet another thermal wave coming. It looks like it will truly be a monster.

Then add in the apparent shutdown of the end of the Gulf Stream as it redirects flow toward the Mediterranean leaving an immense cold pool in the North Atlantic Ocean and the impact of that on the dipole, the immense "blob" in the Pacific and its impact on the jet streams and flows into the Arctic, and all of these together make 2016 look to be THE year. And if not, the prelude or penultimate melt out to it.

[D]

The Gulf Stream has not shut down. You are misinterpreting the strong thermal gradient in the mid Atlantic. The Florida current cable shows that the Gulf Stream has been strong this year. Flow across the Atlantic appears to be faster than normal this summer based on that strong gradient which is also evident in sea surface heights.

Clue: More warm water than normal is moving into the Barents sea and more cold water is flowing out of the Labrador sea.

[AbbottisGone]

I know what I'm saying has no rigour but ..

If we look at, say, Arctic sea ice extent graphs for the ten years before 2012 they are all over the place in regards to minima. Contrast this with the extent graphs after 2012 (of which there are only 2 thus I must admit my theory has no rigour- oh and it does hurt I can tell you but I break out the pop-corn bigtime watching for the next minima to subscribe to my theory or not, haha!!) and we can see that 2012 may have had the effect of 'consolidation'...

Can anyone see what I'm trying to say: in economics you can say that at times markets go through a period of 'consolidation' or 'correction'.

I'm simply trying to grasp what is going on... Like a new balance is being sought ya know.

Struggling for the language. This is science: yay!!!

....Anybody???

[navegante]

@Abbott
It was: 2013 coldness during melting season.
Should 2013 have had this weather's season, forget about consolidation.
The heat this year has been extraordinary. All this MYI melting, which was absent in 2013.

Weather still matters. I Don't know the analogy in Economics.

[Kevin McKinney]

Gotta say, that's quite the image of the Beaufort today on the CT site. I don't remember seeing such huge holes in the pack. That Western Arctic sector looks really, really vulnerable. It also looks as if we'll see some degree of NWP opening this season all right (yeah, I know, I'm not even close to the first to say so.)

At the moment, it looks as if there could be quite the finale to the melt season.

[anthropocene]

D wrote:
"The Gulf Stream has not shut down. You are misinterpreting the strong thermal gradient in the mid Atlantic. The Florida current cable shows that the Gulf Stream has been strong this year. Flow across the Atlantic appears to be faster than normal this summer based on that strong gradient which is also evident in sea surface heights.

Clue: More warm water than normal is moving into the Barents sea and more cold water is flowing out of the Labrador sea."

Got any links or data to back this statement up? Paul Beckwith (and James Hansen) would appear to disagree with you:
https://www.youtube.com/watch?v=sWfldEyCVic

[AbbottisGone]

@ navegante: yes weather still matters but doesn't climate drive weather?

(Also my idea of 'consolidation' appears to be different to what you are thinking, but I won't drive you in circles with my poor naming-systems...

..such is the importance of nomenclature and thus consensus in science but I won't go down that hairy path either, lol!

I was meaning that a new balance point seems to be asserting itself and this can be seen by a strong signal and contrasting the behaviour before and after this strong signal.)

[jdallen_wa]

@AbbotisGone - yes, climate establishes the symmetry point around which weather revolves. I'm not sure that symmetry point has really moved as far as some people would presume.

How far it *has* moved is bad enough; the net energy available in the arctic has increased steadily, 2013 and 2014 not withstanding. The low maximum last winter is mute testimony to that.

I'm reasonably confident weather this year won't drive the ice to a new record minimum. I'm reasonably confident it will displace 2011 and possibly 2007. That in itself is very much bad enough, as 2012 was a "black swan" event far outside of what one would reasonably expect for variations around the mean.

The trend is now reasserted. There is no need to presume things are worse than they actually are. They are quite awful enough.

[AbbottisGone]

Cool, thanx!

[John Christensen]

Remko - you will need to explain yourself a bit further regarding the RRR (And sorry for having a further remark on this Neven!)

You said:
"Your list contains single years. But if you are looking for a 'Stuck' like the RRR, you will have to finds groups of like years, e.g. 2011 until and including 2015. So: was 1898 just a single very dry year, or was it member of a stretch of 3-5 years that each were (almost) as dry?"

And you said:
"It [water consumption]does not affect raw precipitation numbers.
Climate change is about those raw numbers."

So, Remko, please pay very careful attention to the California annual precipitation raw numbers from NOAA:
http://www.ncdc.noaa.gov/cag/time-series/us

2010: 10th wettest year, since 1895
2011: 37th driest year, -
2012: Slightly wetter than normal
2013: Driest year on record
2014: 43rd driest year

There is no multi-year very dry occurrence here, unless you consider 43rd and 37th rankings 'very dry'.

Multi-year droughts in California were primarily 1928-1930, 1946-1949, and 1987-1991, and other groups of years would be in competition also, whereas - in the bigger picture of California climate history - 2013 and the RRR was a one-year event.

Thoughts on that?

[John Christensen]

And this is what a study by Colombia, NOAA, and the NASA Goddard Center concluded after thorough analysis of the 2011-14 California drought:

"The current drought, though extreme, is not outside the range of California hydro-climate variability and similar events have occurred before. Although there has been a drying trend in California since the late 1970s, when considering the full observational record since 1895, there is no appreciable trend to either wetter or drier California winters."

"Our conclusion that the drought was caused by natural variability and not human-induced climate change is in part based on the CMIP5 models, which project wetter conditions in central to northern California in winter but drier conditions in
spring."

http://cpo.noaa.gov/sites/cpo/MAPP/Task%20Forces/DTF/californiadrought/california_drought_report.pdf

And this, finally, will be my last comment on California precipitation, unless of course an entire thread would be opened to discuss rainfalls in this beautiful state..

[AbbottisGone]

..the restraint shown can only be appreciated from a methodical point of view but, being from Western Australia where 30 year patterns of reduced rain fall have been confirmed owing to Antarctic anti-cyclones not reaching into the country as they used to, I certainly welcome all the informative discussion on the topic available!!