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Messages - aslan

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Arctic sea ice / Re: 2019 sea ice area and extent data
« on: November 02, 2019, 08:00:40 PM »
Daily gain 170 k, 46 k MORE than the 2010's average of 124 k.

Still very high, and just three seas (ESS, Laptev & Kara) gained 164 k of that total.


I think this is an important point. The biggest difference with 2016 is the Kara Sea and to a lower extent the ESS. Kara Sea has seen quite unexpectedly high sea ice gain and is ahead of the most recent years (2016 and after I mean). Big gain in ESS and Laptev is a fatality, nothing can make for shallow waters and fresh water. But now that the sea ice has hit the hard land, ESS and Laptev can't see any more gain, this two seas are already near the 100% mark. If Kara sea is not able to sustain the surge in gain, it is likely that a stall in Arctic sea ice extent will happen. As for now, the great battle of this winter for Chuckchi and Barents sea is starting, and easy ice gain are likely over. I am quite ready to bet that Kara Sea will not be able to sustain the pace, and that we are going to see stall shocking the extent growth like in 2016. The biggest hope for now I think is the Beaufort Sea, the only sea which can keep things up for now I think.

Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 19, 2019, 12:17:23 PM »
Even for the Arctic Ocean, we will be hard press to end the winter with at least a 2m first year ice, putting the risk of a memory of this summer. The islands on the russian side are nearing or breaking record which are only a few years old, like Ostrov Vrangel :

versus 2016 :

Or Ostrov Kotelnyj :

versus 2018

Or Ostrov Vize :

versus 2016 :

And again, a layer of low level clouds is keeping in check the refreze, as shown for example with Ostrov Vrangel between 300 and 600 meters since the end of the Summer :

And SSTs are still extrememly warm, locally up to 7 or 8 (!) °C. And with the clouds in place, cooling is going to be slow. It is a sure bet that southern Chukchi would not freeze before December or January, and it is increasingly likely that this sea could not fully refreeze before the end of the winter.
For now, the downward IR flux at surface is a bit less averaged over Arctic comapred to record holder 2018 and 2016, meaning a bit more heat is escaping the furnace of the Arctic. But we are starting with an ocean wich is way warmer than in 2016 or 2018 and to cool down this thing this small diff is not enough...

Consequences / Re: Forests: An Endangered Resource
« on: September 27, 2019, 05:48:20 PM »
Yes, it is already some years that horse chestnut is screaming its sorrow and pain. It is often question of Amazon or Indonesia or California... but here in northeastern France trees are dying everywhere, it is crazy. Bark beetle are eating away forest, and relentless heatwaves are drying trees. You can't walk 5 meters in any forest without spotting dead trees after dead trees, of any species, old one or young one. Leaves are already falling here, which is really early -and while temperatures are still high and there is no frost still-.

In the mean, around 10% to 20% trees are dying now. With an annual harvest of 12 millions m3 it is at least 2 millions m3 of damaged wood for this year for France. But locally up to 80% to 90% (!) of trees are dry and dead. Hornbeam, beech, spruce, ash, douglas, you name it.

Here it is named a "sanitary crisis", but it is no longer a crisis as it is only worst years after years. It was already very, very bad in 2018, and "only" very bad years before. It is just that mass mortality is growing more massive years after years. And in Deutshland or in Switzerland it is no better.

Arctic sea ice / Re: The 2019 melting season
« on: September 06, 2019, 11:44:13 AM »
Sum of forces is definitively not the same. Ice and water does not respond in the same way to winds. And there is also hydrostatic equilibrium, 100 hPa is worth one meter of sea level, but zero point zero meter of ice level. And of course in the end gravity would even out the sea level if the winds stop blowing.

Arctic sea ice / Re: The caa-greenland mega crack
« on: September 03, 2019, 09:47:01 PM »
Yes thanks longwalks ;) If there is specfic interest for the Nare Strait, the work of A. Münchow is worth citing :

"The established flow of seawater from Pacific to Atlantic Oceans through the Arctic has been attributed to higher sea level in the Pacific (Wijffels et al. 1992), associated with the lower salinity of Pacific waters. Sea level in the Atlantic may be more than 0.5 m lower than in the Pacific and 0.1–0.3 m lower than in the Arctic (Muench 1971). More accurate estimates of steric forcing have yet to be determined, but it is probably safe to conclude that much of the drop in sea level between Arctic and Atlantic Ocean occurs along the 530-km length of Nares Strait, thereby providing the impetus for the fluxes that we have measured.'

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 03, 2019, 02:40:21 PM »
Without wanting to look harsh, but I think the discussion is taking a bad way. I am not a specialist of this question, but a big missing piece of data is the problem of land versus ocean distribution in Northern Hemisphere. I mean, in winter, ice edge is constrained more by geography (coast of Russia and Canada) than by physics (warming / cooling atmosphere, ocean currents, and so on). Which is no longer the case in Summer, where ice edge is, but for Greenland, in open Ocean and can retreat as the thermodynamics warrants. This is probably why seasonal cycle changed dramatically after 2005. Until 2005, ice was still mostly bounded by the coast, even in Summer. Now, ice has all the possibility to expand and retreat without being imped by the coasts. One possibility is to look instead at sea ice edge latitude. Doing this, difference between Summer and Winter is lessened and the downward trend is more even.
On top of that, captain obvious helping, it should be noted that sea ice area can't go negative. But this has the implication also that the downward trend should go to zero sooner rather than later, as there is no more ice to melt in summer. Losing 2 million squared km when you have like 20 million at hand is almost nothing, losing 2 million squared km when you have like 1 million at hand is impossible... This is probably the first big answer to the question "why trend is so irregular and the seasonal cycle has gone mad ?".

It should be noted also that from this point of view, the situation is “worsening” on the Pacific side. When the edge was in the Bering Sea, there was still some width to “yielded” big loses. Now that the edge is in the bottleneck of the strait, even a retreat of 1° North –which is quite significant– would amount to almost zero ice area loss. Zero time a thousand km is still zero :p We will have to wait for ice edge in winter to reached Beaufort / Chukchi / ESS for seeing anew some significant ice loss for the Pacific side. Same on the Atlantic side, as Barents and Kara Sea are zeroing, going further North will become complicated in the short term. It will happened in the decades to come of course, but over the course of the coming years, variability of winter sea ice as seen from the metric of extent will probably still be dampened, even if the warming speed up bigly.

P.S. And on top of that "simple" geographical explanation, geaography also lead to "energy yield" vastly different from Winter to Summer. Land and Ocean distribution are also responsible for bigly different thermal answer in Summer and in Winter under the same forcing. We will also probably have to wait that the Ocean becomes an "heat accumulator" in winter for seing warming speeding up in Arctic.

Arctic sea ice / Re: The caa-greenland mega crack
« on: September 03, 2019, 06:42:42 AM »
This topic has drowned into the abyss of this forum, but the mega crack is still here and alive. And there is still sign of melt going on. To justify, Kap Moris Jesup hit 10.3°C the last day of August, a record for this time of year. And to the the North of Ellesmere, the Nares strait export has lead to a big, big hole. Fortunately the season is ending.

An unspoken consequence, here in northeastern part of France, is the sanitary situation of forests. Some plants are dying like never. Spruce, european spruce, beech, ash, bilberry etc... Many plants and trees are dying. And some are still alive but are on the brink of disaster like apple trees or more generally fruits trees which are not enough vernalized in winter. In my valley, there are big brown patches everywhere, like pictures in this article : And in the forest, we can't walk an hundred meters without seeing a tract of land which is dead. In Swiss, there is even a declaration of emergency ... Consequences will be long lasting but big : flooding of the wood market with lower quality tree, increase risk of accidents, increase risk of forest fire, loss of biodiversity etc... The financial burden for some villages could be unbearable in years to come, as many rural towns have big incomes from the trade of wood. I don't know what a valley here could look like without beech, spruce, apples and cherries...

The rest / Re: Are you hoping for a global civilisational collapse?
« on: August 27, 2019, 02:01:34 PM »
It is ongoing, but I am not hoping for it, just preparing and praying the Lord. And reading ancient books from the late Roman Empire. But I am not a big fan of the world "collapse". Collapse will not happens instantly nor globally, but is an already ongoing step downward trend with some periods of temporary improvements, being better or worst here and there, and it is not going to be a global catastrophe over a day or so. Humans are often fascinated by big catastrophes, but the collapse of a civilization never followed this path.

I had problems voting here because I think the concept of collapse as given here is a bit of a straw man. I don't think it likely that it will be Armageddon, with hardly any survivors... but I'm sure there will, at some point, be a major reduction in population, and a reversion to a largely agrarian society in places that aren't used to such lifestyles. Many indigenous cultures will carry on, under trying conditions. What I expect to be the main symptom of collapse is the loss of the framework that allows intensive industrial civilisation. First there will be food shortages, then public unrest and lawlessness, then a new equilibrum will emerge later. The skills and knowledge to survive as sustainable communities still exist, although yes, life would be less comfortable. And yes, I expect this to happen (at least in part) within a few decades.

I fully agree. I am trying to build a sustainable community in my neighborhood, reviving ancient practices from the past.

Arctic sea ice / Re: The 2019 melting season
« on: August 24, 2019, 09:27:12 AM »
Models are trending deeper and deeper. Below 970 hpa will as forecasted now make this complex looking like a GAC. Brace yourself for ice armagedon.....

Arctic sea ice / Re: The 2019 melting season
« on: August 20, 2019, 09:02:24 PM »
If it was 500 or 1000 km toward Beaufort, it would be a party of ice destruction.
In that location it smells season brake of an already braking season.

Again, this is definitively not the opinion of the Euro guy. I am ready to bet that this boy will be closer to the reality than GFS. The IFS at 120h - 144h is extraordinarily bad and the IFS at 96-192h is "only" really, really bad. There is a lot of energy to dissipate and the GFS, sitting like a big fat guy in his chair and waiting God knows what's sighing "Energy, which energy?" is really not a credible option in my opinion. Also, IFS (00Z or 12Z of this day) is able to go to a warm seclusion. This point is also not in favor of GFS. From the season, we have learned that the Arctic is under steroids and a cold, dreary frontolysis is not looking likely. Perhaps I am badly mistaken and fooling myself, but for me this is not looking like anything serious.
The point is really not about the deepening low above the archipelago. Now, every one is ok for a deep low over this region. But after, some models like IFS are able to let the low spinning, with a new feeding of energy from Atlantic and Eurasia, while GFS is letting this thing dying.
Perhaps it is the hour where Denethor is whispering the antithesis of your one signature to the lasts floes of sea ice still standing : "Why do the fools fly? Better to die sooner than later. For die we must."

Arctic sea ice / Re: The 2019 melting season
« on: August 18, 2019, 01:24:17 AM »
As CSNavywx noted a while back, ridges tend to persist and the models often underestimate the persistence. We should not ignore the latest Euro model run. We'll know that the threat to the ice is over when temperatures drop and area losses stop. The recent slowdown in extent losses was associated with a rapid drop in area, an indication that the melt season has not yet stalled out. The DMI 80N graph shows the melt season has gone into extra time.

I don't think that this means this year will catch up with 2012, but there's still time for surprises.

Yes, GFS is probably lost in the wilderness again. I have put also Arpege, a french model which is not often look but is often good and is a close friend of IFS, despite being coded quite differently. At 96-120 h, the low over north Pole must be closely monitored. It is not deep, but again it is deepening against a strong ridge. And so, a sub 995 hPa low vs a top 1025 hPa high result in a strong low level jet over CAB. I don't have all the tools for an analysis, but it also likely that the high and the low are feeding each over. Stronger high with warmer air mass is probably enhancing the baroclinic zone trough stronger temp gradient and stronger wind speed, helping the low to deepen. No GAC again, but these recurrent, nasty low battling strong highs are not helping. A solution like GFS with a broad low sipping a cold drink and waiting I don't know what would be way better but it is not really the most likely outcome.

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: August 17, 2019, 08:34:25 PM »
Yes it is probably the explanation, despite Copernicus showing data available since 2006. And yes it is really frustrating to be blind while the Beaufort sea is beaten like never. The beaufort gyre is quite an important thing, but who know what is really happening ?

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: August 17, 2019, 04:53:35 PM »
I make a quick map to compare 2019 on the 26th of August (forecast from Mercator) to mean from 2016, 2017, 2018. I don't know why, I was not able to download data for prior years, I don't know why... Excepted for the Barents sea which is cooler than over the 3 previous years (also the case for SSTs with a true base period), everywhere the warmth is showing, and even in the central basin there is streams of abnormally warm temperature.

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: August 16, 2019, 04:54:21 PM »
And now ITP 110 has hoisted the white flag and surrender. No news since two weeks. Too bad, as Mercator is showing extreme warmth in Beaufort. It should have been interesting to see what really happens here. The build up of heat shown at 30m and 100m is like nothing ever seen. Will this have an influence on refreeze season ? And Mercator was shown to be warming not enough compared to ITP 100. Depite this, in part of the Beaufort Sea, the big mess is going on and on, with a loosening of the stratification and a build up of energy wich is beyond superlatives and the "spot the difference" game ... Where now the Pacific layer and the halocline ? Where is the freshening and the cooling ? I don't know where we are going at this pace, but here we go.

P.S. : There is no special reason for a comparison with 2016, it was only to give a point of reference for a year wich was in its own quite bad for Arctic.

Arctic sea ice / Re: The 2019 melting season
« on: August 14, 2019, 02:04:57 PM »
Wind is basically going bonkers at the moment.

45 knots off the NE coast of Greenland into Fram. 20 knots from the Kara straight into the CAB and noticably moving the ice edge.

Same in Beaufort with 20 - 30 kts of easterly winds now. Ship NWS003 measured 51 km/h but not sure of the configuration of the anemometer and ASCAT is quite explicit. Wind speed is not extremely high but occuring over a wide swath around the high. Also models have been a notch too low for wind speed. The vertical profile is of course helping, with the lack of strong near surface inversion, but it is still interesting to see models not fully bringing winds to surface.

Arctic sea ice / Re: The 2019 melting season
« on: August 12, 2019, 10:01:36 AM »
I’m really surprised that the lightning strikes 300 miles from the North Pole yesterday did not cause more discussion on the forum. 

The scientists on climate Twitter could not find any instance of lightning so far north.

It was a strange, and in my opinion important, event.  The arctic is changing!

This is from work, so no one has seen the following pictures... The IFS 0.125° for the 11th at 00Z, wet bulb potential temperature at 850 hPa, vorticity at 850 hPa (above 16, step 4), SLP, thickness 500 (Z500-Z100). There is  a front with a ribbon of vorticity to the North, stretching from the low over Barents to the Chucki sea, with low and mid level clouds, as visible from sat pictures. But associated with the low over Laptev, to the west of the head of the low, there is a maximum of vorticity. Sounding show mid level instability from ~800 hPa to ~250hPa with ~100 to ~200 J/Kg. Marginal, be with good forcings enough for TS.
As Rod said, this is significant.
For one part, this is an illustration of the evolving Arctic. Again, CBs were probably not directly linked to the crazy warm SST, but it is definitively showing that Arctic is warming. The warm air advection was extreme, and was able to carry a potentialy instable airmass up to 85°N. Mid level CBs at the head of a thermal wave are not a thing of the Arctic, up to today...
For the other part, this also means that cyclogenesis is on the move on the Arctic. This low had some characteristics of a warm seclusion with a slight max of temperature, TA and wind around 850 hPa - 900 hPa. Cold, pure baroclinic process are loosing a bit of grip and now warm core process and moist instability is starting to play a role. For the second point, it was of course more evident with the low over Beaufort at the start of the month for example. Here a lone CB will not make any meaningfull difference of course. But next year it could be 10 CBs, then etc... And on the end it will change the cyclogenesis process. It could also be noted that Laptev sea being shallow, it could quickly warm without sea ice. With Siberia snow free earlier and earlier, this could mean a quick increases of moist instability with a warming Arctic.

Arctic sea ice / Re: meaningless freezingseason/melting season chatter.
« on: August 01, 2019, 03:44:40 PM »
During the Eocene, CO2 was probably around 1000 pm and orbital factor were probably not a good explanation for equable climate. Despite this, Arctic was perennially ice free with subtropical fauna / flora up to Ellesmere -and the paleolatitude of the island was about the same that today-. But even more, during middle Miocene sea ice was probably restricted to central Arctic during winter (cf. ) while CO2 was around 500 ppm. There is also some other indirect elements, like the fossils of a cool temperature forest on Bank island : -and usually cool temperate forest is not found with sea ice -.
Excepted for central basin (i.e. extent at 5 millions in winter), perennially open Arctic is not likely by 2050 but still possible. If we follow the same trajectory for CO2 emissions, the earliest decade this could really happen is 2070s or 2080s. Open Arctic in winter can probably be sustained with greater CO2, moisture, enhanced cloud cover and ocean heat transport I think. For ocean heat transport, I am strongly convinced by the theory of Kerry Emmanuel, saying that more hurricanes, and more poleward hurricane, could increase the ocean heat transport. The problem is that models needs large scale gradient for heat transport, but paleoclimatology show that it was definitively not the case. As hurricanes are mesoscale system, are not well handled by models, and don't need gradient for mixing heat, they check all the boxes for explaining why models and paleoclimalogy are on an head on collision trajectory.

P.S. : petm was speaking of year-round Arctic ice free but in my head in 50 years we will be in 2050. Excepted, this is no longer the case since 20 years now XD

Arctic sea ice / Re: The 2019 melting season
« on: July 28, 2019, 11:24:57 PM »
No idea what one calls this pattern but 250 hPa on nullschool is pretty impressive! (or a mess if you are looking for a nice rational jet stream!!),88.54,568

Does anyone have a picture of what it should look like, just for those of us who don't exactly know. I'm assuming much more tight and circular?

Usually yes, but seeing polar jet making wild loops is not unusual per se in the NH this said. So I am not sure that the mean will help you, but it's the attached map. I think it is worth emphazing that it is normal for the jet to undulate. And the tropical heating has a huge influence on the jet.  And it was worst at some point in the precedent years. This said this year the jet is definitively weird again this year, Arctic is not helping, and tropics are marching northward.

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: July 25, 2019, 03:21:33 PM »
In this particular case, what are we looking for in a temperature vs salinity chart? I ask because it may be a more efficient way of diplaying the profiles.

Salinity is usually used as a marker for layers of water. Usually, S between 31 and 33 is thought to be the Pacific Warm Water but a freshening of warm waters is ongoing and should increase instability of the water column, as S is around 28 near surface, with the risk that this warmth make surface by mixing. At greater depth, the max at around S=35 is Atlantic water. In Summer, water are fresher (sea ice melt, water runoff) and warmer, with a positive trend due to warming (water source from Chukchi sea is fresher and fresher, warmer and warmer). This is showing in the Beaufort Gyre, with a higher max in temperature at lower salinity for the Pacific Water Layer. There was even some ITP profiles with a Tmax with salinity near 30, and a Tmin with salinity near 28... of course freshening of Pacific Water must reach a limit, and in the same time, as said by Bruce Steele, the warming of Chukchi Sea will shut down the donwelling. I am not sure where we are going, but here we go. And the Ocean is definitively heavily disturbed, there is way too much heat which was accumulated this season, and it is not over.

Inspired by your salinity movies, uniquorn, the illustration below is a suggestion for displaying the actual physical data they are based upon.

It would give a 'traffic light' of salinity at e.g. 0m, 30m, and 100m at the location of each recording device on that date - whether from a tethered buoy, drifting buoy or a ship.

My main immediate motivation in suggesting this is that it would allow a movie that extends back before the June 2017 start of the mercator display movie that uniquorn posted here on the 2019 melting season thread. That would give us a longer term view of how the salinity has changed.

I realize that it would probably be a lot of work to make this, but I think to could be a useful visualization tool. The picture is just an illustrative cartoon - I'm hoping someone will be kind enough and interested enough to produce such a display, or similar, using the actual data. (It's beyond my own personal skills at the moment, unfortunately.)

This said also, Mercator is not seeing the warming and freshening of Pacific Water... The profile is for the model where the ITP buoy made the 601th profile, on the 19th July of this year (cf. above). Quite a difference. And the same on the 19th still, over northern Chukchi sea. For making a movie, I think I don't have the time, nor the motivation, nor the bandwith :s

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: July 24, 2019, 09:57:50 PM »
Probably not yet, but we are nearing this point. The ITP110 buoy, on the 19th -the last complete profile....- was showing strong heat storage at depth, and a thickening of the halocline. Graph can be compared with Fig. 1 here : and Fig. 2 and Fig. 5 here :

But there is also a freshening of the halocline, in connection with its thickening and shoaling (cf second paper). All in all, heat is still building up in the Beaufort but instability of the thing is also probably increasing, while the Chuckchi sea is effectively trying hard to reach breakdown but is not yet fully at this point.

Arctic sea ice / Re: The 2019 melting season
« on: July 23, 2019, 10:45:16 PM »
Hi aslan .. the accumulated solar anomaly north of 70'  is interesting but 2019 needs an update .. is it keeping up with 2012 .. or fading with 2016 ?   We need to know ! :)  b.c.

Probably keeping up, but this are MERRA2 data, which update monthly only, around the 20th. The definitive answer for July is going to be in one month so... But Reanalysis from the NCAR, a bit less good for radiation flux,  but still good enough, and in near real time, is in fact showing that 2019 is still pumping a lot of solar energy in July. Spatial pattern is also important. Maximum anomalies in 2012 were over Atlantic and Greenland front and over land due to record low snow, while in 2019 it is really the Arctic Ocean which is exploding.

Arctic sea ice / Re: The 2019 melting season
« on: July 23, 2019, 10:26:15 PM »
"This said, May 2019 was not so good for building up melting momentum, a point already underlined, and accumulated heat is still trailing a bit behind good years like 2012 from this point of view, as shown in the graph."

Aslan, apart from calling 2012 a "good year", how would you explain the +4 degrees anomaly on 925 Mb over almost all of the central Arctic. That anomaly accumulated all through may, june and july...
This May was the record warmest. Anything stated otherwise is a falsehood, and Aslan's statement is objectively wrong.

The graph is about the solar energy, not air temperature....

"This said, May 2019 was not so good for building up melting momentum, a point already underlined, and accumulated heat is still trailing a bit behind good years like 2012 from this point of view, as shown in the graph."

Aslan, apart from calling 2012 a "good year", how would you explain the +4 degrees anomaly on 925 Mb over almost all of the central Arctic. That anomaly accumulated all through may, june and july...

The graph is about the solar energy, not air temperature....

P.S. And yeah, of course, the phrase "good year" was a bit ironic, and yeah being above the 2010-2018 is of course already something. But again this is NOT about air temperature....

Arctic sea ice / Re: The 2019 melting season
« on: July 23, 2019, 09:47:27 PM »
For the forecast, we can underline the 2 - 3 meters sea with a period of 8 - 10 seconds. Nothing extraordinary (an Irish sailor would probably call it a pleasant day XD) but for the Arctic this is quite a lot of energy for the sea state. I don't have a lot of memory for this kind of stats, but I think the last time the sea was so powerful in Arctic was during late August 2016.
The wind is funneled along the Alaskan coast and has the potential to bring mighty waves even though there is only a shallow low with min pressure hovering around 1000 hPa.
This is not going to help the halocline, by the way. Perhaps ITP110 will whisper something to ours ears in the coming days.

Wait ... this would imply (via the correlation) that sea ice is responding to insolation levels ... what about CO2...?   I would be interesting to see a multivariate regression including both.  Asking for a friend lol.

Of course longwave radiations are increasing at surface, but the effect for sea ice in June is not as important as the increased solar radiation. I did not do a multiple regression, this was not pertinent. The correlation and the variance explained are too low for trying to play with stats. I built the correlation with the net downward longwave radiation, which is negative (the surface gets longwave flux from the atmosphere but in the same time cools to space emitting longwave. The net result is negative). The flux at surface is of course increasing (surface can not radiate heat as effectively now as CO2 increases), but this does not explain a lot of things in Arctic in June. I could have built the correlation with downward flux alone, to eliminate the effect of higher temperature radiating more energy in longwave, but it would have not changed much.

This said, May 2019 was not so good for building up melting momentum, a point already underlined, and accumulated heat is still trailing a bit behind good years like 2012 from this point of view, as shown in the graph. But July is trying hard to push 2019 ahead.


Yeah I think I agree.

Arctic sea ice / Re: The 2019 melting season
« on: July 22, 2019, 11:42:33 PM »
I will update the analysis when June 2019 data from MERRA will be available in late July -when nobody will no longer care as sea ice extent will be many thousands squared kilometers below 2012 and the crash will be beyond obvious XD -. Perhaps MERRA datas are going to show a little miracle, against the reanalysis, but is not really likely.

So without any surprise, MERRA2 data backup NCEP/NCAR reanalysis and confirm that the Arctic suck up energy at an impressive pace in June. The first graph updates the scatter plot of September sea ice extent by the NSIDC, versus the June surface net downward solar flux (with a reverse scale on the left, in blue). As forecasted, Arctic (northward of 70°N) surface solar flux reached 120 W/m², a new record. The second and third graph are a quick comparison of accumulated heat in 2019, 2016, and 2012. And last, the map for June 2019, showing the strong signal in Beaufort, Chukchi and Laptev.

This heat will probably have long lasting consequences. It can be noted that the halocline is showing signs of disruption, even in the Beaufort sea :

And in the Chukchi sea, the warmth is even more impressive and is mixing to great depth (up to 100 meters), with major disruption of the halocline probably going on.

In the immediate future, the strong dipole (with a forecasted 50kt jet at 850 hPa ! )  is probably going to help mixing, and hence melting in connection with the warm sea.

P.S. : From a more aesthetic view of the weather, it can be noted that a shallow low is going to "deepen" (around 1000 hPa) over the northern slopes of Alaska due to interaction of the southerly flow with mountains. This low is going to accelerate the flow, with a funneling effect along the coast. Independently from the mentioned jet over Arctic, a strong gale is going to develop over Beaufort and Chukchi sea. Given the situation, mean wind of up to 40 kt at surface seems almost reasonable, but given that the wind is going to blow over open sea this can become quite an event. It does not always need a deep low for winds reaching high values.

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 11, 2019, 08:01:08 PM »
Sorry to quote myself but the end of the thinking woul have been too much off topic I think :

To add to the discussion about the begining of the end, June 2019 was the warmest month of June regarding SST in Bering sea and Bering strait according to reanalysis.
Aans as an illustration, Kotzebue is near or above record Tn and Td since 4 days :

The transport is strong this year trough the strait, and so the SST are more asymetric than usual, but despite this all the Bering sea and Chuckchi sea are at or above record level, and strong currents are burring this heat to great depth. The chart from the DMI is now saturated with red, after reaching a "low" the 4th. An incredible amount of heat is building into Arctic Ocean, and is now wanting to ease.

In 2009 Eisenman published a paper : which was later criticized : or but not fully rejected :

In the same time, with lower sea ice cover, there is an increase in cloud cover in Autumn and Winter, acting as a positive feedback insulating the open ocean below.

I think we are nearer and nearer to the point where open ocean, increase poleward oceanic heat flux, and increase SST, will make the system unstable. As a warm, sunny, open Arctic in Spring and Summer will build up a lot of energy. In Autumn and Winter, warm ocean, help by poleward heat transport, will moisten the atmospheric column, with an increase in low clouds, insulating the Ocean and allowing the heat build up in Summer to be lost slowly. As the next Summer comes, even though the weather is the friend of ice, as there is no more ice, heat can build up again in the system -and it is quite unlikely to see low cloud cover increased in Summer as in Winter- and bringing the all Arctic to a state change.

Arctic sea ice / Re: The 2019 melting season
« on: July 11, 2019, 07:10:14 PM »
To add to the discussion about the begining of the end, June 2019 was the warmest month of June regarding SST in Bering sea and Bering strait according to reanalysis.
Aans as an illustration, Kotzebue is near or above record Tn and Td since 4 days :

The transport is strong this year trough the strait, and so the SST are more asymetric than usual, but despite this all the Bering sea and Chuckchi sea are at or above record level, and strong currents are burring this heat to great depth. The chart from the DMI is now saturated with red, after reaching a "low" the 4th. An incredible amount of heat is building into Arctic Ocean, and is now wanting to ease.

Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 02:13:50 PM »
A big P.S. also to my post, beyond the fact that June 2019 was abysmal, I wanted to show also, even though it was not explicitly state, that Sun input is increasing bigly in Arctic, with an increase of 1 W/m² in June every four years. It could perhaps have been better to wait MERRA, but the topic was brought again in this discussion so go. But even more importantly, no matter if 2019 is at record or not, we are witnessing the effect of increase Sun input, with Chukchi, Beaufort and Bering running like bats out of hell after records. Of course, it is a progressive state change, but I fear we are nearer and nearer to the point that Bering sea will be perennially open, and even Chucki sea looks to be already in bad state for a good refreeze this winter. If ocean is warm enough, I think that it could supply enough moisture to create a positive feedback with longwave radiation. The warmer, the moister, the moister, the less heat can escape to space. And the warmer, the longer it takes to cool down, and if heat is not able to radiate back to space, it will take even longer. And if a melt season can give hand to the next like it was almost the case last three years, Sun input in summer is going to go trough the roof, etc... Up to now, Arctic was more or less able to erase its memory of the latest melt season during winter, but when I see the SSTs going trough the roof and Arctic pounded by relentless warmth and sun, and the last 3 years, I fear we are reaching the point where it is no longer the case.

Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 01:43:15 PM »
I think what is missing here is a discussion of the impact of increased solar irradiance.

Are you talking about the reduced albedo, low cloud cover, something else?

Looking at only solar irradiance I believe we are at a solar minimum right now with a lower irradiance than in 2012 and most of the rest of this decade (even then that difference is tiny).

The low solar minimum that the earth is presently experiencing is not the key issue that I am talking about. Rather, the key issue is the amount of solar energy entering the system as a result of reduced albedo in the arctic. This difference far offsets the difference in energy coming from the sun due to the solar cycle.

I broadly agree, I have also the feeling that incoming solar radiation is probably a bit an understate factor. It is of course a know fact, and a spoken one, that lower albedo implies a greater heat accumulation. But perhaps that the big train of heat ready to ram us is not fully acknowledge. By the way this is why I'm back here, at ASIF. I'm like a vulture, when I smell the good fragrance of a water bath I am here.

So to continue this discussion, I will try something (each word of this sentence is important XD ). NCEP/NCAR Reanalysis is easier to manipulate and is update with a lag of a few days only. So I already us it, but radiations data are not as good as other dataset. Good enough to say something about big trend and to beat some dead horses, but probably not good enough for details -like the exact magnitude of the June 2019 crash-. MERRA is probably better but will not be available until mid or late July for the month of June. As already state, solar heat input in June above 70°N is a big factor :
With MERRA data up to June 2018 I am going to back up this claim and give some order of magnitude, and with reanalysis up to June 2019 I am going to show that this year things are worst than worse. I will update the analysis when June 2019 data from MERRA will be available in late July -when nobody will no longer care as sea ice extent will be many thousands squared kilometers below 2012 and the crash will be beyond obvious XD -. Perhaps MERRA datas are going to show a little miracle, against the reanalysis, but is not really likely.

I am going to use two different flux. With MERRA, I am using net downward flux at surface (SWGNT for short). State an other way, it is the solar input wich is really accumulating at surface. The part of the Sun wich is not absorbed can be reflected by atmosphere and surface, wich is going back to space as a outgoing shortwave radiation (RSR for Reflected Sun Radiation). And Sun can also be absorbed by atmosphere. I stick with SWGNT cause looking at RSR implies giving weight to heat absorbed by atmoshere, but I don't think this part of the flux is really important. Its variations year over year are not as important, and heat absorbed by atmosphere is probably going to be mixed all over the hemisphere in a few days (as a side note, aerosols and soots -also known as black C- implies that Sun is more easily captured by the atmosphere, wich also have implications for global warming. But, looking only at sea ice year over year, the Sun captured by the atmosphere is not looking like a big factor). So, with MERRA dataset, is is going to be SWGNT. But Reanalysis as not an easy dataset for this flux. I could be possible to mix surface albedo with the downward shortwave flux at surface, but it is starting to look a bit too shaky, given the accuracy of reanalysis. So, with this lad, I am sticking with shortwave outgoing flux at TOA (RSR in the state paper above). Of course, the higher the heat absorbed by the surface, the lesser the heat making an escape to space. As a consequences, many graphs are going to have a left hand y axis, and a reversed right hand y axis. So far, the brains already hurts XD

The first graph is September SIE and SWGNT. The latter is reversed, meaning that the more the Sun is absorbed at surface in June, the less ice survived in September. Correlation is looking quite good, so let's check this.

The two datasets are quite correlated, with a decrease of the September SIE of 1 million square kilometers if absorbed radiation increase by 7 or 8 W/m². It should be note also that extrapolating the trend brings plausible results, with a zero SIE if June heat input is up to around 150 W/m². Definitively in the realm of possibilities.

So now that we have checked we are able to replicate the results of the above study, and that sea ice is screwed if Arctic is pounded by Sun in June, let's look at what the reanalysis is saying about June 2019. Was it bad, or worse than worst ? Short answer, acording to reanalysis June 2019 is abysmal. Values from reanalysis for outgoing solar flux at TOA are correlated with values from MERRA for solar input at surface. Correlation is not so bad (R² 0.45), but 2019 is not a record low point (caramba ^^). This said, it is looking like reanalysis is not going down enough. What I'm going to do is to artificially increase the trend for USWRF. Not for the pleasure of making things looking worst, but because, without MERRA data for June yet, we can only guess what happened. And an educated guess will be that reanalysis is to shy (not a surprise here...). Correlation is improved (R² 0.55) and 2019 is to the basement. Again, this is not intended to manipulate data to prove that June 2019 is a nightmare, but it is really because it is quite probable that reanalysis is not going down enough. Correlation with September SIE is also vastly improved (R² up to 0.43, from 0.20 with bulk values). Again, it is not a surprise that adding a trend to a datset to compare it with a dataset -SIE- where the trend is overwhelming everything vastly improves the correlation -if the slope of a dataset is way higher than its variability, we can correlated it with about any dataset having also a big slope-. But I do think this as a physical meaning.

I let you also the values for SWGNT in June in W/m², and with a conversion to "how many meters of ice could be melt by such and heat input ?" to give a sense of the energy in play.

   SWGNT      Thickness elt
1980   107   0.90
1981   109   0.92
1982   103   0.87
1983   103   0.87
1984   108   0.92
1985   113   0.96
1986   99   0.84
1987   108   0.91
1988   109   0.92
1989   99   0.84
1990   117   1.00
1991   111   0.94
1992   102   0.87
1993   116   0.99
1994   108   0.92
1995   109   0.93
1996   100   0.85
1997   109   0.92
1998   114   0.97
1999   102   0.87
2000   112   0.95
2001   114   0.97
2002   112   0.95
2003   108   0.92
2004   107   0.91
2005   113   0.96
2006   107   0.90
2007   118   1.00
2008   117   0.99
2009   111   0.94
2010   115   0.97
2011   117   0.99
2012   118   1.00
2013   109   0.92
2014   112   0.95
2015   113   0.96
2016   113   0.96
2017   116   0.99
2018   108   0.91

So, if I am not fooling myself, if I did not make any basic calc errors, etc... June 2019 has sucked up a lot of Sun, and probably is the leading horse in this race. Put in another way : die sea ice, die ! And see you again when MERRA will update.

Arctic sea ice / Re: The 2019 melting season
« on: July 07, 2019, 06:09:07 PM »
MASIE is a manual analysis of ice edge, and so is very accurate but not really consistent. Usually, it is good to avoid MASIE for climatological purpose, like comparing two different days.

For Chukchi sea (and Beaufort, and Bering), heat is even building up to great depth, up to 100 meters. The sheer mass of accumulated heat is astonishing this year. It will not have a direct impact on the melting season, but long lasting consequences are likely. And this is not going to end, as the region is still pounded by warmth and Sun.

Arctic sea ice / Re: The 2019 melting season
« on: July 06, 2019, 12:13:13 PM »
And I think I did not exactly answer the question :s Same for upward Solar flux at TOA, with a good scale this time.

For the exact figures, average for latitudes from 70°N to 90°N is around 256 SIU, 259 SIU for 2007, 257 SIU for 2012 and 263 SIU for long term mean ( 1981 - 2010 ). Again, acknowledging the uncertainty in the radiative reanalysis, hoping I did not make a basic calc error, et cetera... But all in all, June 2019 was able to suck up a lot of Sun, especially at "low" latitudes -despite a snow cover slight more extensive than in 2012-, and this is of course no surprise, and is a good reason why near shore seas and Siberia are crazy warm.

Arctic sea ice / Re: The 2019 melting season
« on: July 04, 2019, 01:47:08 PM »
Mercator is showing that heat for the Pacific side of Arctic is building more and more, and the signal is now reaching a depth of 100 meters. While there is still a least a month for ocean heat to build up.... Definitively not good. It will not directly influence the ongoing melting. But if heat starts to accumlulate to such depth, it will be difficult to extirpate it. And this will have lingering effect.

30 m:

100 m :

Arctic sea ice / Re: The 2019 melting season
« on: June 29, 2019, 07:12:27 AM »
Zack Labe is also worrying about the weather forecast :

Arctic sea ice / Re: The 2019 melting season
« on: June 23, 2019, 05:10:40 PM »
16.8°C at Ostrov Kotel'Nyj, record high for the day and for so early in the month, beating the 16.6°C from the 13th of June of this year... The monthly mean temperature for June at this location is set to break the record by more than 2°C. In the same time, Tuktoyaktuk reached 22.5°C the 22th (daily record) and 22.5°C again the 23th. Arctic is under assault from all sides.
Sea ice is now disintegrating along the Siberian shores, and it will not take long now for seeing continuously open ocean from Ostrov Vrangel to Taïmyr peninsula.
And as others have noted, the number of beige pixels in the thickness ice map from the university of Bremen is at record low and digging more more.

Arctic sea ice / Re: The 2019 melting season
« on: June 22, 2019, 05:09:09 PM »
The warmth on the Pacific side is extreme. And this warmth is pouring into Beaufort. Locally SSTs are up to 10 °C ! I like the smell of a water bath in the morning...

Arctic sea ice / Re: The 2019 melting season
« on: June 20, 2019, 03:48:15 PM »
The D+3 is no longer the hammer (it was when D+6), now the blowtorch really baf is D+8. Are we chasing a carrot?

The two forecast are not so different, and are anyway bad for sea ice. Models are tightly clustered, GFS and IFS are quite the same, and the ensemble of both models also. To illustrate, is attached the spread for the ensemble of IFS at H+168. Models are quite stable for the Arctic ridge (and Greenland ridge by the way). On top of that, the european guy Is usualy less prone to go into overdrive mode. But currently IFS is as much, if not even more, crazy than GFS. This Is telling something.

Arctic sea ice / Re: The 2019 melting season
« on: June 20, 2019, 09:49:04 AM »
Ice that enters the Beaufort is as doomed as that leaving the Fram, but it will take until August.

It can be noted again that despite cold, cyclonic conditions over Beaufort and archipelago, min temperatures remains near -1°C and max temperatures near 2 -3 °C, SST remains warm for the region (2 - 3°C) and are note cooling, dew point are not strongly negative and soundings don't show temperature inversion. Beaufort sea is now a graveyard for ice. Open too early, warm too much during Spring.

Arctic sea ice / Re: The 2019 melting season
« on: June 20, 2019, 08:51:52 AM »
I agree about the craziness of the weather forecast. I think it is the worst heatwave in the Arctic ever, even worst than the one in July 2007 or July 2011 or July 2012. As a consequence of the warmth, moisture, and high pressure, Z500 height is mind blowing with values up to 5 800 gdam !
A simple but convenient way to define the northern border of the tropical belt is by using the belt of highest Z500. Here this belt is near to break away with a secondary maximum wich, around the Pacific, is not so secondary as Z500 is about the same other Arctic than over Hawaïi ! I have never seen such a thing.... This also means clear skies but also, as moisture content is high, reduced outgoing longwave radiation.  I agree with Frivolous, we can't overstate how epic is the weather forecast.

Arctic sea ice / Re: The 2019 melting season
« on: June 16, 2019, 09:51:32 AM »
According to the SMOS maps -- which show satellite microwave measurements, displayed on a map of the Arctic by University of Bremen -- 15 June 2019, just released, may have had the smallest area of 'dry' Arctic sea ice on record for the date, going back to 2010 and just pipping the exceptional melt year, 2012.

That's according to the 'beige pixel count' graph by Steven.

EDIT: as Neven has just pointed out in such a timely and informative manner..  :D

Wich is also visible this morning with the spreading of dark red colour on the 3-6-7 band :,MODIS_Terra_CorrectedReflectance_Bands367,VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-06-16-T00%3A00%3A00Z&z=3&v=-4769700.425308427,-1996705.9295692188,3094619.574691573,2119774.070430781

What I'm eager to see later this season is whether the pack could fully break away from any land. The usual reasoning is that the last of ice would be near Ellesmere and Greenland, but this year surface melt is way under way near this coast, and temperatures are really warm near the coast. Perhaps there is a chance that the pack will be a a board in the middle of the ocean, battered by the waves ? Research about past sea ice conditions found proxies of beaches along the Greenland coast. Perhaps we are not so far away from relocating the night clubs of Ibiza near Kape Morris Jesup ...

Also, as some others point out, the Beaufort sea open so early that the cold cyclone was note able to bring down the temperatures at surface, as shown by min temperature in the Canadian sector wich remains near zero the last days :

Etc. As a consequence, surface melt seems to be, slowly but surely, ramping up even in the canadian sector, despite the cyclone -or because of it, as it is raining cats and dogs from an Arctic point of view-.

Arctic sea ice / Re: The 2019 melting season
« on: June 11, 2019, 10:29:00 PM »
Despite cold airmass temperature (below -5°C at 850 hPa), it seems a significant rain event occured over Canadian archipelago, bringing darker blue colors on the 7-2-1 bands :,MODIS_Terra_CorrectedReflectance_Bands367(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-06-11-T00%3A00%3A00Z&z=3&v=-2881554.165245775,-1905727.5617934137,559085.8347542249,-83007.56179341371

compared to 2 days ago :,MODIS_Terra_CorrectedReflectance_Bands367(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-06-09-T00%3A00%3A00Z&z=3&v=-2881554.165245775,-1905727.5617934137,559085.8347542249,-83007.56179341371

I don't know if this observation is valid, but SYNOPs from Grise Fiord are quite crazy :

Despite this, all other observations shows at least a couple of millimeters of rain or (extremely...) wet snow, like Pond Inlet who get its monthly rain in 24h :

Or other stations to the West


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