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Messages - Phoenix

Pages: [1] 2
1
Arctic sea ice / Re: The 2020 melting season
« on: May 31, 2020, 11:50:47 AM »
Triple attack.

2
Arctic sea ice / Re: The 2020 melting season
« on: May 31, 2020, 09:52:03 AM »
Arctic: I can't breathe. The melting pond is expanding and worse than 2012 and 2016.

3
Arctic sea ice / Re: The 2020 melting season
« on: May 30, 2020, 04:20:28 PM »
I guess it has something to do with the rain (darker blue tones).

Click to play.

4
Arctic sea ice / Re: The 2020 melting season
« on: May 30, 2020, 03:53:44 PM »
It is quite usual to see AMSR2 images showing false areas of low concentration as the melt season gets into high gear. It is not so usual to see them persist.

Twixt Laptev and the North pole, up to North of 85, such an area appeared on May 27. Since then it has got bigger and stronger

5
Arctic sea ice / Re: The 2020 melting season
« on: May 30, 2020, 03:13:41 PM »
Disintegration of fast ice has begun. This is from the Laptev today.
A little further north, Lena Delta flood meltwater is visible on the fast ice surface, which is much narrower than 'normal' this year.  https://go.nasa.gov/2MbYaKO, may20-30
edit: closer view here
edit: added uni-hamburg amsr2-uhh of the same area (inset) clearly showing how amsr2 concentration can be confused by surface water resting on ice.

6
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 30, 2020, 01:39:37 PM »
In short, WAA can melt snow, reducing its albedo and letting in the real monster, sunlight. So you cannot completely discount it no matter what calculations show regarding total energy transferred.

7
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 30, 2020, 10:17:00 AM »
On another note, you seem intent on proving that WAAs are very important to the Arctic, and that they do matter. I am not sure why you think this needs proving, it's quite obvious. The question raised by this thread is whether locations that do not often receive WAAs (away from continental landmasses) are highly likely to retain ice at minimum over the next decade, thus enticing a slow transition. To prove this, even just logically with no supporting quantification, requires more than just proving that WAAs are important.


Also, read the Slow Transition thread from start to finish, very relevant.

You took the words right out of my mouth Oren!

I have perused the Slow Transition thread. It doesn't seem like a discussion that is designed for the lay person.
And regarding that thread - many posters on this forum began their residence as lay persons, myself included. To most intents and purposes I am still a lay person, but I make it my business to learn anything I can, enhancing my own understanding and hopefully enabling some more personal contribution. Despite great difficulties in my first year on the forum, and lots of things being total gibberish to me, I recall trying to follow the discussion and even to post some useful(?) questions in that thread at the time. Make it your business to understand the detailed and difficult stuff, and your contribution to the forum will grow accordingly. Skip the hard stuff, and your contribution will be limited to lots of words with no supporting evidence.
Be aware, anyone can calculate simple formulas learned on the forum, and most anyone can use Excel or OpenOffice to make some statistics. It doesn't take a PhD, it's not difficult, but one must decide they want to invest the time and make the contribution.

8
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 30, 2020, 10:02:49 AM »
Quote
Let's separate my suggestion into two elements. The first element is the suggestion that we should strive for proactive measures which give a better sense of what the season portends. The second element is the specific suggestion that the measure be (CAB + CAA + Beaufort).

As far as the second suggestion, I would consider it to simply be a straw man. If the best minds think ESS or Greenland Sea s/b included, I think that's a step in the right direction and would be very pleased with that 5 sea indicator of intra season progress relative to the end game.

As far as the first element, what are your thoughts there ? Do you think this is a direction to pursue? How do you feel about the 5 sea comparison which I infer that you might like better? You are the moderator here, I'm happy to defer to your judgement.
We have discussed it on the forum in the past. My position was and still is that as far as area data goes, the most relevant data is an aggregation of all the seas connected to the Inner Basin with import-export ties, plus the CAA because of its peculiar geography and ice retention. This is because the ice in these seas can move to the CAB, or be received from the CAB, thus making them one interconnected system. The same applies to energy and enthalpy in these regions. Seas that should be excluded are seas that mostly see export from the Inner Basin due to prevailing currents and winds and due to high local melt: Baffin, Barents and Greenland Sea. These seas may retain ice at minimum but that ice is not the ice that is there now, rather it's ice that will be exported to them in August or September.
Funnily enough, this is exactly the index tracked by the relentless Gerontocrat in his area updates and other updates: the High Arctic + CAA. Not because I am a moderator (irrelevant) or because that is my position, but because this has been discussed in the past and it makes sense. And because it's Gerontocrat's position of course. I track this index too in my regional PIOMAS updates, when I get around to making them. Wipneus has an Inner Basin chart that excludes the CAA. Each person that publishes statistics regularly can choose his or her own index to track, feel free to do the same. But if the stats are considered irrelevant by most of the forum, such contributions should be short and to the point and not cause too much noise and clutter. 2-3 lines of daily text and data are welcome, loads of text and repetitive analysis every day will be frowned upon. This happened in the past with some users.
Things change in August: the CAB starts crashing, and the single most important index by then is the CAB itself. But changes in the CAB will be a result of 2D developments that took place in the surrounding seas, and 3D processes in the CAB itself, all unseen in the CAB 2D data. Until August, all you see in the CAB area and extent data is noise (and the local variability of the sector near Svalbard-FJL, which should have been excluded from the CAB).
Note the best 2D index IMHO would be a pixel-level aggregation of ice concentration multiplied by the difficulty of clearing ice from that location, as measured by the statistics from the past 10 years. Thus a year that melts ice near the North Pole (such as 2016) gets more points than a year with early advances in the southern Kara. But this index is currently unavailable.

9
Arctic sea ice / Re: The 2020 melting season
« on: May 30, 2020, 09:49:36 AM »
Just looking at modis we can see how the big high pressure ridge during the middle of May totally left the surface layer of the Arctic broken down to where it will really only take one or two days of warmth or sunshine to go straight to wetness.

Also there have been subtle signs on the models in the medium range of them breaking down the large Greenland locked vortex and going into the three small summer vortex pattern that is highly associated with the gis base dipole anomaly.

Is a medium range there have been various degrees of heights rising while a larger vortex take shape along the Russian coastline.

So far we have not seen the models really pump out a full-blown highly anomalous ridge patterned dipole.  But I wouldn't be surprised.



10
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 29, 2020, 10:27:38 AM »
Two comments off the cuff:
* In the Chukchi and in the Svalbard-JFL line, we have not just a shallow shelf but also an incoming oceanic current which is warm and salty. These current are prevented from sinking below the cold fresh water, thus enhancing ice melt. Ignoring the effect of prevailing currents in general, and these two currents in particular, can lead one to the conclusion that shallowness is a factor in itself.
Other shallow regions do not have these currents and do not have the tendency of enhanced ice melt. Specifically, the ESS is the shallowest Arctic sea and also the most difficult to melt. OTOH, the deep Beaufort is continually fed by thick ice from the CAB during the melting season, as can be seen in the long-term animations upthread and in animations from various melt seasons. Thus its resilience is partially a mirage of ice import.
* I know you do not consider quantification an essential tenet of the hypothesis. However, once a quantification has been served by others I think it shouldn't be ignored.
"Since over 90% of the season ending ice is expected to be in the CAB, CAA and Beaufort, it would be a simple tweak to create a category for the sum of these three seas instead of the current High Arctic grouping."
I have posted data in the Melting Season thread showing that on average more ice survives in the ESS than in the Beaufort. Besides, 90% of the Beaufort and ESS ice is expected not to survive a given melt season. And what about the Greenland Sea? Thus I think your proposed "survivable ice" measure would not be quite helpful.

11
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 29, 2020, 10:11:27 AM »
Also, read the Slow Transition thread from start to finish, very relevant.

You took the words right out of my mouth Oren!

12
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 29, 2020, 01:11:36 AM »
Interesting not to say annoying how each time when I and hopefully others have a great read after someone invested time and energy to write instersting stuff like i.e. the creator of this thread frequently does, that immidiately someone has to nitpick/cherrypick anything irrelevant, often prone to opinion and/or definition of terms, to spoil the party.


So I have high respect for those who post reapeatedly such informative stuff who do not get discouraged by the "oppositon adicts".


I for my part gave up long ago and just enjoy reading most of the time, need my energy for my loved ones


 :)

13
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 28, 2020, 03:17:41 PM »
Quantifying: in the last 10 years there were two August GACs - 2012 and 2016. Both years are also lowest in NSIDC area, similar to each other and far ahead of other years.
Thus, chance of GAC is ~20%/year. Not freak. To break the area record it is probable another GAC will be needed. Ergo, chance of new area record is 10%-20% per year. Or 15%-25%, depending on your assumptions about other factors.
Note: 2012 has a huge lead in min extent, thanks to freak Sep compaction. But area is IMHO more representative of energy in the system.

14
https://www.nature.com/immersive/d41586-020-01446-x/index.html

Quote
During the winter, the atmosphere in the Arctic doesn’t get colder with height, but warmer. To study these temperature inversions, MOSAiC scientists released four weather balloons per day, allowing them to measure the temperature (among other parameters) at one-second intervals as the balloons climbed high into the atmosphere. They also built a meteorological tower that constantly monitored the atmosphere’s temperature at 2, 6, 10 and 23 metres above the surface.
The extreme layering surprised researchers. On several different occasions they saw inversions as big as 5 °C in the lowest 10 or 20 metres of the atmosphere. Yet scientists don’t know how often these inversions occur, or their typical strength.

15
Arctic sea ice / Re: The 2020 melting season
« on: May 28, 2020, 12:13:56 AM »
Imagine you try to hit a nail with a hammer, but hit your finger instead.
Nice analogy.

WAA probably can affect the ice seriously. I got about 50 km3 of ice per day by calculations assuming high moisture. Though part of this energy will not be received by ice. And it reduces albedo sharply. Another thing is drought. May dry air mass cause a dust storm into the Arctic?

16
Arctic sea ice / Re: The 2020 melting season
« on: May 27, 2020, 12:08:50 PM »
Given that an unusual reduction in albedo Is anticipated from 0.9 to about 0.65 over the period of 40 days when solar insolation is 500W/m2, I wonder if anyone has done an estimate of how much extra reduction in sea ice thickness will be caused by this? My own back of envelope estimate suggests about a 1cm extra reduction for each 1W/m2 of heat energy transfer. Theoretically, the sea ice could thin an extra 1.25m! That would mean the oft quoted BOE in August / September. Have I done something wrong? Loss of snow cover cannot have that large an effect surely?

17
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 27, 2020, 12:02:46 PM »
Thanks, well explained.
The pixel-level analysis you described is something I have wanted to do a long time ago and still want to, however I currently lack the skills and especially time to do so. I know the data is available and that it is a feasible calculation, if I have a couple of free months I know I can do it including acquiring the programming skills. Won't ever happen probably.
For each pixel, what is the probability of being ice-covered or ice-free (or % ice concentration), for each given date, looking at statistics from the last 10 years (since 2010 when the Arctic sea ice statistics seem to have stabilized a bit). Best displayed as a color-coded map of probability, animated over the days of the year.
Even better would be to compare this animated map with one containing the data of previous decades (2000-2009, 1990-1999).
A map for AMSR2 data (since 2012 or 2013), and for NSIDC data (full data available), as these have different pixels and vastly different resolutions.
Missing data would have to be interpolated from preceding and following days.
By the time I get down to actually doing it, the Arctic will probably be post-BOE...

I have made do with aggregated regional data, especially the finer AMSR2 data from Wipneus, but also the NSIDC area data. This gives some crude conclusions and insights but is mostly unsuitable to the huge and diversified CAB, in fact to any region that is made up of different ice behaviors or geographies.
Let's wait and see what this season will bring. If I have further contributions to add, I will post them here or in the "when ice free" thread.

18
Arctic sea ice / Re: The 2020 melting season
« on: May 26, 2020, 11:42:48 PM »
I just wanted to post this up since I found it pretty astonishing to compare 2020 to 2019 in terms of snow cover on the Russian side (with the Lena River delta being in the bottom left).

It's so obvious to see the sheer expanse of snow melt. Additionally, 2019's snow cover is what I would consider a decent average in terms of previous years looking more similar than different.

19
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 04:38:50 PM »
Quote
Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting.

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently?
I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

I agree, if you can it would be great to see some kind of data. Most of the time a hypothesis has underlying pilot data. Something other researchers can use to make their own judgements.

I know we all have busy lives outside of ASIF, so please dont interpret this as pushy!

20
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 04:28:39 PM »
Quote
Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting. 

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently? 
I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

21
Arctic sea ice / Re: The 2020 melting season
« on: May 26, 2020, 08:47:30 AM »
And this time the ECMWF agrees. Not much blue left over the CAB. These look more like July charts (for the CAB). 

Warmth right on the ESS coast.

But that is not unusual at this time of year though, most years are fairly similar with most parts of the basin having temperatures around zero

In conclusion, I'm not really convinced this year so far has had as much momentum as people may think but I'm not too convinced how long this ice will last when we get the true warm spells hitting the basin.

Maybe our perception of what is normal is coloured by our memory of recent (warm) summers.

But referring to climate reanalyzer which uses the base 1979-2000, nearly the whole of the Arctic Basin is forecast to have red positive 2m temperatures over the next 5 days with the exception of eastern Beaufort which is at around normal.

But I am not too quick to jump in and say we are worse off than ever before. The coming 6 weeks will really decide it and I am very concerned about the Russian side.

22
Arctic sea ice / Re: The 2020 melting season
« on: May 26, 2020, 08:24:19 AM »
Close up of northern Bering Sea shows cool SST anomalies there for period May 15 to 21.

23
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 06:57:10 AM »
Sorry, laziness, theory is a shorter word to type.

24
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 05:38:51 AM »
Another thing to bear in mind is that temperature is a problematic indicator over the Arctic. As long as there is abundant sea ice, summer surface temps will be pinned to the ice melting point, while the ice might get thinner and thinner. Besides, the Arctic can get a lot of its melting energy directly from the 24-hour sun, with albedo and cloudiness playing an important mediating role in this process.

25
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 05:32:32 AM »
I have seen similar animations of sea ice export over past decades before I found my way to ASIF and acknowledge that ice export is a significant alternative means of transport. Instead of bringing heat to the ice, export transports ice to the heat. I certainly wouldn't rule out the possibility of massive export events leading to eventual BOE.
The point of these videos was not to highlight export but to show the prevailing movement of ice from Siberia towards the CAA, thus explaining why the remaining ice ends up bunched against Greenland, Ellesmere and the CAA in September, with no need for the DHACSOO mechanism of distance from heat advecting continents and shallow open ocean as an explanation. A mechanism which I believe is not a good explanation and will not protect the ice from further warming and more mobility.

Quote
In terms of attempting to prove whether the hypothesis is accurate, I don't have a vision of a classical research paradigm where i'm a principal investigator doing all the work and then presenting my findings for someone else to read.

I'm thinking more in terms of a classroom setting where everyone puts themselves in the role of investigator and putting out an idea for them to consider as we all watch the experiment unfold together.
This could happen if more people felt DHACSOO is a viable explanation and predictor. I am not sure that is the case. If you can't put in the time to quantify your own theory, I expect others, with less conviction than you, will not invest much effort either.
My own initial reaction was skeptical and I've given some reasons (back when this was presented in the "when ice free" thread). Now I see no reason to spend time and effort investigating a theory I haven't seen proof of and am not convinced of its viability.
For example, I believe the location of remaining ice at minimum is not exactly as described in the initial post of this thread, and that deep/shallow plays much less of role than other factors. However, were I to be shown convincing quantified proof of this, I might be more inclined to investigate further.

Quote
I suppose the hypothesis has two separate elements. One element pertains to the outcome (slower rate of progression than the previous linear assumption) and the other relates to the root cause (distance from NA / Asia and non-linear bathymetry). The outcome has the potential to smash the entire hypothesis if the ice moves much further into the Arctic this decade.

If the coming years do not show much further progression of ice loss, then we can be right about the outcome and still wrong about the root cause. In that case, it would be important to evaluate alternative hypotheses which propose to demonstrate that other factors are more important than distance from land based WAA and the transition to deep bathymetry.

I hope others will take these ideas as an invitation to offer their own ideas as to why the melting stops where it does at seasons end. It's an interesting topic.

I care more about the outcome than the root cause. If the ice holds up longer significantly longer than people think based upon completely different factors, I will be very happy. During the interim between now and when the future reveals itself, I'll suggest that there may be merit in promoting possibilities that give people reason to hope that sea ice disaster will be averted. The presence or absence of hope could potentially be a factor in the outcome.
Others have indeed, already, offered their own ideas as to why the melting stops where it does, and why a collapse to BOE is not imminent. But the root cause - and not the end result - is the interesting part. Otherwise we just wait until one year the end result is different. OTOH, a good root cause can be used for prediction, and can be checked against unfolding events.
For example, Chris Reynolds predicted winter volume in the Inner Basin to stabilize, once the long-term process of MYI replacement by FYI is finished, due to freezing season length being stable, FDDs decreasing only slowly, and the low marginal effect of added FDDs on FYI thickening. And with winter volume stable, summer declines should take place much more slowly than expected at the time. A much more convincing and quantified theory than DHACSOO, though with its own weaknesses, exposed during the winter of 2016/17 when freezing was much delayed and Inner Basin volume fell to a new low.
I fear your theory will not see much traction and discussion without a strong initial quantification of its merit.

26
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 25, 2020, 11:47:52 PM »
Some advice:
As background, take a few minutes to study the dynamic behavior of past melting seasons and movements of multi-year ice.





To corroborate the working theory, find a way to quantify where indeed is ice more likely to survive at the annual minimum. This can be done by gridded computing, by animation, by picking certain locations and manually counting the years (e.g. since 2007) in which they were ice covered, or even by using crude regional area and volume statistics . But not quantifying this at all makes the hypothesis into an assumption.

Also, read the Slow Transition thread from start to finish, very relevant. When Chris Reynolds came up with that theory he quantified a lot of its underlying assumptions and postulations. You can also read the posts on his old blog, DosBat.

27
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 25, 2020, 09:10:41 PM »
 Ah okay, so we are talking about an exponential decay in the rate of loss? I agree with this statement, I think many people do.

Im more curious about your DHACSOO. It can be quite difficult to collate data but were you to regress the average velocity/direction of wind coming off the coastlines versus the ice area for the adjacent sea, I think it could be quite interesting. Is the Siberian side terrible at the moment because of current conditions? Or pre-conditioning last year.

Lots to think on.

Occams razor for your working hypothesis is that the ice just follows the mean ocean surface current and accumulates north of the CAA.

28
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 25, 2020, 06:59:37 PM »
Cool stuff, I enjoyed the read.

Could you sum up your hypothesis in one or two sentences?

29
Arctic sea ice / Re: The 2020 melting season
« on: May 24, 2020, 02:45:30 AM »
      FWIW - Useful to clarify the question and frame of reference.  Phoenix puts more emphasis on conditions that affect the ice in the CAB and along the northern edge of the CAA that is considered likely to be the last to succumb to September melt.  Other folks generally refer to conditions for the Arctic overall. 

       So another question within the discussion is to what degree is the "last to go in September" ice isolated vs connected to conditions in the larger Arctic system.  For example, if the Kara Sea gets roasted early this year, as appears to be the case, how much does that affect the overall ASI September minimum?

30
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: May 23, 2020, 02:11:17 PM »
Baking,
You can't go too far back in time, it all happened abruptly and far from the Keystone, and what happened here in the past is not the cause, 12 days is already a long time.
To estimate the relative movements I had taken a point not far from the NE point of the Keystone (400m). I re-did the measurement directly at the point (it is more laborious) and I find the same distance between the NE point and P1 (clearly within the limits of the test).
Between the Keystone and b2 there was a mixture of ice, but perhaps now the Keystone and b2 were touching each other directly.
From all this we can deduce at most a certain Keystone action on b2 and that's it.
b2 was not at all in direct contact with P1, far from it, between the two a mélange of icebergs.
I absolutely do not understand how you can seriously consider a Keystone action on P1 of this magnitude and at this distance.
The fact that we do not understand exactly what is happening in the MIS should not push you to choose unfounded hypotheses, it is better to admit and leave the mystery that exists, while waiting for a decisive observation or an article that will enlighten us.

31
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: May 23, 2020, 12:45:56 PM »
The two images of the 22nd and the 23rd can't be well aligned, so I made an animation with the images of the 27th and the 23rd.
I highlighted the small piece, which came off the MIS together at the iceberg.
The fact that part of the ice mélange remained attached to it has already been highlighted by Blumenkraft
The cushioning mélange between b2 and the Keystone has dislocated...
In the next few days we will see where the mélange ice front will temporarily stabilize upstream.

32
Policy and solutions / Re: Batteries: Today's Energy Solution
« on: May 21, 2020, 09:37:34 PM »
Northvolt unveils its own Tesla Powerpack/Megapack competitor: Voltpack
Quote
Swedish startup Northvolt, who secured massive backing from VW, has unveiled its own stationary energy storage solution to compete with Tesla Powerpack and Megapack.

Northvolt is a battery startup founded by two former Tesla executives who worked on Tesla’s Gigafactory 1 in Nevada with Panasonic. The Swedish startup received investments from several companies, including Volkswagen, to build a massive battery factory in Sweden.

Volkswagen’s investment also came with the option to create a 50/50 joint-venture with the startup to build another battery factory to supply the automaker. The deal was finalized last year. The company is poised to replicate the success of Tesla Gigafactory Nevada in Europe to supply batteries for Volkswagen’s electric vehicles. But now we’ve learned that like Tesla, they also want to produce their own stationary energy storage products.

Northvolt is launching the ‘Voltpack Mobile System’, a new modular energy storage system in partnership with Vattenfall:

“Northvolt and Vattenfall today announced the launch of a new battery energy storage solution, Voltpack Mobile System – a rugged, highly modular lithium-ion battery system envisioned as a zero-emission alternative to replace diesel generators.”

The company is emphasizing its modular capability enabling quick deployment and mobility, but they are aiming at applications similar to other products on the market like Tesla’s Powerpack and Megapack, including “powering remote electricity grids, reinforcing weak grids, supporting electric vehicle charging and delivering grid services such as balancing power, flexibility, or other ancillary services.”
https://electrek.co/2020/05/20/northvolt-voltpack-tesla-powerpack-megapack-competitor/

33
Arctic sea ice / Re: Nullschool Forecasts
« on: May 21, 2020, 03:14:14 PM »
      FG  and others - when you comment on a benign or threatening forecast, please specify what it is you are referring to.  Otherwise, I may not be able to see what you are seeing, and I suspect neither do a lot of other people.  Sorry to nag, but this has happened a lot lately by various posters - noting something extreme or of supposed importance without specifying what it is. 

34
Consequences / Re: Floods
« on: May 20, 2020, 04:34:27 AM »
Dam failure in central Michigan (northern US) with another one imminent. Additional flood warnings for east central states.

https://www.upi.com/Top_News/US/2020/05/19/Edenville-Dam-breaks-sparking-immediate-evacuations-in-Michigan/9161589933323/

The Edenville Dam structure broke in Gladwin County, Mich., which sparked immediate evacuations in the area Tuesday evening. Now, the Sanford Dam that is downstream is at risk of failure.

Areas around Midland reported 3 inches to 4 inches of rain since Sunday, which produced a "tremendous" amount of runoff and is causing significant rises on the river system, the National Weather Service said.

The Tittabawassee River in Midland entered major flood stage Tuesday morning when the river was observed at 28.46 feet, according to a Midland County news release. The flood stage is 24 feet, and the river is expected to crest at 30.6 feet early Wednesday before levels start to subside over the next couple of days.

35
Consequences / Re: Floods
« on: May 20, 2020, 02:46:13 AM »
Dam failure in central Michigan (northern US) with another one imminent. Additional flood warnings for east central states.

36
Arctic sea ice / Re: The 2020 melting season
« on: May 19, 2020, 12:30:59 PM »
In the first half of May 2020 was lagging 2016 and 2019 in the High Arctic Albedo-Warming Potential indicator, which basically multiplies open water and latitude-based insolation (developed and calculated by Nico Sun). However, there's a long season ahead and the recent snow conditioning over wide parts of the High Arctic is much more important at this stage.

37
It's work from the Mosaic people, Stephan. Yes it would be nice to see more of this performance analysis.

As per request I did a comparison on 23rd/24th February, when Polarstern was nearest the pole (88.6 N).

Compared with the more recent comparison checks, the GFS performance wasnt that bad. Of the 17 checks, it never deviated by more than 2.5 C, and on 7 occasions differed from the Polarstern reading by only 1 C or less. 

Perhaps this was weather related, as the weather over this 48 hour period was quite similar with low pressure over Franz Josef Land steering stiff winds from a NE direction (winds were between 30 and 50 km/hr). 

38
Arctic sea ice / Re: The 2020 melting season
« on: May 17, 2020, 08:24:01 PM »
Ice drift map. We have the whole ice pack rotating clockwise.

39
Arctic sea ice / Re: River ice
« on: May 15, 2020, 11:47:10 PM »
The Siege of the North, May 15. The Yenisei River broke up ice in Dudinka. 21 days earlier compared to 2019. 6 days earlier than ever. Broken ice retreats to the Arctic Ocean. This reinforcement is not huge but it still requires energy to melt and keeps water cold. Sometimes the river delivered high quality 1.5...2 meter thick ice. 10+ meter high mountains was built and destroyed and built again in just seconds. This year the ice looks much thinner.


40
Arctic sea ice / Re: River ice
« on: May 13, 2020, 10:00:01 PM »
A movement of ice in Dudinka. The biggest Arctic river finally wakes up there. Breakup is expected in 1-2 days.

41
Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 06:31:16 AM »
The GFS is probably too warm.

I appreciate your concurrence.

The purpose of my posts are to provide less informed readers some guidance not to put too much faith in the accuracy of GFS forecasts being provided here and on the data thread. Seems you agree that these forecasts are overstating temperatures.

Yeah it's always done that.


42
Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 03:58:43 AM »
Well a large part of the basin is sunny but near the pole and at times the Beaufort sea its cloudier, I don't think that is unusual in itself especially with high pressure in charge.

Obviously what is unusual is just how high the pressure is in this high(around 1045MB) and the 'warm' air for the time of year that is inside it, if albeit the cavet the GFS 2M temps may be overdoing it somewhat basing on other discussions on here.

Indications from the model this high will transfer towards the ESS/Laptev and may finally weaken and a fairly slack set up may occur. The coldest conditions likely to be in the Beaufort sea and ice drifting along the Beaufort Gyre may slow down also and it may start covering any open water there. Either way, I'll be very surprised if we see a repeat of last year in the Beaufort and it will be all eyes on the ESS.

I also think it's too simple saying high pressure is bad for the ice and low pressure is good for the ice, I think the issue with this high for me is that the air has warmed up to above average levels for the time of year and its at lower latitudes of the basin so sunshine damage may play more a part than if the high was over the pole itself.

43
Arctic sea ice / Re: The 2020 melting season
« on: May 12, 2020, 10:39:01 PM »
Edit: Uniquorn just posted a video of this years freezing season, and it clearly shows the counterclockwise movement I was talking about.
https://forum.arctic-sea-ice.net/index.php/topic,2417.msg263883.html#msg263883
Well let's just leave it that I don't agree with your interpretation of that animation. :)

44
Arctic sea ice / Re: 2020 Melting Season Predictions
« on: May 12, 2020, 07:26:06 PM »
Some fairly unimpressive losses in the past month have made me think my 4.0sqMm prediction was a bit on the low side...

Going by NSIDC 1981-2010 median data, July and June are the two biggest melt months (for extent).

It's only beginning now. A long way to go yet. :)

45
Arctic sea ice / Re: The 2020 melting season
« on: May 12, 2020, 09:08:06 AM »
A year ago to the day, there was forecasted high pressure that resulted in some interesting analysis. Take a look at the 2019 melting season thread from 5/12/19 through about 5/21/19: https://forum.arctic-sea-ice.net/index.php/topic,2591.800.html

46
Ahh yes, I had to revive this thread as it's one of my favorites.

BEHOLD!!

47
Arctic sea ice / Re: The 2020 melting season
« on: May 11, 2020, 12:32:55 PM »
For temperatures at 2 metres, I have not found the GFS to be particularly accurate across the Arctic basin. These are modelled temperatures and it tends sometimes to err on the positive side. (sometimes too it can go the other way).

Real data is sparse. We do have the Polarstern reporting currently at 83.5 N 13.1 E

Its temperature at 9UTC today was -13.4 C. Using Nullschool, the GFS model is showing a temperature of -9.3 C for same time/location. 

850hPa temps are useful to help show the expected air mass moving in. But it should always be remembered that these are temps at circa 1500 metres, way above the ice.

The Arctic is well known for temperature inversions (as mentioned already by BFTV). Fog/mist and stratus can often form over the surface of the ice keeping temps there cool when the sun is shining only a short distance higher up.



I think this low pressure in the Fram Strait on Wednesday will be very significant for ice export. NE coast of Greenland is expected to be battered by north winds gusting to 120 km/hr, extending well down the Fram.   

48
Arctic sea ice / Re: The 2020 melting season
« on: May 08, 2020, 10:38:20 PM »
...
Thus, CryoSat-2 thicknesses stop at April 30 and SMOS (respectively CryoSat-2/SMOS) thicknesses stop at April 15.

No.



The SMOS product (ex University Hamburg, now AWI) that goes into CryoSat-2/SMOS stops at April 15.

49
Arctic sea ice / Re: The 2020 melting season
« on: May 08, 2020, 10:30:07 PM »
...
Thus, CryoSat-2 thicknesses stop at April 30 and SMOS (respectively CryoSat-2/SMOS) thicknesses stop at April 15.
No.
Please read....https://seaice.uni-bremen.de/thin-ice-thickness/
Quote
Thin sea ice occurs during the freezing season. In the melting season, the thickness of sea ice is highly variable and the emission properties in the microwave change due to the wetness of the surface and occurrence of melt ponds in the Arctic. Therefore, thickness data are calculated only during the freezing season, that is from October to April in the Arctic and from March to September in the Antarctic. During the melting season, the procedure does not yield meaningful results.
uni-bremen are kind enough to continue to provide the service as other information may be inferred from the data...at the user's discretion

50
Arctic sea ice / Re: The 2020 melting season
« on: May 08, 2020, 08:24:06 PM »
Will you tolerate this thread saying "there are no melt ponds in April" and also saying "no data from CryoSat-2 for 2nd half of April because meltponds confuse sensors"?

There are two separate issues here as the CryoSat-2/SMOS thickness/volume is based on two different sensor types.

CryoSat-2 (radar altimetry): It is common practice to not compute thickness in the Arctic beyond April, since the snow will get wet in May which causes extinction of the radar waves. Open melt ponds that form later are a different issue.

SMOS (L-Band radiometry): Here, the method of thin-ice thickness estimation is based (in essence) on the temperatur difference between the sea water and the ice surface. And this difference can get too small at already in the end of April for reliable ice thickness estimates.

Thus, CryoSat-2 thicknesses stop at April 30 and SMOS (respectively CryoSat-2/SMOS) thicknesses stop at April 15.

Cheers, Stefan

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