Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - crandles

Pages: [1]
1
Arctic sea ice / Re: Latest PIOMAS update (March mid-monthly update)
« on: March 19, 2019, 11:42:32 AM »
Volume and volume-anomaly graphs.

2
Policy and solutions / Re: Tesla glory/failure
« on: February 25, 2019, 02:11:46 AM »

Best of all, Tesla claims to have well over a billion miles worth of data put into their "learning neural network", yet they do not have FSD. How is the next billion miles supposed to provide the breakthrough that the first billion could not?!? The whole concept is silly.

it's a pitty somehow, you post many things that make a lot of sense, often are simple facts for those who know but will never convince those who prefer "believe" over kowledge and then you make one or two angry errors that destroy credibility and ammunitions you opponents, so you feed them, this time you made it even "best of all"

what i'm referring to ist that:

yes leve 5 which is the only FSD that counts as such is far away and will probably be first implemented by another company than tesla, i have good reason/insight to say so but beside that
you say that more mileage of data gathering won't make a difference and that's unfortunately wrong, simply wrong, no buts and nothing, because no matter when FSD will be ready for consumers, latest on that very day each mile of data gathered throughout the previous years counts.

if only you guys, both sides, would be more open to the other sides reasoning and discuss instead of preaching what was already said and what's already obvious each from his point of view.

the truth like so often lays somewhere in between the extremes. why not honor what tesla/musk does and did well and criticise what's going wrong?

you have so many good point, just try to keep it cool or let the believers waste their life energy into illusions. after all we have almost proof that there is no god (old man with the beard who speaks from clouds) and there will still be no way to convince the pope or any other believer who commited 90% of his life to his religion/believes.

what i found funny or in fact not so funny is that after you came up with some insight (for others with insight the insight is visible, for those without insight it's just another blabla... LOL) and in reply to your post there were guys statin that there are no people with economic knowledge and insight.

i can tell you there are, it's just not recommended to come up here with real names but some would probably be surprised to whom they're talking and some people here, i can tell for sure, have degrees, experience in economics and decent to high positions in large enterprises.

like a weatherman will recognize a weatherman, a studied economist will recognize another expert of his own field.

3
Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: February 24, 2019, 12:28:14 PM »
Oh my god, someone has created AI bots with multiple names like Zizek, GoSouthYoungins, Lurk ... just not sure whether funded by Tesla shorts or by FF interests trying to ruin the signal to noise ratio here on Neven's blog by posts and by deliberate flailing wind up attempts.

How is this sort of post contributing anything?

No I don't really think so, but it feels like it sometimes.

Now how can I be as nasty, as dismissive, as big a liar, as delusional, as presumptuous, as rude, as insulting and as abusive as this poster has just been without getting my comment edited or deleted? Let me think about that a while and I'll get back to you.

Crandles was being sarcastic, holding up a mirror to zizek.

Look, I don't mind the anger, it's understandable, but short comments containing snark only (like zizek's comment that started this shit avalanche, though containing a pearl of peace by Bruce), is a waste of everyone's time and thus a sure way to moderation.

4
Antarctica / Re: Latest GIOMAS/PIOMAS volume data for Antarctica
« on: February 12, 2019, 07:31:27 PM »
Animated GIOMAS Antarctic sea ice thickness, the first forty years...

5
Arctic sea ice / Re: AMSR2 Sea Ice Volume/Thickness
« on: December 09, 2018, 01:56:15 AM »
I've been brooding over PIOMAS volume data the last 3 days, following some discussion elsewhere about trends vs "weather" and the kind.

I'm staring here as I write at 4 graphs I derived from the PIOMAS data downloaded from the U.of Washington Polar Science center.  I'm pondering what it implies about past changes in the Arctic and what import it has for the future.

Let me back up for a moment and describe what I've done first, and why.

There's been a lot of discussion on the Arctic forums recently around three dimensions we use to evaluate Arctic system health.

In our discussions and arguments we've wrestled with the reality that two of those measures - extent and area, particularly as they appear at the end of melt season - have become increasingly difficult to evaluate to make a skillful determination of how the Arctic will look in a few years. Our discussion has shifted and expanded now to where over the last two years there has been much more tracking and examination of the annual refreeze.  This has given us some hints and generated quite a few more questions.

Roll back to what I'm doing now.  I'm using PIOMAS daily volume data going back to 1979 (http://psc.apl.uw.edu/data/)

My analysis is more empirical than theoretical.  At this moment I'm less interested in prediction than I am the data set.  I have a particular interest in volume as well. Unlike extent and area, it represents a far better proxy for key forces at work in the Arctic - heat exchange and total system enthalpy.

My second purpose is contrast volume changes with changes that have taken place during the time period in question and see if a pattern appears which follows or is affected by them.

Methods:

Simply digesting a raw and fairly substantial pile of data is unlikely to produce anything useful.  However, I don't want to fall into the trap of over-analyzing the information - while it is good to reduce "noise", over-processing values can remove meaningful signals it contains.  My approach to this is three fold.

1) Create a sample average from a meaningful but more controllable time frame.

Most analysis of this data has been around extreme endpoints in annual variation - the annual maximum extent/area/volume and corresponding minimum - which land on arbitrary dates and are very narrow samples.  For my work here, I've picked to arbitrary but significant dates March 21 (Day 80/81 of each year) and September 21 (Day 260/262).  I then averaged the daily volume for a time frame window which extends from two weeks before until two weeks after those dates to get what I call "Vernal" and "Autumnal" volume numbers for those dates.

My logic in doing this is this: Rather than use a metric which is volatile and fundamentally disconnected from other forces in play at the time they take place (annual minimum/maximum), I wanted to anchor the analysis to two specific points in them where we know predictable and measurable changes are taking place (the Spring and Fall equinoxes).  Further, to make the new metric sensitive to conditions during the specific year and season, rather than simply pluck out one number, an average over a near-term time frame would better incorporate and smooth other signals from forces in play at the time.

In addition to these two numbers, I also created a baseline value for tracking behavior on a broader time scale.  In this case, I created an annual average for each year, summarizing all volume measurements from January 1 to December 31 for each year in question.

2) Create a derivative average which further smooths the Vernal and Autumnal numbers over a wider time frame. 

In this case, I created a second data set from my spring and fall averages, starting with 1983, which is a simple 5 year running average of those numbers.  The goal here is to round off peaks and valleys without losing all of the signal they contain, and hopefully permit underlying trends to be more visible, and more importantly, better identify transitions in system behavior.

3) Create a third derivative/index to show system volatility.

At the start, these were actually the numbers I was most interested in. We've discussed this some on the forums, but the summary of my thought here is, this, and also may qualify as a hypothesis:  As the Arctic as a system approaches behavioral limits, the volatility of the system - the relative change against base values - will increase.

Again keeping it simple, I created three values for each year in question.  These were (a) The absolute difference between Vernal and Autumnal values (b) the Percent that value represented of the Vernal volume and (c) the Percent that value represented of the Annual volume as derived in (1) above.  I did this for both the raw and 5 year running averages of Vernal, Autumnal and Annual values.

Note: all values I used were rounded up to three decimals. I figured the significance of fractional cubic KM of ice were meaningless based on the confidence of the measurements.

Findings:

From raw data and graphic analysis by Jim Pettit, Zach Labe and many others it's already clear that sea ice volume has been declining steadily over the time period in question.  What isn't necessarily clear is the nuances of how those changes have taken place.

Both the smooth and averaged data clearly shows this trend. No surprises (nor were any expected).

However, annual seasonal loss has shown only a very modest increase - less than 10% over all - with an average of 14.242K KM3, median of 14.034K KM3 and deviation of 1.164K KM3.  Breaking the loss dataset in half shows the 2nd half loss rate only increasing by about 1000KM3, and 2nd half loss volatility actually declined slightly. The 5 year running averages are correspondingly closer.  This suggests strongly that large year to year variations in melt are not significant contributors to the reduction in volume over the period measured.

The first think that jumped out at me in particular in the averaged data, is I think I'm seeing two historical locations where I think there's a signal identifying a fundamental change in how the system behaves.  The first is in the 1990-1994 time frame. There I think spring, fall and yearly average graphs start a break in slope, falling into the glide path that takes us down hill to where we are now.  I'm not sure what the specific conditions were at the time, or, considering hysteresis, how far back we need to look for the trigger, but it strikes me that is a specific place in time and space we can point at where the system signals a change has taken place.

The second was the 2010-2013 time frame.  in that range all three measures - Annual average, spring and fall - flatten out.  As another interesting and possibly key item, annual loss intersects and then starts to follow the annual average curve.  I'm not sure what this means yet, but it sure looks like a strong signal.  Also, while the three major curves flatten, the *vernal* curve is still trending down.  I think the running 5 year equinox graph shows this the best.

My general take away - I think the graphs support another of my thoughts - that as the total energy available to the system increases (reduced ice), the overall volatility of its metrics will increase - especially area and extent - which actually are more derivative of this than volume.

I'll be interested to hear what other folks think.  If someone can point me in the right direction, I'll post the spreadsheet with my raw numbers someplace for people to tear apart.

 (P.S. - the average volume will be off a bit for 2018 as we haven't finished the year.  That said, we are far enough along it that the relative change is small enough to be negligible to my analysis.)

6
Antarctica / Re: PIG has calved
« on: November 13, 2018, 06:34:30 AM »
All,

Due to Neven's management style in this forum I have decided to stop posting here,

Sayonara,
ASLR


Did Neven lost his temper for once in 5 years? Well, he is human, like the rest of us.
I want to thank Neven for all the effort on this Forum and on the ASIB. And I want to thank AbruptSLR for the same reason. It is happening to several of us. Just a lot of psycological pressure, with all that it is happening on climate change and feeling that the governments are not reacting well enough. So, thank you both.

AbruptSLR, I will ask you to reconsider your decision. Hope to see you around here soon!

7
Science / Re: 2018 Mauna Loa CO2 levels
« on: November 02, 2018, 05:56:19 AM »
I calculated 406.10 ppm for October.  That's a year-over-year change 2.47 ppm.  That's the highest monthly growth rate since August 2017.  Pretty clear we've passed the cyclical bottom(typically ENSO related).  I will update graph when official numbers come down.

8
Antarctica / Re: PIG has calved
« on: October 29, 2018, 12:10:12 PM »
Yes it calved again. Sentinel 1 images, medium resolution (EW=40m/pix scaled to 80m/pix).

9
Antarctica / Re: PIG has calved
« on: October 25, 2018, 04:55:12 PM »
Three image (60m/pix) animation, showing the developments in the cracking field.

10
Arctic sea ice / Re: Latest PIOMAS update (October)
« on: October 06, 2018, 06:12:05 PM »
So extrapolating data up to 2010, it was 5 years ahead and extrapolating data up to 2018, it was 6 years ahead

Indeed, the exponential extrapolation for the September PIOMAS minimum has been basically stuck at "ice free in (approximately) 5 years".  Gompertz follows a similar path but is a bit further in the future.  And the end date for the linear extrapolation decreased in the 2000s but didn't change much in the 2010s.



11
Arctic sea ice / Re: Latest PIOMAS update (October)
« on: October 04, 2018, 10:58:35 AM »
Latest thickness map, compared with previous years and their diff's.
Click for big size.

12
Arctic sea ice / Re: Latest PIOMAS update (October)
« on: October 04, 2018, 09:18:05 AM »
The 2018 minimum is now available, that means some old graphs focusing on extrapolating the future volume data have been updated as well.

Here is the graph with different curve fittings. Compared with a year ago, most extrapolations to "zero ice" have also advanced by about a year. Extrapolating the extrapolations gives zero ice at infinity.

13
Arctic sea ice / Re: Latest PIOMAS update (September mid-monthly update)
« on: September 24, 2018, 09:41:10 AM »
The PIOMAS gridded thickness data was updated, last day available is 15 September.
Volume calculated from the thickness gives 5.00 [1000km3]. On that day volume still decreasing, so the minimum may not have been reached yet.

Attached are the daily volume and volume-anomaly graphs.



14
Policy and solutions / Re: Batteries: Today's Energy Solution
« on: September 11, 2018, 07:36:31 PM »
Solid-state battery startup secures backing from several automakers as it claims breakthrough for electric vehicles
Quote
Several automakers interested in electric vehicles are turning to solid-state batteries for next-gen electric cars in the “post Li-ion era.”

Now a startup developing all solid-state batteries (ASSB) secured backing from several high-profile investors, including several automakers, as it claims a breakthrough for the technology that will enable better electric cars.

Solid Power is a Colorado-based startup that spun out of a battery research program at the University of Colorado Boulder.

The company claims to have achieved a breakthrough by incorporating a high-capacity lithium metal anode in lithium batteries – creating a solid-state cell with an energy capacity “2-3X higher” than conventional lithium-ion.
https://electrek.co/2018/09/11/solid-state-battery-startup-bmw-hyundai-samsung-breakthrough-electric-vehicles/

lSolid-state batteries are thought to be a lot safer than common li-ion cells and could have more potential for higher energy density, but they also have limitations like temperature ranges and electrode current density. Not to mention we have yet to see a company capable of producing them at large-scale and at an attractive price point competitive with li-ion.”

15
Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: September 09, 2018, 04:40:51 PM »
Quote
All I see 
I guess seeing is in the eyes of the beholder. I see Tesla as highly innovative, implying a very strong drive to "thinking out of the box". Small example- when everyone thought the Tesla Semi was impossible due to range/battery weight, Tesla designed it with the drag coefficient of a sports car, changing the problem parameters significantly
Though OT for this thread, I do see the same in SpaceX (rockets landing back, very low launch costs), and maybe in the Boring company as well. I believe the common denominator of these companies is Musk, and that his approach to innovation can find solutions to problems previously considered impossible. Hence my belief that he makes very important contributions to Tesla, though he also seems to make quite a few errors as well.
But to only see the tweets and the interviews, to see nothing of the output of the companies he founded and has been leading, and to assume that the rest of his unseen time is spent being totally useless, that takes a very strong filter.

16
Science / Re: 2018 Mauna Loa CO2 levels
« on: September 06, 2018, 06:02:24 AM »
August came in at 406.99 ppm.  1.92 ppm year-over-year change.  The running 12-month growth rate is at its lowest level since 2012.  Rates didn't take off until ~October 2015 so impacts from ENSO are still a month or 2 away.

17
Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: August 17, 2018, 04:35:50 PM »
It is not that their opinions differ from mine. It is an unconditional disregard for all evidence on one side of the spectrum. It is a total dismissal of anything anti-Tesla. It's the equivalent of telling someone "you are stupid that you think GHGs matter. all heat comes from the sun, and the sun is getting less bright. we need the sun to survive. you are an enemy of humanity." or "CO2 is plant food. we need plants to survive. we can't feed 8 billion ppl without a lot of CO2 in the air. you are an enemy of humanity."

When the mainstream media is leading with stories about Telsa, but they are disregarded in this forum cuz it has negative implications for Tesla, that's fanboy behavior. Yes, it is hyperbole to say there is a 0% chance of profitability, but yikes things don't look good. If it all works, I'll happily admit I was wrong. However, I have a fundamental problem with Tesla. I believe they suck in a lot climate activism energy to a project that promises no compromises, perfect solution. We need to realize that our way of life needs to change, not just whats "under the hood". Tesla prevents that change by claiming to have an immaculate solution. A Tesla is nothing more than a rich persons way to feel better about themselves without having to make any sacrifices.

This entire thread from beginning till end has been tesla drones deflecting any criticism of musk and tesla as fud, lies, oil & gas lobbyist.  The critics have been attacked relentlessly. And now that everything is unraveling, and everything we've said is true, we still have to give musk and tesla the benifit of the doubt?
Defending musk is no longer about facts and data. It's grown into an unhealthy obsession. Everyone with some common sense needs to give it up.

Here is what it looks like to someone else on this thread:
It is not that their opinions differ from mine. It is an unconditional disregard for all evidence on one side of the spectrum. It is a total dismissal of anything pro-Tesla. It's the equivalent of telling someone "you are stupid and gullible because you see things differently".
When the mainstream media is full of negative stories about Telsa, lots of these coming from people with a financial interest in Tesla's failure (shorts, lawyers suing, companies who stand to lose big time if Tesla succeeds in its economic disruption) and they are posted in this forum as objective analysis, while positive stories are ignored cuz they has positive implications for Tesla, that's haters behavior.

And:
This later part of this thread has been full of anti-tesla drones deflecting any positive opinions and news of musk and tesla as lies, fraud and fanboy and mainstream media fawning.  The critics have attacked relentlessly. And now that the company is managing to deliver lots of cars and approaching profitability, they baselessly claim everything is unraveling, and everything they've said is true.
Attacking musk is often no longer about facts and data. It's grown into an unhealthy obsession.



I think it would be best for all to stop the snark and disrespect, and just discuss facts and objective opinions without hitting anyone on the head with a hammer and without attaching any labels to any poster. There's clearly a great divide between those who believe Tesla, wholly or partially, and those who disbelieve anything coming out of the company. Posting about it ad nauseum is not going to convince or help anyone. Why not wait 6-12 months and see where the actual developments take Tesla, Musk and all that bunch?

18
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 04, 2018, 12:44:24 PM »
Thickness map of 31 July, compared with previous years.

19
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 04, 2018, 12:11:24 PM »
Here are the updated volume and volume-anomaly graphs (with volume in July 2018 calculated from thickness).

21
Arctic sea ice / Re: Land snow cover effect on sea ice
« on: July 07, 2018, 07:26:10 PM »
As a result, prediction for Sept 2018 September sea ice extent is quite high at 5.19 km2, with a standard deviation of 340 k km2.

I tried to reproduce your calculation, using the Rutgers and NSIDC data for June.  I reproduced your prediction of 5.19 M km2 for the September 2018 NSIDC extent.  But for the standard error of the regression, I calculated 0.38 M km2 rather than 0.34 M km2.

I guess you calculated the standard deviation of the residuals like this:


where e1, e2, ..., en are the residuals and you use n=26 years of data.

However, for the standard error of the regression, this formula should be replaced by



where k is the number of parameters in your regression model.

For a simple linear regression, k=2  because there are 2 parameters: the slope and intercept of the regression line.

In your case, k=4  because your regression model has 4 parameters: one parameter for each of your 3 predictor variables (area, extent and snow cover) and one intercept parameter.

That gives me a regression standard error of 0.38 M km2 for your model.

22
Policy and solutions / Re: Batteries: Today's Energy Solution
« on: June 22, 2018, 10:00:22 PM »
+1 for Bob’s and numerobis’ comments.

Musk has indeed said the world only needs about 100 gigafactories to get completely off fossil fuels.  Tesla will be building three more (China, Europe, North America, with new car factories) in the next few years.  Battery recycling will definitely become a thing; as Musk has said, you have your ingredients right there, why go to the expense of mining more?  Early batteries no longer performing well enough to power a vehicle are being used in stationary storage products by several automakers.

Battery technology — and battery management software — keeps improving, meaning less battery materials are needed to build a battery, and smaller batteries will perform as well as bigger batteries did just a few years ago.  Tesla has already reduced the amount of cobalt in its batteries from 8% to about 2%.

Degradation of newer, thermally-managed battery packs looks quite low, and we see estimates of batteries lasting 500,000 miles.  Tesloop has a Model X running daily shuttles with over 300,000 miles on the original battery.
https://twitter.com/tesloop/status/1002641861842853888

It is unwise to assume the world will need to replace ICE vehicles with EVs on a one-to-one basis.

Model 3 Battery: the most energy dense pack in the industry. We do the math to confirm.
https://insideevs.com/new-tesla-model-3-battery-details-images-released/

Tesla battery degradation at less than 10% after over 160,000 miles, according to latest data
https://electrek.co/2018/04/14/tesla-battery-degradation-data/

Tesla battery data shows path to over 500,000 miles on a single pack
https://electrek.co/2016/11/01/tesla-battery-degradation/

23
Consequences / Re: Global Surface Air Temperatures
« on: June 21, 2018, 03:25:35 AM »
The image just provided uses Fahrenheit while the one above it uses Celsius.

24
Arctic sea ice / Re: How soon could we go ice free?
« on: June 18, 2018, 12:25:28 PM »
I think Figure 1 from Tietsche et al 2011 is important.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL045698

This shows two things - firstly, the general shape of the (modelled) decline in Arctic ice over the coming decades, and secondly the time taken to recover from extreme events such as the summers of 2007 and 2012.

For the latter, the conclusion is quite simple - the Arctic has a "memory" of about two years, and so any major excursion will bounce back to the long-term trendline within a couple of years.  They only modelled downward excursions, but my guess is that it holds the other way too - even if by chance we have a particularly good year for ice retention, it'll be gone in another couple of years.  The paper discusses the mechanisms for this, but fundamentally it's quite simple - if you have a massive loss of ice one autumn, that means a correspondingly massive extra heat loss in the following winter.  By the end of spring, first year ice has grown back. A low summer minimum has very little effect on the following maximum.  This is believable, and we've seen it after every major loss year for more than a decade now.

For the longer term decline, look at the shape of the curve.  Note how it's staggered and stepped.  This reflects the shape of the Arctic ice basin. There are shallow seas around the edge, and a deep central portion that covers about 5 million square km. So, as ice loss progresses, there's an initial period of rapid decline that plateaus at around 4.5 to 5 million until about 2020.  That's exactly where we are now, in that plateau, where the summer minimum roughly covers the deep parts of the Arctic Ocean but the peripheral seas melt out each summer. Subsequently, there's another period of rapid decline that plateaus again at 1.5-2 million.  This is the "remnant above Greenland" stage.  The final collapse comes after that.

The shape looks entirely plausible to me, all that we need to work out is the scaling on the X axis, and to be honest I'd be surprised if they're far off. Right now we're on the verge of the second period of decline - but it'll plateau again in another couple of decades, probably before hitting the "ice free" threshold of 1 million.

It may be we need to squash the X axis up by 10% or so to fit reality - someone with more time than I can probably make an overlay - but it's really not far off.

25
Arctic sea ice / Re: Svalbard
« on: June 08, 2018, 03:14:24 AM »
The polar bear made it out of that window?! No way!  ???

Well, when you're trying to skip out on the hotel bill, motivation can work wonders.  I hear the charges were un-bearable.

26
Permafrost / Re: Northern Hemisphere snow cover
« on: June 06, 2018, 08:19:42 AM »
Most of you know that I am using Northern Hemisphere snow cover in spring and summer as a predictor for the September minimum. Here is a guest post on ASIB of my method :
http://neven1.typepad.com/blog/2013/07/problematic-predictions-2.html

This method of prediction works really well for June data, but even for May data it has some skill.

Now that Rutgers Snow lab published the Northern Hemisphere snow cover for May (see attached picture), I ran my regression formula on the 1992-2015 training period, using May data for snow cover, ice concentration and ice area, and arrived at a prediction for September sea ice extent minimum of 4.84 M km2.

This number makes sense, since snow cover in May was still fairly high (compared to the previous 10 years), and even though sea ice extent in May was at a record low, sea ice area is actually just 3rd or 4rth lowest. This means the ice pack is still fairly 'compact' which reduces the amount of heat the ice pack will absorb from the ever higher sun in the Arctic.

Standard deviation over the prediction is 460 k km2, which is substantially better than a linear decline as a predictor (which has a standard deviation of about 550 k km2).

So the method has some skill with May data, but for an accurate prediction, please wait for the start of July, when the June data is in, since that has real skill with about 300 k km2 standard deviation.

Until then, the prediction of 4.84 M km2 stands.

[edit] I will submit my prediction to the SIPN this year again :
https://www.arcus.org/sipn

27
Arctic sea ice / Re: Latest PIOMAS update (June)
« on: June 03, 2018, 08:34:05 PM »
Updated volume and volume-anomaly graphs.

28
Arctic sea ice / Re: Latest PIOMAS update (May mid-monthly update)
« on: May 21, 2018, 06:46:16 PM »
Updated daily volume and volume-anomaly graphs.

29
The forum / Re: Comments/posts can be liked now
« on: May 12, 2018, 02:44:09 PM »
That's something I can fix, crandles! And I'm also seeing the Like button now.

So, it's back to square one.

30
Jacobshavn during the dark season in 16 Sentinel 1B images.

Pages: [1]