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Arctic sea ice / Re: Freeform season chatter and light commentary

« on: June 19, 2019, 03:36:23 PM »

It gets a bit annoying when a forum read regularly by hundreds of people suddenly becomes the private chat room of a few newbies.

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Arctic sea ice / Re: Freeform season chatter and light commentary

« on: June 19, 2019, 03:30:37 PM »

What is the world coming to?

I asked kindly, others did the same. But you feel treated unjustly so badly when asked to stop.

That's not a problem with us, it's a problem in your head.

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Arctic sea ice / Re: Do we make too much of 2012 ?

« on: June 07, 2019, 08:12:12 AM »

For how i understand it, the problem with volume measurement is that it is widely believed to be unreliable.

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Arctic sea ice / Re: The 2019 melting season

« on: April 21, 2019, 11:05:07 PM »

Yikes!

8 days from now. Please, try to emphasize when you post forecasts beyond 6 days, because they're unreliable, and the writing on that map is small.

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Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask

« on: January 19, 2019, 12:57:17 PM »

If ppm of C02 are increasing in the atmosphere, that must mean ppm of something else is declining. What other atmospheric gas is declining as CO2 increases, and does this need for something else to decline at all effect the rate of growth of CO2 ppm in the atmosphere?

Carbon in fossil fuels are burned(oxidised) to create CO2, so it is O2 in atmosphere that is declining. The effect on O2 in the atmosphere is negligible:

CO2  280 ppm  -> 410ppm (46% change)
O2 209590ppm -> 209460ppm (0.06% change i.e. you experience more effect of less oxygen at top of small hill than at bottom)

Obviously this change in O2 hardly makes any difference to the ability to burn fossil fuels.

Edit ppm typos

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Arctic sea ice / Re: 2019 sea ice area and extent data

« on: January 15, 2019, 10:00:25 PM »

So, if we have the new temperatures for 30 years, some could say that the climate (on average) is the same, even that the weather is not.

Per Tamino, in his January 2nd post on 'What is Climate? Really?',
climate is not ever "just the average."

Climate is the probability density function of weather.

The catchy way I like to say it is:

Climate is the odds. Weather is the roll of the dice.

And the odds in January are never the same as the odds in July.

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Arctic sea ice / Re: Arctic sea ice changes: Natural variation vs human influence

« on: November 10, 2018, 03:27:26 PM »

The fingerprint is the particular pressure pattern in the Arctic summer in high loss years and the weather patterns that connect it to particular temperature variations in the Pacific. The same pattern is seen in the control run, and the historically forced runs and the data. 

To be clear, FTA:

The mechanisms of this teleconnection appear to be similar in observations and models, but the specific source areas and path of wave activity underlying the establishment of the high pressure in the Arctic are displaced in the model.

That important caveat, combined with the failure of most of the model runs to account for the Arctic loses tell me that

The internal variability isn't the difference between the historical data and the ensemble mean, its the spread of the ensemble. Look at the band of grey lines in 1e. The internal variability is the difference between the top of that band and the bottom of that band.

To me this says that if the Models are sufficiently accurate representations of the system, then the variability is given by the spread of the models. The problem is that the models have significant difference with observations. They are not sufficiently good representations of the system. I think the paper does a fantastic job illustrating the big differences between the models and the observations. Fig. 4 is particularly interesting.

There's not enough historic data to pull the variability from it alone. That's one of the key points from this paper. In 30 years time it might be possible to assess the variability from the historic data, but the record is still too short to properly characterize the climate.

I agree with that. There is statistical uncertainty due to the short record. Luckily, mathematical statistics are not the only tool we have to inform our decision making process. We have physics that dictate that the warming will continue and will increase. There is every reason to believe that "internal variability" will vary as the climate changes.

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Arctic sea ice / Re: The 2018/2019 freezing season

« on: October 21, 2018, 07:15:36 PM »

Yes. We need more data. I am sure there is enough information and speculation in this thread to design a really good experiment. Now we just need someone to get the grant to do the research! It's really interesting that the one observation we have is so at odds from what one expects from simple thermodynamics.

It might be that a good model that fits observations will be widely applicable, and possibly give us more insight as to just how downwelling IR affects the freezing of the Arctic.

ps. I repressed how science funding works: Build the model, get the results, and then perhaps get a grant to do the work.

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Arctic sea ice / Re: The 2018/2019 freezing season

« on: October 14, 2018, 02:17:53 AM »

The shift the past six years is the difference in 20C worth of monthly temps in some months for many regions.

Can you give some examples? This strikes me as quite hyperbolic.

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Arctic sea ice / Re: Arctic Image of the Day

« on: September 15, 2018, 03:29:23 PM »

Icesat-2 launched this morning, a video of the launch can be seen on NASA TV.
https://www.nasa.gov/nasalive

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Arctic sea ice / Re: The 2018 melting season

« on: September 04, 2018, 07:30:22 PM »

The sun is less than 7.5arcdeg above the horizon at the North Pole & will be just over a trace above 7arcdeg tomorrow. Almost all direct Total Solar Irradiation (which has been at sub-normal levels for 12+ years) is being reflected back to space & no direct solar energy will soon be the Arctic norm. Already, Arctic temperatures above the 80th parallel have fallen ~ 3degC. from summertime high temperatures. Despite 12 years of sub-standard TSI, Arctic temperatures above the 80th parallel average temperatures are 1+ degC above normal..... above the norm & well above the norm, increasingly the "norm" for the 21st century fall, winter & early spring seasons.

Solar Energy is One Thing. Arctic Amplification through Ocean Currents & Atmospheric Convection will still make some spikes.

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Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask

« on: August 22, 2018, 02:08:57 PM »

There is a line of denier argument that I often hear, it goes something like: the extra warmth means more ice is lost allowing that heat to be radiated to space thus cooling things down. To which I can't help but respond with: so warming leads to cooling? But its still warmer.

That kind of situation sounds self-contradictory, but it's actually quite common in environmental systems. 

Say you have one unit of warming that is externally forced. 

A negative feedback will partially counter that forcing.  Maybe the negative feedback is a multiplier of -0.2.  That reduces the warming to 0.8.  But this lower warming makes the negative feedback weaker, so it adds back 0.04 (-0.2 * -0.2) of warming.  Another iteration of the negative feedback reduces it by -0.008 (-0.2 * -0.2 * -0.2).  After an infinite number of iterations, the initial warming settles in at 0.833333 units:



So the negative feedback has reduced the amount of warming, but it hasn't caused actual cooling, just a reduction in the warming.

A positive feedback will have the opposite effect.  It will amplify the initial warming, and will also amplify itself.  For example, a positive feedback that is a multiplier of +0.2 will increase the initial warming to 1.2 units, then will amplify itself to add another +0.04 units, and another +0.008 units, etc.  Eventually, the warming will approach a limit of +1.25 units:



So the negative feedback reduced the warming, and the positive feedback amplified it. 

People often make the mistake of thinking that the negative feedback must turn warming into cooling (reverse the sign of the original effect), or that positive feedback must cause the warming to spiral out of control.  Neither of those happens as long as the absolute value of the multiplier is less than one (i.e., it's within the range [-0.9999, +0.9999]).

If the multiplier is greater than +1, or less than -1, the system will run away on either the positive or negative side, respectively.  That is rare in most environmental systems (fortunately).

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Arctic sea ice / NASA to Host Media Briefing on New Ice-Monitoring Mission

« on: August 18, 2018, 12:05:39 AM »

"NASA will host a media teleconference at 1 p.m. EDT Wednesday, Aug. 22, to discuss the upcoming launch of the Ice, Cloud and land Elevation Satellite (ICESat-2), which will fly NASA’s most advanced laser altimeter to measure Earth’s changing ice. The teleconference will stream live on NASA’s website.

ICESat-2 is scheduled to launch Sept. 15 on a mission to provide critical, precision measurements of Earth’s ice sheets, glaciers and sea ice, which will help scientists better understand how changes at the poles will affect people around the world."

https://www.nasa.gov/press-release/nasa-to-host-media-briefing-on-new-ice-monitoring-mission

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Arctic sea ice / Re: When will the Arctic Ocean (CAB) go Ice Free in Winter?

« on: August 10, 2018, 07:48:52 PM »

e.g.
https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

Aehm.. that link references a paper that claims:
"In fact, the terraces suggest several meters of sea-level rise may have occurred on the scale of just decades during this time."

That paper claims, that sea-level rose by several meters within multiple decades. So lets say several meters are 3 meters and multiple decades are 5 decades. That would be a rise of 0.06 m per year.

Those who have worked in the South Pacific know that coral reefs are very sensitive to water depth. I found the "claim" in the paper very persuasive and logical. Yet another bit of evidence to support Hansen's abrupt SLR views. Whether that supports the argument for a winter ice free Arctic I have not a clue.

However, those living in Florida, London, New York, New Orleans, Shanghai et al, may find the findings of more immediate concern.

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Arctic sea ice / Re: When will the Arctic Ocean (CAB) go Ice Free in Winter?

« on: August 09, 2018, 05:27:34 AM »

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

An ice free Arctic Ocean by itself has no impact on sea level rise and what papers are predicting sea level rise of tens of meters in less than a decade?

I am having a hard time following this conversation. It's as if everyone is talking past the others.

Ice free arctic wouldn't directly have an effect on sea level, but greenland melt would probably go into overdrive. Maybe there would be more snow too but melt would probably overwhelm a snow increase.

I agree, we are all talking past each other. I think it speaks to the complexity of the issue. The weight each person puts on different factors.  There really is no way to definitively prove the impact of any given component. Uncharted territory.  This is why I find proclamations that certain things WILL BE a certain way decades or centuries in the future quite annoying.

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Arctic sea ice / Re: When will the Arctic Go Ice Free?

« on: August 02, 2018, 04:40:32 PM »

...
Previous rapid warming events over the last 2 million years, when going from glaciation to intermediary, were caused by orbital change with added feedback from CO2 and methane. The current rapid warming goes against the effects of orbital change (the climate should be cooling rapidly) and is mainly caused by a large increase in CO2, so it is reasonable to expect the pattern of warming being different this time.

I will quibble only with the parenthetical "the climate should be cooling rapidly" due to Milankovich forcing.  Without AGW, I understand Earth's climate would be cooling slowly during my lifetime (that is, on a human scale), although I'll accept "rapidly" in the geological scheme of things.

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Arctic sea ice / Re: The 2018 melting season

« on: July 18, 2018, 06:23:55 PM »

This is slowly shaping up to become the billion dollar question. As far as I have seen, no scientists have addressed it as of yet.

Aren't we addressing it? Aren't we all scientists? At least armchair ones ......

*Warmer* winters simple mean less FDD days, so less ice forms. That is visible in ice volume and extent.

I think there is a weak consensus on the Forum that the climate of the Arctic switched to a more Maritime climate sometime during 2015/2016 (look at the winter anomalies in the DMI temps north of 80°C). How long does that take to affect the ice? We have seen two years of this change. Does the Arctic ice/ocean/atmosphere system take 2 years to adjust and reach equilibrium, or 10, or 100? What will that equilibrium look like as we continue to see a warming planet? Are we now eroding a protective halocline that took 5 decades to form or does it reform every year? Is the change to a cloudier Arctic a permanent change because of Anthropogenic global warming? Unfortunately we wont know the answers to these questions for a while, and it is a terrifying and absorbing experiment that we have undertaken.

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Arctic sea ice / Re: SMOS

« on: July 14, 2018, 11:38:02 PM »

An even better way is to look at them both. And then compare, compare, compare to what has happened in the recent past.

That SMOS graph doesn't mean much if it isn't compared to the ones from 2007-2017.

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Arctic sea ice / Re: How soon could we go ice free?

« on: June 14, 2018, 09:42:16 PM »

Wow, I take it you haven't been doing much research on climate change.  You may want to educate yourself by reading the most recent IPCC report.  Here's the link:

To just toss off decades of science done by hundreds (perhaps thousands) of dedicated, well-educated people smacks of denialism.

there are a few problems:

a) he is right

b) you are asking a question while seeking confirmation for an already made up mind

c) you jump to false conclusion based on someone tells the truth

b + c are very modern and horrible attitudes IMO, beside other factors denying the truth brought the world very it currently stands and will bring either doom or at least more disaster to mankind.

further i find it interesting that someone who in the process of discarding facts blames others doing the same, interesting but not surprising because that too is human behaviour as long back as
the records are showing

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Arctic sea ice / Re: How soon could we go ice free?

« on: June 14, 2018, 08:02:26 PM »

The real answer is that we don't have a clue.

None of the models has been around long enough to have a valid skill metric assigned to them, and all the models have been way off in one way or another.  The "science" of Arctic Sea Ice is more like Alchemy than Chemistry.  We do not have an equivalent to the periodic table.  Everything that is said is based upon guesses about what is and has been going on.

(This is not to disparage the good work being done.  It is intended to reject the useless expectations people have about that work.)

Wow, I take it you haven't been doing much research on climate change.  You may want to educate yourself by reading the most recent IPCC report.  Here's the link:

http://www.climatechange2013.org/report/

To just toss off decades of science done by hundreds (perhaps thousands) of dedicated, well-educated people smacks of denialism.

No insults please. Dharma Rupa is not a denialist, nor dismissing research.  I think he (And I now) are pointing out that we are attempting to derive system behavior from an *effect* rather than a cause, or at least, an rather incomplete one.

We have very incomplete data. For instance, we have only a vague sense of how total ocean enthalpy is increasing in the Arctic.  We dont know a lot about heat inflow from currents.  Atmospheric chemistry is changing.  Weather itself is a dynamic property that will completely turn our expectations on their heads.

We need much better data about heat, and weather will make a certain prediction impossible even with that.

What we are left with is probabilities and unanswered questions.

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Arctic sea ice / Re: How soon could we go ice free?

« on: June 14, 2018, 07:44:08 PM »

The real answer is that we don't have a clue.

None of the models has been around long enough to have a valid skill metric assigned to them, and all the models have been way off in one way or another.  The "science" of Arctic Sea Ice is more like Alchemy than Chemistry.  We do not have an equivalent to the periodic table.  Everything that is said is based upon guesses about what is and has been going on.

(This is not to disparage the good work being done.  It is intended to reject the useless expectations people have about that work.)

Wow, I take it you haven't been doing much research on climate change.  You may want to educate yourself by reading the most recent IPCC report.  Here's the link:

http://www.climatechange2013.org/report/

To just toss off decades of science done by hundreds (perhaps thousands) of dedicated, well-educated people smacks of denialism.

I think the state of the models as revealed in that IPCC report is pretty well summed up  in Dharma Rupa's comment.

I see some signs that it will be better next time around, but an informed reading of the 2013 report is not going to inspire any confidence in model predictions of future Arctic Sea Ice cover.

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Arctic sea ice / Re: The 2018 melting season

« on: June 14, 2018, 06:47:58 PM »

.      COYOTEYOGI:
 I have a basic question for Hyperion and others. How and when will we know IF the gulf stream has connected with the warm water coming into the Chukchi from the Pacific? Are there buoys taking this measurement? Ships? it seems like it would be beyond the capacity of satellites if it happens under the ice.
It does strike me that this would be a game changing event for the durability of the ice cap. 

If there are then they are being kept secret. It may be worth checking argo buoys there was one north of Svalbard about a month ago, might have got out a report two. And itp, 100, 101, 108 are in the Beaufort. There may be military sub's on the ESAS. But they sure ain't sharing.
When there's ice soup the SST is a proxy for salinity. So that might be our best bet. If there's -1.8 temperature along the ESAS then we know the fresh water lid is busted. Technically the Atlantic and Pacific water underlies the whole basin from 50 m down. Its when they expel the halocline to near surface its a problem. Because then the heat from below can freely mix to surface. So this is troubling:

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Arctic sea ice / Re: The 2018 melting season

« on: May 27, 2018, 02:35:23 PM »

I am puzzled.  Hasn't recent research https://www.nature.com/articles/d41586-018-04086-4 indicated that the AMOC (aka the North Atlantic oceanic gyre) has slowed in the past decade or so?   AMOC going AWOL?  Clarification would be welcome.

The claim is there but so far the evidence has been pretty weak, and unless you can relate that to what is going on this Summer the discussion ought to continue elsewhere.  There is a warm pool in the Atlantic, but it will be months at least before that means anything.

What we know so far about the Atlantic as it relates to the Arctic this Summer is the continuing hot spots in the North...at least that is all I really know about this season.

I agree with this. There is a warm pool in the Atlantic and a cold pool south of Greenland. The discussion on this thread about these two items should be its influence on weather patterns and melt for this season. For example, will such a set up result in more powerful storms? Let's watch.

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Arctic sea ice / Re: The 2018 melting season

« on: May 26, 2018, 08:42:37 PM »

There's a negative correlation between the intensity of the Atlantic hurricane season and transport of heat from the tropics towards the pole on the Atlantic side. Thus, heat built up in the tropical Atlantic at an extremely high rate last July when the Arctic had cold weather.

This May, strong trade winds and intense storms in the Labrador sea, Greenland tip region have transported heat northwards at a far greater rate than normal. There is more heat available for melting ice and less for supporting intense hurricanes.

The weather patterns are subject to change this time of year so July could be very different from May, but I am very concerned about the rapid heating of the ocean this May in the Barents sea and far north Atlantic. It's great that the overturning circulation looks so strong in the Labrador sea, but it's draining cold fresh water that originated in the Arctic ocean and it's replacing it with warm salty water from both the Atlantic and Pacific oceans. There's going to be greater than normal Arctic ice melting from below this summer because of this oceanographic situation.

We got lucky last summer when July turned cold. I'm doubtful our luck will hold out another summer, but the weather constantly surprises me.

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Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask

« on: May 24, 2018, 06:02:05 PM »

This might seem like a stupid question: I am in the right place.

I'm going to state something that seems obvious; As far as I can tell the ice melts out from the boundary of the ice coverage. I'm going to generalize. Holes don't typically melt out in the center of the pack. The melting boundary seems to be a few miles wide, perhaps, but is pretty much always at the edge of the pack. Even as the ice warms and thins with melt ponds, the melt edge is at the point of open water. I assume that the mechanism is where energy gets transferred from water to ice.

Is there clear understanding of the mechanism of how energy gets transferred from open water to the ice pack to make it melt?

That boundary between ice and sea seems like it would be complex mix of temperatures and densities. Fresh water forming and sitting at the surface as ice melts, Insolation of the dark water, wave action. How quickly does the ice boundary melt out? Without mixing I would think slowly, the newly formed fresh water lens sits on top of salt warm water, warming up from insolation, how does this change when it's the fresh water lens itself warming? If its below 18 PSU of salinity then the density increases as it warms, generating convection with, one assumes, warm, more saline water below the pack. It seems that the mechanism of how energy from the warming water is transferred to the edge of the pack is critical to our understanding of rate of melt. It also points to Neven's observation that you need both insolation and mixing to melt the pack efficiently.

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Arctic sea ice / Re: First year PIOMAS volume below 1000km^3 poll 2018

« on: May 13, 2018, 02:43:51 PM »

Poly fits of course don't describe any physical process. They just show possible trends in the yearly final results, which are the outcome of many different (feedback) processes.  And there are many unknowns at play.
What i find interesting  is that in recent years the shape of the graph is slowly morphing, showing more and more a dent in september/october where the montly numbers used to be in a smooth, straight line in the 80's, 90's and even 00's.

I don't quite follow.  Please clarify.

This might suggest that some sort of regime change is taking place and certain effects are becoming more dominant than they used to be. Or new processes are getting started. Maybe that's because of the appearance of blue water at the continental edges as you mentioned.
Anyway, for now it seems to imply that volume in september could decline even more rapidly in years to come.

I'd be inclined to see it as a cascade of regime changes, and I am expecting at some point the ice will simply all melt without regard to time of year, but I haven't found a good hook for predicting when.  I always predict "this year" on the theory that I will eventually be right.

In the arctic death spiral graph below i marked the recent 'dented' trend line, compared to the decades before. In the good old days volume declined over the summer months at a certain pace and from october on it increased again. All very smooth. Although volume losses have been accelerating over the years for all months, in august and september this acceleration is even accelerating. To me this suggests that new dynamics are coming in to play. 

I agree with you that one year it will suddenly all melt out and this could be in 2018 as well. I only voted for 2019-2021 to enhance my chances a bit.
I am very curious what would happen after that. With no ice in the arctic basin, would ice growth have to start from the coasts or the few reigons where there is still some ice left? But i am getting of topic here i guess.

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