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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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What is the world coming to?
Yikes!
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?
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.
Climate is the probability density function of weather.And the odds in January are never the same as the odds in July.
The catchy way I like to say it is:
Climate is the odds. Weather is the roll of the dice.
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.
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.
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.
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.
The shift the past six years is the difference in 20C worth of monthly temps in some months for many regions.
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.
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.
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.
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.
...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.
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.
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.
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.
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.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.
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.
. 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.
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.
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.I don't quite follow. Please clarify.
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.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.