Fwd: Arctic climate modeling too conservative, says new research
Ron Baiman
From: Ron Baiman <rpba...@gmail.com>
Date: Mon, Mar 13, 2023 at 2:43 PM
Subject: Fwd: Arctic climate modeling too conservative, says new research
To: geoengineering <geoengi...@googlegroups.com>, Philip Bogdonoff <pbogd...@gmail.com>
From: Philip Bogdonoff <pbogd...@gmail.com>
Date: Mon, Mar 13, 2023 at 12:14 PM
Subject: Arctic climate modeling too conservative, says new research
To: Herb Simmens <hsim...@gmail.com>, Ron Baiman <rpba...@gmail.com>
Ron Baiman
Subject: Re: Arctic climate modeling too conservative, says new research
To: Michael MacCracken <mmac...@comcast.net>
Cc: Ron Baiman <rpba...@gmail.com>, H simmens <hsim...@gmail.com>
Hi Ron--Everything is coupled together--and again, the models have possibly been in a time lag due to the atmospheric effects. I understand that these are the present differences, but what is their cause is the question?
Another quite possible underlying explanations is inadequate model resolution, a problem forced by limitations in computer speed, etc. And there may well be other causes.
What I did not like about the article was the sort of implication that one would tune the model to the results? Doing that gives no confidence that any future result will be right or that changes will occur as would play out. What one has to to do is figure out what aspect(s) of the physics (chemistry, biology, etc.) is not being properly represented and get that fixed if one is going to be able to justify having at least some confidence in projections into the future.
Best, Mike
On 3/13/23 10:00 PM, Ron Baiman wrote:
Hi Mike,
The lead of author of the paper seems to blame it on more voluminous incoming warm ocean currents and uncertain levels of Arctic Ocean stratification:"In reality, the relatively warm waters in the Arctic regions are even warmer, and closer to the sea ice. Consequently, we believe that the Arctic sea ice will melt away faster than projected," explains Céline Heuzé, climatologist at the University of Gothenburg and lead author of one of the studies.
Warm water flows into the Arctic Ocean via Fram Strait between Greenland and Svalbard. However, the volume of water in these ocean currents and its temperature in the climate models are too low, which is one of the reasons why the climate models' projections will not be accurate. Even the stratification of the Arctic Ocean is incorrect. The researchers argue that since roughly half of the models project an increase and the other half a decrease in stratification, the consequences of global warming cannot be estimated accurately"
And applying a generic model to the Arctic rather than one specific tailored to the unique conditions there:
" We need a climate model that is tailored to the Arctic. In general, you can't use the same model for the entire planet, as conditions vary considerably. A better idea would be to create a specific model for the Arctic that correctly factors in the processes occurring in the Arctic Ocean and surrounding land areas," Céline Heuzé explains."
So they seem to believe that the problem lies more with Ocean modeling than with atmospheric effects, though of course these should be linked in the models which it seems is what you're thinking?
Ron
On Mon, Mar 13, 2023 at 4:26 PM H simmens <hsim...@gmail.com> wrote:
Hi Mike,
Thanks for the clarification. Leon Simons was on Andrew’s podcast last year if anyone is interested.
Herb SimmensAuthor A Climate Vocabulary of the Future@herbsimmens
On Mar 13, 2023, at 5:01 PM, Michael MacCracken <mmac...@comcast.net> wrote:
Hi Herb--I'm not in touch with Leon. Actually, I was referring to powerplant SO2 emissions from the US and Europe that surely put sulfate into the Arctic into the 1980s, etc. Indeed, it would be interesting for someone to look at the time around the years when they opened and later closed the smelter in Canada that was putting out 5% or so of North American emissions as lofting emissions extended the S lifetime in the atmosphere from a day or to to a week or two (and thus reduced local ecological damage at the site of the plant).
But now that you mention it there is also the issue of the emissions from shipping, another source term not likely considered in the global models but could have undue effects in the Arctic. So, it is true not good to use models for predictions as opposed to for projections.
Best, Mike
On 3/13/23 4:33 PM, H simmens wrote:
That’s really interesting Mike. Are you in touch with Leon Simons who as I’m sure you know has done work to quantify the impact of the regulatory requirement that ships reduce their use of sulfur intensive fuel by I think 90% from 2020 on.
He often discusses his work on Twitter.
Herb
Herb SimmensAuthor A Climate Vocabulary of the Future@herbsimmens
On Mar 13, 2023, at 4:23 PM, Michael MacCracken <mmac...@comcast.net> wrote:
This was noted quite some time ago and the question is why. Perhaps a decade ago I tried to broker a peace between the two opposing sides, namely the observationalists who were insistent their data on the changing Arctic was correct and the modelers who insisted they had all the physics included and done properly. I pointed out that there was a third component to be considered, and on this other aspect, namely the forcing from aerosols was quite uncertain. So, for example, were the aerosols affecting cloud albedo and might the reductions in SO2 emissions in the North Atlantic Basin have led to less bright clouds due to a drop in the amount of sulfate loadings/cloud brightening? And what about soot lofting into the Arctic--might that have affected surface albedo, etc.? I did not get much traction from the two sides--unfortunate that this question has yet to be resolved and so there persists a lag in the models as compared to observations (i.e., one could characterize the problem either in terms of not enough change indicated for the early 2020s, or the model results are lagging the observations by of order a decade). Whether this subtlety really has affected the policies, who knows.
Mike
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