Claim: Scientists find the error source of a sea-ice model varies with the season

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

Research News

IMAGE
IMAGE: SCHEMATIC DIAGRAM OF THE SEA-ICE SIMULATION ERROR SOURCES OF A REGIONAL CONFIGURATION OF MITGCM. view more CREDIT: YUE SUN

Arctic sea ice has been rapidly declining in recent decades, and changes in arctic sea ice can have a significant impact on global weather and climate through interactions with the atmosphere and oceans. In addition, the Arctic shipping routes are a shortcut to connect the major countries in the Northern Hemisphere. The Arctic region is also rich in natural resources and biological resources. Simulation of the Arctic sea ice could provide valuable information for Arctic shipping as well as climate studies, and it is therefore urgent to evaluate the ability to simulate Arctic sea ice and diagnose the sources of simulation errors.

To address the issue of error source identification, Prof. Fei Zheng and his team from the Institute of Atmospheric Physics at the Chinese Academy of Sciences, evaluated the sea-ice simulations of the Arctic regional ocean-ice coupling configuration of the Massachusetts Institute of Technology general circulation model (MITgcm).

“We evaluated the model’s performance in the Arctic cold season (March) and warm season (September), and found the model performances are different in the two months,” says Zheng. “Due to the uncertainty of the model, the model’s insufficient response to the signal of atmospheric forcings, and the insufficient response to the ocean boundary signal, there were disagreements between the simulations and observations in both March and September.”

According to their paper, published in Advances in Atmospheric Sciences, the characteristics of seasonally varying model error sources could be fully considered by means of an ensemble approach, so as to achieve the goal of improving the simulation and prediction of the Arctic sea ice in different seasons in future work.

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Scissor
December 31, 2020 6:14 pm

GIGO.

MarkW
Reply to  Scissor
December 31, 2020 7:57 pm

They are working to find the errors and fix them. Instead of fixing the data, they are fixing the model. That’s how science is supposed to work.

M Courtney
Reply to  MarkW
January 1, 2021 3:00 am

But instead of evaluating why the models don’t reflect reality in the same way at different time of the year they are adopting an “ensemble approach”.
That means they will be right in one model of the ensemble at some times and right with a different model at other times.
And still wrong with those models at the times not tuned for. So they cannot be right for the real reasons.
It’s a way of increasing retrospective fitting without increasing actual knowledge.

Reply to  MarkW
January 1, 2021 5:30 am

It’s models all the way down.

Ron Long
December 31, 2020 6:21 pm

“…there were disagreements between the simulations and observations in both March and September.” So throw out the observations and go with the simulations, which tend to produced the desired result anyway. There, fixed it. Next.

MarkH
December 31, 2020 6:33 pm

“there were disagreements between the simulations and observations in both March and September.”

I’m sure it’s nothing that a bit of homogenisation couldn’t “fix”

lee
December 31, 2020 7:25 pm

“seasonally varying model error sources could be fully considered by means of an ensemble approach”

Because more models means more delights.

eck
December 31, 2020 8:11 pm

I wouldn’t, and don’t) trust anything that came from any (Communist) China source at all. Everything is controlled by the CCP. Assume falsities is the opening position. Then inquire.

philincalifornia
Reply to  eck
December 31, 2020 8:25 pm

You don’t need to assume, you can look at the data and see that the opening position is a falsity (in addition to bad English):

Arctic sea ice has been rapidly declining in recent decades, …… “

The summer Arctic sea ice extent minimum has flatlined for the last decade.

fred250
Reply to  philincalifornia
December 31, 2020 8:56 pm

Not only has the RECOVERY from the EXTREMES of the LIA and 1970s stalled…..

comment image

It has done so at an extent FAR ABOVE the Holocene normal.

David A
Reply to  eck
January 1, 2021 2:09 am

Don’t know about the CCP controling everything, yet I am quite certain they control a fellow named Biden.

n.n
December 31, 2020 8:41 pm

Natural forcings continue to deny the consensus and delight the native lives of planet Earth.

Mike
December 31, 2020 9:12 pm

 it is therefore urgent to evaluate the ability to simulate Arctic sea
Why do they need to simulate sea ice when they can just go look it up?
Declining in recent decades”…..So what? Why is that bad? In the 50-70s it was increasing…was that good? What’s the difference?
Who the hell are these people?

griff
January 1, 2021 12:46 am

Never mind the models: physical evidence shows the ice has declined in extent, volume, thickness and age over the last 40 years: historical evidence shows it now lower than at any point in the currently collated records from across the region (now available to the 1860s). In all probability this is the lowest since the arctic ocean froze over at the end of its Eemian low.

And this is emphatically not ‘just’ the lowest point in a/any cycle.

and the models? Well the rapid decline is throwing up new and unexpected patterns of change now on a yearly basis… the break up of ice in summer along the entire northern Canadian and Greenland shore, for example or this years extraordinary late freeze in the Laptev. I suspect the models can’t keep up with this dynamic change.

Mike
Reply to  griff
January 1, 2021 6:10 pm

Did someone say KFC?

Peta of Newark
January 1, 2021 1:10 am

Pointless waste-of-time verbiage..
Quote:
“”changes in arctic sea ice can have a significant impact on“”

Can= weasel word. I don’t wanna know what ‘can‘ happen. What does happen?
Define ‘significant’
C’mon boyz & girlz, YOU are the self appointed teachers, scientists & explainers.
Why do we have to imagine what you are talking about?

Quote:
“”response to the ocean boundary signal“”
What’s that, something on the beach?

Quote:
“”urgent to evaluate the ability to simulate Arctic sea ice“”
Possibly, but what IS the urgency.
Is there another Titanic about wreck yet another iceberg?
Patently not, there are pictures of Cruise Ship graveyards all over the interweb currently
Are there people out on the ice gonna sink and perish?
Why do you need to use language that instil fear and worry?

Quote:
“”The Arctic region is also rich in natural resources and biological resources“”
What’s the word resource doing there?
Are you planning on going out to drill, mine, harvest, farm, hunt, shoot and fish?
IOW: Destroy
To satisfy what – your own greed by any chance? ##

Quote:
“”model’s insufficient response to the signal of atmospheric forcings“”
By who’s definition is it ‘insufficient’?
Not least, (apart from when a tree or your house gets blown over) What Are Atmospheric Forcings?
The Sun and the Earth’s surface force the atmosphere. Carts do not pull horses around.
Maybe they do things differently in China?
OK, fine.
Diversity is good and that’s their choice but its MY Choice if I want to follow their lead.
maybe not this time eh

## The giveaway. The Human Animal Cannot Lie.
They certainly try but its a very stressful thing to do.
So they eat Comfort Food, drink alcohol and smoke cannabis to alleviate the stress.
Then they get fat, lazy and stupid and everything goes down the pan.
As we see.

Last edited 26 days ago by Peta of Newark
Greg
January 1, 2021 1:40 am

Arctic sea ice has been rapidly declining in recent decades,

Nonsense. Almost all of the reduction happened between 1997 and 2007. Recent summer minima are very close to 2007 levels. There was very little change from 1978 to 1997. So the only way you can make that claim is by drawing a straight line through 43 years of detailed daily data and reducing it to a single scalar value !!

That kind of naive, simplistic “analysis” with NOT give you any insight into what is happening. That is why climate models initially failed to anticipate the rapid change from 1997 – 2007 and failed to anticipate 2019 being the same as 2007.

Their models have zero skill because they are intent on modelling something they can attribute to CO2 instead of trying to model the sea ice data.

Dave Fair
Reply to  Greg
January 1, 2021 12:48 pm

And that data is cyclic, independent of CO2.

Tenuc
January 1, 2021 2:21 am

First thing they need to do is find a GCM which comes close to being able to accurately hind-cast climate for the last two hundred years. I wish them all good luck with that endeavour.

Jim Gorman
January 1, 2021 5:26 am

Layman’s explanation of ensemble, average multiple wrong outputs and chance alone will insure that you get the correct answer. /sarc

Captain Climate
January 1, 2021 4:08 pm

I would love to know who an ensemble of models are going to track down an error in theory. Honest question.

Ulric Lyons
January 1, 2021 4:41 pm

“Arctic sea ice has been rapidly declining in recent decades, and changes in arctic sea ice can have a significant impact on global weather and climate through interactions with the atmosphere and oceans.”

That’s the tail wagging the dog, it’s the mid altitude weather and the AMO warm pulses which impact the sea ice. It’s not as if they had modeled the rapid decline in sea ice since 1995 anyway, because the circulation models have increasingly positive NAO with rising CO2 forcing, but it’s negative NAO which drives AMO and Arctic warming.

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