New Paper: Sources of Multi-decadal variability in Arctic Sea Ice Extent

[donsutherland1]

A new paper published in Environmental Research Letters discusses the accelerating decline in September Arctic sea ice extent since the 1990s. Some major points include:

- There is little evidence of a relationship between the Arctic Oscillation (AO) and September Arctic sea ice extent.

- There is a significant correlation between the AMO and Arctic sea ice extent (March and September). For the 1979-2010 period, the AMO explained approximately 5%-31% of the average sea ice extent decline per decade.

- The longer-term decline in Arctic sea ice extent "is more likely to be representative of the anthropogenically forced component" not the AMO.

- Uncertainty still exists and a larger ensemble of control simulations could reduce some of that uncertainty.

The paper can be found at:

http://iopscience.io..._7_3_034011.pdf

[ben4vols]

A new paper published in Environmental Research Letters discusses the accelerating decline in September Arctic sea ice extent since the 1990s. Some major points include:

- There is little evidence of a relationship between the Arctic Oscillation (AO) and September Arctic sea ice extent.

- There is a significant correlation between the AMO and Arctic sea ice extent (March and September). For the 1979-2010 period, the AMO explained approximately 5%-31% of the average sea ice extent decline per decade.

- The longer-term decline in Arctic sea ice extent "is more likely to be representative of the anthropogenically forced component" not the AMO.

- Uncertainty stil exists and a larger ensemble of control simulations could reduce some of that uncertainty.

The paper can be found at:

http://iopscience.io..._7_3_034011.pdf

I disagree with the 5% to 31% estimation. They are coming to that conclusion by comparing the 1979-2010 period vs ??? What? There is nothing to compare it against. We have no clue what the conditions where during the last +AMO. So they are comparing it to expected results from modeled outcome? Yeah, that is reliable. The bigger picture here is they found significant correlation with AMO. The rest is just speculation.

[Jonger]

I disagree with the 5% to 31% estimation. They are coming to that conclusion by comparing the 1979-2010 period vs ??? What? There is nothing to compare it against. We have no clue what the conditions where during the last +AMO. So they are comparing it to expected results from modeled outcome? Yeah, that is reliable. The bigger picture here is they found significant correlation with AMO. The rest is just speculation.

I'm not weighing in on this, I don't know much about AMO, but I do detest historical data being used in modern science. Look, I understand we have to use our best available data to compare patterns of today to, but its so difficult to draw solid science based on TERRIBLE pre-satellite gathered data. IMO, sea ice extent pre-1979 is just a general guess based on ship traffic and local recollections.

As little as I know about the AMO, this chart seems to line up well with the surge of warmth in the arctic after the mid 1990's onward.

[skierinvermont]

sea ice extent pre-1979 is just a general guess based on ship traffic and local recollections.

And what expertise in the fields of statistics do you possess that allow you to throw out the uncertainty estimates offered by peer-reviewed papers? Why have you not taken these findings of yours to be published?

[TerryM]

Jong

I think trans polar commercial flights were introduced in the 50's. The 40's, first with WW2, then with the cold war spawned bunches of "scientific" research from both sides. While sat. views may not have been available until the early 60's, there was certainly plenty of reliable data being compiled.

AMO has apparently been instrumentally recorded for at least 130 yrs per wiki, but I recall reading that temperature differentials between the Azores and Spitsbergen had been utilized for hundreds of years to forecast Atlantic sailing conditions (no link)

A quick scan of the paper seems to indicate that if even their most extreme correlations proved true, we'd still have a 7%/decade loss of min. SIE.

Terry

[Jonger]

Jong

I think trans polar commercial flights were introduced in the 50's. The 40's, first with WW2, then with the cold war spawned bunches of "scientific" research from both sides. While sat. views may not have been available until the early 60's, there was certainly plenty of reliable data being compiled.

AMO has apparently been instrumentally recorded for at least 130 yrs per wiki, but I recall reading that temperature differentials between the Azores and Spitsbergen had been utilized for hundreds of years to forecast Atlantic sailing conditions (no link)

A quick scan of the paper seems to indicate that if even their most extreme correlations proved true, we'd still have a 7%/decade loss of min. SIE.

Terry

Nobody can deny that sea ice is declining, I'm just not sold on what the state of the ice was before we really has a reliable way to measure it... What are the possibilities that WW2 aerosols resulted in ice extent growing beyond historical limits and the reduction of aerosol is crashing them back to normal... Couple that with the AMO and we are all now scrambling to figure out the arctic.

It's a shame that this is a problem that appeared right when we became technologically able to monitor the situation.

[skierinvermont]

lol @ WW2 Aerosols

[Jonger]

lol @ WW2 Aerosols

I should have been more specific, WW2 era aerosols and throughout the cool period, this is the accepted duration Mann states.

[skierinvermont]

I should have been more specific, WW2 era aerosols and throughout the cool period, this is the accepted duration Mann states.

That is post WW2.

[TerryM]

I happen to think that WW! & WW2 stirred up a lot of stuff, but Arctic ice doesn't need to be constantly monitored to prove it's retreat. I've posted the 3700 year period between the most recent breakup of Hunt-Ward, and the 700? year period since the breakup north of Flade Isblink. If the Arctic had reached present temperatures in the intervening years, we would know that with great certainty.

This paper finds that the human contribution to Arctic SIE is between 70% and 95%. This seems to be in rough agreement with past studies, and more recent ones indicating a diminishing possibility of a decadal halt to the melt. I was surprised that the AO wasn't a factor - particularly a decade or so ago when thicker, more compact ice was present.

Terry

[TerryM]

Skier

Have recorded other aerosols? Perhaps even black carbon?

Terry

[skierinvermont]

I happen to think that WW! & WW2 stirred up a lot of stuff, but Arctic ice doesn't need to be constantly monitored to prove it's retreat. I've posted the 3700 year period between the most recent breakup of Hunt-Ward, and the 700? year period since the breakup north of Flade Isblink. If the Arctic had reached present temperatures in the intervening years, we would know that with great certainty.

This paper finds that the human contribution to Arctic SIE is between 70% and 95%. This seems to be in rough agreement with past studies, and more recent ones indicating a diminishing possibility of a decadal halt to the melt. I was surprised that the AO wasn't a factor - particularly a decade or so ago when thicker, more compact ice was present.

Terry

Bingo.. numerous studies have concluded based on sound evidence that there is less arctic sea ice than in thousands of years. There are ice formations thousands of years old that are disintegrating.

[skierinvermont]

Skier

Have recorded other aerosols? Perhaps even black carbon?

Terry

Black carbon did rise in the arctic before WW2, but black carbon causes melting instead of cooling and freezing which is the opposite of what Jonger (he suggested the thick expansive ice mid century was due to unnatural aerosol cooling). The aerosols which cause cooling (sulfur emissions) are caused by massive industrialization in the 2nd half of the 20th century.

This paper contains graphs of black carbon concentration:

http://ess.uci.edu/~esaltzma/pub_pdfs/McConnelletalScience07.pdf

[The_Global_Warmer]

Bingo.. numerous studies have concluded based on sound evidence that there is less arctic sea ice than in thousands of years. There are ice formations thousands of years old that are disintegrating.

This point is brought up a a lot and no one every refutes it.

To add to it, not only is it happening, the speed at which it's happening in the last decade to now is like going from impulse to warp.

But I am sure it's just the AMO.

[ben4vols]

If the Arctic had reached present temperatures in the intervening years, we would know that with great certainty.

How would you know with great certainty?

[The_Global_Warmer]

I'm not weighing in on this, I don't know much about AMO, but I do detest historical data being used in modern science. Look, I understand we have to use our best available data to compare patterns of today to, but its so difficult to draw solid science based on TERRIBLE pre-satellite gathered data. IMO, sea ice extent pre-1979 is just a general guess based on ship traffic and local recollections.

As little as I know about the AMO, this chart seems to line up well with the surge of warmth in the arctic after the mid 1990's onward.

The fact that you keep saying 1979 is the start of remote sensing is crap, the chart you posted is crap, what you think you know about arctic sea ice monitoring (pre 1979 as you call it) is worse than crap it's embarrassing.

And worse it shows you have spent less than 1 second doing any research for yourself and copy everything you say here from someone else.

For your sake I truly hope you wake up one day.

[Jonger]

For your sake I truly hope you wake up one day.

What is at stake that I need to agree with you?

[The_Global_Warmer]

What is at stake that I need to agree with you?

IMO, sea ice extent pre-1979 is just a general guess based on ship traffic and local recollections.

Sea ice

Nimbus satellites collected orbital data on the extent of the polar caps in the mid-1960s, recorded in the visible and infrared parts of the spectrum. These first global snapshots of Earth's icecaps provide invaluable reference points for climate change studies. During a narrowing window of opportunity for data archaeology, the National Snow and Ice Data Center (NDISC) and NASA were able to recover data that allowed the reconstruction of high-resolution Nimbus 2 images from 1966 showing the entire Arctic and Antarctic ice caps.^[1]

When the Nimbus 5 spacecraft launched in 1972, scientists planned for its Electrically Scanning Microwave Radiometer to collect global observations of where and how much it rained across the world. However, a new priority for the sensor evolved in the months following its launch: mapping global sea ice concentrations. When Nimbus 7 launched in 1978, technology had improved enough for scientists to distinguish newly formed (i.e., "first year") sea ice from older ice, with the Scanning Multichannel Microwave Radiometer (SMMR) sensor. The data it collected during its 9-year lifespan provide a significant chunk of the long-term record of Earth's sea ice concentration that today's scientists use for studies of climate change.

Among the most serendipitous discoveries that the Nimbus missions made possible was that of a gaping hole in the sea ice around Antarctica in the Southern Hemisphere winters of 1974-76. In a phenomenon that has not been observed since, an enormous, ice-free patch of water, called a polynya, developed three years in a row in the seasonal ice that encases Antarctica each winter. Located in the Weddell Sea, each year the polynya vanished with the summer melt, but returned the following year. The open patch of water may have influenced ocean temperatures as far down as 2,500 meters and influenced ocean circulation over a wide area. The Weddell Sea Polynya has not been observed since the event witnessed by the Nimbus satellites in the mid-70s.

That's just one of the satellites we used to track sea ice extent back then.

Men and Women dedicate their career's to building those machines and giving us this data and you can't take 10 seconds and use google to find out the facts before coming on this board and making things up?

PS. And just because you have no idea the technology we have been using to reconstruct reliable sea ice data the past century because your to lazy to do the research doesn't make it un true, nor does it make it not exist. This is a board of science, a lot very smart people come here to learn. How much more time of theirs are you willing to waste? You have done this time and time again. I have tried so hard to be considerate and patient when it comes to this stuff, but this is ridiculous. We are adults. And this is a dedicated forum to this science and the study of it. We are not on an Oprah forum having an Off Topic discussion about climate change, I would expect to see comments like the one you made above there, not here.

[skierinvermont]

That's just one of the satellites we used to track sea ice extent back then.

Men and Women dedicate their career's to building those machines and giving us this data and you can't take 10 seconds and use google to find out the facts before coming on this board and making things up?

PS. And just because you have no idea the technology we have been using to reconstruct reliable sea ice data the past century because your to lazy to do the research doesn't make it un true, nor does it make it not exist. This is a board of science, a lot very smart people come here to learn. How much more time of theirs are you willing to waste? You have done this time and time again. I have tried so hard to be considerate and patient when it comes to this stuff, but this is ridiculous. We are adults. And this is a dedicated forum to this science and the study of it. We are not on an Oprah forum having an Off Topic discussion about climate change, I would expect to see comments like the one you made above there, not here.

Well put Friv.. I think Jonger has begun to become familiar with some of the basic facts of agw.. but he still repeatedly is dismissive of information and knowledge with which he is not yet familiar. Only once this information is shoved down his throat does he acknowledge it. But at least he usually ends up acknowledging it unlike some other posters here. This is another classic example of being dead wrong and willful ignorance. When one is so wrong so often, it really requires a conscious step backwards and a new approach.

How and why we accept new scientific knowledge I think is very important. Over the years I have found myself repeatedly misled and found myself jumping to invalid conclusions. The best approach is to rely only upon reliable sources of information and attempt to familiarize oneself with them as much as possible. To the extent that these sources are technically beyond one's level of expertise, it is often best to trust the consensus of only the most reliable sources.

[The_Global_Warmer]

Well put Friv.. I think Jonger has begun to become familiar with some of the basic facts of agw.. but he still repeatedly is dismissive of information and knowledge with which he is not yet familiar. Only once this information is shoved down his throat does he acknowledge it. But at least he usually ends up acknowledging it unlike some other posters here. This is another classic example of being dead wrong and willful ignorance. When one is so wrong so often, it really requires a conscious step backwards and a new approach.

How and why we accept new scientific knowledge I think is very important. Over the years I have found myself repeatedly misled and found myself jumping to invalid conclusions. The best approach is to rely only upon reliable sources of information and attempt to familiarize oneself with them as much as possible. To the extent that these sources are technically beyond one's level of expertise, it is often best to trust the consensus of only the most reliable sources.

I totally agree with what your saying. Personally I am not to worried about about being wrong about the smallest details. When we argue over something like will it snow 6-8 inches or 5-7 or will the resulting forcing be .26w/m2 or .31w/m2.

Or even which factor is the largest contributor to the big time warming in the arctic, ice albedo, snow albedo, or ghg forcing. or all three?

All of the things we discuss here that go beyond doubtless facts, like the satellite sensing stuff is 100% factual.

But all of this stuff just takes steps and leaps of logical strings of ideas and data and even lleaps of faith in instances that are backed by data, logic, facts and reasoning.

But how the do people end up on what seems like irreversible courses that do not exist in our reality? I don't need to describe them, but you know what I am saying? Is this ideology? What? How can people process the data that we all process but end up so far off? But truly believe it in the face of incredible overwhelming evidence? I don't think it's insanity, what is it?

[Sundog]

People have a hard time believing things they don't understand, especially when they have preconceived ideas on the subject.

I have a bachelors and masters in geology and I've had people ask me for example how do I know so and so rocks are really 1 billion years old? They don't believe it because they don't understand it or they have heir own ideas that conflict with my facts. The same thing is happening here in this forum.

Do these people constantly question their doctors in the same manner they question sound science in this forum?

[TerryM]

Black carbon did rise in the arctic before WW2, but black carbon causes melting instead of cooling and freezing which is the opposite of what Jonger (he suggested the thick expansive ice mid century was due to unnatural aerosol cooling). The aerosols which cause cooling (sulfur emissions) are caused by massive industrialization in the 2nd half of the 20th century.

This paper contains graphs of black carbon concentration:

http://ess.uci.edu/~...alScience07.pdf

Thanks for the link

Neither the sulfur nor the BC graphs are what I would have expected - it's good to have a reality check before my expectations lead me too far astray. Back to the drawing board.

Terry