Annual arctic sea ice report in for 2016 and just above 7 year average.

[studiot]

Year.... Cukm of ice.

 

2010.... 5900

2011.... 4500

2012.... 4600

2013.... 7800

2014.... 6800

2015.... 6200

2016.... 6200

-----------------

Av ........ 6000

 

http://www.bbc.co.uk/news/science-environment-34619291

Edited October 26, 2015 by studiot

[swansont]

How do they have 2016 numbers?

[studiot]

Because they report in October.

[Mike Smith Cosmos]

Year.... Cukm of ice.

2010.... 5900

2011.... 4500

2012.... 4600

2013.... 7800

2014.... 6800

2015.... 6200

2016.... 6200

-----------------

Av ........ 6000http://www.bbc.co.uk/news/science-environment-34619291

.

Well by these sequence of figures the area of sea ice is rising marginally . According to your quote , the model says that if sea temperature is rising , then sea ice should by lowering .

 

Link quote " Climate models forecast a general downward trend in sea-ice cover in the northern polar region as temperatures rise." As per BBC :- " Cryosat tracks Arctic sea ice freeze-up"

 

Mike

Edited October 27, 2015 by Mike Smith Cosmos

[studiot]

Well by these sequence of figures the area of sea ice is rising marginally . According to your quote , the model says that if sea temperature is rising , then sea ice should by lowering .

 

Which may be why this study is worth discussing.

Although the timespan is woefully inadequate for decent data analysis.

 

The report also proposes that the volume of ice is a more important indicator than the area.

This point is certainly worth noting.

 

Of course, this is 'their' model, not 'the' model.

 

Edited October 27, 2015 by studiot

[swansont]

Because they report in October.

 

That's the 2015 number. There is no 2016 number mentioned in the article. The satellite was launched in April 2010 and the first October data point is 2010, not 2011.

[billiards]

According to the website (http://www.cpom.ucl.ac.uk/csopr/seaice.html) an unusually cold summer in 2013 was the cause of a jump in sea ice production.

 

'The volume of Arctic sea ice increased by a third after the summer of 2013 as the unusually cool air temperatures prevented the ice from melting.'

 

However, overall, sea ice production is declining over the long-term.

 

'Although the jump in volume means that the region is unlikely to be ice free this summer, temperatures are likely to rise in the future, and so the events of 2013 will have simply wound the clock back a few years on the long-term pattern of decline.'

[iNow]

https://www.skepticalscience.com/increasing-Antarctic-Southern-sea-ice-intermediate.htm

Antarctic sea ice has been growing over the last few decades but it certainly is not due to cooling - the Southern Ocean has shown warming over same period. Increasing southern sea ice is due to a combination of complex phenomena including cyclonic winds around Antarctica and changes in ocean circulation.

<snip>

The most common misconception regarding Antarctic sea ice is that sea ice is increasing because it's cooling around Antarctica. The reality is the Southern Ocean surrounding Antarctica has shown strong warming over the same period that sea ice has been increasing. Globally from 1955 to 1995, oceans have been warming at 0.1°C per decade. In contrast, the Southern Ocean (specifically the region where Antarctic sea ice forms) has been warming at 0.17°C per decade. Not only is the Southern Ocean warming, it's warming faster than the global trend. This warming trend is apparent in satellite measurements of temperature trends over Antarctica:

 

Oceanographic data also find that the waters in the Southern Ocean are warming. The waters of the Southern Ocean's Antarctic Circumpolar Current have warmed more rapidly than the global ocean as a whole. From 1960 to 2000, water temperature increased by 0.068°C per decade at depths between 300 and 1000 metres. This warming trend has increased to 0.098°C per decade since the 1980s (Boning 2008).

 

If the Southern Ocean is warming, why is sea ice increasing? There are several contributing factors. One is the drop in ozone levels over Antarctica. The hole in the ozone layer above the South Pole has caused cooling in the stratosphere (Gillet 2003). A side-effect is a strengthening of the cyclonic winds that circle the Antarctic continent (Thompson 2002). The wind pushes sea ice around, creating areas of open water known as polynyas. More polynyas leads to increased sea ice production (Turner 2009).

 

Another contributor is changes in ocean circulation. The Southern Ocean consists of a layer of cold water near the surface and a layer of warmer water below. Water from the warmer layer rises up to the surface, melting sea ice. However, as air temperatures warm, the amount of rain and snowfall also increases. This freshens the surface waters, leading to a surface layer less dense than the saltier, warmer water below. The layers become more stratified and mix less. Less heat is transported upwards from the deeper, warmer layer. Hence less sea ice is melted (Zhang 2007).

 

Antarctic sea ice is complex and counter-intuitive. Despite warming waters, complicated factors unique to the Antarctic region have combined to increase sea ice production. The simplistic interpretation that it's caused by cooling is false.

[billiards]

https://www.skepticalscience.com/increasing-Antarctic-Southern-sea-ice-intermediate.htm

Care to comment?

 

Also: Antarctic ≠ Arctic

Edited October 27, 2015 by billiards

[studiot]

Comments?

 

1)

I had understood that the ozone gap over the antartic had pretty well recovered.

 

2)

So are they are saying that the ice acts as an insulator, allowing heat to build up in the deep?

Why do they say there is less upward heat transfer?

[billiards]

2)

So are they are saying that the ice acts as an insulator, allowing heat to build up in the deep?

Why do they say there is less upward heat transfer?

 

Hi studiot,

 

Not exactly. They say there is more rain and snow now which creates a layer of fresh water at the surface. This layer prevents warmer deeper waters from reaching (and melting) the sea ice at the surface. The (salty) warm deep waters were always there -- only now they cannot mix to the surface so effectively. (Disclaimer: I haven't read the original paper: Zhang, 2007)

[studiot]

 

This layer prevents warmer deeper waters from reaching (and melting) the sea ice at the surface

 

I don't follow the mechanics of this.

 

How does a surface layer prevent a deeper layer rising, when there must be a gravitational imperative for it to do so?

 

Secondly how does it remain the same, and not warm up if it can't give up heat to something else (the snow and ice).

Since Zang it saying it formerly did this, it must have either cooled down in the past or had a source of heat in the past.

[iNow]

Care to comment?

 

Also: Antarctic ≠ Arctic

Okay. This then: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2489.html

 

What comments are you seeking? I feel that claiming seasonal increases in sea ice debunk anthropogenic climate change to be roughly equivalent to suggesting the existence of snow storms in winter debunk anthopogenic climate change.

[studiot]

I don't think anyone is trying to debunk climate change, I certainly did not offer any evidence towards this and commented to this effect in my OP.

 

However you did introduce a claim that there is less upward heat tansfer, which implies that heat build up lower down but have not responded to my question about this.

[iNow]

Sorry. Your OP was a list of numbers and a link. Your intended discussion topic was unclear and I perhaps guessed wrongly at your intent.

 

Now, what claim are you saying I've made / question you've asked me that I've ignored? You seem to have potentially confused me with someone else.

[billiards]

 

I don't follow the mechanics of this.

 

How does a surface layer prevent a deeper layer rising, when there must be a gravitational imperative for it to do so?

 

Secondly how does it remain the same, and not warm up if it can't give up heat to something else (the snow and ice).

Since Zang it saying it formerly did this, it must have either cooled down in the past or had a source of heat in the past.

 

I think the idea is that the surface layer is buoyantly stable -- i.e. there is not a "gravitational imperative" for the deep layer to rise to the surface. It is stable because it is less dense than the water below, and it is less dense because it is fresher (less salty). This is despite the fact that it is also colder (which would tend to make it more dense).

 

I don't quite understand the second point. I do not think it "remains the same". In fact I think the whole ocean is constantly circulating and one would have to look at the sources and sinks of the water. I think the question you might be looking for is: what is the source of the cold surface layer in the Southern Ocean?

Okay. This then: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2489.html

 

What comments are you seeking? I feel that claiming seasonal increases in sea ice debunk anthropogenic climate change to be roughly equivalent to suggesting the existence of snow storms in winter debunk anthopogenic climate change.

 

Hi iNow,

 

Yes, that link is essentially the source of the information I previously had summarised (the same research group even). So we are on the same page!

 

I only asked for comments because you posted a lot of information without giving any context. I wanted some discussion context for all that information.

 

Thank you for clarifying your position. Now your previous posts make sense!

[overtone]

How does a surface layer prevent a deeper layer rising, when there must be a gravitational imperative for it to do so?

Very cold fresh water, as from melting ice and snow, is lighter than somewhat warmer salt water. It flows in on top, and forms a layer of cold water on top of the warmer ocean. In areas protected from wind - such as just under an ice pack - this layer can be stable for some time. Warming by diffusion of heat is very slow. Even in open water - as south and east of Greenland - continual replenishment from land melt can keep the surface of the ocean colder than deeper waters for long periods of time.

 

As far as the OP - apparently there was a cold snap in 2013, and this new satellite caught its effects. Why is that news? Was there some question as to whether this new satellite was calibrated properly, etc?

Edited October 28, 2015 by overtone

[studiot]

Thank you, billiards and overtone for that explanation. I hadn't considered that aspect.

 

However that will not prevent the warmest salty water rising to the top of the saline layer, where it will be in direct contact with the colder fresh water.

 

So heat will still be transferred over by conduction at this junction.

 

So it does not prevent the heat rising and merely slows the transfer to the top layer which is the definition of an insulator.

[billiards]

Thank you, billiards and overtone for that explanation. I hadn't considered that aspect.

 

However that will not prevent the warmest salty water rising to the top of the saline layer, where it will be in direct contact with the colder fresh water.

 

So heat will still be transferred over by conduction at this junction.

 

So it does not prevent the heat rising and merely slows the transfer to the top layer which is the definition of an insulator.

 

True, but this is a much slower process of heat transfer, which explains why the ice does not melt so rapidly. I think we've reached consensus in understanding the mechanism.