Antarctic Ice Discussion

[Relativistic]

Who's to say that the forcings that drove the year on year increases from the early 80's also allowed further extension in certain areas due to alterations in wind/storm tracks? 

 

If we are seeing this phase ending then the sort of 'slowdown' we witnessed this year may become increasingly common over the whole of the re-freeze period limiting the extent by unfavorable wind/wave action at the ice edge?

 

No matter how much ice is created at the shore polynias the 'extent' is maintained by destruction /float off and melt of ice at the outside of the pack?

 

The key word being if. From what I gather the super Nino had an impact on the ice this year. It will be interesting to see how the ice responds next Austral Winter.

[knocker]

Ozone hole is very big and very persistent this year: still 26 mln km2, larger than N-America.

[stewfox]

Ozone hole is very big and very persistent this year: still 26 mln km2, larger than N-America.

 

Doesn't seem to get the same press these days but still worrying

 

When should see a improvement, given the reduction in mans contribution ?

Edited October 26, 2015 by stewfox

[knocker]

it's a pretty slow process as the original compounds are so stable and long-lived that an ozone hole will exist each Antarctic spring for at least another 50 years. Plus there is a higher percentage of the compounds in the stratosphere than originally thought.

[Midlands Ice Age]

Ozone hole is very big and very persistent this year: still 26 mln km2, larger than N-America.

 

 

Knocker, but why is it that we seem to have made no reduction and particularly that this year we seem to have extreme persistence?

 

I thought that we had reduced the CFC's to virtually nil and scientists were claiming it as a great achievement when the Ozone  hole reduced dramatically a few years back.  If it was reducing then why has the extent gone back up again, if the 'forcing' has been removed?

 

Is it possible it regenerates itself without the help of CFC's.?

 

Not denying the science, but something looks badly understood or gooky here!

 

Perhaps previous claims about decreasing the CFC's had caused  the desired  effect on ozone were not really valid? Maybe the previous declines in Ozone were, heaven forbid,  natural!

 

MIA

Edited October 26, 2015 by Midlands Ice Age

[knocker]

The forcing hasn't been removed as already stated and it's thought developing countries are actually adding more. So it's a slow process and there are year on year variations depending on conditions in the stratosphere. The colder the strat, (probably due to global warming) then an increase in PSCs leads to more ozone destruction.

 

As you correctly say there is no denying the science.

Edited October 27, 2015 by knocker

[knocker]

Now here's a coincidence Richard Telford has a short blog on the subject.

 

CFC concentrations not emissions affect ozone

[4wd]

Since we don't know anything about Ozone holes before about 1970 how do we know it isn't an entirely natural thing for it to vary on a long term basis?

I find the determination not to even consider this (e.g. your blogger) rather revealing.
The recent steadily decline was happily being attributed to the elimination of most sources, but now it has increased again that must be because CFCs must be more lived than expected...cookie science I'm afraid.

[Midlands Ice Age]

 

Now here's a coincidence Richard Telford has a short blog on the subject.

 

CFC concentrations not emissions affect ozone

 

 

Knocker,

 

Ok, but the point I was really making was that the hole (in addition to be slightly larger) appeared to reach its maximum later (beginning of Oct) and has lasted much longer than ever before -  inspite of the fact that the total CFC levels have dropped by about 5%. (see your graph above). Its really the persistence that concerns me!

 

It seems to me that if it only keeps reducing at the Oct rate then come Dec we may still have more than some Sept max's.

It would also seem that (after reducing quite nicely in the 2 or 3 preceeding years)  we have gone back to the level observed in the 2007 to 2009 period. Are some countries not sticking to the agreement?

 

Something seems to have changed....

 

That is what concerns me NOT just the  very slightly greater extent.

 

Is that down to  extremely cold temps in the strat over Antartica this year, or could something else be affecting it?

 

 

MIA

Edited October 27, 2015 by Midlands Ice Age

[knocker]

Since we don't know anything about Ozone holes before about 1970 how do we know it isn't an entirely natural thing for it to vary on a long term basis?

I find the determination not to even consider this (e.g. your blogger) rather revealing.

The recent steadily decline was happily being attributed to the elimination of most sources, but now it has increased again that must be because CFCs must be more lived than expected...cookie science I'm afraid.

 

Let's start with this

 

 

Since we don't know anything about Ozone holes before about 1970 how do we know it isn't an entirely natural thing for it to vary on a long term basis?

 

I assume you plucked 1970 out of the air. In reality G.M.B. Dobson set up a chain of measuring stations using his spectrophotometer in the 1930s. Systematic measurements using this were started in 1957 in Antarctica. The interest at the time was it could be used as a tracer of atmospheric circulation at high levels.

 

In 1973 Lovelock on a cruise in Antarctic water found that CFCs were accumulating in the lower atmosphere but he assumed they constituted no conceivable hazard.

But in 1974 Molina and Rowland pointed out that CFCs would be photolysed to yield active chlorine, which in turn would destroy ozone.

 

Fast forward to 1984 when BAS observations detected a catastrophic fall in the deep minimum with values down a third on the 1957-77 values.

 

Cutting a long story short which various governments did as well this led to the Montreal Protocol of 1987.

 

Now we obviously don't know the ozone levels earlier than this but it's totally irrelevant as the science that led to the Protocol is well established and we were on course to an unmitigated disaster. But don't let that stop you indicating what the natural processes could be that just happened to coincide with the above.

 

 

I find the determination not to even consider this (e.g. your blogger) rather revealing.

 

I find your determination to ignore the science for an airy fairy notion of it might be down to natural causes far more revealing.

 

 

The recent steadily decline was happily being attributed to the elimination of most sources, but now it has increased again that must be because CFCs must be more lived than expected...cookie science I'm afraid.

 

Afraid not. It was always known that CFCs had a long lifetime in the atmosphere which is why action was taken so quickly. There is nothing particularly surprising about the current situation as there will always be yearly fluctuations due to atmospheric processes.

 

Frankly given your philosophy the MP would never have been signed which is straight out of the deniers handbook of let's wait 30 years to see what happens. And if you are going to question established science then it would be appreciated if you would produce some scientific rebuttal or else this area will return to the bad old days.

Edited October 27, 2015 by knocker

[knocker]

Ozone destroyer drops mysteriously

 

Something strange has happened to the atmospheric concentration of a newly discovered, human-made, ozone-destroying gas: it has suddenly dropped and nobody knows why.

The gas, HCFC-133a, is a type of hydrochlorofluorocarbon, ozone-destroying compounds used in some industrial processes, including the manufacturing of refrigerants. The use of HCFCs, which are also powerful greenhouse gases, is restricted under the Montreal Protocol. A study last year first identified HCFC-133a as one of four previously undetected human-made gases in the atmosphere that are contributing to destruction of the ozone layer, but the source of HCFC-133a remains a mystery.

 

http://blogs.agu.org/geospace/2015/10/06/ozone-destroyer-drops-mysteriously/

[knocker]

Grounding line retreat of Totten Glacier, East Antarctica, 1996 to 2013

 

Totten Glacier, East Antarctica, a glacier that holds a 3.9 m sea level change equivalent, has thinned and lost mass for decades. We map its grounding line positions in 1996 and 2013 using differential radar interferometry (InSAR) data and develop precise, high-resolution topographies of its ice surface and ice draft using NASA Operation IceBridge data, InSAR data, and a mass conservation method. We detect a 1 to 3 km retreat of the grounding line in 17 years. The retreat is asymmetrical along a two-lobe pattern, where ice is only grounded a few 10 m above sea level, or ice plain, which may unground further with only modest amounts of ice thinning. The pattern of retreat indicates ice thinning of 12 m in 17 years or 0.7±0.1 m/yr at the grounding line on average. Sustained thinning will cause further grounding line retreat but may not be conducive to a marine instability.

 

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065701/full

 

Article

 

http://www.washingtonpost.com/news/energy-environment/wp/2015/10/26/east-antarcticas-biggest-glacier-is-melting-from-below-study-confirms/

[knocker]

The ozone hole reached its peak on 10/2 expanding to 10.9 million square miles. Details here http://go.usa.gov/ccwbT 

 

 

Cold temperatures fuel ozone loss

Unusually cold temperature and weak dynamics in the Antarctic stratosphere this year resulted in this larger ozone hole. In comparison, last year the ozone hole peaked at 24.1 million square kilometers (9.3 million square miles) on Sept. 11, 2014. Compared to the 1991-2014 period, the 2015 ozone hole average area was the fourth largest.

“While the current ozone hole is larger than in recent years, the area occupied by this year’s hole is consistent with our understanding of ozone depletion chemistry and consistent with colder than average weather conditions in Earth’s stratosphere, which help drive ozone depletion,†said Paul A. Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The ozone hole is a severe depletion of the ozone layer above Antarctica that was first detected in the 1980s. The Antarctic ozone hole forms and expands during the Southern Hemisphere spring (August and September) because of the high levels of chemically active forms of chlorine and bromine in the stratosphere. These chlorine- and bromine-containing molecules are largely derived from man-made chemicals that steadily increased in Earth’s atmosphere up through the early 1990s.

[BornFromTheVoid]

Interesting new study based on satellite altimeter measurements of Antarctica (measure ice height using lasers)

 

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses

 

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

 

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

 

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed   to 82 billion tons of ice per year between 2003 and 2008.

 

More here http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

[stewfox]

Interesting new study based on satellite altimeter measurements of Antarctica (measure ice height using lasers)

 

 

More here http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

 

Given Antarctica is effectively a desert for snow (low precipitation) I would have though any warming would lead to increase snow

 

Glad to see some empirical evidence to supports it

Edited November 1, 2015 by stewfox

[BLAST FROM THE PAST]

Given Antarctica is effectively a desert for snow (low precipitation) I would have though any warming would lead to increase snow

 

Glad to see some empirical evidence to supports it

 

Which then leads to increased ice...as we are seeing which happens over long periods of time.  Interesting too that its taking a measurement away from sea level rise.  

I remember an article too saying Antartica had been cooling overall for 30 year...it may have been the interiror and Eastern side of the continent.  I believe that the western peninsula is being affected by geo thermal activity in that region.

 

 

BFTP

Edited November 2, 2015 by BLAST FROM THE PAST

[Methuselah]

Is there any evidence for a substantial increase in geothermal activity, Fred? Possibly, just possibly, that part of the continent is simply warming, along with the rest of the planet?

[Hocus Pocus]

Is there any evidence for a substantial increase in geothermal activity, Fred? Possibly, just possibly, that part of the continent is simply warming, along with the rest of the planet?

Without wanting to sound pedantic but the globes surface hasn't shown any increases in warming for over 18 years, of course that's not to say the warming in Antarctica isn't related to the anthropogenic effect, or otherwise.

[Methuselah]

Without wanting to sound pedantic but the globes surface hasn't shown any increases in warming for over 18 years, of course that's not to say the warming in Antarctica isn't related to the anthropogenic effect, or otherwise.

What, with last year and this year both recording all-time highs? I thought the 'pause', 'hiatus', or whatever the preferred term is, has been shown to be non-existent? Anwho, I was merely asking about the presence, or not, of evidence of any unusual degree of geothermal energy...Sufficient to warm part of a continent?  

[Hocus Pocus]

What, with last year and this year both recording all-time highs? I thought the 'pause', 'hiatus', or whatever the preferred term is, has been shown to be non-existent? Anwho, I was merely asking about the presence, or not, of evidence of any unusual degree of geothermal energy...Sufficient to warm part of a continent?  

The former has been discredited Ed, the hiatus continues for now but with a strong Nino in place until the end of the year at least that should put an end to that argument. The geothermal point is one I've looked at but I've seen very little evidence to suggest that this is the case here, although I wouldn't discount it either but theres so little we know about our oceans that any theories put forward haven't got sufficient evidence to back them up, yet.

[knocker]

Without wanting to sound pedantic but the globes surface hasn't shown any increases in warming for over 18 years, of course that's not to say the warming in Antarctica isn't related to the anthropogenic effect, or otherwise.

 

Streuth don't tell me that old chestnut is still doing the rounds.

 

The alleged hiatus in global warming didn’t happen, new research shows.

 

 

There are two new scientific research papers looking at variation over the last century or so in global warming. One paper looks at the march of annual estimates of global surface temperature (air over the land plus sea surface, not ocean), and applies a well established statistical technique to ask the question: Was there a pause in global warming some time over the last couple of decades, as claimed by some?

 

The answer is, no, there wasn’t.

 

The paper is open access, is very clearly written so it speaks for itself, and is available here. One of the authors has a blog post here, in German.

 

The other paper looks at the so called global warming “pause†and interrogates the available data to see if the pause is supported. It concludes that it isn’t. The paper is written up in a blog post by one of the authors, here.

 

http://scienceblogs.com/gregladen/2015/08/04/the-alleged-slowdown-in-global-warming-didnt-happen-new-research-shows/

 

Or check out Nick Stokes

 

http://www.moyhu.blogspot.com.au/p/temperature-trend-viewer.html

 

Or a graph.

[Methuselah]

And now, I think, we should all go back to discussing what the thread's actually about...Antarctic ice?  

[Hocus Pocus]

Makes the MetO look daft then.

 

http://www.metoffice.gov.uk/research/news/recent-pause-in-warming

 

More so when countless climate scientists agreed on the pause, so that makes any future predictions and  literature just as vulnerable to change then.

[Methuselah]

Be that as it may, HP...anyone else wants to 'discuss' the 'pause' your posts will be deleted. We've all had our say. So, back to the topic - Antarctic ice!

[Hocus Pocus]

Be that as it may, HP...anyone else wants to 'discuss' the 'pause' your posts will be deleted. We've all had our say. So, back to the topic - Antarctic ice!