Antarctic Ice Discussion

[stewfox]

Ok

 

Is your signature referring to Antarctic ice in general or sea ice?

 

Global sea ice , suggest we leave that for a while. 

[knocker]

With all of this quibbling over graphs (and the misinterpretation of same) let's not lose sight of other important aspects so a reminder of a recent paper.

 

Gravity data show that Antarctic ice sheet is melting increasingly faster

 

During the past decade, Antarctica's massive ice sheet lost twice the amount of ice in its western portion compared with what it accumulated in the east, according to Princeton University researchers who came to one overall conclusion — the southern continent's ice cap is melting ever faster.

 

The researchers "weighed" Antarctica's ice sheet using gravitational satellite data and found that from 2003 to 2014, the ice sheet lost 92 billion tons of ice per year, the researchers report in the journal Earth and Planetary Science Letters. If stacked on the island of Manhattan, that amount of ice would be more than a mile high — more than five times the height of the Empire State Building.

 

http://www.princeton.edu/main/news/archive/S43/04/11E77/index.xml?section=topstories

Edited August 23, 2015 by knocker

[BornFromTheVoid]

Antarctica sea ice area now lowest on record for the time of year.

 

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

[stewfox]

Antarctica sea ice area now lowest on record for the time of year.

 

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

100 days ago it was the highest on record and now the lowest on record.

 

That is a amazing turnaround which is cause for celebration at IPCC head office (supporting picture attached)

Edited August 24, 2015 by stewfox

[Gray-Wolf]

100 days ago it was the highest on record and now the lowest on record.

 

That is a amazing turnaround which is cause for celebration at IPCC head office (supporting picture attached)

 

And will hopefully highlight just how frail the extensions to the sea ice actually are? We are talking about the furthest ice away from the coast and so the thinnest. One storm , as we have seen many years when approaching max, and you lose a million sq km. when this occurs in the Arctic we have all sort of debates about it ( GAC12) but down south it passes without comment???

 

If last year was the transition ( PDO had only just swung Positive and nino was trying to form) then this year may show us the fully fledged 'new' forcings that this configuration of naturals/AGW drives?

 

It does have me wondering just how melt season will progress and how the 'new' forcings treat Ross/Thwaites/P.I.G. ( and the rest of course!) over the Southern Summer?

[stewfox]

And will hopefully highlight just how frail the extensions to the sea ice actually are? We are talking about the furthest ice away from the coast and so the thinnest. One storm , as we have seen many years when approaching max, and you lose a million sq km. when this occurs in the Arctic we have all sort of debates about it ( GAC12) but down south it passes without comment???

 

If last year was the transition ( PDO had only just swung Positive and nino was trying to form) then this year may show us the fully fledged 'new' forcings that this configuration of naturals/AGW drives?

 

It does have me wondering just how melt season will progress and how the 'new' forcings treat Ross/Thwaites/P.I.G. ( and the rest of course!) over the Southern Summer?

 

El Niño activity is clearly regarded as key driver in this change

 

If wind activity can explain all of the recent years +Ve abnormalities and we see a key driver (El Nino) switch the extent back to average to below in the next few years then 'hats off etc'

 

I'm not sure if there is a strong correlation between EL nino years and reduced extent  , there is a 'suggestion' there is, in the attached report which Knocker found.

 

http://hot-topic.co.nz/antarctic-sea-ice-the-end-of-the-trend/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+co%2FRbRF+%28Hot+Topic%29

Edited August 25, 2015 by stewfox

[Gray-Wolf]

The report appears to go further and link the end of the 'hiatus' to the end of extreme ice extents around Antarctica? 

 

With the ongoing reports of extreme events around the globe this year what vestiges of disinformation will the 'paid deniers' feed their faithful with from here on in??? surely not 'fudged/altered' data alone???

[BornFromTheVoid]

CT area shooting upward again, +250k in the last day. Now well away from record low territory.

[knocker]

The current wind regime looks quite a bit different to the chart posted above

Chart weatherbell

 

[stewfox]

CT area shooting upward again, +250k in the last day. Now well away from record low territory.

 

 

NSIDC made a good call.

 

Extent up 500,000 in the last week.

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?S

 

With another month of refreeze will be interesting where we end up

[Relativistic]

NSIDC made a good call.

 

Extent up 500,000 in the last week.

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?S

 

With another month of refreeze will be interesting where we end up

 

The extent increased by a million square kilometers from 21st August to the 29th:

 

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

In fact, the 2015 extent for the 29th is only 350 000 square kilometers lower than the 2014 extent for the same date!

Edited September 1, 2015 by Relativistic Sting Jet

[Nights King]

http://www.theguardian.com/environment/2015/sep/11/burning-all-fossil-fuels-will-melt-entire-antarctic-ice-sheet-study-shows

 

Has anyone seen this latest article? Not convinced whatsoever that all the ice could ever melt out?

[Gray-Wolf]

I think folk need read up on the levels of atmospheric CO2 when Antarctica first started to amass ice? Never mind the GHG's we are feeding into the atmosphere from a reserve long locked away from the Carbon cycle but we also have remnants of the carbon cycle that used to exist buried beneath the ice. We stuff our fossil fuel GHG's into the air and then Nature will shove her contribution up there for good measure........ How much GHG forcing do we need? The only 'unknown' is the time it takes to melt out all that ice?

[Nights King]

I think folk need read up on the levels of atmospheric CO2 when Antarctica first started to amass ice? Never mind the GHG's we are feeding into the atmosphere from a reserve long locked away from the Carbon cycle but we also have remnants of the carbon cycle that used to exist buried beneath the ice. We stuff our fossil fuel GHG's into the air and then Nature will shove her contribution up there for good measure........ How much GHG forcing do we need? The only 'unknown' is the time it takes to melt out all that ice?

 

Surely even a 10c rise would not be warm enough to thaw out the land?!

[knocker]

It is a research article covering the next 10,000 years.

 

Article

 

http://advances.sciencemag.org/content/1/8/e1500589.full

 

A couple of videos might be of interest

 

 

 

 

Edited September 12, 2015 by knocker

[Gray-Wolf]

Though I fully accept the risks from the oceans we appear have very little understanding of the mechanical collapse of the ice as the glacier/shelf deflates? We know that ice can only stand 200ft high before it is no longer 'stable' and will collapse........we have 2 mile depths of ice over Antarctica....... During the last deglaciation we noted 'saddle and lobe' melt with upland ice ( saddle) collapsing into the lower areas ( lobe) under gravity.Of course lower down thew temps are higher so melt occurs there. Are we set to see this behaviour compound the losses from ocean forcing?

[BornFromTheVoid]

Antarctic sea ice area back to 4th lowest on CT. Quite a variable winter down there

[Relativistic]

A very odd year, and possibly a very early maximum (around 5th September). Anyone know which year had the earliest maximum?

 

Given the extensive area of anomalously cold SSTs down there I suppose there is the potential for another refreeze before the melt season starts, but time is running out.

[Gray-Wolf]

I don't think we'll see it regain the dizzy heights it made this time last year? it'd need to put on 2.4 million overnight!!!! 

 

It has meant that global sea ice levels have returned to their 2007/2012 levels after seeming to 'recover' over recent years?

 

So , is this Nino? is this Pacific cycles flipping positive ( PDO/IPO)? is it a combination of both?

 

If Nino we should expect the opposite once Nina sets in but if the other naturals have inputed then any Nina counter would be impacted by the naturals?

 

We know the models show Antarctic Sea ice collapse before 2050 so are we regaining that trajectory that the past decades of Pacific forcings had swamped since the early 80's?

[stewfox]

 

We know the models show Antarctic Sea ice collapse before 2050 so are we regaining that trajectory that the past decades of Pacific forcings had swamped since the early 80's?

 

I will be interesting to see what the mins are for their summer.

 

Sea ice , both hemispheres is always going to be subject to natural seasonal variations although this year has been marked

[Gray-Wolf]

I think if you are a 'natural forcing' then when you are chipping away against the grain ( i.e. cooling a warming world) you will make a different 'impact' to plots than when you suddenly do a 180 and begin to go 'with' the grain?

 

If we have seen naturals fighting against a warming trend and making progress over the 80's onward then maybe we are at the end of an oscillation (mainly impacting the southern ocean and Antarctica?) would see a rapid reverse in the sea ice fortunes as 'naturals' add into the background warming?

 

It might be just the impacts of Nino and so a short term 'change' in the current trend or it might be a first sight of the 'new' direction that the flip of Naturals, to such as to augment to background warming, has driven? If the latter then expect a poor ice year next winter and it be Ross that bares the losses?

[knocker]

US National Ice Center in August, labelled B-35, it was reported to be 12.66 miles (20.4 km) long by 8 miles (12.8 km) wide. The iceberg indicated in the Sept. 24 image is not B-35.  It is much smaller than B-31 that broke off in 2013, but is approximately 14 km long and 8 km wide.  There are two other icebergs indicated that also broke off over the winter from Pine Island Glacier, into the polyna.

As Operation IceBridge begins its 2015 southern campaign I am sure we will learn much more about this iceberg. Details on the 2013 Calving illustrate a slower process from rift formation to calving. Pine Island Glacier is remains a key glacier that is undergoing rapid change.

[Tasboy]

A very odd year, and possibly a very early maximum (around 5th September). Anyone know which year had the earliest maximum?

 

 

I don't know that it is all that odd. Interesting, but not odd.

 

Yes. 1994 had the earliest annual daily maximum (based on data since 1979) - on 31st August.

See colour coding at http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html

Note that the 2015 data are based on the NASA Team near-real-time data and will be updated once their final data are available.

[Relativistic]

I don't know that it is all that odd. Interesting, but not odd.

 

Yes. 1994 had the earliest annual daily maximum (based on data since 1979) - on 31st August.

See colour coding at http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html

Note that the 2015 data are based on the NASA Team near-real-time data and will be updated once their final data are available.

 

Fantastic, thanks for the link.

 

By odd I was referring to the fact that May saw the highest sea ice area on record, whereas during the SH Winter months the values have been close to or at the lowest on record a number of times.

[Tasboy]

Fantastic, thanks for the link.

 

By odd I was referring to the fact that May saw the highest sea ice area on record, whereas during the SH Winter months the values have been close to or at the lowest on record a number of times.

No probs.

 

Yes, the growth in areal extent did slow quite quickly. But it's not an unusual event - not unusual enough to perhaps make it "odd", but we won't worry about semantics. The sea ice distribution (and seasonality) is responding to one of its main drivers - ENSO. A similar thing happened in 2008 as the Pacific went from being cool (La Nina) to neutral. Right through January to early May the net sea ice extent was at (for then) record levels but dropped over the next few months to be at below average in September. See the chart here: http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh_extent_anom_past.html.

 

What I find interesting is what might happen next, after this El Nino. There are at least two competing thoughts: sea ice extents will return to their well-above averages; or, we will see the end of the upward trends in sea ice extents.