Antarctic Ice Discussion

[oldsnowywizard]

Let's wait and see what becomes of the bootstrap issues before we start calling for such records eh? We now know there is a major problem with the counting of ice down there so before we all go scrabbling for understanding lets now make sure there is a reason for such?

GW i get the impression you would argue white was black.. its a wonder keith keeps posting on here as it seems to me everytime he posts something he immediately gets a strong retort from a few on here.. even if there was an issue with the bootstrap issues it doesnt take much away from the fact that the current data suggests an increase.. the reasons why can be argued for the next 50 years.. we dont know enough about the area down there so all we can rely on is what we have... which shows an increase... it looks to me like we could be close to the minimum..

[Gray-Wolf]

If we find that the crossover in the early portion of the sat era inflated later extents then we may be looking at ice levels returning to the levels we saw in the early 80's? That's a big change from "Highest ever recorded on this date" isn't it?

 

Until we get confirmation that the data has been re-aligned we should all be careful with what we have been 'believing' about what was going on down there?

 

When we did not know that there was an issue we needed to look for reasons for the anomalies but now the data is not 'sound' we should hold fire lest we end up looking foolish in our thirst for good news?

[4wd]

"More adjustments needed" to keep the data on message.

[BornFromTheVoid]

"More adjustments needed" to keep the data on message.

 

It's the adjustments that may have increased the trend, so it's sensible to suggest caution until the issues are resolved.

 

Of course, when the adjustments aren't in favour of the "AGW sceptics" there's claims of grand conspiracies. it should be surprising how different the reactions are when adjustments are actually in favour of the "AGW sceptics", but then, "sceptic" is a misnomer in this situation. 

[Gray-Wolf]

As we've said earlier in the thread this is another example of science doing what science does to enable the end product to always be a more refined understanding than earlier understandings?

 

When I hear folk complaining about science moving forward I have to wonder just what kind of 'scientists' they would make? I also cannot see 'change' as a 'winners and losers' thing? We all win if the data is more accurate surely?

 

It is a shame we see the kind of dismissal we occasionally get from some posters? When they benefit from a scientific advance in their daily living do they treat it in the same way? Did they whine on about having to go from dial up to broadband I wonder?

[Tasboy]

It's not a Bootstrap issue. NASA Team (independent from Bootstrap) is also showing the highest ever summertime area and extent for Antarctica:

http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html

http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_area.html

 

Now, I wonder what's causing that?

[Gray-Wolf]

 

If you take a look Tas you'll see just where the 'stubborn ice is? You can also see a couple of 'tongues' in that area that will suddenly drop off over the coming days?

We have been treated to new data on the Strengthening of the trade winds over this warming slowdown and this is similar to seeing a permanent La Nina which , in Antarctica, alters some of the wind fields.

If you look at Weddell you can see that it is well protected from the stormy southern oceans by the peninsula but recently the large polynia  that we used to see up against the coast of weddell has been very muted since 07'. This plumps up the sea ice area there not via extension into the southern ocean ( which like those tongues would be prey to southern ocean weather?) but inside The protection of the Weddell Perennial ice.

 

As for the 'bootstrap' issue. Nobody is saying that Antarctic sea ice has not increased over the period since the 80's. it may well have increased more than we currently think? It is just that the data has been shown to have a glitch at a couple of points when algorithms were switched. As we've said many times it is better to investigate ice growth when we know what that growth is than be tempted to explain the mechanisms only to find that wrong because such growth was not occuring ( or was much larger)?

[Gray-Wolf]

Well that 'stubborn ice' lost a goodly portion today and looks likely to do the same over the next 7 days at least?

 

Should we begin posting it's decline into the pack of other years, as ice levels become lower than recent years, or is that not a 'thing'?

[BARRY]

Well that 'stubborn ice' lost a goodly portion today and looks likely to do the same over the next 7 days at least?

 

Should we begin posting it's decline into the pack of other years, as ice levels become lower than recent years, or is that not a 'thing'?

how the hell can you say that ice levels are getting lower when they are higher than anytime since 1979

[Gray-Wolf]

how the hell can you say that ice levels are getting lower when they are higher than anytime since 1979

 

I believe I just did? Take a look at ice concentrations with over 4 weeks of melt to go? Weddell has been the main area to 'plump up' ice figures but this year the central section is thinning and the polynya looks set to appear?

[Tasboy]

Yes, GW, sea ice in the Weddell has well and truly started to retreat. However, total (net) sea ice is still close to record levels for this time of the year and coastal exposure (http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh_coastal_exposure.html) is also.

 

It never ceases to amaze me how quickly things can happen down there. Have a look at the sea ice just to the west of the Ross Sea - about 150E to 180E (http://www.cawcr.gov.au/staff/preid/seaice/gsfc_daily_maps.html). Flick back to the 22nd of December 2013 and move forward a few days. Notice how quickly the one cyclonic event can impact on what was highly concentrated sea ice in this region. And despite the (relative) cold SSTs in that region (http://www.cawcr.gov.au/staff/preid/sst/reynolds_antarctic.html) it didn't recover.

 

I hope things are well there in the soggy UK.

[knocker]

We are just awaiting the next storm Tasboy, due in a few hours. I must admit it's been pretty grim for many.

[Gray-Wolf]

The final days of melt season are always exciting! The next storm down there might drop levels further? Now we're getting more of an idea as to how the Nina impacts Pig melt we might find other drivers impacting Weddell in the same way? Could the PDO/Nina/Southern Oscillation cause differing wind patterns across the peninsula allowing ice to be pushed further out into Weddell than the circumpolars normally allow? If so then the 20 years of extra growth may well quickly reverse as the forcings 'flip' back to the other sign?

 

There still looks to be some easy losses across Weddell and the rest of the remnant ice so maybe we'll see levels fall back further into the pact of earlier years?

[knocker]

FLORAL ENCROACHMENT

 

One of the more unusual pieces of evidence that the Antarctic is changing can be seen on the Antarctic Peninsula. where Professor Lloyd Peck. individual merit scientist at the BAS, and colleagues have documented plants growing where there was ice 25 years ago. And looking out to sea, the picture becomes even more stark. Along the Antarctic Peninsula alone. Peck and colleagues estimate that an area of more than 5,100 square kilometres that was covered by sea ice before the 1980s is now open water in summer. The US National Snow and Ice Data Centre (NSIDC) has also noted similar decreases in sea ice around the Bellingshausen/ Amundsen sea.

 

Elsewhere on the continent. 87 per cent of the 244 marine glaciers have retreated over the past 50 years. Peck says. 'We know we can never convince the die-hard sceptic. and no one event can be directly attributed to climate change- but we can say we understand how the Southern Ocean works, we understand how the wind and weather patterns work. and the warming of the Antarctic Peninsula is entirely consistent with a global warming effect." he says. 

A reminder of a couple of papers from last year.

 

Summer melt season is getting longer on the Antarctic Peninsula, new data show

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=2113

 

Global warming expands Antarctic sea ice

http://www.nature.com/news/global-warming-expands-antarctic-sea-ice-1.12709

Edited February 20, 2014 by knocker

[knocker]

Previous rapid thinning of Pine Island Glacier sheds light on future Antarctic ice loss

 

New research, published this week in Science, suggests that the largest single contributor to global sea level rise, a glacier of the West Antarctic Ice Sheet, may continue thinning for decades to come. Geologists from the UK, USA and Germany found that Pine Island Glacier (PIG), which is rapidly accelerating, thinning and retreating, has thinned rapidly before. The team say their findings demonstrate the potential for current ice loss to continue for several decades yet.

 

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=2514

[knocker]

Bit more of same.

 

https://www.llnl.gov/news/newsreleases/2014/Feb/NR-14-02-12.html#.Uwfhls7FCVI

 

Corrected the link.

Edited February 21, 2014 by knocker

[keithlucky]

Nonsense talked on here Antarctic Sea ice 23% above normal

[Crepuscular Ray]

Keith, is that extent or volume?

[knocker]

Nonsense talked on here Antarctic Sea ice 23% above normal

 

I sometimes wonder whether you are being deliberately obtuse and if it's me that's talking nonsense I'd rather you said.

 

I think everyone on here is aware that NSIDC reckon Antarctic September sea ice has been increasing at 1.1 per cent per decade relative to the 1981-2010 average, mainly around the southern Indian Ocean and Ross Sea. This increase has been discussed enough times.

 

But the recent discussions have been about the ice sheet, and not sea ice unless you are disputing BAS observations around the Peninsula.

 

To recap briefly. The science is emphatic- parts of Antarctica are among the most rapidly warming regions on Earth. According to scientists at the British Antarctic Survey (BAS), air temperatures at some weather stations are 'rising at four to six times the global average rate'. On the Antarctic Peninsula, the air temperature has increased by as much as 3°C( in the past 50 years),

The impact of this temperature rise is being felt across the continent. On the small scale, it has led to an increase in the growth of moss and the activity of soil microbes on the Antarctic Peninsula. On a larger scale, it's causing the volume of ice in the Antarctic Ice Sheet to decline. The ice sheet losses are mainly from the northern Antarctic Peninsula and the Amundsen Sea sector of West Antarctica - primarily from the acceleration of outlet glaciers. In all, the average rate of ice loss from Antarctica has increased five-fold in the two decades, from 30 gigatonnes a year between 1992 and 2001, to 147 gigatonnes a year between 2002 and 2011 (some estimates put the current rate as high as 250 gigatonnes a year).

 

Scientists are now highly confident that the Antarctic Ice Sheet is in a state of net mass loss and that its contribution to sea level is also likely to have increased in the past two decades.

 

Please feel free to tell me I'm talking nonsense.

 

Edited February 22, 2014 by knocker

[knocker]

Keith, is that extent or volume?

 

Extent CR.

[knocker]

Study projects big thaw for Antarctic sea ice

 

Antarctica’s Ross Sea is one of the few polar regions where summer sea-ice coverage has increased during the last few decades, bucking a global trend of drastic declines in summer sea ice across the Arctic Ocean and in two adjacent embayments of the Southern Ocean around Antarctica.

 

Now, a modeling study led by Professor Walker Smith of the Virginia Institute of Marine Science suggests that the Ross Sea’s recent observed increase in summer sea-ice cover is likely short-lived, with the area projected to lose more than half its summer sea ice by 2050 and more than three quarters by 2100.

 

http://www.vims.edu/newsandevents/topstories/ross_sea_thaw.php

Edited February 27, 2014 by knocker

[keithlucky]

Second highest sea ice minimum ever recorded(click red number for source)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(

Edited March 2, 2014 by keithlucky

[knocker]

Global warming felt to deepest reaches of ocean

 

A new study shows that the 1970s polynya within the Antarctic sea ice pack of the Weddell Sea may have been the last gasp of what was previously a more common feature of the Southern Ocean, and which is now suppressed due to the effects of climate change on ocean salinity.

 

http://www.sciencedaily.com/releases/2014/03/140302143515.htm

[Gray-Wolf]

We also see the impacts of the warming planet on freshening the southern oceans...... and fresher surface water means quicker freezing..... odd that eh? glacier run off and more rain? you could even expect more ice to form eh?

 

I also wonder what the loss of the polynia does to ice extent/area? a hole the size of New Zealand healing up? What if we subtracted such an area from current sea ice levels down there??? 

[knocker]

A little more on this.

 

http://www.dailykos.com/story/2014/03/05/1281907/-The-Antarctic-Half-of-the-Global-Thermohaline-Circulation-is-Collapsing