Antarctic Ice Discussion

[Gray-Wolf]

It appears that the last paragraph of KL's piece is seen to be coming true and that the AGW forced increase in snowfall has indeed been overtaken by ice sheet discharge?

 

I find it odd for KL to be holding up the increased snowfall stat esp. with the knowledge we all now hold on 'refreeze' and the impact of snow on open water? He has also chosen to include mass loss (increased fresh,cold water discharge into the southern ocean) into his logic?

 

Shame he's not included the anomalous winds around Antarctica? Some bright soul might have spotted a link between sea ice rebound (toward its 1950's/1970's average?) and the impacts of these 3 changes?

[knocker]

Not a bad brief overview.

 

http://www.antarcticglaciers.org/glaciers-and-climate/antarctic-ice-sheet-surface-mass-balance/

[keithlucky]

It appears that the last paragraph of KL's piece is seen to be coming true and that the AGW forced increase in snowfall has indeed been overtaken by ice sheet discharge?

 

I find it odd for KL to be holding up the increased snowfall stat esp. with the knowledge we all now hold on 'refreeze' and the impact of snow on open water? He has also chosen to include mass loss (increased fresh,cold water discharge into the southern ocean) into his logic?

 

Shame he's not included the anomalous winds around Antarctica? Some bright soul might have spotted a link between sea ice rebound (toward its 1950's/1970's average?) and the impacts of these 3 changes?

What the articles fail to mention is that the melting is occurring only on the West Antarctic Peninsula, which comprises only 2 percent of the entire Antarctic continent.

[Gray-Wolf]

i think you need to revisit the data KL? If you were focusing on our 1980's knowledge of the topic you's be bang on but science is not like that and we move forward with our data and understanding of the systems we study? The last I heard from Cryosat2 we were looking at mass loss outstripping increased snowfall across near all the continent over the past 3 years?

 

Considering the flux we see Antarctica in I personally would expect to see rapid changes over the next 20 years esp. the ice loss draining from P.I.G. and Wilkes ( but do not ignore Ross as it is now long overdue a 'natural calve' but with the NASA noted snow melt up to 1 mile up in the trans Antarctic range to its rear I have to wonder what impact this has had on the ice streams feeding Ross and whether any major calve leads to a rapid retreat on the Roosevelt island side (like Wilkes is crumbling now?))??? 

 

As if to emphasise that 'flux' we get this;

 

http://scienceblog.com/74633/changing-antarctic-waters-trigger-steep-rise-sea-levels/#Fj2Csqf2Tw8Mrm1W.97

 

sooooooo, the could fresh outflow from the melting ice sheets helps trap the warmed layer below in a feedback loop for the land ice leading to rapid ice sheet losses ( in the past )? 

 

If it wasn't funny enough to see dip sticks heralding a portent of doom as a good news story we now how a glimpse at the final installment  of this period of 'Flux'.........

Edited October 25, 2014 by Gray-Wolf

[knocker]

Mass changes of outlet glaciers along the Nordensjköld Coast, northern Antarctic Peninsula, based on TanDEM-X satellite measurements

 

Abstract

We analyzed volume change and mass balance of outlet glaciers of the northern Antarctic Peninsula over the period 2011 to 2013, using topographic data of high vertical accuracy and great spatial detail, acquired by bistatic radar interferometry of the TanDEM-X/TerraSAR-X satellite formation. The study area includes glaciers draining into the Larsen-A, Larsen Inlet, and Prince-Gustav-Channel embayments. After collapse of buttressing ice shelves in 1995 the glaciers became tidewater calving glaciers and accelerated, resulting in increased ice export. Downwasting of most glaciers is going on, but at reduced rates compared to previous years in accordance with deceleration of ice flow. The rate of mass depletion is 4.2 ± 0.4 Gt a^−1, with the largest contribution by Drygalski Glacier amounting to 2.2 ± 0.2 Gt a^−1_. On the technological side, the investigations demonstrate the capability of satellite-borne single-pass radar interferometry as a new tool for accurate and detailed monitoring of glacier volume change.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014GL061613/pdf

[Gray-Wolf]

http://io9.com/weve-lost-so-much-antarctic-ice-its-causing-a-dip-in-ea-1639502535/all

 

So how will the deniers argue against that little nugget? Well they could always deny the data? , criticise the equipment? Claim its all propaganda? Ignore it?......... they will certainly not embrace it that's for sure!

 

Even with enhanced snowfall over the region we see losses so great as to alter the earths gravity over the region...... that's a lot of melt........ how long before Greenland/Antarctica are the main drivers of global sea level rise? With the doubling of losses less than ten years how long before we see hikes in sea level that even Four can't put down as meaningless?

[knocker]

Earliest satellite images of Antarctica reveal highs and lows for sea ice in the 1960s

https://www.climate.gov/news-features/featured-images/earliest-satellite-images-antarctica-reveal-highs-and-lows-sea-ice?utm_content=bufferfaf02&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

Cause of Melting Antarctic Ice Caps Revealed by Robots

http://www.caltech.edu/content/robotic-ocean-gliders-aid-study-melting-polar-ice

Edited November 10, 2014 by knocker

[Nights King]

Cause of Melting Antarctic Ice Caps Revealed by Robots

http://Robotic Ocean Gliders Aid Study of Melting Polar Ice - See more at: http://www.caltech.edu/content/robotic-ocean-gliders-aid-study-melting-polar-ice#sthash.9R4advzY.dpuf

 

Link seems to be broken as it just opens up this page again?

[knocker]

Link seems to be broken as it just opens up this page again?

 

Ta. It would have helped if I'd put in correctly in the first place. It's okay now.

[keithlucky]

Cause of Melting Antarctic Ice Caps Revealed by Robots

http://www.caltech.edu/content/robotic-ocean-gliders-aid-study-melting-polar-ice

Robot sub finds suprisiing thick Antarctic ice  http://t.co/fGpehwzA9U

[knocker]

To add some meat to the bone regarding the above.

 

Thick and deformed Antarctic sea ice mapped with autonomous underwater vehicles

 

Satellites have documented trends in Antarctic sea-ice extent and its variability for decades, but estimating sea-ice thickness in the Antarctic from remote sensing data remains challenging. In situ observations needed for validation of remote sensing data and sea-ice models are limited; most have been restricted to a few point measurements on selected ice floes, or to visual shipboard estimates. Here we present three-dimensional (3D) floe-scale maps of sea-ice draft for ten floes, compiled from two springtime expeditions by an autonomous underwater vehicle to the near-coastal regions of the Weddell, Bellingshausen, and Wilkes Land sectors of Antarctica. Mean drafts range from 1.4 to 5.5 m, with maxima up to 16 m. We also find that, on average, 76% of the ice volume is deformed ice. Our surveys indicate that the floes are much thicker and more deformed than reported by most drilling and ship-based measurements of Antarctic sea ice. We suggest that thick ice in the near-coastal and interior pack may be under-represented in existing in situ assessments of Antarctic sea ice and hence, on average, Antarctic sea ice may be thicker than previously thought.

 

 

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2299.html

 

A good summation by HotWhopper with a couple of vids.

 

http://blog.hotwhopper.com/2014/11/an-unsustainable-planet-and-yellow.html#more

Edited November 25, 2014 by knocker

[knocker]

Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats

 

Abstract. The northern Antarctic Peninsula (nAP, < 66° S) is one of the most rapidly changing glaciated regions on earth, yet the spatial patterns of its ice mass loss at the glacier basin scale have to date been poorly documented. We use satellite laser altimetry and satellite stereo-image topography spanning 2001–2010, but primarily 2003–2008, to map ice elevation change and infer mass changes for 33 glacier basins covering the mainland and most large islands in the nAP. Rates of ice volume and ice mass change are 27.7± 8.6 km³ a^−1 and 24.9± 7.8 Gt a^−1, equal to −0.73 m a^−1 w.e. for the study area. Mass loss is the highest for eastern glaciers affected by major ice shelf collapses in 1995 and 2002, where twelve glaciers account for 60% of the total imbalance. However, losses at smaller rates occur throughout the nAP, at both high and low elevation, despite increased snow accumulation along the western coast and ridge crest. We interpret the widespread mass loss to be driven by decades of ice front retreats on both sides of the nAP, and extended throughout the ice sheet due to the propagation of kinematic waves triggered at the fronts into the interior.

 

http://www.the-cryosphere.net/8/2135/2014/tc-8-2135-2014.pdf

[stewfox]

Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats

 

http://www.the-cryosphere.net/8/2135/2014/tc-8-2135-2014.pdf

 

The area you refer to is just under 1% of the land area of Antarctica

 

It will be interesting when more research is done on the Eastern Antarctica which is 60 times the area and 2000 times the ice volume

 

Would be interesting to see how this desert for dryness is influence in future years by man/natural fluctuation just think if you increase snow fall by 20% in the interior what impact that would have of global sea levels

[knocker]

Anthropogenic influence on recent circulation-driven Antarctic sea-ice changes

 

Abstract

Observations reveal an increase of Antarctic sea ice over the past three decades, yet global climate models tend to simulate a sea-ice decrease for that period. Here, we combine observations with model experiments (MPI-ESM) to investigate causes for this discrepancy and for the observed sea-ice increase. Based on observations and atmospheric reanalysis, we show that on multi-decadal time scales Antarctic sea-ice changes are linked to intensified meridional winds that are caused by a zonally asymmetric lowering of the high-latitude surface pressure. In our simulations, this surface-pressure lowering is a response to a combination of anthropogenic stratospheric ozone depletion and greenhouse gas increase. Combining these two lines of argument, we infer a possible anthropogenic influence on the observed sea-ice changes. However, similar to other models, MPI-ESM simulates a surface-pressure response that is rather zonally symmetric, which explains why the simulated sea-ice response differs from observations.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014GL061659/abstract?utm_content=buffer624c7&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

West Antarctic melt rate has tripled

 

WASHINGTON, D.C. – A comprehensive, 21-year analysis of the fastest-melting region of Antarctica has found that the melt rate of glaciers there has tripled during the last decade.

 

The glaciers in the Amundsen Sea Embayment in West Antarctica are hemorrhaging ice faster than any other part of Antarctica and are the most significant Antarctic contributors to sea level rise. This study by scientists at the University of California, Irvine (UCI), and NASA is the first to evaluate and reconcile observations from four different measurement techniques to produce an authoritative estimate of the amount and the rate of loss over the last two decades.

 

http://news.agu.org/press-release/west-antarctic-melt-rate-has-tripled/

[knocker]

Antarctic seawater temperatures rising

The temperature of the seawater around Antarctica is rising according to new research from the University of East Anglia.

Read more at: http://phys.org/news/2014-12-antarctic-seawater-temperatures.html#jCp

[keithlucky]

Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats

 

http://www.the-cryosphere.net/8/2135/2014/tc-8-2135-2014.pdf

http://www.climatedepot.com/2014/12/09/geologist-dr-don-easterbrook-the-west-antarctic-ice-sheet-is-not-collapsing-the-retreat-of-these-small-glaciers-is-not-caused-by-global-warming/

Edited December 9, 2014 by keithlucky

[knocker]

IMO people like Morano and Easterbrook have no place whatsoever in any reputable scientific discussion. They are just lackeys of the Heartland Institute which is an oil funded cabal of climate deniers.

 

EDIT

I should have added if the original post had been in the sceptical thread I wouldn't have replied.

 

http://mediamatters.org/research/2012/12/27/climate-change-misinformer-of-the-year-marc-mor/191878

 

http://www.desmogblog.com/2013/09/10/climate-denial-playbook-marc-morano-s-history-bullying-scientists

 

http://www.desmogblog.com/don-easterbrook

 

http://www.skepticalscience.com/don-easterbrook-heartland-distortion-of-reality.html

Edited December 10, 2014 by knocker

[Gray-Wolf]

Seems odd that KL's linked piece looks at 'current rates' when we know that local conditions had reversed the speed of loss, due to ENSO teleconnections, since 2012??? Too nice a cherry to ignore? ( a common theme with misleaders to zone in on any small trend buck to discredit research done on the trend?).

 

As it is we are now entering the opposite ENSO forcing and look to be exiting the forcings that underlay the 'faux pause' in warming in atmospheric global temps? How do we think the southern continent will react to this suite of forcings?

 

For me the Elephant in the room is just down the coast from the Pine island/Thwaites complex. We know that the warm bottom waters have now reached Ross and that any issues with the ice shelf ( the size of France and many hundreds of feet thick) will bring both instant consequences to sea level but also set us on the track to the kind of ice coverage last seen when global CO2 was at current levels ( ice free west Antarctica and no Ross ice shelf and Greenland with 2/3rds current ice cover).

 

The next major calve from Ross is due and the fissure running from Roosevelt island to the central shelf looks favourite to be the site? This would be larger than the last major calve and allow the warmer waters access to the ice front/sea floor contact further into the glaciers feeding this end of Ross ( Ross is a drain for large sections of the EAIS).

[knocker]

Eric Steig on sea ice trends. I found this quite compelling.

 

Making sense of Antarctic sea ice changes

 

http://climatechangenationalforum.org/making-sense-of-antarctic-sea-ice-changes/

Edited December 11, 2014 by knocker

[stewfox]

 

Eric Steig on sea ice trends. I found this quite compelling.

 

Making sense of Antarctic sea ice changes

 

http://climatechangenationalforum.org/making-sense-of-antarctic-sea-ice-changes/

 

 

Not sure if its 'making sense' it does seem to suggest that a westerly element (wind) is too simplistic to explain the increasing Antarctica sea ice but he looks at different wind patterns. The actual causes of the wind changes are not looked into or why the Arctic doesn't match it in anyway (I appreciate the topography is different) but even so. However there isn't much spin so a interesting read.

Edited December 14, 2014 by stewfox

[knocker]

Eric Steig isn't really in to spin Stew.

 

http://earthweb.ess.washington.edu/~steig/

[keithlucky]

Scientists worried about possible eurption of volcano under the west Antarctic ice sheet http://news.yahoo.com/violent-volcanic-blasts-ripped-antarctic-ice-sheet-twice-115608903.html

Edited December 18, 2014 by keithlucky

[stewfox]

Eric Steig isn't really in to spin Stew.

 

http://earthweb.ess.washington.edu/~steig/

 

I said there wasn't much spin which was re freshing