Antarctica Has Sea Ice Rabbit Ears, a V for Victory or Maybe It's a Peace Sign?…

Leo Geiger says:
January 19, 2014 at 1:47 pm

That’s not an additional “fact”…

Keep is simple then. Is the grounding line of Pine Island glacier retreating? No computer models needed to answer that. Is it retreating while Antarctic sea ice extent has grown?…..

Leo, you might be interested in the following. Furthermore check out 2,200 year ago volcanic explosion spreading ash, got buried and is today causing much slip and slide.
http://dx.doi.org/10.1038%2Fngeo106
http://wattsupwiththat.com/2010/06/21/new-research-sheds-light-on-antarcticas-melting-pine-island-glacier/
It must be global warming, hot, bubbling magma just cannot melt a damned thing.
http://www.livescience.com/2242-buried-volcano-discovered-antarctica.html

Do these “fingers of ice” break off and later melt or do they melt without breaking off? Would not a long ice sheet undergo stress (is that the correct word?) from tides and shoaling waves?

FWIW the Larsen B Ice Shelf appears to have regrown since it famously broke up in 2002. Of course the entire area is encased in fast ice, but there does appear to be a clear ridge where the shelf boundary is. A good image date is Dec 19, 2012.

Leo Geiger says:
January 19, 2014 at 3:01 pm
…It’s that simple, eh? But, at the same time, somehow not so simple that one would expect those warm ocean currents to impact observations of calving rates or basal melt (ice shelf elevations)…
>>>>>>>>>>>>>>>
WHAT warm ocean currents?
I think you are mixing up the Arctic that has warm water from the Gulf Stream head in its direction vs the Antarctic with its Antarctic Circumpolar Current or ‘West Wind Drift’ that completely isolates the Continent form waters from the equator.
The opening of Drake Passage at the tip of South America (Cape Horne) allowed this current that completely circles the continent to form plus the closing of the Isthmus of Panama is thought to be the geologic events that sent the earth into the present ice age.
…
From some of my recent searches:
The Cape Horn Current: “…The Cape Horn Current is a cold water current that flows west-to-east around Cape Horn. This current is caused by the intensification of the West Wind Drift as it rounds the cape….” WIKI

The Antarctic Circumpolar Current (ACC) is the most important current in the Southern Ocean, and the only current that flows completely around the globe. The ACC, as it encircles the Antarctic continent, flows eastward through the southern portions of the Atlantic, Indian, and Pacific Oceans…. The Antarctic Circumpolar Current’s eastward flow is driven by strong westerly winds. The average wind speed between 40°S and 60°S is 15 to 24 knots with strongest winds typically between 45°S and 55°S. Historically, the ACC has been referred to as the ‘West Wind Drift’ …
http://oceancurrents.rsmas.miami.edu/southern/antarctic-cp.html

From another source that I trust a heck of a lot more, Maritime Safety Information CHAPTER 31 OCEAN CURRENTS: TYPES AND CAUSES OF CURRENTS I start at the beginning of the passage which talks of the southern Atlantic. The chapter also has a map that shows that some of the cold water heads up along the west coast of South America. And it show the West Wind Drift as COLD water going round and round the continent of Antarctica.

…That branch of the South Equatorial Current which curves toward the south off the east coast of South America, follows the coast as the warm, highly-saline Brazil Current, which in some respects resembles a weak Gulf Stream. Off Uruguay it encounters the colder, less-salty Falkland or Malvinas Current forming a sharp meandering front in which eddies may form. The two currents curve toward the east to form the broad, slow-moving, South Atlantic Current in the general vicinity of the prevailing westerlies and the front dissipates somewhat. This current flows eastward to a point west of the Cape of Good Hope, where it curves northward to follow the west coast of Africa as the strong Benguela Current, augmented somewhat by part of the Agulhas Current flowing around the southern part of Africa from the Indian Ocean. As it continues northward, the current gradually widens and slows. At a point east of St. Helena Island it curves westward to continue as part of the South Equatorial Current, thus completing the counterclockwise circulation of the South Atlantic. The Benguela Current is also augmented somewhat by the West Wind Drift, a current which flows easterly around Antarctica. As the West Wind Drift flows past Cape Horn, that part in the immediate vicinity of the cape is called the Cape Horn Current. This current rounds the cape and flows in a northerly and northeasterly direction along the coast of South America as the Falkland or Malvinas Current….
During the northern hemisphere summer, a weak northern branch of the South Equatorial Current, known as the New Guinea Coastal Current, continues on toward the west and northwest along both the southern and northeastern coasts of New Guinea. The southern part flows through Torres Strait, between New Guinea and Australia, into the Arafura Sea. Here, it gradually loses its identity, part of it flowing on toward the west as part of the South Equatorial Current of the Indian Ocean, and part of it following the coast of Australia and finally joining the easterly flowing West Wind Drift. The northern part of New Guinea Coastal Current both curves in a clockwise direction to help form the Pacific Equatorial Countercurrent and off Mindanao turns southward to form a southward flowing boundary current called the Mindanao Current. During the northern hemisphere winter, the New Guinea Coastal Current may reverse direction for a few months….

A comment from Jinlum Zhang at Harris-Mann Climatology

….On Saturday, September 28, the icepack reached 19.51 million square kilometers, according to data posted on the National Snow and Ice Data Center website. That figure topped the 19.48 million square kilometers set on September 23, 2012. Records on Antarctic sea ice began in October of 1978.
According to a new study in the Journal of Climate by a University of Washington scientist, Jinlum Zhang, “strengthening and converging winds around the South Pole can explain 80 percent of the puzzling increase in Antarctic sea ice.”
Zhang adds, “the polar vortex that swirls around the South Pole is not just stronger than it was when satellite observations were begun in the late 1970s, but it likewise has more ‘convergence,’ meaning it shoves the sea icepacks together causing ridging. This creates thicker, longer-lasting ice while exposing surrounding open waters and thin ice to blisteringly cold winds that result in additional ice growth.”
….scientists have likewise witnessed a similar growth of the continental land ice, particularly in the eastern half of Antarctica.
Antarctic cold fronts have been pushing much farther north than usual during the winter months, sometimes actually reaching areas of South America north of the Equator.
This past winter across much of South America was one of the coldest and snowiest winter seasons on record dating back, in some cases, more than 200 years. Parts of northern Argentina, Paraguay and southeastern Brazil saw their first measurable snowfalls in at least a century. A hard freeze last month in central Argentina killed at least 22 percent of the 2013 winter wheat crop.
Australia and New Zealand likewise had colder than normal winter temperatures as did parts of South Africa, where ‘rare’ snowfalls fell in Johannesburg. Some glaciers in extreme southern Argentina and Chile, as well as in New Zealand, are showing “definite signs” of advancing after an extended period of retreat….

The actual paper: Modeling the Impact of Wind Intensification on Antarctic Sea Ice Volume

justthefactswuwt says:

Why would surface ice measurements help “draw conclusions about the temperature of the deeper water.”?

Ice shelves float. 9/10 below water, 1/10 above water. If the surface elevations are observed to decrease with time, it means the ice shelf is getting thinner below, and vice versa. Ice shelf surface measurements tell you if the bottom is melting or growing, and at what rate, which indicates basal temperature.
It is more complicated than that, but that is the general idea. Pine Island has been thinning continuously for decades. Does that count as observational evidence of warm currents?
But the real point here is that it *is* complicated. Enough so that drawing conclusions about ice shelves based on sea ice extent is a very bad idea. Consider the paper you quoted:

The thermocline in the sea adjacent to the glacier calving front (where ice is discharged) lowered by 250 meters in the austral summer of 2012. This change exposed the bottom of the ice shelf to colder surface waters rather than to the warmer, deeper layer, thereby reducing heat transfer from the ocean to the overlying ice and decreasing basal melting of the ice by more than 50% compared to 2010.

Here is the press release:
http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=2452
“It is not so much the ocean variability, which is modest by comparison with many parts of the ocean, but the extreme sensitivity of the ice shelf to such modest changes in ocean properties that took us by surprise…”
Consider that. On top of the decadal thinning because of the Circumpolar Deep Water (CDW), a change in the depth of the thermocline, in two short years, lowered the temperature enough to decrease the basal melting rate by 50%. Would your plot of sea ice extent have told you either of those things?
The reason there are “no apparent signs” is because you are looking at sea ice extent. It’s the wrong tool for the job.
I’m sorry if the Pine Island glacier example is too far removed from Filchner-Ronne Ice Shelf in the Weddell Sea, but it is the area I’m most familiar with.

richardscourtney says:

The ice shelves are growing, and your links each says that warm ocean currents under the ice are the major cause of “ice shelf mass loss”. Thanks for providing such clear evidence that your assertions are rubbish.

The ice shelves are growing? You wouldn’t by chance be confusing sea ice and ice shelves, would you? Not the same thing.

“….A hard freeze last month in central Argentina killed at least 22 percent of the 2013 winter wheat crop…”
Good maybe wheat in Kansas City will stay above $7.00/bushel.