Polar Ice for 2017

In celebration of the 2017 Solstice, time to start another polar ice watch:

• Daily AMSR2 sea ice maps
• NSR - Ice Concentration | Northern Sea Route Information Office
• Sea Ice Index
• Arctic Sea Ice Graphs
• CryoSat Operational Monitoring - Sea Ice

Arctic





Northern Hemisphere Sea Ice Area

Antarctica







Southern Hemisphere Sea Ice Area

In about 6-7 months, the Northeast passage will open for navigation. Then the Northwest passage for a couple of weeks. As for land based ice, still looking for current observations.

Bob Wilson

 

Actually I had been looking for the big Larson C break but realized the existing sea ice would coral and mask it. Talk about a lot of nothing.

Regardless, the nearly ice free Antarctic should have uncorked 3/4th of the sea terminating glaciers. It should have also given a strong bloom of photoplancton too.

Later,
Bob Wilson

 

And the edit clock ran out. Thanks, you are of course right or I was ~90 days off.

Bob Wilfon

 

There may be satellite images showing the Larson C, big berg break:

There is a bite out the Larson c ice shelf right where the reported breaking berg would be located. It appears to be pulled away showing open water.

Bob Wilson

 

That turns out to be one of my major criticisms of the paper: Influence of the recent high-latitude atmospheric circulation | PriusChat

By looking at just the summer melt season, the failure to freeze up as much in the winter is left unaddressed. Sad to say, their 'natural variation' was taken to mean man-made global warming plays no part ... in some lay press reports.

Bob Wilson

 

Greenland was funny last year too: Greenland Ice Sheet Today | Surface Melt Data presented by NSIDC

Bob Wilson

 

As expected, the current, polar ice data is coming from non-USA sources: Arctic Sea Ice: Uni Bremen

After a drop of almost 262 thousand km2 in just three days, it looks highly likely that the maximum for sea ice extent was reached two weeks ago, according to the data provided by JAXA, the Japan Aerospace Exploration Agency (via ADS-NiPR ; it used to be provided by IJIS).

It's a new lowest maximum record, and the third time in a row that extent stayed below the 14 million km2 mark. The previous lowest max on record was reached in 2015 (13.942 million km2), almost beaten last year (13.959 million km2), but this year SIE went lower still and peaked at 13.878 million km2.
​

Bob Wilson

 

No need to set one's hair on fire but it seems a major, Greenland glacier is showing some unusual cracking.

Source: Scientists just found a strange and worrying crack in one of Greenland’s biggest glaciers - The Washington Post

. . .
Jeong and Howat were also struck by the Petermann images and conducted some additional analysis. They suggested that the new crack may be caused by the larger pre-existing one, which could be exerting additional stress across the shelf. They also suggested that floating sea ice at the front of Petermann glacier is likely keeping the cracks from widening further by holding the shelf in place — but noted that this bracing function will disappear as summer approaches and the sea ice dissipates.


“I’d say that the rifting process is on hiatus right now, but it is very likely that the cracks will continue to grow in this summer,” said Jeong by email.​

Bob Wilson

 

This looks interesting: https://www.nature.com/nature/journal/v544/n7650/full/nature22049.html

Surface meltwater drains across ice sheets, forming melt ponds that can trigger ice-shelf collapse1, 2, acceleration of grounded ice flow and increased sea-level rise3, 4, 5. Numerical models of the Antarctic Ice Sheet that incorporate meltwater’s impact on ice shelves, but ignore the movement of water across the ice surface, predict a metre of global sea-level rise this century5 in response to atmospheric warming6. To understand the impact of water moving across the ice surface a broad quantification of surface meltwater and its drainage is needed. Yet, despite extensive research in Greenland7, 8, 9, 10 and observations of individual drainage systems in Antarctica10, 11, 12, 13, 14, 15, 16, 17, we have little understanding of Antarctic-wide surface hydrology or how it will evolve. Here we show widespread drainage of meltwater across the surface of the ice sheet through surface streams and ponds (hereafter ‘surface drainage’) as far south as 85° S and as high as 1,300 metres above sea level. Our findings are based on satellite imagery from 1973 onwards and aerial photography from 1947 onwards. Surface drainage has persisted for decades, transporting water up to 120 kilometres from grounded ice onto and across ice shelves, feeding vast melt ponds up to 80 kilometres long. Large-scale surface drainage could deliver water to areas of ice shelves vulnerable to collapse, as melt rates increase this century. While Antarctic surface melt ponds are relatively well documented on some ice shelves, we have discovered that ponds often form part of widespread, large-scale surface drainage systems. In a warming climate, enhanced surface drainage could accelerate future ice-mass loss from Antarctic, potentially via positive feedbacks between the extent of exposed rock, melting and thinning of the ice sheet.​

It is interesting because the well know loss of ice mass comes from calving of sea terminating glaciers. Yet there have been more than a few papers describing Greenland ice melt. So now we're seeing a paper describing not the quantity but how wide spread this is across Antarctica.

Ok, so ice melts, obvious, true, but having laid down the mark documenting the phenomena in Antarctica, it will hopefully lead to more studies to quantify the effect.

The press release: Water Is Streaming Across Antarctica | Lamont-Doherty Earth Observatory

Massive summer melting on East Antarctica’s Amery Ice Shelf, seen from NASA’s Landsat 4 satellite. The image shows about 520 square miles. (NASA)​

Bob Wilson

 

I remember seeing a discussion about it before but don't remember the source. It is one of the reasons I prefer satellite data even though we are often finding calibration and processing to be non-trivial.

Bob Wilson

 

One of the missing pieces is the connection between climate and weather. It looks like we're finding the 'smoking gun':

Apparently there is a polar vortex, in effect a permanent jet stream that separates the Arctic air mass from the temperate masses. In the past, this polar vortex would have wave associated effects (i.e., there is no 'end' or 'start' but a constant flow.) This leads to a natural 'resonance' or frequency in this polar vortex. As this resonance/wave varies in time, it dips down to bring cold, dry air to the temperate areas only to be replaced in other northern areas by warm, moist air invading from the lower latitudes.

As I understand it, these natural frequencies in the polar vortex are increasing in amplitude and sometimes changing frequencies. This can lead to more extensive and unexpected heat waves and cold, dry spells. The challenge is to understand how this 'heat engine' works. One side is the cold, polar radiator and the other, the increasing temperature and heat.

On a personal note, I'm seeing heat in Alaska often means cold in Dixie. My thinking is if we can find current maps of the polar vortex (very possible in the satellite era), we can perhaps see longer range effects beyond 10 days.

I'm probably using the wrong terms, this is not my area of expertise, so perhaps @wxman might do a 'sanity' check. No, this does not mean we have a direct link from climate to weather models but it looks to be a promising area of investigation.

Bob Wilson