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Messages - jimbenison

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1
Arctic sea ice / Re: The 2016 melting season
« on: June 17, 2016, 07:40:18 AM »
Eureka has been smoking hot for the past few days. Melting has kicked into overdrive up there.

Their CANDAC weather page is still up with webcams. Not easy to find since their site redesign.

 http://candac.ca/candac/Data/PEARL_Weather/weather.php




2
Antarctica / Re: Southern Ocean Cold Spots
« on: May 21, 2016, 11:32:15 PM »
That link to the insurancejournal article was particularly disturbing. But unfortunately it may be worse than changing circulation and your typical "new field data".

In a discussion that ironically tries to downplay new predictions of greatly accelerated sea level rise, Margaret Davidson, the NOAA executive that presented the preliminary findings, had this to say:

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current work re cryosphere and mass water balance which is a more recent area of science work

and reports regarding current field observations as mentioned and discussed by experts at various scientific mtgs in presentation rooms and corridors within past 6 months

WA deteriorating rapidly...
portions of shelf are now ungrounded with a lens of water underneath like greenland but different

https://climatecrocks.com/2016/04/21/caution-new-sea-level-story-may-be-a-step-too-far/

The part that should put the fear of god in you (even if you're an athiest):

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portions of shelf are now ungrounded with a lens of water underneath

So while it appears that some of the numbers are still speculative, the disintegration of WA has begun.

Rather than a catastrophic possibility, destabilization of the WAIS looks to be a forgone conclusion.

3
Antarctica / Re: What's new in Antarctica ?
« on: February 18, 2016, 08:12:11 PM »
150,000 penguins die after giant iceberg renders colony landlocked
http://www.theguardian.com/world/2016/feb/13/150000-penguins-killed-after-giant-iceberg-renders-colony-landlocked
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Penguins of Cape Denison in Antarctica effectively trapped by iceberg the size of Rome and face 120km round trip to feed
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves.
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves. Photograph: Alamy

Guardian staff

Saturday 13 February 2016 06.56 GMT
Last modified on Saturday 13 February 2016 10.15 GMT

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An estimated 150,000 Adelie penguins living in Antarctica have died after an iceberg the size of Rome became grounded near their colony, forcing them to trek 60km to the sea for food.

The penguins of Cape Denison in Commonwealth Bay used to live close to a large body of open water. However, in 2010 a colossal iceberg measuring 2900sq km became trapped in the bay, rendering the colony effectively landlocked.
Penguins suffering from climate change, scientists say
Read more

Penguins seeking food must now waddle 60km to the coast to fish. Over the years, the arduous journey has had a devastating effect on the size of the colony.

Since 2011 the colony of 160,000 penguins has shrunk to just 10,000, according to research carried out by the Climate Change Research Centre at Australia’s University of New South Wales. Scientists predict the colony will be gone in 20 years unless the sea ice breaks up or the giant iceberg, dubbed B09B, is dislodged.

Penguins have been recorded in the area for more than 100 years. But the outlook for the penguins remaining at Cape Denison is dire.

“The arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins breeding at Cape Denison must travel in search of food,” said the researchers in an article in Antarctic Science.

“The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out”

“This has provided a natural experiment to investigate the impact of iceberg stranding events and sea ice expansion along the East Antarctic coast.”

In contrast, a colony located just 8km from the coast of Commonwealth Bay is thriving, the researchers said.

The iceberg had apparently been floating close to the coast for 20 years before crashing into a glacier and becoming stuck.

Some are suggesting that the penguins haven't died; they just moved.

http://news.discovery.com/animals/dead-antarctica-penguins-are-probably-fine-160216.htm

Also, it appears that the fast ice cleared out of Commonwealth Bay on about the 15th. The berg is still there though.

4
I stumbled upon this gem while hunting down data for a project I'm working on. It's a satellite photo from the now declassified ARGON mission in May 1962.

Credit to Dr. Ken C. Jezek and Ph.D. Guoqing Zhou (Byrd Polar Research Center of The Ohio State University).

Yes very interesting, thanks! The year 1962 also correspond to this image:

That is a cutout from a much larger mosaic. The full images show the entire island. Petermann, Humboldt, and many other regions have good shots. Unfortunately 79N and Zachariae are obscured by clouds.

I didn't realize anything this old existed. So I imagine that there are others who are unaware of them as well.

https://nsidc.org/data/docs/daac/nsidc0118_greenland_disp.gd.html

5
I stumbled upon this gem while hunting down data for a project I'm working on. It's a satellite photo from the now declassified ARGON mission in May 1962.

Credit to Dr. Ken C. Jezek and Ph.D. Guoqing Zhou (Byrd Polar Research Center of The Ohio State University).

6
Permafrost / Re: This is not good.
« on: July 15, 2014, 11:28:12 AM »
I'd like to share this resource as I think it could be very relevant to the discussion of how free methane in places like the ESAS might find its way out through a permafrost cap. It relates to nanomedicine but the physics are applicable.

Viscosity and Locomotion in Ice

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An equally relevant but far more serious challenge is locomotion through solid water ice. Just below freezing, crystalline ice viscosity is ~1010 kg/m-sec, requiring a 1-micron nanorobot to expend on the order of ~200,000 pW to creep forward at 1 micron/sec (Eqn. 9.73) by viscoplastic flow in which ice crystals are deformed without breaking. Just halfway from freezing to liquid nitrogen temperature, at 164 K, viscosity has already risen to ~1021 kg/m-sec, roughly equivalent to solid mantle rock, and the power requirement has increased 100-billionfold, clearly prohibitive.

http://www.nanomedicine.com/NMI/10.5.2.htm

A bit more detail is in the publication. But the important take home message is that as the temperature of ice increases by even fractions of a degree the amount of energy needed to get through it via viscoplastic flow decreases by orders of magnitude.

The ice doesn't need to melt. It only needs to warm a tiny tiny little bit.

7
A-Team, I like where you are going here. I have also contemplated doing something like this.

I'm thinking we should convert the dataset into geojson or import it into a PostGIS database. Openlayers could be used for the front end. Then we could use a web framework like Django or Symfony2 to create a REST server for getting the data to the front end. That way it could be fully interactive.

8
Looks like NASA has picked up on the recent calving.

http://earthobservatory.nasa.gov/IOTD/view.php?id=83837&eocn=home&eoci=iotd_readmore

I tend to agree with Espen on Zachariae. Jakobshavn is relatively narrow and may be already flowing about as fast as it can. It's like a firehose. Zachariae is very wide, it's deep, and it's waking up.

9
@icefest

That's not the one. This is a little better (see figure 1), but it still does not even hold a candle to the level of detail in the one I saw.

http://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/52825/1/Herzfeld_etal_2012_AnnGlac.pdf

I looked through dozens of papers today trying to find it. My best guess is that it's now behind a paywall.

10
A couple of years ago I stumbled across a paper that showed the bedrock topography of this glacier near the calving front of the south branch in great detail. I have been looking for it for the last week and cannot find it for the life of me. Epsen's image from Sep 27 2013 shows a couple of important features related to it thanks to the lighting angle.

Notice that just upstream of the calving front in the main south ice stream a couple of longitudinal bumps are visible. One is toward the north side and one is almost dead center. These are pinning points with relatively shallow bedrock that pushes the ice higher in these areas. Inland from there the glacier bed gets deeper. The really deep (-1500 meters) portion of the bed is actually a few kilometers upstream of where this branch makes a 45 degree turn due east.

If I can find the paper I will post it. The relationship between surface features on the ice stream and the bedrock topography are pointed out very clearly. It would be extremely handy here.

11
There's always Hotel Arctic webcam at Ilulissat, which may be north of where you're looking. It's not showing anything exceptional right now.
http://www.hotel-arctic.gl/om_hotel_arctic/webcam/

That is way away from where the action is (only about 45 km).

It is far away, but large calving events can push energy all the way out the fiord and move those big bergs. Viewing a time lapse is more informative than a still.

http://www.lookr.com/lookout/1310041325-Ilulissat

13
Developers Corner / Domain name
« on: August 02, 2013, 04:51:36 PM »
I have the domain name polarmelt.org which I'm allowing to expire because I didn't do anything with it. I'm not selling it, I'm basically just giving it away. If anyone wants it please contact me.

If anyone needs web work done I'm a professional developer with an expertise in drupal. Like the bad businessman I am I'll probably do most all that for free too if you have a good idea.

Best

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