NOAA to Map Alaska’s Increasingly Ice-Free Arctic Waters

[Row6]

The arctic:

"The National Oceanic and Atmospheric Administration (NOAA) has launched a program to update some of its nautical charts, thanks largely to climate change.

The revisions affect Alaska’s coast, which has America’s only Arctic seafront. As a result of global warming, ice that has historically blocked Arctic waters, even in summer, has been plummeting in recent years, with 2012 ice melting back to the smallest extent since satellite records began. And as sea ice recedes, said NOAA Coast Survey director Rear Admiral Gerd Glang in a press release, “vessel traffic is on the rise.”...

It’s no surprise, since a shortcut through the Arctic Ocean shaves many thousands of miles off the normal shipping routes between Europe and Asia, through the Panama or Suez canals. And while an easier-to-navigate Arctic Ocean and surrounding waters are raising national security concerns for nations that border that chilly sea, NOAA’s job, in part, is to make the area safe for commercial vessels.
Because many of these routes have traditionally been ice-choked, especially along the shore, the agency has never done the sorts of exhaustive surveys that would show precisely where the bottom lies in many places. The 14 new charts planned by NOAA would fill in those gaps as quickly as possible...."

- See more at: http://www.climatecentral.org/news/n....Fz2JWvuv.dpuf

Meanwhile, in the antarctic:

"...The news was worse from Antarctica. Here, work by Alley and others has focused on the dynamics of exit glaciers that hold back the flow of large glaciers near the West Antarctic Peninsula. The key thing that regulates the flow of these glaciers is what's called a "grounding line," or the place where the glacier's end is in contact both with the ocean floor and with the ocean itself (this is in contrast to the floating ice that sometimes spreads past this site).

While a glacier is on the grounding line, Alley said there are a lot of feedbacks that tend to keep it there. The sediment it carries gets dumped there, raising the ocean bottom. The Earth itself, with less ice above it, rebounds from the weight that was present during the last ice age, also keeping the contact between the ice and ocean floor intact. These and a few other feedbacks help keep the grounding line stable even as rising temperatures would otherwise tend to force the glacier to break up and retreat.

The problem is that, when the feedbacks are finally overcome, the grounding line fails catastrophically, and the ice tends to retreat rapidly to the next potential grounding line. This behavior shows up in models of the glacier's behavior, and it's apparent in imaging of the ground under the ice, where there's little sign of retreat from past melts outside a handful of grounding lines.

What does this mean for the particular glacier Alley chose to focus on? If its current grounding line fails, there's another a bit behind it that it will likely retreat to. If that one fails, however, there's enough ice between it and the one behind that to raise sea levels by two meters. And, from a geological perspective, that retreat could occur in a flash—fast enough to obviate any long term plans for adaptation...."

http://arstechnica.com/science/2013/...limate-change/

[wygator]

In the meantime Antarctica, which is enjoying its summer now, had the second highest minimum ice cover on record. Summer minimum sea ice is increasing on a trend line of 140,000 KM per decade. Five of the top six minimum extents occurred since 2000.



more info

[enviroGator]

Originally Posted by wygator

In the meantime Antarctica, which is enjoying its summer now, had the second highest minimum ice cover on record. Summer minimum sea ice is increasing on a trend line of 140,000 KM per decade. Five of the top six minimum extents occurred since 2000.

Not to say it isn't correct, but linking to a blog that doesn't show it's source of data is kind of suspect.

[enviroGator]

Did a little digging to see what to make of the antarctic ice increase and found this..

http://news.nationalgeographic.com/n...lobal-warming/

Says this is consistent with a warming planet due to a bunch of things.

[malligator]

I can believe that there is a difference in warming rates between the N and S hemispherere, but I'm having a hard time believing that would make ice increase in Antarctica. If the ice was receeding slower, sure, but increasing? Makes no sense.

Also, if greenhouse gases were causing warming wouldn't diffusion equalize the gases over the globe and cause more uniform warming?

I'm all for discussion of the GW issue, but if EVERYTHING is going to point to human-induced warming I have to raise an eyebrow.

[wygator]

Originally Posted by enviroGator

Not to say it isn't correct, but linking to a blog that doesn't show it's source of data is kind of suspect.

Considering the precise figures he was posting elsewhere on the blog, I figured he had a good original source.

He posts this chart with overlapping data for each year back to 1979:



I found this graph of the past 2 years with one line showing the average for the 1979 to 2010 period at the National Ice & Snow Data Center at the University of Colorado:



Looks like a match! Appears he is using the NSIDC for his source. Also quoted at the NSIDCsite:

Antarctic sea ice remained extensive due to an unusual northward excursion of ice in the Weddell Sea. December of 2012 saw Northern Hemisphere snow cover at a record high extent, while January 2013 is the sixth-highest snow cover extent on record since 1967.

The thing to keep in mind is that you don't have the same weather, or weather trends, in the whole world at the same time. You can be having record warmth in one part of the world while having record cold somewhere else. As even the IPCC is admitting now, world average temps have been level for 17 years.

[PIMking]

lol it's not like the world hasn't gone in cycles before, and will continue to do it

[wygator]

Found this chart at the NSIDC to match the first graph that I posted in the thread:

[gatorev12]

Originally Posted by PIMking

lol it's not like the world hasn't gone in cycles before, and will continue to do it

It's a well-known fact that dinosaurs were the first known living creatures on earth to engage in snowball fights--with the T-Rex being especially notorious for their fastball-like delivery from their cannon-like arms. The entire thing was spoiled when pre-humans started mastering fire and warmed the Earth too much, melting the snow and causing the dinosaurs to go extinct.

[g8orbill]

the sky is falling

the sky is falling

[gatorman_07732]

Originally Posted by PIMking

lol it's not like the world hasn't gone in cycles before, and will continue to do it

Man made crises