Thread: Global sea ice
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Old June 16th 17, 12:09 AM posted to uk.sci.weather
Alastair Alastair is offline
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Default Global sea ice

On Thursday, 15 June 2017 20:29:44 UTC+1, Graham P Davis wrote:
On 15/06/17 18:02, N_Cook wrote:
On 15/06/2017 17:08, JohnD wrote:
See that there's some speculation that we might be heading for the
lowest sea ice extent _maximum_ in the recent record (at least as far as
the first (July) max of the year is concerned - last year the second
(Nov) max was no greater than the first). See eg:

https://sites.google.com/site/arctis...t_byyear_b.png




I read this piece today
https://www.theguardian.com/world/20...m-temperatures


Wednesday 14 June 2017 10.00 BST Last modified on Wednesday 14 June 2017
22.00 BST

Scientists in Canada have been forced to abandon an expedition to the
Hudson Bay to research the impact of climate change, after warming
temperatures created perilous ice conditions off the coast of Newfoundland.

In late May, 40 scientists from five Canadian universities set off from
Quebec City on the icebreaker and Arctic research vessel CCGS Amundsen.
The expedition was the first leg of a four-year, C$17m research project
designed to delve into the effects of climate change on Hudson Bay.
Cold snap: massive iceberg just off coast draws Canadians eager for
close-up

The icebreaker was soon diverted. Dense ice – up to 8 metres (25ft)
thick – had filled the waters off the northern coast of Newfoundland,
trapping fishing boats and ferries.

“It was a really dramatic situation,” said David Barber, the
expedition’s chief scientist. “We were getting search and rescue calls
from fishing boats that were stranded in the ice and tankers that were
stranded trying to get fuel into the communities. Nobody could manage
this ice because it was far too heavy to get through.”

Barber, a climate change scientist at the University of Manitoba, and
the other scientists did what they could to help the Coast Guard rescue
the vessels and carved a path for the tankers. They also took the time
to study the ice that surrounded them, discovering that much of it was
the multiyear ice typically seen in the high Arctic.

It was an unexpected find, said Barber, given the time of year and how
far south they were. “It’s not something you would expect to see there
and not something we’ve seen there before,” he said. “In the high
Arctic, climate change is causing the ice to get thinner and there to be
less of it. What that does is that it increases the mobility of ice.”

The decision to cancel the first leg of the expedition was made after it
became clear that continuing north would interrupt search and rescue
operations and probably put lives at risk.
Arctic stronghold of world’s seeds flooded after permafrost melts
Read more

The irony was not lost on Barber. “We’re doing a large-scale climate
change study and before we can even get going on it, climate change is
conspiring to force us to cancel that study.”

The decision was a costly one, as the project had already spent hundreds
of thousands of dollars getting the scientists and their gear on the
vessel. The next leg of the expedition, scheduled to start on 6 July, is
expected to go ahead, but the study will probably need to be extended by
at least six months and may require more funding, he said. “It’s a real
mess.”

Barber – who has spent decades researching the impact of climate change
on sea ice – described his week spent on the frontlines of battling a
changing climate as a stark reminder of the reality the world is facing..
“We’re very poorly prepared for climate change,” he said. “We pay lip
service to the fact that we think we know it’s coming and society is
trying to grapple with the complexity of it, but when it really comes
down to brass tacks, our systems are ill prepared for it.”


I read about this elsewhere and it made no sense to me at all but this
version clears it all up. Thanks!

The problem with the article I read was that they'd made no reference to
multiyear ice. The source for this old ice could have been from last
summer's break up in the Canadian Archipelago but I suspect that it is
ice that has been feeding through the gap between Greenland and
Ellesmere Island.

When I worked in the Met Office's Ice Unit (1965-73) Kane Basin was
covered with fast ice all year round. Now, it not only contains broken
ice during the summer but also right through the winter, allowing the
multiyear ice to move south through the channel throughout the year.
During my time in the Ice Unit, the only time I knew there would have
been multiyear ice in the area was when the ice in Baffin Bay failed to
melt one summer and so became multiyear ice with the onset of winter.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
Web-site: http://www.scarlet-jade.com/
Never approach a bull from the front, a horse from the rear,
or an idiot from any direction! [Irish proverb]


The passage from the Arctic Ocean to Baffin Bey is called Nares Strait after Captain Nares https://dawlishchronicles.com/so-muc...oceanographer/

There is an interesting description of the physics of the strait he https://icyseas.org/2014/09/21/a-sho...trait-physics/

What I have noticed is that the melt of Baffin Bay can begin at the southern end of Nares Strait and then spread south! I am now guessing that the strong brine from brine rejection, https://en.wikipedia.org/wiki/Brine_rejection , flows under the Nares ice and melts the fresher ice in Baffin Bay.