http://www.scarlet-jade.com/arctic-i...ears-can-make/

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

On Thursday, September 15, 2016 at 8:55:06 AM UTC+1, Graham P Davis wrote:
http://www.scarlet-jade.com/arctic-i...ears-can-make/

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

Very interesting

Graham
Penzance

Graham P Davis wrote:

http://www.scarlet-jade.com/arctic-i...ears-can-make/

Interesting stuff, Graham. Even if allowance is made for some possible
over-estimation of ice cover in the non-satellite era the shrinkage over 100
years is very striking. I can't help but think that, as this trend continues,
it must have some effect on N. Hem. atmospheric circulation patterns which
would, of course, affect weather patterns in some areas. The climate of our
little bit of the planet is still very much dominated by W-SW winds. Any change
to that could have a very profound effect on our climate. (That's not a
forecast!)

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

@GrahamD: At the risk of thread drift, I'm curious about something related
that you might be able to offer a comment on:

Today's Bremen Arctic sea-ice map shows Lancaster Sound (NW of Baffin
Island) to be free of ice, as far as one can judge from the map image. But
the PolarOcean log for yesterday says: 'We got the latest ice charts, and a
huge amount of 9/10ths old ice has blocked Lancaster Sound and Prince Regent
Inlet. It looks like we got through by the skin of our teeth.'

I'm not sure which ice charts PO is referring to, maybe eg the Canadian
ones, but why the discrepancy with the Bremen picture (and where did the
'old ice' come from)? Or is it simply that the satellite imagery still has
some way to go to catch up with the sea surface reality?

On Thu, 15 Sep 2016 10:00:08 +0100
"JohnD" wrote:

@GrahamD: At the risk of thread drift, I'm curious about something
related that you might be able to offer a comment on:

Today's Bremen Arctic sea-ice map shows Lancaster Sound (NW of Baffin
Island) to be free of ice, as far as one can judge from the map
image. But the PolarOcean log for yesterday says: 'We got the latest
ice charts, and a huge amount of 9/10ths old ice has blocked
Lancaster Sound and Prince Regent Inlet. It looks like we got through
by the skin of our teeth.'

I'm not sure which ice charts PO is referring to, maybe eg the
Canadian ones, but why the discrepancy with the Bremen picture (and
where did the 'old ice' come from)? Or is it simply that the
satellite imagery still has some way to go to catch up with the sea
surface reality?


As the old fast-ice in the northern Canadian Archipelago broke up
during the summer, it has been drifting into the northernmost route
through the NW Passage. However, according to the satellite charts,
this has been mostly limited to the western section (Melville Sound).

When I was producing ice maps fifty years ago, I relied on maps
from Canadian aircraft reconnaissance flights for ice conditions in
this area. I would imagine that they are still being generated in
order to provide more detailed information than that available to us
from satellites. I suspect that is where PolarOcean got their data.

There was an intense low (about 980hPa) near Lancaster Sound at 00Z
this morning and the NW'ly gales associated with it could have driven
old ice from the channel west of Devon Island into the Sound.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

Graham P Davis wrote:

On Thu, 15 Sep 2016 10:00:08 +0100
"JohnD" wrote:

@GrahamD: At the risk of thread drift, I'm curious about something
related that you might be able to offer a comment on:

Today's Bremen Arctic sea-ice map shows Lancaster Sound (NW of Baffin
Island) to be free of ice, as far as one can judge from the map
image. But the PolarOcean log for yesterday says: 'We got the latest
ice charts, and a huge amount of 9/10ths old ice has blocked
Lancaster Sound and Prince Regent Inlet. It looks like we got through
by the skin of our teeth.'

I'm not sure which ice charts PO is referring to, maybe eg the
Canadian ones, but why the discrepancy with the Bremen picture (and
where did the 'old ice' come from)? Or is it simply that the
satellite imagery still has some way to go to catch up with the sea
surface reality?


As the old fast-ice in the northern Canadian Archipelago broke up
during the summer, it has been drifting into the northernmost route
through the NW Passage. However, according to the satellite charts,
this has been mostly limited to the western section (Melville Sound).

When I was producing ice maps fifty years ago, I relied on maps
from Canadian aircraft reconnaissance flights for ice conditions in
this area. I would imagine that they are still being generated in
order to provide more detailed information than that available to us
from satellites. I suspect that is where PolarOcean got their data.

There was an intense low (about 980hPa) near Lancaster Sound at 00Z
this morning and the NW'ly gales associated with it could have driven
old ice from the channel west of Devon Island into the Sound.


On the days when there isn't too much cloud cover this one gives a good
indication of the ice cover

https://worldview.earthdata.nasa.gov/

You can zoom right in. The daily archive goes back to 2012. Pity about the
cloud cover, though :-(

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

On Thursday, 15 September 2016 11:14:13 UTC+1, Norman Lynagh wrote:
Graham P Davis wrote:

On Thu, 15 Sep 2016 10:00:08 +0100
"JohnD" wrote:

@GrahamD: At the risk of thread drift, I'm curious about something
related that you might be able to offer a comment on:

Today's Bremen Arctic sea-ice map shows Lancaster Sound (NW of Baffin
Island) to be free of ice, as far as one can judge from the map
image. But the PolarOcean log for yesterday says: 'We got the latest
ice charts, and a huge amount of 9/10ths old ice has blocked
Lancaster Sound and Prince Regent Inlet. It looks like we got through
by the skin of our teeth.'

I'm not sure which ice charts PO is referring to, maybe eg the
Canadian ones, but why the discrepancy with the Bremen picture (and
where did the 'old ice' come from)? Or is it simply that the
satellite imagery still has some way to go to catch up with the sea
surface reality?


As the old fast-ice in the northern Canadian Archipelago broke up
during the summer, it has been drifting into the northernmost route
through the NW Passage. However, according to the satellite charts,
this has been mostly limited to the western section (Melville Sound).

When I was producing ice maps fifty years ago, I relied on maps
from Canadian aircraft reconnaissance flights for ice conditions in
this area. I would imagine that they are still being generated in
order to provide more detailed information than that available to us
from satellites. I suspect that is where PolarOcean got their data.

There was an intense low (about 980hPa) near Lancaster Sound at 00Z
this morning and the NW'ly gales associated with it could have driven
old ice from the channel west of Devon Island into the Sound.


On the days when there isn't too much cloud cover this one gives a good
indication of the ice cover

https://worldview.earthdata.nasa.gov/

You can zoom right in. The daily archive goes back to 2012. Pity about the
cloud cover, though :-(

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

TY, shows the stark reduction so well. Mind you, it is a well know fact that 1916?was a complete one off and there was hardly any ice at all in 1915, or 1917. 😂😂

On 2016-09-15, Graham P Davis wrote:
http://www.scarlet-jade.com/arctic-i...ears-can-make/


We're stuffed, aren't we.
--
f451

On Thursday, September 15, 2016 at 8:55:06 AM UTC+1, Graham P Davis wrote:
http://www.scarlet-jade.com/arctic-i...ears-can-make/

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/

Here is evidence of Arctic sea ice from even earlier:
https://www.theguardian.com/world/20...assage-attempt

Compare that with Bellot Strait: The most worrying aspect of the transit is that we didn’t see one piece of proper ice, not even a floating ice cube for a G & T.
http://polarocean.co.uk/6798-2/

"Alastair" wrote in message
...

Compare that with Bellot Strait: The most worrying aspect of the transit is
that we didn’t see one piece of proper ice, not even a floating ice cube
for a G & T.

Alastair's blatant spin doesn't do it for me I'm afraid. Here's a more
objective overall summary from the crew log: 'On that note, the North West
Passage has already frozen behind us. So as it turns out we went through a
very short window. The V Strait closed almost as soon as we went through,
the same was true of Barrow. So despite the very obvious melting that’s
been happening we were lucky to get through.'

So, very likely, it's a passage that wouldn't have been possible at all a
few years back, but there's no pretence that it's plain sailing as yet.