319 replies to this topic

[songster]

jethro, on 29 September 2011 - 10:57 , said:

Thanks for the input folks.

Over in this thread: http://forum.netweat...2/page__st__280 post 296, page 15 there is a graph showing the current re-freeze level - doesn't look too bad to me.

The IJIS graph has a bit more context: that NSIDC one only shows the record low (2007) and the long-term average.
http://www.ijis.iarc..._Ice_Extent.png

Thus far we're more-or-less tracking 2008. What happens next will be important: will 2011 stick with 2008 and re-freeze rapidly (back to the pack by mid/end of October), or will it follow the 2009/2010 pattern of slow re-freeze (2010 in particular stayed low right till the end of Dec).


Edit: Yes, I'm curious what that paper really offers. All it really says is that over the short term (i.e. a few years), the noise is larger than the trend, and thus ice can go up as well as down. This shouldn't be news to anyone with any understanding of what constitutes a trend, or noise!

Edited by songster, 30 September 2011 - 09:47 .

[stewfox]

songster, on 30 September 2011 - 09:46 , said:

The IJIS graph has a bit more context: that NSIDC one only shows the record low (2007) and the long-term average.
http://www.ijis.iarc..._Ice_Extent.png

Thus far we're more-or-less tracking 2008. What happens next will be important: will 2011 stick with 2008 and re-freeze rapidly (back to the pack by mid/end of October), or will it follow the 2009/2010 pattern of slow re-freeze (2010 in particular stayed low right till the end of Dec).


Edit: Yes, I'm curious what that paper really offers. All it really says is that over the short term (i.e. a few years), the noise is larger than the trend, and thus ice can go up as well as down. This shouldn't be news to anyone with any understanding of what constitutes a trend, or noise!

All years this century were in a cluster by 1st November, there was some small variations, including a small drift for December 2010 for the first 3 weeks of that month but thats all.

The only trend I can see in the winter is ice refreezes and end figures always within 1SD

My prediction 14,102,344 March 29th 2012

Edited by stewfox, 30 September 2011 - 16:00 .

[BornFromTheVoid]

A few stats to look out for in the coming month.

Average daily gain - 73,661km2/day
Average extent by 15th - 8,213,919km2
Average extent by 31st - 9,278,228km2

[summer blizzard]

BornFromTheVoid, on 03 October 2011 - 17:01 , said:

A few stats to look out for in the coming month.

Average daily gain - 73,661km2/day
Average extent by 15th - 8,213,919km2
Average extent by 31st - 9,278,228km2

What are the current statistics?

[BornFromTheVoid]

summer blizzard, on 03 October 2011 - 20:46 , said:

What are the current statistics?

For the first 2 days, 84,766km2/day.
Total Extent, 5,162,969km2

[BornFromTheVoid]

Things over the next week are looking quite mixed for the refreeze. On one hand, we have rapidly cooling uppers which look much better than the last 2 years and close to 2008.


On the other hand, we have a very strong dipole developing which may slow the gains from the very cool air.



Will be interesting to see what happens. Without the dipole driving ice out through Fram, I say we could be looking at consistent ~100k gains, but with the dipole in place, maybe something closer to average is to be expected, or perhaps even below. I guess we'll have to wait see

[Gray-Wolf]

I think we must remember the 'heat content' of the ocean BFTV?

No matter (in past years) what the 2m temps are forecast to be the ocean below them needs to be low enough to freeze or we end up with temps reflecting that 'heat loss' and not the forecast (with a 'Faux H.P.' plumped up by this rising heat?)?

Is the GFS up on Arctic Amplification I wonder?

[BornFromTheVoid]

The SSTs around the ice are still close to 0C so, with surface temps well below 0C across across the vast majority of the Arctic Ocean, it would only take a few days of cooling to get them down to the -2/3C required I would think?
Pity that IJIS isn't updating, is that just a problem on my side?

[SteveB]

BornFromTheVoid, on 06 October 2011 - 11:25 , said:

The SSTs around the ice are still close to 0C so, with surface temps well below 0C across across the vast majority of the Arctic Ocean, it would only take a few days of cooling to get them down to the -2/3C required I would think?
Pity that IJIS isn't updating, is that just a problem on my side?

Nope, it hasn't been updating since the re-freeze begun.

[BornFromTheVoid]

SteveB, on 06 October 2011 - 11:40 , said:

Nope, it hasn't been updating since the re-freeze begun.

Cryosphere Today hasn't been either. Perhaps they use the same satellite it's experiencing some glitches at the moment?
Actually, just spotted the notice above the graph "Sea-ice data update stops for a while due to the suspension of AMSR-E observation"
Hopefully this doesn't last much longer.

Edited by BornFromTheVoid, 06 October 2011 - 11:49 .

[Gray-Wolf]

We've had a couple of 'solar storms' (now the suns awake) so the sats may be on some 'downtime' for protection?

[SteveB]

BornFromTheVoid, on 06 October 2011 - 11:48 , said:

Cryosphere Today hasn't been either. Perhaps they use the same satellite it's experiencing some glitches at the moment?
Actually, just spotted the notice above the graph "Sea-ice data update stops for a while due to the suspension of AMSR-E observation"
Hopefully this doesn't last much longer.

Hopefully back up & working soon.

[BornFromTheVoid]

Just found this http://nsidc.org/data/amsre/news.html

Seems there's a problem with the satellite

Quote

the AMSR-E instrument on board the Aqua satellite stopped producing data due to a problem with the rotation of its antenna.

[Gray-Wolf]

Thanks for that BFTV. Hope it's a fixable issue?

[songster]

Nope, AMSR-E is out for the count. It was on borrowed time anyway, apparently 3+ years beyond its designed 6-year lifespan. The replacement, AMSR2, is due for launch in early 2012. Until then the only source of information will be the SSM/I satellite used by NSIDC and Norsex. This has lower resolution, but is probably better for year-on-year comparison anyway since they have an unbroken record going back to 1979 with the same type of sensor.

[BornFromTheVoid]

They seem to be working on the issue, so perhaps they can salvage another few months from it?

Anywho, with the Dipole Index I'm working on, September has come in at -8. That makes it the lowest September since 1992, 4th lowest since 1979 and the lowest "melt season" (Apr-Sept) month since April 2006.
This melt season overall has finished on +22, which is very close to average (+20), and well below 2007 (+66)

[songster]

They've been working around it for months. It's not something that can be fixed: the lubrication in the spinning bearings has just finally succumbed to the vacuum of space and evaporated. The instrument was shut down to stop it sending the whole satellite into an unrecoverable spin.
http://www.drroyspen...l-observations/

[stewfox]

songster, on 06 October 2011 - 16:14 , said:

They've been working around it for months. It's not something that can be fixed: the lubrication in the spinning bearings has just finally succumbed to the vacuum of space and evaporated. The instrument was shut down to stop it sending the whole satellite into an unrecoverable spin.
http://www.drroyspen...l-observations/

Is there going to be any link to anything this winter. ?

Its a pity if we have to wait to 2012

[Gray-Wolf]

A helping hand for those 'cyclical' guys out there;

http://www.scienceda...11006084040.htm

[songster]

stewfox, on 08 October 2011 - 09:53 , said:

Is there going to be any link to anything this winter. ?

Its a pity if we have to wait to 2012

NSIDC will keep reporting using the SSM/I instrument . Monthly updates (usually) at http://nsidc.org/arcticseaicenews/

Bremen are (I believe) transitioning to using SSM/I too - may make their graphs go a bit odd due to splicing data from different instruments, we'll have to see.
http://www.iup.uni-b...n.de:8084/amsr/