Comments on: Interesting analysis of IARC-JAXA Arctic sea ice data

By: Spector

Spector — Tue, 27 Oct 2009 09:51:11 +0000

I notice that many of the AMSR-E curves show a sharp jump on or about the first of June for each year. Does anyone know if this is a yearly recalibration for system drift? These are much more evident after removing the annual periodic melt-freeze cycle from the data.

By: savethesharks

savethesharks — Thu, 08 Oct 2009 04:43:14 +0000

hotrod (14:56:57) : “Like an electrical circuit, the Atlantic , if you give it a big enough shove in the negative direction, would overshoot its median temperature, while it absorbs the negative input (melts the ice) and then slowly recovers back toward its stable value.
It seems to me that the sudden introduction of all that ice into the N. Atlantic is a plausible cause for the transition from a positive AMO trend to a negative AMO trend.
Larry”

I hope you are putting your scientific aptitude to good use, Larry.

The world needs people like you, Crosspatch…and the many other smart ***kers on here to help solve its problems.

I am serious when I say this.

Chris
Norfolk, VA, USA

By: savethesharks

savethesharks — Thu, 08 Oct 2009 04:35:01 +0000

Thank you Pamela, as always.

Very important distinction.

Chris
Norfolk, VA, USA

By: Pamela Gray

Pamela Gray — Thu, 08 Oct 2009 04:23:41 +0000

Some people are confused with PDO event vs condition. There is a difference. When the PDO has flipped to its 30 to 60 year cold phase, there will be El Nino’s. Just not as many. When it has flipped to its warm phase, there will be La Nina’s. Just not as many. Go here to learn more about whether or not we are in an event or a condition.

http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

By: Phil.

Phil. — Thu, 08 Oct 2009 04:07:15 +0000

Dave Middleton (04:50:42) :
Now that the PDO is negative, low cloud cover is increasing, “global” temperatures are cooling and Arctic sea ice extent is growing… Antarctic sea ice extent should start declining.

Really, the last time I looked the PDO index was posiitve for the last two months.

By: George E. Smith

George E. Smith — Wed, 07 Oct 2009 21:28:47 +0000

Well the DMI arctic temperature graph still seems to be in hiccup mode. Wish I knew why it does that; but It does seem to be slowing down the refreeze.

Ah well, what would life be like if we didn’t have some unpredictable events occurring.

Hey why bother living if you can predict the future; I live just to see what Gaia is going to throw at us next; you won’t catch me trying to make predictive climate models.

By: rbateman

rbateman — Wed, 07 Oct 2009 12:25:30 +0000

Blinking the Cyrosphere Today image (Oct 5) with 2 weeks ago (Sept 18) it is obvious where the growth of the Arctic Sea ice is: Toward’s Canada and Greenland. And some of it has shifted away from Siberia.
Lookout N. America: it’s headed your way.

By: Fred Lightfoot

Fred Lightfoot — Wed, 07 Oct 2009 08:47:38 +0000

Watching the Russian Tv channel RT in English they showed a documentry of about one hour, 2 trucks with trailors in July drove to the magnetic North Pole and returned, no water, but ploenty of broken pack ice, the BBC was notibly absent.

By: Spector

Spector — Wed, 07 Oct 2009 04:31:28 +0000

Minor correction: NSIDC not NSDIC.

By: Spector

Spector — Wed, 07 Oct 2009 04:28:29 +0000

I have recently downloaded the 30-year NSDIC record in the txt files for each month and resorted this data by year and month. After developing a special cosine-series to remove the average annual melt-freeze cycles from this data, I see several minor recovery intervals: 1984-1987, 1990-1994, and 1996-1998.

I think we may have to wait several more years before we can say the previous long-term melting trend has been reversed.

By: Pamela Gray

Pamela Gray — Wed, 07 Oct 2009 02:16:35 +0000

DMI tracings seem to be significantly affected by calculated adjustments made to compensate for the changes in melt pools for satellite derived data. Since they also add on-the-ice buoy temperature sensors (at least the ones that are still operating) to compensate for cloud cover and calculated satellite adjustments, the up and down direction of the temp trace looks like a floating bit of sea ice is carrying the sensors in and out of warmer areas.

By: J H Folsom

J H Folsom — Tue, 06 Oct 2009 22:16:43 +0000

I was just curious. What is the reasoning for using the mean instead of mode for ice extent or area when trying to determine what “normal” ice extent/area is?

With the recent Yamal stories, im wondering if there are massive outlier events affecting the average, up or down. What does the mean of the ice extents year over year actually mean?

By: hotrod

hotrod — Tue, 06 Oct 2009 21:56:57 +0000

crosspatch (22:39:32) :
… There are at least three different trends visible since 1979. One flat, one steady down with a drastic down during the wind anomaly of 2007, and then a trend up in recovery.

Oh, and so far I expect 2010 to be near 2006 levels.

DeWitt Payne (13:31:04) :

…

FYI, I think you are probably correct, but you can’t prove it yet. It all depends on whether the AMO index continues to decline as expected.

One intuitive observation that comes to mind, is that when there is an Arctic ice dumping episode like in 2007 where lots of ice gets pushed out into the Atlantic there are really two things going on.

The arctic ice extent/volume must be declining while that happens — Many are assuming that is due to warming rather than physical transport of the ice.

And not so obviously, the Atlantic must be cooling as all that ice load melts.

Could that sort of ice purging be a significant forcing that switches on the AMO shift from a positive warming trend to a cooling trend?

If you suddenly take all the ice out of your ice tea and dump it in your hot soup, the ice tea will be warmer than you expect and the soup will cool much faster than you expect.

You can’t have one without the other, all that latent heat capacity in the ice has got to suck lots of heat energy out of the Atlantic .

Like an electrical circuit, the Atlantic , if you give it a big enough shove in the negative direction, would overshoot its median temperature, while it absorbs the negative input (melts the ice) and then slowly recovers back toward its stable value.

It seems to me that the sudden introduction of all that ice into the N. Atlantic is a plausible cause for the transition from a positive AMO trend to a negative AMO trend.

Larry

By: Gary Pearse

Gary Pearse — Tue, 06 Oct 2009 21:46:44 +0000

Well you can sure see the point where the ice was swept out in summer 2007. Move the curve up that down sloping line and you would have the trend up if this mechanical reduction in ice hadn’t occurred. The 2007 re-freeze after September was very strong (steep).

By: George E. Smith

George E. Smith — Tue, 06 Oct 2009 21:20:28 +0000

“”" LarryOldtimer (12:21:31) :

Pamela Grey

Regarding an object of mass, if all of the forces acting it or will act on it are known, then its rate of acceleration and position in the future can be predicted. “”"

Well according to Heisenberg, it is inherently impossible; no matter what, to even determine the present dynamic state of anything; ie simultaneous knowledge of position and momentum. Any method of increasing the positioning precision, will result in increasing the uncertainty of the momentum; and verse vicea.

So absent exact knowledge of the present; the future is most certainly unpredictable (well except in a probability sense) and as they say; on average nothing much will happen; it’s the deviations from average wherin lies the interesting details.