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Climate trends ultimo feb 2011

Posted by Frank Lansner (frank) on 27th February, 2011
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How might we detect if recent temperatures is about to loose warming trend possibly due to natural mechanisms?

As discussed earlier, we might detect a changing trend by examining: "how for back can we go from todays data and still have a flat temperature graph?".

Doing so today - just after the warm El Nino year 2010 - 3 of 5 examined global temperature sources still show decade long flat trends:

 

Fig 1.

Hadrcut shows flat trend back to June 1997 (13 years, 7 months) /RSS shows flat trend back to July 1997 (13 years, 6 months) /NCEP shows flat trend back to Mar 2001 (9 years 10 months).

GISS and UAH "almost" shows decadial flat trend: GISS will go flat from 2001 and foreward with justone month of GISS global temperature of+0,23 K or two months of +0,39 K.

 Arctic ice approx thickness update PIPS2, first of March 1999-2011 :

 

 Fig 2: 2011 shows so far largest area of thick ice > 2 meters thick. In addition we see that thick ice areas with thickness 2m and above has more than doubled during the last 3 years.

PIPS2 original display first of march 2008, 2009, 2010 and 2011:

 

For ice volume (multiplying ice area with thickness) we get:

Fig 3: 2011 appears to have an ice volume near average of 1999-2011.

And more, ice volume from ice with more than 2 meters thickness has doubled during the last 3 years. The ice volume from Arctic ice thicker than 2 meter appears to be very close to highest level since 1999.

The > 2 m thick ice is far most located in the Arctic ocean itself rather than in other NH areas, and thus, the central Arctic thick ice appears to be growing fast.

 

Pixel readings from Cryosphere maps / Ice concentration and area:

fig 4: Feb 1 measurements. The unit is pixels (divide with 1,4 and you have 1000 squarre km2, roughly). The above figure shows a level drop around 2006. However, the areas with highest ice concentration appears growing in latest years.

Area of ice multiplied with the concentration, that is only pure ice area:

fig 5. The ice concentration or "pure ice area" falls from a level of around 19000 px (approx 13,5mio km2) to 17500px (approx 12,5 mio km2) around 2006.

Update 1 mar begin *********************************************************

When working with the Cryosphere maps I noticed that snow is introduced on their maps after 2005. The problem is, that the snow is indicated in a larger area than the land area. In other words: After snow indication was introduced to Cryosphere maps, the ocean and thus sea icea area has been reduced:

I have thereore used automated pixel count to find out how much sea ice has been reduced due to winter snow indications on the Chryosphere maps. The sea ice appears to be around 1200 pixels reduced in size in winter due to snow indication.

Therefore our pixel reading of sea ice extend systematically gets around 1200 pixels too small for each year where snow indication has been used by cryosphere:

- That is, the winter readings after 2005 are all around 1200 pixels too small.

Correted data series:

- in addition, i have divided with 1,4 to get a rough estimate in km2. The level - fall after 2005 has been reduced by the correction.

One might argue that the snow indication added after 2005 makes it wrong to compare pre and post 2005 data.

Update 1 mar end ********************************************************** 

1 oct - near summer minimum:

fig 6. Large drop in total ice area over the last decade, but strikingly, the more compact ice area is larger in recent years. So lets again calculate the ice concentration - "pure ice area":

fig 7. The oct 1´ trend 1995 - 2010 shows still a decline. We see a level around 1997-2004 9000 px (6,4 mio km2) versus the lower 2006-2010 level around 6800 px (4,8 mio km2).

Still the most interesting detail here is the growing more compact ice in fig 6. This supports the idea, that winds has been not only driving ice out oc the Arctic but has made the remaining ice more compact.

 

The method: Pixel counting done by freely available software:

http://mypixelpal.com/

I make a Pallete of the colors used in the picture, and then retrieve number of pixels for each color.

To ensure that my approach is useful i have produced the picture using the pixels identified by the programe (original march 1, 2007 left / reproduced right):

I have used color for concentrations 5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90, 92.5 ,95,97,98,99,100  % ice concentrations. 

Last changed: 1st March, 2011 at 09:01:16

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Comments

Hi Bamboozled! By Frank Lansner on 27th September, 2011 at 09:54:14
Thankyou for writing, and i really should do an update on ice thickness, temperatures etc. Coming up, within a week.
I have been working much on several writings (see "RUTI" in the left) and a biggie is coming online soon. Thats why everything else has been slow this summer.
Thanks for writing, its appreciated. K.F. Frank Lansner
Summer trend? By Unknown on 26th September, 2011 at 23:05:30
I would like to hear your analysis of the claims by NSIDC and others regarding the summer minimum (just passed).
Bamboozled.
Data request By Unknown on 6th March, 2011 at 18:32:32
Dear Frank Lanser

I will be pleased if you can make your pixel-reading public in such a way that other can verify and audit the data.

Regards
Klaus Flemløse

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