It looks as if we are about to see the turn in Arctic sea ice, and if so it will be earlier than last year. But right at that same time, JAXA has decided to switch horses mid-stream.
They say timing is everything, and this timing couldn’t be more wrong. You”d think they would have waited until after the minimum had been recorded, so that there would be no questions or issues with the timing. But for some reason, JAXA has decided that now is the opportune time, right when everyone is watching. An update on their Arctic Sea-Ice Monitor page dated September 6th shows that they are switching from Version 1 to Version 2, and revising 2012. Of course the revision is for less ice:
In Sep. 2012 the arctic sea ice extent renewed the smallest record in observation history, but as the result of the version 2 using AMSR2 data of 2012, minimum sea ice extent became 3.18×106km2 which was 0.3×106km2 smaller value than Version 1 result using WindSat.
Here is what they display, on the plus side, at least they are keeping version1 in place until September 30th:
I have overlaid the two graphs, and it looks like all of the sudden about 250,000 square kilometers of ice has disappeared.
Note: I don’t have issues with their methodology, which is to remove uncertainty/noise related to the land mask boundary, which is always a good thing. But, the timing is certainly odd.
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From their update page:
With the version upgrade of AMSR-E Level 1 brightness temperature data, geolocation errors were improved from ±10km to ±1km.
The Version2 sea ice extent was calculated after the analyzing the arctic sea ice concentration derived from the upgraded AMSR-E brightness temperature data.
In addition, the other satellite observational data (1980, 1990, 2000 and 2010′ s average of SMMR, SSM/I and WindSat) was used to calculate sea ice concentration after adjusting the brightness temperature of each sensor using AMSR-E as standard data, and the adjustment of the sea ice concentration threshold which counts the sea ice extent was applied to consist with the AMSR-E sea ice extent.
The modified processing point due to the improvement of the geometric precision of AMSR-E Level 1 brightness temperature data is shown on description below.
With version 1, sea ice can be falsely detected along coasts due to contamination of ocean pixels by the passive microwave emission of land (the false sea ice). To decrease this false sea ice, we applied the “land expanded mask” (See Fig.1).
By improvement in AMSR-E geometric precision and decreasing of the false sea ice, we stopped the land expanded mask in the processing of version2.
Compared to Version 1, Version 2 sea ice extent has increased.
For the purpose of eliminating the false sea ice near the coast, Land Expanded Mask consider horizontally and vertically adjacent pixels as land when the 3×3 box centered on the land pixel.
Version 1 used the land-ocean mask which is provided for SMMR and SSM/I, but for Version 2, due to the AMSR-E geometric precision improvement, we made new land-ocean mask which is adjusted for footprint size of the 18GHz band of AMSR-E (IFOV: 16×27km) and applied to the analysis of sea ice concentration.
Compared to Version 1, the sea ice extent of Version 2 has decreased.
![fig1-ii-1-SIC_AMSE_N_PS12_20030301_05diff_only-cncl[1]](http://wattsupwiththat.files.wordpress.com/2013/09/fig1-ii-1-sic_amse_n_ps12_20030301_05diff_only-cncl1.png?quality=75)
In version 2, the false sea ice near the coast has decreased by the geometric precision improvement of the AMSR-E. But the false sea ice still cannot be removed completely, so we applied the land filter which Cho (1996) proposes. When at least one of 3×3 pixels was inspect as land, as the considering that the central pixel is effected by land spill over and has increased in sea ice concentration, central pixel will be replaced with the minimum value within the 3×3 pixels.
By applying this land filter process, sea ice extent of Version 2 has decreased in the melting period compared to Version 1.
After the observation halt of AMSR-E, the sea ice extent was calculated by WindSat in Verion 1, but in version 2, it was replaced by AMSR2 since July 2012.
In Sep. 2012 the arctic sea ice extent renewed the smallest record in observation history, but as the result of the version 2 using AMSR2 data of 2012, minimum sea ice extent became 3.18×106km2 which was 0.3×106km2 smaller value than Version 1 result using WindSat.
Furthermore, there is no modification in ranking of the successive sea ice extent due to the latest upgrade.
![fig2-1-Sea_Ice_Extent_ver1[1]](http://wattsupwiththat.files.wordpress.com/2013/09/fig2-1-sea_ice_extent_ver11.png?quality=75)
![fig2-2-Sea_Ice_Extent_ver2[1]](http://wattsupwiththat.files.wordpress.com/2013/09/fig2-2-sea_ice_extent_ver21.png?quality=75)
Fig.4 Arctic Sea Ice Extent during the minimum period
(Left:Ver.1, Right:Ver.2) – click to enlarge
Of course they’ll compare current V2 extents with older V1 extents to show that it is indeed worse than we thought…
ready for supporting AR5?
They would not do this so that minima looks comparatively smaller, could they? Nah, our gov labs never skew the data on climate change issues, do they?
Anthony, question from the bleachers here… if they adjust this year’s model or data, would they not have to adjust all preceding years as well?
So the 2013 recovery is better than we thought?!
Your all so naive here its beyond belief I have been shouting from the roof tops for years how these guys manipulate ice extent ALWAYS when it appears to be NOT going the desired way. CT etc are all the same they CANNOT AFFORD to lose this last precious icon of supposed AGW DMI and norsex both Scandinavian may be trusted.
it’s one of the AGW miracles, adjustments always going in one direction
as far as I’m concerned it’s a small step away from deception
So are they going to reduce the 1979- 2012 sea ice area by “0.3×106km2” ? And how many times have they done this since 1979? How do we know if they are measuring sea ice the same way as they were in 1979? Maybe the steady reduction in sea ice is simply the steady software/measurement method updates over the years.
OT, But is this Trenberths missing heat.
http://www.ibtimes.co.uk/articles/504226/20130906/world-s-biggest-voclano-confirmed-scientists-tamu.htm
Oh, don’t worry. They’ll adjust for it.
/sarc
If you scan the web you will note that no two ice extent measuring services give the same value and they vary by nearly 10^6 km².
In terms of data manipulation and distortion (and I agree with Anthony that it’s not happening here); when it does happen, it can only go on so long before it falls into the “give them enough rope” category.
You really can feel some of the people all of the time, as Lincoln said, but not all of the people all of the time.
At least they adjusted all the previous years too so the relative changes don’t look terribly messed up. (And didn’t do the GISS trick of cooling the past.) The percentage improvement from the 2012 minimum to 2013 might be significantly greater.
Funny how ‘corrections’ to climate related data are always in one direction, that is whatever makes the most dramatic change to prop up the ‘It’s worse than we thought’ meme. I remember going through the older CT images for NH ice and found they changed the sea edges by showing snow extent. This coincides with the step function at 2005. I found the sea area had diminished by pixel count the amount of the step, some 4-500K sq km.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
Ric Werme says:
September 6, 2013 at 9:47 am
I agree with Ric that it shouldn’t really matter as long as all previous years were consistently adjusted. Moreover, the increase in sea ice extent from last year will be quite obvious.
omnologos says
“it’s one of the AGW miracles, adjustments always going in one direction.”
I agree. Does anyone keep track of these “one direction adjustments”? If not, perhaps we should encourage Anthony to set up a separate tab where we could track them. It might be enlightening to see just how many “one direction adjustments” to temperature data, ice data, tide data, weather station data, etc. have been made. It might be equally enlightening to see who made them and when.
So is this Climate Change or just Climate Data Change?
I wonder if Mikes Nature Trick could be used to Hide the Decline?
Eliza says:
“Your all so naive here its beyond belief I have been shouting from the roof tops for years…” &etc.
Eliza, some of us, probably most of us, are on the same page as you are. Note omnologos, Steve Keohane, Louis Hofstetter, Ric Werme, Harold Amblet, etc., etc. [sorry for all those I left out].
We all see that CT is diddling with the data. Arctic ice is rapidly increasing, as the data shows. Once again, the alarmist predictions have been shown to be 100% wrong.
It’s the start of the school year, and they have a fresh batch of interns with new ideas.
If it is a land mass correction then shouldnt the correction be the same across the board…on all years the same amount of change?
I see variable changes, year over year, in the differences between the minima when they should all have the same step wise land mass correction.
These people are liars and should be put trial for mass public deception. Disgraceful what other purpose could there be but deception.
Note that this has happened for the “1980’s average” and “1990’s average” as well. As far as I’ve been able to determine, they weren’t updated to become “apples-to-apples” either. With exactly the same issue – determining the land-sea boundary. (And then not re-evaluating every single photo.)
JAXA was a source I thought I could trust–guess not.
Timing shows either corruption or incompetence, so no “explanation” will suffice.
Anthony
You increasingly have some ‘clout’. Have you emailed them?
REPLY: Thanks, but say what? Put it back? The horse has left the barn – Anthony
Look on the bright side. At least they did not adjust the ice extend downwards in 2007…