In today’s report
- Arctic Sea Ice on the rise again, presently in the range of normal levels
- Antarctic Sea Ice is at slightly above normal levels
- Why is early satellite data for Arctic and Antarctic Ice extent referenced in the first IPCC report missing from today’s data?
- Is revisionism going on with the date of the famous USS Skate photo in the Arctic?
- Bonus – it seems NOAA is taking Arctic soot seriously
First the Arctic from NSIDC:
After being out of the ±2 STD area since before peak melt last year, Arctic extent has spent most of March in near normal territory. After what looked like a maximum earlier this month, it was false peak, and ice is on the rise again.
NORSEX SSM/I shows the current value within ±1 STD
A caution, as we saw in 2010, extent hugged the normal line for quite awhile, and that didn’t translate into a reduced or normal summer melt. So, forecasting based on this peak might not yield any skillful ice minimum forecasts.
Antarctic Sea Ice is at slightly above normal levels, as it has been for some time:
Why is early satellite data for Arctic and Antarctic Ice extent referenced in the first IPCC report missing from today’s data?
In a post last week, Steve Goddard pointed out that in the original IPCC FAR in 1990, there was an interesting graph of satellite derived Arctic sea ice extent:
This is from page 224 of IPCC FAR WG1 which you can download from the IPCC here
And here is figure 7.20 (a) magnified:
The IPCC descriptive text for these figures reads:
Sea-ice conditions are now reported regularly in marine synoptic observations, as well as by special reconnaissance flights, and coastal radar. Especially importantly, satellite observations have been used to map sea-ice extent routinely since the early 1970s. The American Navy Joint Ice Center has produced weekly charts which have been digitised by NOAA. These data are summarized in Figure 7.20 which is based on analyses carried out on a 1° latitude x 2.5° longitude grid. Sea-ice is defined to be present when its concentration exceeds 10% (Ropelewski, 1983). Since about 1976 the areal extent of sea-ice in the Northern Hemisphere has varied about a constant climatological level but in 1972-1975 sea-ice extent was significantly less. In the Southern Hemisphere since about 1981, sea-ice extent has also varied about a constant level. Between 1973 and 1980 there were periods of several years when Southern Hemisphere sea-ice extent was either appreciably more than or less than that typical in the 1980s.
I find it interesting and perhaps somewhat troubling that pre-1979 satellite derived sea ice data was good enough to include in the first IPCC report in 1990, but for some reason not included in the current satellite derived sea ice data which all seems to start in 1979:
Since the extent variation anomalies in 1979 seem to match with both data sets at ~ +1 million sq km, it would seem they are compatible. Since I’m unable to find the data that the IPCC FAR WG1 report references so that I can plot it along with current data, I’ve resorted to a graphical splice to show what the two data sets together might look like.
I’ve cropped and scaled the IPCC FAR WG1 Figure (a) to match the UUIC Cryosphere Today Arctic extent anomaly graph so that the scales match, and extended the base canvas to give the extra room for the extended timeline:
Click image above to enlarge.
Gosh, all of the sudden it looks cyclic rather than linear, doesn’t it?
Of course there will be much wailing and gnashing of teeth over my graphic, and the usual suspects will try to pooh-pooh it, but consider the following
- Per the IPCC reference, it is data from NOAA, gathered by the American Navy Joint Ice Center
- It is satellite derived extent data, like Cryosphere Today’s data
- The splice point at 1979 seems to match well in amplitude between the two data sets
- The data was good enough for the IPCC to publish in 1990 in the FAR WG1, so it really can’t be called into question
- If Mike Mann can get away with splicing two dissimilar data sets in an IPCC report (proxy temperature reconstructions and observations) surely, splicing two similar satellite observation data sets together can’t be viewed as some sort of data sacrilege.
Of course the big inconvenient question is: why has this data been removed from common use today if it was good enough for the IPCC to use in 1990? Is there some revisionism going on here or is there a valid reason that hasn’t been made known/used in current data sets?
If any readers know where to find this data in tabular form, I’ll happily update the plot to be as accurate as possible.
Is revisionism going on with the date of the famous USS Skate photo in the Arctic?
It seems our favorite photo of the USS Skate has had it’s date revised.
Since yesterday was the anniversary of the March 17th surfacing of the USS Skate, WUWT contributor Ric Werme was interested in what the photographic conditions might look like on March 17th 1959 when the sun was just below the horizon, and so found a sub and attempted to recreate the photo conditions himself to see if the photograph was actually possible.
Turns out it was, but then he stumbled on something he didn’t expect to find. The date for the surfacing has been changed from March 17th, 1959 to August, 1958 (with no day given) in Wikipedia and in NAVSOURCE. He at first thought I’d made a mistake in citation, but it turns out dates have been changed since I wrote my original article on the USS Skate on April 26th, 2009.
I wrote about how the original date remains on NAVSOURCE in the Wayback machine
Anthony Watts says:
Navsource, in the Wayback machine, had it stated as March 17th 1959, just days before my original article. This is the April 18th 2009 snapshot from Wayback:
The caption then reads:
Skate (SSN-578), surfaced at the North Pole, 17 March 1959.
I remember checking NAVSOURCE for accuracy before publishing, my caption then says:
Skate (SSN-578), surfaced at the North Pole, 17 March 1959. Image from NAVSOURCE
History on that photo changed there at NAVSOURCE since then, probably due to alarmist pressure from Wiki etc. and other folks like Neven who went ballistic over the picture when I highlighted it. It is “inconvenient” in March (during peak ice season) but soothing for them in August (during near peak melt season).
The picture may have been taken a couple of days after the funeral photo in March alluded to upthread.
Se EM Smith comment in my original thread. http://wattsupwiththat.com/2009/04/26/ice-at-the-north-pole-in-1958-not-so-thick/#comment-122932
Oddly, NAVSOURCE now shows a caption of:
So what had been certain and unchallenged for years now all of the sudden is uncertain and may be in August 1958. Seems like a case of the tail wagging the dog.
Obviously there is a need to pin this date down, but I’m amused that so much attention has been brought to this photo since I first blogged on it.
BONUS: I’ve always said that the current drop in Arctic Ice Extent might have roots in soot from the industrialization of Asia causing an albedo change which really took off in the 1990’s, would show up in the summer melt season when solar irradiance is at a peak in the Arctic. Now it seems NOAA is taking Arctic soot seriously:
From the video description:
Small, new, remotely-operated, unmanned aircraft are being flown in the Arctic to measure black soot. The soot is produced by burning diesel fuel, agricultural fires, forest fires, and wood-burning stoves. It is transported by winds to the Arctic, where it darkens the surface of snow and ice, enhancing melting and solar warming. See http://saga.pmel.noaa.gov/ and http://www.pmel.noaa.gov/edd/manta.html
As always, check the latest sea ice conditions on the WUWT Sea Ice Reference page.
UPDATE: Robert Grumbine disputes some the the points related to the IPCC1 report and sea ice with EMMR equipped satellites here. – Anthony