I’ve watched the hubbub over the AccuWeather video by Joe Bastardi that called NSIDC’s Sea Ice data into question, because it “seemed” to show lower Arctic Sea Ice values than that of JAXA or DMI. Here they all are:
JAXA AMSR-E Sea Ice Extent -15% or greater – click to enlarge
NANSEN Artic ROOS- Sea ice extent 15% or greater – click for larger image
NSIDC Arctic Sea Ice Extent – 15% or greater – click to enlarge
As you can see above, NANSEN shows more ice than NSIDC, and JAXA seems to be a bit less than 2007, in line with NSIDC’s presentation. It all boils down to different algorithms and methodology giving different interpretations.
Like Mr. Bastardi, many people are comparing NSIDC graphs to other similar graphs on a daily basis and they will continue to do so. For some, it’s like a sport, and there’s even Vegas style betting done on sea ice minimums now, and in some cases real money is used.
But as we’ve seen, eyeballing can be an error prone activity, and a risky bet.
Mr. Bastardi erred due to eyeballing, of that there is no doubt. NSDIC was gracious enough to fill him in on his mistake and Mr. Bastardi corrected his mistake once he was made aware of it. He had to retract his original video and replace it with the update on Sunday (a day early). It has been my impression that he’s got a weekday shift at AccuWeather.com, and if so, good for him to come in and make a new video on a Sunday. Here is his correction:
A poor quality copy of the original video (with the mistake) is here
As Joe found out, eyeballing can get you in trouble. I’ve made similar eyeballing mistakes in the past. It gets compounded when you use that mistake as a basis to call out some organization like NSDIC. I’ll echo Joe Bastardi in saying that my contact at NSDIC, Dr. Walt Meier, has been “above board” with me and maintains an open line of communication. This is despite our differences of opinion on the sea ice. The fact that we can communicate in a friendly and cordial way despite our difference in opinion, is why you’ll find guest posts from Dr. Meier here on WUWT, such as this one wrapping up the 2010 melt season.
Like there have been good things coming from our collaboration with NSDIC, there can be a something good come from this eyeballing mistake and video retraction.
As I’ve said before in previous posts, a lot of eyeballing can be avoided by NSIDC publishing the daily data as other sea ice organizations do. I suggest again that NSIDC publish daily data, so that there’s no need for eyeballing when hard numbers can be compared.
As many know, NSIDC’s Dr. Mark Serreze has made the sea ice issue very high profile with his “death spiral” comments to major media, resulting in NSIDC being highly scrutinized in the current, ahem, “polarized” debate on sea ice.
While Dr. Serreze’s statements have the unfortunate side effect of raising their profile, I think the best choice for the public that they serve (after all, it is a U.S. government funded organization) is to rise to the scrutiny your organization has created for itself and publish the daily sea ice extent data. Everyone wins when such a thing occurs, and it could go a long way towards eliminating the perception (right or wrong) that NSIDC is the “odd man out” on sea ice if they would publish the hard data as other organizations do.
I’m hopeful to see NSDIC’s daily absolute values published regularly like JAXA does here, NANSEN does here, the University of Bremen does here, and UIUC (Cryosphere Today) does here. By doing so, there’s then no excuse for not using hard numbers in addition to graphs rather than simply eyeballing squiggly lines when comparing to NSIDC. If there’s a question on one of the plot lines, a simple look at the daily data will settle it immediately, assuming NSIDC publishes in a form that the public can easily use. Here’s to hoping that they do.
In other news, the temperature of 80N has hit a low about equal to the low of normal climatology, (the green line) but a bit early: