A Little Bit of Magic
Posted by Jeff Condon on February 28, 2009
Sorry for the delay, I haven’t actually been lazy at all. I have been working on a couple of what I find very interesting posts this one today and possibly another tomorrow. You aren’t going to believe this…
Those who have followed the Steig reconstruction know that 3 curves were used with different weightings to recreate the entire antarctic. The 3 curves look like this.
Linear combinations of these 3 curves make the temperature trend for the entire antarctic. RegEM was used to create the data prior to 1982 for the satellites by basically copying surface station data onto the ends of the sat data. RegEM is supposed to follow the data that exists so the PC’s should look the same in the pre 1982 period as the post. But they don’t! The paper makes the statement that 3 pc’s are used in RegEM however in the result PC3 is near zero and therefore there are really only 2. In this post I made a video of the Steig temperature anomalies for the antarctic. None of the data in this video is real, ALL of it is highly processed. The data post 1982 is derrived from PCA analysis of real data. The pre 1982 data is pasted on ‘imputed’ data.
Here are some plots of the distribution of he 3 pc’s or eigenvectors as calculated by Steve M at climate audit. These graphs are not temperature but rather weightings (positive and negative multipliers) times the 3 pc’s to create the final temperature anomaly.
Here’s the video of raw temp anomalies I created from R. If you consider the pc3 in the very first graph is basically zero until 1982 when it suddenly steps we see what we expect in the video. An oscillation blue and red of the whole continent (PC1) combinded with a top to bottom oscillation which corresponds to PC2 (you can see the boundary). These are the only PC’s of consequence in the pre-1982 RegEM reconstruction portion. After 1982 PC3 kicks in and the data begins fluctuating left and right on the graph as well. If you’re wondering what that means let me put it this way, temperature patterns did NOT change in Antarctica in 1982 coincidentally with the launch of a polar satellite! (that was fun.)
The video is a little difficult to interpret when you don’t know what you’re looking for so I did a second one where removed the mean of the plot from each month. So this video is the same as above except that it shows an equal amount of positive and negative anomaly for each frame (month). The idea was to bring out more of the features in the data…. IT DID!
Note the pink ring of reversed trend around the mid Antarctic. This is not a minor point at all. It shows quite clearly in the second video the ring around the antarctic is OPPOSITE in temperature from the land immediately adjacent. When the center is blue, the edge is red and they change positions constantly. I don’t know how this happened because we don’t have the REAL data only this PC nonsense, but I sure as heck don’t see an explanation in the paper anywhere. If you take a close look at Steve McIntyre’s plot of eigenvalues it’s in there too. PC1 has yellow creeping all around the rim PC2 has some as well from the bottom edge. Let’s see where the actual data comes from.
The real data is all around the edge. Somehow these guys managed to invent some math which reversed the trend of the surface stations within a couple hundred kilometers from the actual stations themselves and apply the reversed trend to the entire area circumscribed by the actual data where nobody knows what really happened.
Update — here are some of the still frames from the second movie. Keep in mind this is the data as presented on Steig’s own website from the dataset representing the final conclusion of the paper.
So now we know how they got a warming trend when many of the eastern stations showed cooling. If it’s related to ocean air, I would expect it to follow inner temps at some time but it does not. If we had the real data we would know but it doesn’t look good for Steig 09 to me.