Roman M has already done one post on the impact of the Harry error. Ryan O has also done so [see comment here]. As has Steig.
I show below some graphics that I’ve just done on AWS recon trends.
At Steig’s website, he now states:
awsreconcorrected.txt is a correction to the above file, using corrected AWS data at two AWS stations. See the note under “Raw Data”, below. [Note that corrections have been made to AWS stations “Harry” and “Racer Rock”. See the READER web site for details. ] The resulting differences in the reconstruction are too small to be discernable in Figure S3, or in the trends for individual stations given in Table S1 in the Supplementary Information that accompanies the paper in Nature. (Corrections for all stations in the Table S1 are in the third decimal place (that is <0.01 degrees C/decade)). The mean trend for Antarctica changes by less than 0.004 degrees C/decade. The mean trend for West Antarctica changes by less than 0.02 degrees C/decade. Note also there is a typo in Table S2. The correct coordinates for station ‘Harry’ are 83.0 S 238.6 E. Note that none of these corrections have any impact on the satellite-based reconstructions; no AWS data were used in those reconstructions.
Several different trend period are used in the article. In the main text, Figure 4 uses a period of 1979-2003 as shown below (for AVHRR data.)
Steig Figure 4e. Comparison of reconstructed and modelled mean annual temperature trends (degrees Celsius per decade) for the periods; e–h, 1979–2003.
Figure 2. Steig Figure S3 excerpt.
To “facilitate comparison” with Steig et al Figure 4, I calculated trends for the 1979-2003 period for the AWS reconstruction, with trends being illustrated more or less emulating the style of Figure S3 (I’ll post scripts up in the comments.) I’ve labeled some of the stations in play.
Harry is the station with the largest 1979-2003 trend in the entire reconstruction, as you can readily see below. Harry, Racer Rock, Clean Air, Elaine and Butler Island, have all been mentioned in recent comments with amendments of one type or another being required to the first four stations (though only Racer Rock and Harry changes are incorporated in the present update.)
The Harry trend (the one with the screwed up data) is a very distinct feature in West Antarctica.
Figure S3. Spatial pattern of temperature trends (°C/decade) from reconstruction using AWS data. a) Mean annual trends for 1957-2006. b) Mean annual trends for 1969-2000, to facilitate comparison with ref. (2).
I just downloaded the “corrected” versions from Steig’s website, yielding the plot below. In this period, I submit that it is clearly not the case that the “resulting differences in the reconstruction are too small to be discernable”.
I’ll experiment a bit tomorrow to see why there are such differences in results for the 1979-2003 period and the 1969-2000 period that Steig discusses.