As noted yesterday, the main enterprise of Steig et al is a re-interpretation of West Antarctica, saying that “no one really has paid much attention to” this area in the past and saying that their study improved over prior studies because previously:
“People were calculating with their heads instead of actually doing the math,” said lead author of the study Eric Steig, of the University of Washington in Seattle. “What we did is interpolate carefully instead of just using the back of an envelope.”
I observed yesterday that NASA GISS used the same source data for surface and AWS stations as Steig (READER) but were unable to calculate trends in West Antarctica (blank on the trend map -see yesterday’s post), a “defect” that Steig attributed above to Hansen’s group “calculating with their heads instead of actually doing the math” and “just using the back of an envelope”. Hansen’s bulldogs, Gavin and Tamino, who usually defend Hansen against the smallest slight or perceived slight, are strangely silent to Steig’s damning accusations against Hansen.
Today I’m going to look at the station data to see whether Steig’s accusations against Hansen are fair or not.
Figure 1 below is a location map of stations listed in Steig Table S2. The green boundary is more or less the outline of the “West Antarctica” hot spot in Steig’s graphics. There are 5 dots in the GISS-empty portion of this area, which I’ll discuss after you have a chance to locate the dots: 3 blue, one green and one red.
Four of the stations are AWS stations shown in the bottom of Steig Table 2, excerpted below: MT Siple, Siple, Byrd and Harry. There are two surface stations: Byrd (in the same spot as Byrd AWS which operates a number of years after the surface station) and Russkaya (on the coast). I had a little trouble with my original plot of station locations because I used the information from Steig’s SI shown below.
In Steig’s location table, Mt Siple and Harry AWS stations have identical latitude and longitude (first two columns). In fact, they have different locations: Mt Siple is shown with its correct location (a blue dot on the coast), but Harry’s coordinates are wrong. Harry is the green dot in this map. Are these coordinates incorrect only in the Nature SI? Dunno. Would it even “matter” in Mannian methodology if they were incorrect? Dunno. It hasn’t “mattered” in any other Mannian effusion and, in this case, it might not matter if Harry were on Broadway or in Antarctica. It’s hard to say. You’d think that they’d be on the look-out for geographic mislocations given Mann’s prior rain in Maine/rain in Spain problems, but I guess not.
Below is some information (including looked up GISS numbers) on these six West Antarctic stations, that appear to underpin the Steig reinterpretation for their “AWS” reconstruction. I looked up these 6 data sets in GISS dset0, dset1 and dset2. Hansen only qualified one of the six stations as meeting his dset2 standards (Byrd 1957-1975.) Thus, in Hansen’s view, the data quality problems (coverage, length of record etc) with Russkaya surface and Mt Siple, Siple, Byrd and Harry AWS stations all disqualified them from dset2 status. In addition, the coverage period for Byrd surface dset2 annual average was only from 1957-1970, thus not qualifying for a 1979-2003 trend. That’s why West Antarctica is blank in the GISS trend map.
name lat long id start end gissid
8 Byrd -80.0 -120.0 89125 1957.000 1975.000 70089125000
35 Russkaya -74.8 -136.9 89132 1980.250 1990.083 70089132000
43 Mt_Siple_AWS -73.2 -127.1 89327 1992.167 2006.000 70089327000
44 Siple_AWS -75.9 -84.0 89284 1982.000 1992.167 70089284000
45 Byrd_AWS -80.0 -120.0 89324 1980.167 2008.750 70089324000
46 Harry_AWS -73.2 -127.1 21355 1987.000 2002.917 70021355000
Let’s now turn to Steig’s allegation that Hansen (like all of Steig’s predecessors) “calculated with his head instead of actually doing the math” and that he “just used the back of an envelope.” While I may seem like an unlikely defender of Hansen and GISS, fair’s fair. I see no evidence to support Steig’s allegation. On the contrary, there is clear evidence that Hansen put the information for all six stations into the GISTEMP algorithm. Whether the GISTEMP algorithm is any good is a different question, but Steig’s characterization of the process, appealing as it might be to Hansen critics, is surely uncalled for.
Here’s a plot of the READER version of the six stations. Given the importance that Steig placed on re-interpreting West Antarctica, it would have been nice if he had included a plot of the data, as even RegEM covariance matrices ultimately are related to data. At a first glance, this doesn’t seem like a whole lot of data to work with.
Steig’s recon_aws reconstruction offers anomaly reconstructions for 63 AWS sites, including the 4 West Antarctic AWS sites, which are plotted below, with their slopes over the 1979-2003 (used in the color trend maps yesterday. One of the four sites (Mt Siple) has a slightly negative trend; two of three (Siple, Byrd AWS) have modestly positive trends; while one site (Harry) – the one with the incorrect location – has a very strong trend of 0.81 deg C/decade.
Stay tuned for some interesting news about Harry.