Comments on: Orland CA and the New Adjustments

By: Hide the Decline – Data at Orland is Chopped | Digging in the Clay

Hide the Decline – Data at Orland is Chopped | Digging in the Clay — Fri, 13 Aug 2010 00:41:28 +0000

[...] alteration of Orland data by Steve McIntyre, with his customary thoroughness, here and here. Figure 2. Orland USHCN raw data/GISS homogenized data blink comparison. Animation courtesy of [...]

By: sky

sky — Wed, 01 Jul 2009 00:26:12 +0000

Re: Andrew (#22), The Orland station is in the Central Valley, 84 km south of Redding, according to GISS.

By: McIntyre on USHCN2’s “warmer” trend treatment of Orland « Watts Up With That?

Tue, 30 Jun 2009 20:38:32 +0000

[...] on USHCN2’s “warmer” trend treatment of Orland 30 06 2009 Orland CA and the New Adjustments by Steve McIntyre on June 29th, [...]

By: Andrew

Andrew — Tue, 30 Jun 2009 19:31:42 +0000

Re: Steve McIntyre (#18), Probably this is what you refer to:

Christy, J.R., W.B. Norris, K. Redmond and K. Gallo, 2006: Methodology and results of
calculating central California surface temperature trends: Evidence of human-induced
climate change? J. Climate, 19, 548-563.

I don’t know where in California Orland is, but they focused on the difference in trends between T-Max and T-Min and the trends in the Valley and up in the Sierras. The conclusion was that the only temperatures which rose significantly were T-Min in the valley, which they attribute to agriculture.

By: John S.

John S. — Tue, 30 Jun 2009 19:21:59 +0000

Orland shows very significant cross-spectral coherence with neighboring Willows, the squared values rising from 0.62 at zero frequency to 0.99 near that of the QBO. It fits in perfectly sensibly between Redding, which shows some UHI effects and Willows, which doesn’t.

Sometime I’ll learn to post graphs.

By: Steve McIntyre

Steve McIntyre — Tue, 30 Jun 2009 17:16:14 +0000

Re: Jeff C. (#16), Menne et al 2009 says:

The algorithm also makes use of station history information, when available, to improve the identification of artificial shifts in temperature data ... The cluster of dates falling within overlapping confidence limits is then conflated to a single date at the target in one of two ways: 1) it is assigned to the date of a known event in the target station's history that occurs within the confidence limits for a shift of that magnitude; or 2) it is assigned to the most common changepoint date that falls within these simulated confidence limits, which means that the discontinuity appears to be truly undocumented.

By: Steve McIntyre

Steve McIntyre — Tue, 30 Jun 2009 17:12:56 +0000

The underlying article describing the algorithm is here
ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/pairwise-rev8.pdf

and the companion article describing the new USHCN is here
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2008BAMS2613.1

By: Steve McIntyre

Steve McIntyre — Tue, 30 Jun 2009 17:09:09 +0000

Re: John D. (#15), John Christy did a paper on this sort of issue. Orland might even be in his target area.

By: John S.

John S. — Tue, 30 Jun 2009 16:46:04 +0000

Since the MAX/MIN thermometer was installed in 1907, the only necessary TOBS adjustment is for the 3 daily readings taken before then. But since the times of those readings are unknown, there is no solid basis for making an adjustment. What is being done blatantly is to bring Orland data into line with far-more-corrupted records.

By: Jeff C.

Jeff C. — Tue, 30 Jun 2009 16:39:25 +0000

Looks to me like there are two interesting things about the V2 minus TOBS chart (the second plot). If you look at the GISS plot shown in Anthony’s site photo above, the V2 minus TOBs plot looks to be very close to the mirror image of it. It appears that the V2 correction would turn the GISS temp record into something close to a flat line.

The second point is that the steps in the V2 correction coincide with the date of new entries into the station history file. The station history file has a new date entry when a station moves, equipment changes, the observation time changes, or even something as seemingly mundane as a change in the observer’s name.

I recall reading about one of the reasons for the V2 algorithm was to sniff out unreported location or equipment changes. I bet that the algorithm uses the station history dates in implementing this function. If the algorithm notices a temp difference between two adjacent station history time periods, it assumes there must be an unreported change. It then applies and adjustment to coerce the record into what it thinks is the correct temperature.

How it knows the correct temperature is anybody’s guess.