Simple GISS diagram illustrating warming effect of conventional “adjustments” of “step” in T data due to site moves outward from urban centre.
January 2nd, 2011 by Warwick HughesI have been reading the 169 page NIWA pdf – “Report on the Review of NIWA’s “Seven-Station” Temperature Series December 2010″ – downloaded here
I have not yet found the BoM review – only the one page letter from the BoM – see pdf page 13 in the above.
I draw readers attention to the excellent little GISS diagrams which perfectly illustrate the warming effect of adjusting out the multitude of step changes which are common throughout all temperature data as thousands of recording sites have been moved outwards in their respective urban areas.
GISS illustrating typical urban T data with a step due to outward site move – before adjustment.
GISS illustrating typical urban T data with a step due to outward site move – after adjustment – now with UHI warmed trend built in.
Reading their 169 page pdf report above – it is crystal clear that NIWA do exactly this – repeatedly adjusting out step changes – all through their seven station series – in this way NIWA cement UHI warming in their NZ 7 station century long adjusted trend.
PS: I had a little post on this in 2006
Posted in IPCC, NZ Climate Science Coalition, Surface Record, Urban Heat Islands | 9 Comments »
January 2nd, 2011 at 8:39 pm
NZ temperature record 1900-2008 before and after adjustment by NIWA
nzclimatescience.net/images/PDFs/app3.graph.pdf
The following may also be of interest:
nzclimatescience.net/images/PDFs/niwa.ct.docs.pdf
January 3rd, 2011 at 1:28 am
Thank you for this!
I never understood how honest adjustments could create a dishonest trend – and there it is, in two simple panels.
Perhaps I’m unusually dense, and everyone else following the debate already understands the point, but I think this point bears repeating.
January 3rd, 2011 at 6:48 am
Warwick,
I’d be very interested in your response to a challenge I’ve issued around NZ re the 7SS
www.climateconversation.wordshine.co.nz/2011/01/rotted-minds-at-hot-topic/#comment-34625
The de-trending exercise uses Akasofu’s 0.5 C/100 yr recovery from the LIA since 1850.
climaterealists.com/attachments/ftp/akasofu.jpg
Full paper here
www.scirp.org/Journal/PaperInformation.aspx?paperID=3217&JournalID=69#abstract
I’m also curious as to what similar data smoothing ans de-trending reveals in the Australian record.
(Referred here thnx to val majkus)
January 3rd, 2011 at 6:54 am
Forgot the main point.
The residual warming after de-trending may be the UHI that you have documented in the post.
BTW, a rough as guts linear regression of the unadjusted 7SS composite actuals 1999 – 2009 11 years -0.05145 cooling.
-0.468 degrees per century
January 3rd, 2011 at 7:21 am
Your diagrams and explanations are very clear, thank you. I’d be keen to hear more comments from you in due course on the NIWA review.
It’s curious the BoM’s review is not published. I’ve asked NIWA under the OIA for copies of communications between them and the BoM concerning the review. I hope they reply as a matter of urgency.
I reveal the strange date mismatches in the documentation in this post (at the end).
January 3rd, 2011 at 7:36 am
Warwick thank you for this post; however for people like me with no scientific training those graphs just looked like 2 stairways to heaven (one with a bit of a trip on the way) until I read your earlier posts which you’ve linked and david brewer’s comment of March 5th, 2006 at 8:04 am (commenting on your 2006 post)
January 3rd, 2011 at 7:56 am
I should have added that the term “undisturbed temperature” on the GISS diagrams refers to the trend if the city had never been built.
January 3rd, 2011 at 8:13 am
Good post, Warwick. Albert Park in Auckland is a prime example.
November 5th, 2011 at 2:17 pm
[...] Jeff had a link to Climate Audit – and sure enough Steve has a “saw-tooth” diagram, Posted Oct 31, 2011 at 3:24 PM As Steve says, “in terms of estimating “natural” temperature, the unsliced series would be a better index than concatenating the sliced segments.” Dead right. As far as I can tell, this diagram expresses exactly what the two GISS diagrams did in 2001 – see from Hansen, J.E., R. Ruedy, Mki. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl 2001. A closer look at United States and global surface temperature change. J. Geophys. Res. 106, 23947-23963, doi:10.1029/2001JD000354. and a pdf can be downloaded. I have a page here explaining the thing – Also a blog post. [...]