Saturday, May 2, 2015

An early GHCN V1 found - hardly different from latest V3 unadjusted


Clive Best has come up with an early version of GHCN V1, which he says is from around 1990; GHCN V1 was released in 1992, and I think this must be from a late stage of preparation. Anyway, he has kindly made it available. I have been contending that GHCN unadjusted is essentially unchanged , except by addition, since the inception, despite constant loud claims that NOAA is constantly altering history.

I thought I would compare with the latest GHCN V3 unadjusted, which has data up to March 2015. This turns out to be not so simple, as the numbering schemes for stations have changed slightly, as have the recorded station names. Stations have a WMO number, but several can share the same number in both sets. They have a modification number, but these don't match.

So for this post, I settled on just one country, Iceland. GHCN is supposed to have done terrible things to this record. A few weeks ago, we had Chris Booker in the Telegraph:
"When future generations look back on the global-warming scare of the past 30 years, nothing will shock them more than the extent to which the official temperature records - on which the entire panic ultimately rested - were systematically "adjusted" to show the Earth as having warmed much more than the actual data justified.
...
Again, in nearly every case, the same one-way adjustments have been made, to show warming up to 1 degree C or more higher than was indicated by the data that was actually recorded. This has surprised no one more than Traust Jonsson, who was long in charge of climate research for the Iceland met office (and with whom Homewood has been in touch). Jonsson was amazed to see how the new version completely "disappears" Iceland's "sea ice years" around 1970, when a period of extreme cooling almost devastated his country's economy."


This was reported by NewsMax under the headline:
"Temperature Data Being Faked to Show Global Warming"

The source, of course, was Paul Homewood. Euan Mearns chimed in with:
"In this post I examine the records of eight climate stations on Iceland and find the following:
There is wholesale over writing and adjustment of raw temperature records, especially pre-1970 with an overwhelming tendency to cool the past that makes the present appear to be anomalously warm."


So what did I find? Nothing that could be considered 'systematically "adjusted"'. There were differences, mainly with a clear reason. I'll list the eight stations below the jump.

Clive's V1 is accessible here. V3 in CSV format is here (10Mb zipfile). I have put the extracts relevant to Iceland on a small zipfile here.

Early note on April 2015 global

Most of the NCEP data for April global surface temperature is in. It was the coolest month so far in this warm year. As is common lately, it started cool, and only really warmed up to average (relative to current warmth). It was however, a bit warmer than last November, when GISS reported 0.63°C. March was &0.84°C. My guess for GISS in April is a bit over 0.7°C.

Thursday, April 30, 2015

UAH v6 trends


Roy Spencer has announced the beta version of V6 of the UAH lower troposphere temperature index. Sou has the story.

The result now look much more like RSS. The big things that made this happen seem to be that
  • UAH now uses a previously deprecated diurnal correction
  • UAH has reduced sensitivity to land surface emission, making it a more purely tropospheric measure (and more different from surface)

Incidentally, Dr Spencer's announcement is very informative on how the UAH sausage is made.

I was curious to see what difference it made to the back trend plots, as available here with the trendback button. It shows the trend from the various years on the x-axis to present. UAH is now similar to RSS, though not as low, and the pause is back. And the distinction between surface and troposphere indices is very clear. Here is the plot:




Wednesday, April 29, 2015

Movies for global CO2 and CH4

These have been around for a while, but I didn't know about them. Starting about 2007, NOAA has had a Carbon Tracker program. It is a kind of reanalysis program that assimilates mainly ground-based data to form a global model. I was reminded of it when I saw this recent conference paper which compared results with the two pre-OCO satellite data sets AIRS and GOSAT.

And it has movies. Lots of them, from about 2000 to 2010, of both atmospheric CO2 and CH4. When the first OCO movies came out late 2014, there was some murmuring that these would upset the CO2 applecart. Those were of course for just one part of the seasonal cycle, and some features they showed, such as an Amazon Basin hotspot, could seem unexpected. But they are there on the earlier NOAA movies, although those have much more NH CO2 at that time of year.

So are they reliable? Well, according to the linked paper, somewhat. They have resolution limitations, and do overstate the NH at times, but a lot seems reasonable. I'll add the link to the directory to the portals page, but of course, Moyhu has to have a gadget. This will allow you to choose by gas (CO2, CH4), year, and projection - global (Hammer), or orthographic (US-centered). Some movies are Quicktime (.mov), so you might need to have a plug-in. Others are animated GIF. One year/season is about 10 Mb, so may take a while to download.

Monday, April 27, 2015

GWPF Draft

As foreshadowed, I've drafted a submission to the GWPF panel. It's basically a collection of the things I've been writing about in recent months, but structured according to their remit. I was glad to have the incentive to get it all together.

They have required that it be in PDF format, so the draft is here (about 860 Kb). I'd be grateful for any comments.

Update. They suggest less than 10 pages. I'm at 21. They allow multiple submissions, but I think I'll prune the blog posts.


Sunday, April 26, 2015

GWPF inquiring into temperature adjustments

Well, this is an interesting one. GWPF has announced an inquiry into temperature adjustment practices. It is being boosted by Booker at the Telegraph ("Top scientists start to examine fiddled global warming figures") which is a bad dent in its credibility. However, it has a reasonably qualified panel, so it may be interesting to see what they develop. They have asked for submissions by June 30, so I might try to come up with something. But the remit sounds like they have been advised by Paul Homewood. For now, I'll just review that:

Are there aspects of surface temperature measurement procedures that potentially impair data quality or introduce bias and need to be critically re-examined?

Are they talking about current practice? Or that of years past? Are they going to recommend how it should have been done back then?

How widespread is the practice of adjusting original temperature records? What fraction of modern temperature data, as presented by CRU/GISS/NOAA/BEST, are actual original measurements, and what fraction are subject to adjustments?

This is framed Steven Goddard-style. How widespread is the practice of doing arithmetic? People use records to calculate spatial averages etc, and may well wish to adjust for that purpose. As they should. Is detrending, say, an adjustment? Or calculating an anomaly?

 CRU/GISS/NOAA/BEST do present data. NOAA explicitly offers unadjusted and adjusted data. GHCN Daily is largely an unadjusted copy of what the national Mets have, and GHCN Monthly unadjusted is a straight average of that (for long-record stations). But the primary business of CRU/GISS/NOAA/BEST is the calculation of spatial indices. That is basically a spatial integration, and requires manipulation. They have to calculate estimates of what actually happened in sub-regions, and they publish that.

Are warming and cooling adjustments equally prevalent?

Goddard again. No. Why should they be? Adjustments are for the repair of bias. If the identified bias is down or up, the repair will rightly have the opposite effect. TOBS, in the US, has a clearly cooling bias. The reasons are well established in terms of observing practices of the past, and so correction is clearly warming.

Are there any regions of the world where modifications appear to account for most or all of the apparent warming of recent decades?

This is straight Homewood. There may be some. The inference is that there was a cooling bias that masked all of the warming. But it isn't common. If it helps them, the broad regional breakdown is here.

Are the adjustment procedures clearly documented, objective, reproducible and scientifically defensible? How much statistical uncertainty is introduced with each step in homogeneity adjustments and smoothing?

Well, it will be interesting if naysayers finally bring themselves to read the papers of Menne and Williams etc. But agenda may intrude. Statistical uncertainty of what, I wonder? Anyway, I'll probably send in a submission. I've been working out how to convert the html of blog posts to pdf. We'll see.

ps ATTP

Update. I noted something amusing. Booker's articles (based on Homewood) have clearly been influential in setting up the inquiry, and at GWPF, Peiser has prominently featured Booker's announcement in the Tele. But he modified the headline to
"Top Scientists Start To Examine Adjusted Global Warming Figures"
As I noted above, Booker's headline is actually:
"Top Scientists Start To Examine Fiddled Global Warming Figures"

I guess GWPF likes to sound a little more objective.

Update again. Here at Homewood's blog is Booker celebrating their achievement in staging the inquiry
"It was entirely prompted by the two articles I wrote in the Sunday Telegraph on 24n January and 7 February, which as I made clear at the time were directly inspired by your own spectacular work on South America and the Arctic."

Wednesday, April 15, 2015

March GISS up 0.06°C

As several commenters have noted, GISS is up by 0.06°C, from 0.78 to 0.84. I had expected a small rise; David Appell was close. That's one of the hottest months on record, and makes 2015 a very warm year so far. TempLS rose by a smaller amount, and the troposphere indices declined.