Re fitting exponential curve.

Simply, the curve does not contemplate cases where there is a small population and a weather station some distance away. This would require a start to the curve which was flat on the X-axis for a while before the rise started. The graph shown is also counter-intuitative because it assigns the greatest rate of UHI increase to the smallest increase in population.

I mean we have non-linearity, non-stationarity, multiple correlated signals, core variance. The list goes on and on.

Seriously this sort of work should “slay the stick” once and for all.

Why not team up wuth Steve M. and get this published?

FWIW, one of my “pet peeves” about the GHCN, USHCN, and by extension GIStemp products is that a site is allowed only ONE flag and only in the present time for the Urban / Rural state.

So a place like Sacramento would be flagged as Urban, because it is so today. But when did it START being urban? And how much has it changed over what period of time?

GIStemp (and anyone else attempting a UHI correction) must make assumptions about when to start applying any UHI correction. It knows nothing about the past history of urban / rural state as a function of time.

Clearly the UHI time profile of London or Rome will be different from that of Tucson Arizona or Sacramento, California or Las Vegas, Nevada (that was literally a ‘cow town’ until developed after water was available from Lake Mead / Boulder Dam / Hoover Dam post WWII ). Yet all of them are treated the same in GIStemp.

The Urban / Rural flag ought to be stored for each year of the record (and, IMHO, ought to be a ’size proportional’ flag not just an “is / isn’t” flag… )

And frankly, on that issue alone, I think the GIStemp “UHI adjustment” is invalidated and ought to be thrown out.

FWIW, there is a similar issue with the “Air Station” flag. Berlin / Temple was THE key airport of the Berlin Airlift. It has records going back to when it was an open pre-aviation era military field. It is now decommissioned and being turned into shops. Right Now, the record says it is an Urban Airport. In a few years, it will say Urban, not an airport and you get to assume IT NEVER WAS AN AIRPORT. In the past it was rural, be we don’t care about the past… Soon the acres of tarmac and concrete runways will fade into the past and be forgotten as well…

And because this is in the base data, it impacts ALL users of the data.

I have now read the paper you cited. It is very good. Obviously the UK’s climate zone is not the same as Australia’s, so there are important differences regarding the amount of heat that builds up in the day, night time temperatures, humidity etc. OKE is a much cited expert on UHI and I do tend to think his figures are a little exaggerated.(I’m sure my opinion will worry him!)

However it all points to two things

1) Giss/IPCC don’t allow enough for the many data sets that have become urbanised over the years.
2) It is very difficult to see a co2 warming signal-the overwheming factors are natural variability, a UHI margin
and land use changes.This latter may particularly apply in ther rural areas you mention.

Tonyb

Ah a cunning plan I see

Lucy and Geoff

I don’t disagree with anything either of you say, it just struck me that -however imperfect- a logarithmic curve is not a bad representation. Clearly there is an upper limit to UHI and clearly there is a lower limit.

Amount of wind, height,proximity of roads,shelter, trees, water etc etc all play a role. However I think there is some kernel there and the curve is more believable than many of the numerous (30 or so) UHI studies I have read. If a station is in the middle of a big park in a windy place UHI is going to be fairly limited, one situated surrounded by buildings in a non windy place is likely to see a quite different effect.

In reality EVERY location is different and needs its own factor but as far as I’M aware that doesn’t happen and the result is a UHI amount applied by Giss that seems unrealistically small.

Tonyb

I hardly think the global warmist can be blaimed for the demise of the aluminum smelters in the northwest. This smelter has for years benefited from sweetheart deals with the BPA.

And you would be, at the very least, miguided, if not outright incorrect.

Finally the public utilities of the northwest have fought to eliminate these deals because of rising demand and the fact the BPA was created to help all of the northwest rate payers not just the aluminum companies.

Then ask yourself this: in the face of rising demand, why was there no other supply besides Bonneville for their power? Why are there no new coal-fired power plants? No new nuclear power plants?

Perhaps if environmentalists had not made it so ridiculously difficult to build new power plants sweetheart deals would not have been required to keep the Al plant open.

As one who believes the global warmist are pushing a dangerous and unproven theory, I don’t believe they can be blamed for the demise of these smelters.

Then you are apparently not looking deep enough into the true impact of their actions.

Mark

I hardly think the global warmist can be blaimed for the demise of the aluminum smelters in the northwest. This smelter has for years benefited from sweetheart deals with the BPA.

Finally the public utilities of the northwest have fought to eliminate these deals because of rising demand and the fact the BPA was created to help all of the northwest rate payers not just the aluminum companies.

As one who believes the global warmist are pushing a dangerous and unproven theory, I don’t believe they can be blamed for the demise of these smelters.

And there’s Goldman Sachs “Doing God’s work” funding the leveraged buyouts that have put our best industries in foreign hands. They believe in “Climate Change” too…

Not a future I look forward to.

Isn’t that what a police officer is trained and supposed to do? While she should be commended for her act that is exactly what she is supposed to do.

[snip]

[REPLY]:Congratulations, you are the 11th in something like 9000 people to get snipped – be proud. I have asked politely in the post not to bring up the old thread. This woman is a hero and you need to rethink what happened, I nearly left your post up as an example of wrongthink but there is no point. Your welcome for not leaving it up as an example.

Speaking in the most general terms, something that fascinates me is the power of statistical treatment to show meaning where a casual inspection of the data doesn’t show any. And to assign significance (e.g. P) to the relationship being considered.

This is a great thing, because correlations in large and complex data sets are typically difficult or impossible to see. Without statistical analysis, their significance is usually impossible to grasp.

The other edge of this sword is that improper application of statistical analysis could highlight relationships within the data where none exist.

In this regard, I looked at near-raw Lake Korttajarvi proxy data graphically, setting the X-axis (Time BP) the same as for Mann et al’s Fig. S8a. “Another Correction” thread, Comment #9.

In Fig. S8a, the calculated temperature anomaly takes a pronounced dip from 810 to 850. The Green Trace and the Black Trace are essentialy the same for the eighth through tenth centuries. This shows that the calculation of the anomaly during the dip is not affected by inclusion of the Lake Korttajarvi proxies in the input to the CPS algorithm.

Yet there is no obvious “cooler” signal in the raw Lake Korttajarvi proxy data for 810-850, compared to preceding and subsequent decades.

This is counterintuitive. Intuitively, if there’s no strong “cooler” signal in the four added-in proxies, the Black Trace should show a more modest dip than the Green Trace.

It may be that correct application of signal-processing methods is bringing out non-obvious but real information. If you’re so inclined, could you offer your perspective on this question (or suggest a link)?

This is what it’s all about: Their heroes selfishly take innocent lives while ours selflessly put their lives in harm’s way to save them. Cultures are defined by their heroes.

And how fitting is it that a rampage by yet another dime-a-dozen Islamofascist be brought to an end by a woman.