Well, LeRoy (1999), the handbook for NOAA/CRN lists CRN4 and 5 sites as having an offset of ≥2C.

The basic conclusions of LeRoy are confirmed by Yilmaz, et al (2008).

Seven out of ten stations are CRN4 or 5, as demonstrated by photographs and/or aerial surveys+curator interviews. Having done over 200 of these surveys (both photographic and satellite) and supplementing around 100 more as a devoted member of the Thermometer Team (Mercury Monkey division, Satellite Strike regiment), I can speak with some small authority on the subject.

REPLY: Next time you see a thread with a tag of CO2 would be appropriate. In the meantime, try not to poison yourself with your own breath. – Anthony

Its just a rescaled plot lookining at the minimums on a sensitive temperature scale.

But you can see the classic rise of UHI in it, the mins have been steadily getting warmer, exactly what you’d expect in an urban station.

Wouldn’t you expect this in an warming situation.
Population by Year Change Rate
2000 12,268 N/A
2001 12,454 1.52%
2002 12,558 0.84%
2003 12,599 0.33%
2004 12,491 -0.86%
2005 12,131 -2.88%
Not the most expansive of towns. So where does your UHI originate in a growth function.
I still suggest that there should be a step change as the car park was paved – it is not visible.

be sure the data you are using is truly “raw”.

3 sets of data were presented, UHCN, Combined, and homogenized. The first was used and if the record was incomplete in one un-homogenised plot then they were combined without modification. A second plot is presented which is the homogenised version and a 3rd shows the difference between them.

Asphalt, concrete, etc isn’t always a step jump, as it often creeps in gradually, this is what city UHI is all about. The transformation at Marysville was not all at once.

I am surprised that they built a carpark as and when required – it is a lot easier to do the lot in one go.

For a comparison between sites it is necessary for the location, what’s under the sensor, what heat sources close to the sensor, etc to be the same. But grass is not ideal as this will cool and retain water, concrete retains heat, gravel retains heat etc. If looking for possible trends at a station then consistency is the most importent requirement. it should not be moved the underlying material should not change, and objects withing a 30m? radius should not change. This will give consistent results. The underlying stuff will affect daily and seasonal differences but from year to year there will be no distortion of temperature and trends will be the only perturbation.

thanks for the link:
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf

Also you never answered if you had read the NOAA Climate Reference Handbook describing the siting ratings. Did you read it?

Yes the French as well as the NOAA. This does explain the source of your numerical system, but does not prove the error at each location.

REPLY: Bill, we aren’t assigning an absolute error to each location, nor have I ever said that Marysville has an absolute 5C error, we are simply using the rating system as a way to bin the raw, TOBS, and FILNET temperature data so that we can do trend analysis on well sited versus poorly sited stations. I have not done this yet on a publication basis because I wanted to get an undisputedly large sample before I did so. Now approaching 80% we are trying out those sorts of analyses.

The rating system is the only one in existence on Earth, and while not perfect in its broad assignment, is the only one we have to work with, and it was signed off on by the director of the NCDC himself. I figure it is good enough.

Yilmaz et al though shows some significant errors over different surfaces, so following that, if we wanted to do a comparison of Marysville versus a grassy field a mile or two away to determine the magnitude of the absolute error, that might be an interesting experiment to try.

“I am surprised that they built a carpark as and when required – it is a lot easier to do the lot in one go.” I agree, but this is also a fire training facility, and the rear lot changed with training needs. There’s also the cell phone tower, and 2 equipment sheds for it with a/c units, these were added around 2001-2002 if I remember correctly. The lesson here is that it is a dynamic environment. – Anthony

Great job of keeping us all well informed. I just wanted to let you know that your website has been blocked for sometime in China. And, the authorities in China are beginning to talk on the lines of the current US administration.

My only hope is that somebody can stop the madness before future generations have to suffer an ice age. Valuable resources are being wasted that could be spent in preparation for mile deep sheets of ice, if the world would only open its eyes, and see the wizard standing behind the curtain.

Unfortunately I think it is going to take ice on the equator before the modelers will admit that they were wrong.

The substance of the skeptic argument is that CO2 is not a pollutant.

Then it’s an erroneous argument. A pollutant is a substance where it’s not supposed to be. CO2 is often a pollutant. It can be a deadly gas. How can a killer gas not be a pollutant when it’s in concentrations that make it deadly?

REPLY: Ed that is just silly. We are talking about 290 parts per million in Earth’s atmosphere now, trace gas levels. The levels in free air are far lower than what you’d get in a room full of people at a party, which is about 2500 ppm. To get to “killer gas” levels, you’d have to reach 50,000 ppm. at a worst case rise of 2ppm per year, based on current MLO CO2 trends, we have over 24,500 years to get there.

Source – Carbon Dioxide Information and Analysis Center: http://cdiac.esd.ornl.gov/pns/faq_othr.html

CO2 is part of Earth’s natural cycle, it is not a pollutant. And if you were to look far back in time, you’d find that the Earth once had an atmosphere that was mostly CO2. Then plant life evolved to make use of it, and oxygen they gave off became the “pollutant” by your definition.

Source – http://teachertech.rice.edu/Participants/louviere/history.html

No need to worry, CO2 in the atmosphere won’t kill us anytime soon, in fact without it we would not be having this conversation.

And again, I’ll remind EVERYONE this thread is about weather stations and data quality, not CO2. Etiquette please.- Anthony

The plots show monthly averages (daily variations will not be apparent. Here is the min of the monthly data. Again it would be impossible to assign any shift in temperature at the suggested dates for paving of the field.
http://img54.imageshack.us/img54/2594/marysvillemin.jpg

The same data with the raw data filtered (Hodrik Prescott) still reveals no step or slope change.
http://img54.imageshack.us/img54/6420/maryvillehpfiltered.jpg

If an expected 5deg C change were present. Wouldn’t this show?

REPLY: The plots that you are doing look very odd, for example the min plot is clipped, what sort of software are you using? I’ve never seen a plot output like this where the top is truncated. But you can see the classic rise of UHI in it, the mins have been steadily getting warmer, exactly what you’d expect in an urban station.

On the Tmean plot, be sure the data you are using is truly “raw”. If you are uisng GISS data, and it looks like you are, your are working with data that has already been highly adjusted/homogenized. Get the NOAA data from NCDC.

Asphalt, concrete, etc isn’t always a step jump, as it often creeps in gradually, this is what city UHI is all about. The transformation at Marysville was not all at once. The trend difference between well sited stations and poorly sited ones are what we are looking at.

But if you want to see some supporting peer reviewed science on temperature differences over such surfaces, in absolute measurement, see Yilmaz et al (2008 ) Heat over grass/soil/concrete.
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf

There are several stations stations I can show you where the change was dramatic, when moved to an asphalt environment from grass, one is Lampasas, TX:

http://wattsupwiththat.com/2008/02/14/how-not-to-measure-temperature-part-51/

Here’s more on Marysville and Orland to give you an idea of what the difference is in plotting output I’m familiar with:

http://www.climateaudit.org/?p=1844

Also you never answered if you had read the NOAA Climate Reference Handbook describing the siting ratings. Did you read it?

Anthony

For a review of siting issues and the estimates see the NOAA siting standards on the Climate Reference Network. That is what I’m using, their rating system for site quality.

The Climate Reference Network Site Handbook, including explanation of the CRN 1-5 rating system used by surfacestations.org here:

http://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/program/X030FullDocumentD0.pdf

Anyway. assuming the worst. then since the MMT is surrounded by “parking” we would be looking at a 5deg C error.
There is none showing in the unadjusted temperature record. Why?
http://img40.imageshack.us/img40/8494/marysvillemax19502000.jpg

I see that evanmjones was quicker on the draw than me, and provided information on the tolerance of various stations.

As you can see here, the accuracy of the station sitings varies by quite a bit.

Based on the Surface Station network, how can anyone claim to know that there was a 0.6° C change in temperature — when the tolerance of 69% of the stations in the network are only accurate to ≥2° C?

I can’t offer proof, but it is NOAA/CRN’s own estimate, as signed off on by Dr, Karl, himself (as per LeRoy, 1999).

http://www.ccrom.org/documentspublics/2007thematique/documentstechniques/Classification_environnement-note_technique35-2.pdf

(See p. 6.)

http://gallery.surfacestations.org/main.php?g2_itemId=57529&g2_imageViewsIndex=1

Can you point out the proof of the 5degC error Please?
I also mentioned the change from field to tarmac does not show up in the record. Any explanations?

http://img40.imageshack.us/img40/8494/marysvillemax19502000.jpg

[source of graph]

And the bill will not do anything but raise taxes.

Reply: Those analogies have no place here. ~ charles the moderator

Charles, my apologies, this wasn’t the right thread. Nonetheless, given the comments about capital punishment for ‘climate deniers’ on Climate Progress, I believe the best way to avoid the mistakes of the past is to constantly remind ourselves of them.

I tried to do this on Climate progress, but my post was censored….

Thanks as always for your patience and balance.

I generally don’t understand why it matters whether or not global warming is real… We still should be taking the steps to reduce our emissions, simply because somebody is going to have to breathe what we emit into the air.

The reasons are many. First, it is morally and scientifically reprehensible for some of our most educated people to accept funding in exchange for preconceived conclusions. There is now and has been since the alarm first sounded, plenty of evidence against the AGW theory. That evidence has not been allowed to enter the debate as it should in any honest scientific inquiry.

Second, “our emissions” include a quantity of CO2 with each exhalation of human breath. Do you suggest human beings breathe less often? The substance of the skeptic argument is that CO2 is not a pollutant. It is the Earth’s natural plant fertilizer and we have no evidence that in the quantities emitted by man it causes any warming global or otherwise.

Rishabh, most people on this board have no objection to countering real, toxic pollutants like CO and SO4. The AGW alarmists cling to their tattered claims that man has set the world afire. They do so to mask their real agenda which is to halt western economies, limit the distribution of energy and thereby control the expansion of human civilization. Their mistake was in focusing their agenda around a facade. That facade has been torn down.

I generally don’t understand why it matters whether or not global warming is real. We still should be taking the steps to reduce our emissions, simply because somebody is going to have to breathe what we emit into the air.

I would prefer that most of the world avoids ending up like Mexico City; where people frequently have to wear masks due to the condition of the air.

Of course, that’s just my personal preference.

Of course, failing to fight global warming will cost the economy $19.2 trillion and 3 million lost jobs by 2030. Why do they always fail to mention the offset?

REPLY: Citations?

Numbers SWAGged, just as Heritage did.

Think about it for a moment: If we fight global warming, it will most likely create jobs. A thousand harbors need construction, hundreds of miles of levees in the U.S. alone, rivers of cities near the ocean need seawalls and maybe seagates.

Heritage assumes the only way to fight global warming is to shut down industries. That’s not been the first or second or third choice for fighting any pollution since the U.S. got into the business in the 1800s.

For instance this station MARYSVILLE, CA, GISS (GISS plot of USHCN data)
has the following comment by the site surveyor: “This is probably the worst temperature measuring location ever seen by this
observer in his 30 year history as a meteorologist.”

http://gallery.surfacestations.org/main.php?g2_itemId=57529&g2_imageViewsIndex=1

I could not find any other temperature plot taken in an acceptable location concurrently with any of this data. Perhaps you could point the link out to me, Thanks.

If this is unavailable how do we know there are 5degC errors?

A notable point from the Curator:”The entire rear area used to be grass field but was converted to parking lot about 20-25 years ago, the sensor IR shield was moved to its current location when the cell tower was erected. Their used to be a Stevenson Screen shelter at this location but was switched to MMTS”

So 20 to 25 years ago (1984 to 1989) there should be a step change of a few degrees when the tarmac was laid.
but looking at this plot showing max temperatures I can see no step change at the expected dates or am I looking at the wrong data?
http://img40.imageshack.us/img40/8494/marysvillemax19502000.jpg