2012 Global Temperatures

[Jonger]

There is no 'may' about it - what I said is true and what Jonger posted above is false. This isn't a matter of opinion.

Your being an apologist for him and his disinformation does not help him or you. It just comes across as a demonstration of denialist tribalism.

Creating a green space around the station would return the station back to a natural state. There remains the possibility that trees may have grown taller next to a station and newly shaded stations may reflect a drop in temp.

While possible, the opposite being a growth of buildings and urban landform change is more likely to show a warm bias.

Warm station bias is probably 100:1 over cool. Just a hunch...

[PhillipS]

So you think there is more spurious cooling than heating being recorded in the station data?

Jongers assertion above was "Considering there is no logical way a human structure or site placement can give off artificially low readings, it can only skew high". A strong assertion, I think you'll agree.

I simply pointed out that he was wrong - by listing three of a number of ways in which site placement can cause low readings. He shouldn't make ridiculous assertions.

I did not say that site placement causes more cooling than heating - if you interpret that from my words then you need to work on your reading comprehensoin.

.

[PhillipS]

Creating a green space around the station would return the station back to a natural state. There remains the possibility that trees may have grown taller next to a station and newly shaded stations may reflect a drop in temp.

While possible, the opposite being a growth of buildings and urban landform change is more likely to show a warm bias.

Warm station bias is probably 100:1 over cool. Just a hunch...

Your statement was "Considering there is no logical way a human structure or site placement can give off artificially low readings, it can only skew high". [added emphasis mine] There is a huge gulf between that assertion and saying "Warm station bias is probably 100:1 over cool.". Hopefully you can understand the distinction.

If you want to be considered a credible, logical poster you should avoid claims like the first. Hyperbole from either side tends to trigger the readers' BS detectors.

[tacoman25]

There is no 'may' about it - what I said is true and what Jonger posted above is false. This isn't a matter of opinion.

Your being an apologist for him and his disinformation does not help him or you. It just comes across as a demonstration of denialist tribalism.

Seriously?

My point was just that no matter what negative impacts on temperature you want to point to with urban/suburban development, the fact is that overall human development makes warmer temperatures more likely.

[The_Global_Warmer]

UHI is not just artificial high readings.

It also absorbs and radiates more heat than what typically was there before.

Increased GHG's with natural radiating heat= adding to the Earth's energy budget.

[TerryM]

Undoubtedly the 'heat island' effect is the cause of Death Valley's ridiculously high temperatures. If man made structures were responsible for huge temperature divergences, wouldn't the highest temperatures be found where humans congregate?

Seriously, what ever happened to the study that Watts pledged to rely on - BEST wasn't it?

Terry

BTW

If someone was to stick a thermometer in the Ubehebe Crater, just an hour north from Furnace Creek, where they now say the all time high was recorded,(there is a warm spring in the vicinity) they'd undoubtedly record a new record. No structures around, just a bowl of black ash baking in the desert sun.(albedo matters)

Terry

[tacoman25]

Undoubtedly the 'heat island' effect is the cause of Death Valley's ridiculously high temperatures. If man made structures were responsible for huge temperature divergences, wouldn't the highest temperatures be found where humans congregate?

Seriously, what ever happened to the study that Watts pledged to rely on - BEST wasn't it?

Terry

BTW

If someone was to stick a thermometer in the Ubehebe Crater, just an hour north from Furnace Creek, where they now say the all time high was recorded,(there is a warm spring in the vicinity) they'd undoubtedly record a new record. No structures around, just a bowl of black ash baking in the desert sun.(albedo matters)

Terry

Not sure what your point here is, Terry. Obviously, a desert valley in the Southwest below sea level is going to have very hot summer temperatures...regardless of human influence. UHI is only relative to the natural environment. And it has a much stronger effect on low temperatures than high temperatures, anyway. As you say, albedo matters and concrete certainly plays a large role in that for cities.

If you are curious to how UHI affects a desert environment, there have been many studies on its profound effect on Phoenix temperatures.

[TerryM]

Taco

Intended as tongue in cheek - except for the BEST bit.

BEST was funded by Koch, open sourced and vetted by every denier available as to the reliability of the results - until the results came in. To now go back and imply that the results aren't accurate isn't consistent or reasonable.

I led groups into Death Valley for a number of years, although we always scheduled for spring or fall. The place where they came up with the hottest ever temperature is very close to a warm spring & should probably be stricken from the record books.

BTW I've always suspected that the official temperatures in Las Vegas were taken under a sprinkler system.

Terry

[Snow_Miser]

You could argue that the Southern Hemisphere is more important then the Northern Hemisphere when it comes to sea level rise. Most of the land ice is locked up in Antarctica.

That's a good point. I hadn't thought of that.

[Snow_Miser]

Are some really trying to deny the impact of urbanization on temperature trends? Come on, guys.

http://www.agu.org/p...0JD015452.shtml

Monthly mean surface air temperature data from 463 meteorological stations, including those from the 1981–2007 ordinary and national basic reference surface stations in east China and from the National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) Reanalysis, are used to investigate the effect of rapid urbanization on temperature change. These stations are dynamically classified into six categories, namely, metropolis, large city, medium-sized city, small city, suburban, and rural, using satellite-measured nighttime light imagery and population census data. Both observation minus reanalysis (OMR) and urban minus rural (UMR) methods are utilized to detect surface air temperature change induced by urbanization. With objective and dynamic station classification, the observed and reanalyzed temperature changes over rural areas show good agreement, indicating that the reanalysis can effectively capture regional rural temperature trends. The trends of urban heat island (UHI) effects, determined using OMR and UMR approaches, are generally consistent and indicate that rapid urbanization has a significant influence on surface warming over east China. Overall, UHI effects contribute 24.2% to regional average warming trends. The strongest effect of urbanization on annual mean surface air temperature trends occurs over the metropolis and large city stations, with corresponding contributions of about 44% and 35% to total warming, respectively. The UHI trends are 0.398°C and 0.26°C decade⁻¹. The most substantial UHI effect occurred after the early 2000s, implying a significant effect of rapid urbanization on surface air temperature change during this period.

[Snow_Miser]

It looks like 2012 is running close to the middle of the pack in the Troposphere as of now.

[nflwxman]

Are some really trying to deny the impact of urbanization on temperature trends? Come on, guys.

http://www.agu.org/p...0JD015452.shtml

Monthly mean surface air temperature data from 463 meteorological stations, including those from the 1981–2007 ordinary and national basic reference surface stations in east China and from the National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) Reanalysis, are used to investigate the effect of rapid urbanization on temperature change. These stations are dynamically classified into six categories, namely, metropolis, large city, medium-sized city, small city, suburban, and rural, using satellite-measured nighttime light imagery and population census data. Both observation minus reanalysis (OMR) and urban minus rural (UMR) methods are utilized to detect surface air temperature change induced by urbanization. With objective and dynamic station classification, the observed and reanalyzed temperature changes over rural areas show good agreement, indicating that the reanalysis can effectively capture regional rural temperature trends. The trends of urban heat island (UHI) effects, determined using OMR and UMR approaches, are generally consistent and indicate that rapid urbanization has a significant influence on surface warming over east China. Overall, UHI effects contribute 24.2% to regional average warming trends. The strongest effect of urbanization on annual mean surface air temperature trends occurs over the metropolis and large city stations, with corresponding contributions of about 44% and 35% to total warming, respectively. The UHI trends are 0.398°C and 0.26°C decade⁻¹. The most substantial UHI effect occurred after the early 2000s, implying a significant effect of rapid urbanization on surface air temperature change during this period.

Im pretty sure UHI is accounted for in the GISS data set and NCDC. Secondly, I wonder why they only focused on eastern China?

[Snow_Miser]

Im pretty sure UHI is accounted for in the GISS data set and NCDC. Secondly, I wonder why they only focused on eastern China?

It may be, but this is clear evidence that the UHI substantially impacts the trend in temperatures with such strong urbanization related temperature trends in China. One can only wonder if the small urban adjustments in the USCHN dataset are enough to fully account for this bias.

[nflwxman]

It may be, but this is clear evidence that the UHI substantially impacts the trend in temperatures with such strong urbanization related temperature trends in China. One can only wonder if the small urban adjustments in the USCHN dataset are enough to fully account for this bias.

Doesnt the GISS dataset use gridded satellite data to supplement USCHN as well? After UHI adjustments are applied the trend between rural and urban stations are very similar worldwide.

[Snow_Miser]

Doesnt the GISS dataset use gridded satellite data to supplement USCHN as well? After UHI adjustments are applied the trend between rural and urban stations are very similar worldwide.

GISS doesn't use satellite data for the land based areas.

They use weather station data and HadSST2/Reynolds v2 to produce the monthly temperature anomalies.

I don't think that you can say the second sentence with absolute certainty. Multiple studies, including the one I posted say that there is a significant urban component still present within the data.

[donsutherland1]

Im pretty sure UHI is accounted for in the GISS data set and NCDC. Secondly, I wonder why they only focused on eastern China?

It is. The global temperature record is not tainted by UHI.

http://pubs.giss.nasa.gov/docs/2010/2010_Hansen_etal.pdf

[Alpha5]

It is. The global temperature record is not tainted by UHI.

http://pubs.giss.nas...Hansen_etal.pdf

Thanks for the link Don, UHI is really just more of a nuisance when people begin citing things about how warm it is in NYC.

For example, the first freeze took place last year in late October for much of the NYC metro area (Central Park was down to 33-34), but did not freeze until mid December. Now, what annoys me is the media (and some poster's) tendency to run around using this data as the poster child for how warm its getting, when in reality, UHI is to blame.

Food for thought

[nflwxman]

Thanks for the link Don, UHI is really just more of a nuisance when people begin citing things about how warm it is in NYC.

For example, the first freeze took place last year in late October for much of the NYC metro area (Central Park was down to 33-34), but did not freeze until mid December. Now, what annoys me is the media (and some poster's) tendency to run around using this data as the poster child for how warm its getting, when in reality, UHI is to blame.

Food for thought

Good point Alpha. Climate scientists and statisticians generally don't have much heartburn over UHI as it seems to be fully and accurately accounted for. The public/media, however, does have the tendancy not to mention auxillery things like UHI when discussing local weather. The example you mention is a good one. Conversely, people often use heavy snowfalls or a cold winter as a case against global warming.

[Jonger]

It is. The global temperature record is not tainted by UHI.

http://pubs.giss.nas...Hansen_etal.pdf

Hansen describes downward adjustments based on night time light radiance. While this might get the true numbers closer, it still will not get it completely there.

Man-made structures, parking lots, WWTP decomposition... All these factors add up to artificially high temps, even in more rural settings.

The people responsible for placing these stations ~100 years ago would probably never given it any thought that we would care to even dispute 1-2 degrees of inaccurate readings. Here we are though.

I really need to give this one a rest though, the topic is bad for my health.

This is probably the STANDARD for site stations. I just can't accept that those runways aren't jacking temps up by 1 degree and many of these runways are in rural pitch black regions.

[ben4vols]

It is. The global temperature record is not tainted by UHI.

http://pubs.giss.nas...Hansen_etal.pdf

I don't agree.

From your link, "The homogeneity adjustment

procedure [Hansen et al., 1999, Figure 3] changes the

long‐term temperature trend of an urban station to make it

agree with the mean trend of nearby rural stations. The

effect of this adjustment on global temperature change was

found to be small, less than 0.1°C for the past century."

You really think the UHI effect is that small?

From Roy Spencer's study...

A few station locations have 2 USCRN sites located relatively close to each other, presumably to check calibration. A particularly interesting pair of sites is near Stillwater, OK, where one site is a few hundred meters from residential Stillwater, while the paired site is about 2.4 km farther out of town:

Regarding that Stillwater, OK USCRN station pair, the site closest to the Stillwater residential area averaged 0.6 deg. C warmer year-round (0.5 deg. C warmer in summer) than the more rural site 2 km farther out of town. This supports the view that substantial UHI effects can arise even from small towns.

I would say these preliminary results, if they pan out, indicate we should be increasingly distrustful of using the current NOAA USHCN data for long-term trends as supporting evidence for global warming, or for the reporting of new high temperature records. As the last 2 plots above suggest:

1) even at “zero” population density (rural siting), the USHCN temperatures are on average warmer than their Climate Reference Network counterparts, by close to 0.5 deg. C in summer.

2) across all USHCN stations, from rural to urban, they average 0.9 deg. C warmer than USCRN (which approaches Anthony Watt’s 2 deg. F estimate for July 2012).

This evidence suggests that much of the reported U.S. warming in the last 100+ years could be spurious, assuming that thermometer measurements made around 1880-1900 were largely free of spurious warming effects. This is a serious issue that NOAA needs to address in an open and transparent manner.

[donsutherland1]

Ben4vols,

In part, you quote Roy Spencer's blog entry, which states:

...these preliminary results, if they pan out, indicate we should be increasingly distrustful of using the current NOAA USHCN data for long-term trends as supporting evidence for global warming, or for the reporting of new high temperature records.

However, NOAA puts out an annual report on USCRN each year and the most recent annual report states:

The USCRN annual CONUS air temperature departures for the period from 2004–08 are extremely well aligned with those derived from the national USHCN V2 (Figure 15). For these five years, the USCRN explains 99.7% of the maximum temperature and 99.5% of the minimum temperature variance in the USHCN V2 annual air temperature departures, with a mean bias of -0.03°C for both maximum and minimum temperature. This finding provides independent verification that the homogenization adjustments made to the USHCN V2 data do not lead, in the last five years of the record, to a different result than one would derive from science-quality measurements taken at pristine locations.

IMO, if Spencer feels strongly enough about his findings, which are at odds with the NOAA's own work, he should put together an article on his work and submit it to one of the meteorological or climate journals. That's probably the most effective way to see whether his findings stand up to rigorous examination.

[TerryM]

Don

You have the patience of a saint.

Terry

[ben4vols]

However, NOAA puts out an annual report on USCRN each year and the most recent annual report states:

IMO, if Spencer feels strongly enough about his findings, which are at odds with the NOAA's own work, he should put together an article on his work and submit it to one of the meteorological or climate journals. That's probably the most effective way to see whether his findings stand up to rigorous examination.

Don,

Once again NOAA is hard at work adjusting those temps. Their reasoning, a fan aspirator. Give me a flipping break. Which of course begs the question...why do they continue to adjust current readings upwards? Should they not be adjusting temperatures downward to correct for the heat bias due to USHCN stations not having the magical fan aspirator?

USCRN and USHCN V2 air temperature measurements cannot be directly compared in raw form, as air temperature is measured by an instrument aspirated by a fan in the case of USCRN and by natural ventilation in USCRN V2. However, a highly significant regression relationship can be constructed between the two data types, and then used to generate a synthetic time series for the 1971–2000 normals period at the location of the USCRN sites.

Don would you mind touching on the part of Roy's study that looked at the Stillwater, OK USCRN stations? Yes they both contain the magical fan aspirator. The one closer to the populated area of Stillwater records a temp around .6C higher than the one outside of town. Yet your paper you linked says UHI has very little effect and has less than .1C difference on global temps.

[tacoman25]

It is. The global temperature record is not tainted by UHI.

http://pubs.giss.nas...Hansen_etal.pdf

Just because it is accounted for on some level does not mean it is done flawlessly.

[donsutherland1]

Don would you mind touching on the part of Roy's study that looked at the Stillwater, OK USCRN stations? Yes they both contain the magical fan aspirator. The one closer to the populated area of Stillwater records a temp around .6C higher than the one outside of town. Yet your paper you linked says UHI has very little effect and has less than .1C difference on global temps.

UHI has very little impact after homogenization. Most of the bias from UHI is removed via homogenization. A good paper that includes mention of the UHI issue can be found at: ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2009.pdf. Another useful paper can be found at: ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2010.pdf.

In the raw data, UHI can have a large impact (UHI is real, not imaginary). Biases inherent in the raw data are precisely why homogenization is necessary (a point that some in the blogosphere are unable or unwilling to understand).

If researchers believe that homogenization is inadequate, they most definitely should submit papers outlining their findings, along with the data and methodology they used to arrive at their findings. Then those possible issues can be further examined in a robust scientific fashion.

[donsutherland1]

Just because it is accounted for on some level does not mean it is done flawlessly.

Agreed. Perfection is probably not feasible. So long as the temperature record reasonably reflects the climatic evolution, that's probably the best one can expect.

[The_Global_Warmer]

Channel 5 temps have diverged from 2011.

Now 2011 is 0.200C below 2012 at channel 5.

Things are warm relative to Enso and Septmber is looking like a .40 anomaly or so.

2012 is looking to finish around 4th to 6th warmest on UAH.

[tacoman25]

No love for RSS these days?

[The_Global_Warmer]

RSS

UAH:

I think the warming is still evident on these, but any pattern besides ENSO is just brutal to pick up. I think we are close to not dropping below 0.0C on UAH on our current course of action.

[ben4vols]

UHI has very little impact after homogenization. Most of the bias from UHI is removed via homogenization. A good paper that includes mention of the UHI issue can be found at: ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2009.pdf. Another useful paper can be found at: ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2010.pdf.

In the raw data, UHI can have a large impact (UHI is real, not imaginary). Biases inherent in the raw data are precisely why homogenization is necessary (a point that some in the blogosphere are unable or unwilling to understand).

If researchers believe that homogenization is inadequate, they most definitely should submit papers outlining their findings, along with the data and methodology they used to arrive at their findings. Then those possible issues can be further examined in a robust scientific fashion.

Again, I think you are wrong. UHI is not properly accounted for after homogenization as Roy Spencer (and Anthony Watts to some degree) has shown time and time again. If you have one station sitting outside of town that reads .6C cooler than the one sitting in town the only thing homogenization is going to do is overly warm the area by .3C. It doesn't make sense that they continue to upwardly adjust temperature readings.

Unfortunately they don't "homogenize" fairly either. They obviously weight temperatures from urban area's more than they do temperature's from rural areas. This was shown in a study done by Edward Long comparing urban and rural raw temperature data vs their adjusted data. As you can see below the urban data is hardly effected by the "homogenization" or adjustments but the rural data is effected heavily. His paper can be found here.