US Temps Adjusted

[valkhorn]

Let me preface this by saying I accept AGW and that global temperatures are rising. However, I've heard a few people argue that temperatures in the US are being manipulated - and I can't seem to figure out if (a) they are right and ( if so why this would be done.

 

I realize that US temperatures are just 2% of the surface of the earth, and satellite data says that we are warming and that surface obs are sometimes unreliable, but I found this today from a denialist source and I'm not sure what to make of it:

 

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=425000173040&dt=1&ds=14

http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=425740010020&dt=1&ds=1

 

The surface obs were adjusted upwards, but I see no reason given and I have googled around and haven't found why NOAA adjusts temperatures per station. I can't see the reason why it was adjusted in the data either, so I figure there's more data that was used than is shown.

I can see why they would adjust an average temperature across 100s of stations because they aren't always distributed equally, but why would one station be adjusted?

 

Thanks!

 

Also:

I found this:
http://data.giss.nasa.gov/gistemp/

But it doesn't give me a very specific reason why temperatures were adjusted. Maybe they were adjusted for when measurements were taken, if the station had moved, etc.? Obviously a 'low' at midnight isn't a 'low' at 6AM, but I'm just postulating at this point.

[ORH_wxman]

The biggest adjustments come from time of observation (TOBS) bias. In earlier coop stations, a lot of them took their once per day measurement in the afternoon which means excessively hot temps could be "double counted"...as the current day and previous day's high since the day flips over every time they make their measurement. The opposite is true in current coops where the time of observation is frequently 7am which can double count a cold reading.

 

There's other adjustments they make too like UHI and stations moving. Some of these are semi-subjective but the overall effect has been relatively small at least since the satellite era.

[Snow_Miser]

I would question some of the adjustments before the satellite record, but the overall message of a rising trend in temperatures over the last 100-150 years is a sound one. The satellites show slightly less warming than surface temperatures during the late-20th century.

I also accept AGW as a cause of the warming. I don't accept though that we know how large the contribution of AGW to the warming trend is though.

[valkhorn]

The biggest adjustments come from time of observation (TOBS) bias. In earlier coop stations, a lot of them took their once per day measurement in the afternoon which means excessively hot temps could be "double counted"...as the current day and previous day's high since the day flips over every time they make their measurement. The opposite is true in current coops where the time of observation is frequently 7am which can double count a cold reading.

 

There's other adjustments they make too like UHI and stations moving. Some of these are semi-subjective but the overall effect has been relatively small at least since the satellite era.

 

 

I would question some of the adjustments before the satellite record, but the overall message of a rising trend in temperatures over the last 100-150 years is a sound one. The satellites show slightly less warming than surface temperatures during the late-20th century.

I also accept AGW as a cause of the warming. I don't accept though that we know how large the contribution of AGW to the warming trend is though.

 

 

I figured as much but again I wasn't 100% sure. I probably won't be able to explain this to denialists who have already made up their mind about everything.

[ORH_wxman]

I figured as much but again I wasn't 100% sure. I probably won't be able to explain this to denialists who have already made up their mind about everything.

 

 

I think there is some valid criticism of the adjustments, but it will only affect the trend by maybe 20% at most...so it doesn't really invalidate the surface temperature datasets. Probably the biggest one is TOBS since 2000...we've seen hefty adjustments in the post-2000 readings that are contrary to papers like Menne et al which showed TOBS between 1985-2006 should only account for roughly +0.02C per decade....mostly because we have basically transitioned to stations reporting all in the morning versus the afternoon which some stations used to do.

[Jonger]

As a labeled denier, even I accept that there has been a 0.6C rise over the past 100 years. The US temps were probably 0.3 to 0.5C over the 100 year average back in the 1930's, so in the country its not that much more than what we saw back then. There has been some fudging with previous records and I also think UHI is probably responsible for more warming than has been attributed by GISS.

[Geos]

I see the AGW theory as just that, a theory and nothing more. Humans haven't been studying the climate long enough to be able to properly determine if we are affecting it at all - especially when you take into account that the industrial era is only 200 years old or so. That doesn't mean we haven't affected the atmosphere with pollutants. I'm all for cutting down on fossil fuels and being more sustainable, but affecting something as complex as the Earth's climate seems like an impossible feat outside of a nuclear war.

The warming that I do believe in by humans is the UHI and I agree with Jonger that some of the data that is used is contaminated by the UHI. 

Our main climate driver is solar activity with the next driver is the oceans, then the next factor worth mentioning would be volcanic activity. 

[tamarack]

 

The biggest adjustments come from time of observation (TOBS) bias. In earlier coop stations, a lot of them took their once per day measurement in the afternoon which means excessively hot temps could be "double counted"...as the current day and previous day's high since the day flips over every time they make their measurement. The opposite is true in current coops where the time of observation is frequently 7am which can double count a cold reading.

 

There's other adjustments they make too like UHI and stations moving. Some of these are semi-subjective but the overall effect has been relatively small at least since the satellite era.

Seems quite logical. My guess (having never seen real data, if such exists) is that, for a given station, 4P Obs would be on the order of 0.5C milder than 7A Obs, with midnight about centered between. Of course, if roughly the same number of locations were corrected from 4P as from 7A, they'd cancel each other out.

[f2tornado]

I see the AGW theory as just that, a theory and nothing more. Humans haven't been studying the climate long enough to be able to properly determine if we are affecting it at all - especially when you take into account that the industrial era is only 200 years old or so. That doesn't mean we haven't affected the atmosphere with pollutants....

 

Scientific theory is a well tested hypothesis much like gravitational theory describes why the objects attract each other. Physics dictate an increase in GHG concentration will increase temperature in the absence of negative feedback. Further, it's not all about gasses. Folks like Roger Pielke have been banging the land-use change drum for years. AGW or ACC (climate change) theory is on firm ground given the (often misused) 97% of climate researchers are on board. This figure probably approaches 100% if you don't look at it in global context. The real debate is how much. Even the most skeptical of scientists support at least a 0.3C warming per doubling of CO2. Unfortunately, this very healthy discussion/debate gets lost in the shuffle of a lot of garbage science being bantered about by the media and politicians, Gore on one end, Inhofe on the other. Gore makes more people doubt climate scientists with his often debunked alarmist rubbish. Inhofe gives skeptics a bad name. I am personally highly skeptical of the high end projections of the GCMs (see the recent water vapor feedback thread for my logic).

[FloridaJohn]

affecting something as complex as the Earth's climate seems like an impossible feat outside of a nuclear war.

 

Interesting analogy. Are you aware that the earth is absorbing energy at a rate of four Hiroshima bombs every second?

[Geos]

Interesting analogy. Are you aware that the earth is absorbing energy at a rate of four Hiroshima bombs every second?

 

Yeah I figured it was an immense amount of energy - didn't know that amount per second though.

I'm just saying we do have the power to affect the climate greatly, but it would take more than gases - either methane or CO₂.

[Geos]

Scientific theory is a well tested hypothesis much like gravitational theory describes why the objects attract each other. Physics dictate an increase in GHG concentration will increase temperature in the absence of negative feedback. Further, it's not all about gasses. Folks like Roger Pielke have been banging the land-use change drum for years. AGW or ACC (climate change) theory is on firm ground given the (often misused) 97% of climate researchers are on board. This figure probably approaches 100% if you don't look at it in global context. The real debate is how much. Even the most skeptical of scientists support at least a 0.3C warming per doubling of CO2. Unfortunately, this very healthy discussion/debate gets lost in the shuffle of a lot of garbage science being bantered about by the media and politicians, Gore on one end, Inhofe on the other. Gore makes more people doubt climate scientists with his often debunked alarmist rubbish. Inhofe gives skeptics a bad name. I am personally highly skeptical of the high end projections of the GCMs (see the recent water vapor feedback thread for my logic).

 

I used to be a believer of the extreme global warming theory up until about 2004, then my opinion changed when I actually started learning more about atmospheric chemistry and understood what was garbage and what wasn't. Indeed there is a lot of garbage science out there and for the average person they don't know the difference between what is true and false information regarding climate change. 

I will say there is a chance that we have warmed certain areas of the planet by a very small amount and we've polluted our atmosphere too much. When I look at climate change I look at the long range geology history of climate fluctuations. At times in the past CO₂ was higher than it was today as well as average temperatures. I definitely agree that increased water vapor is a big culprit in affecting temperatures and I more so support that water vapor drives temperature regimes. 

I'll have to read through your thread.  

[Jonger]

I used to be a believer of the extreme global warming theory up until about 2004, then my opinion changed when I actually started learning more about atmospheric chemistry and understood what was garbage and what wasn't. Indeed there is a lot of garbage science out there and for the average person they don't know the difference between what is true and false information regarding climate change. 

I will say there is a chance that we have warmed certain areas of the planet by a very small amount and we've polluted our atmosphere too much. When I look at climate change I look at the long range geology history of climate fluctuations. At times in the past CO₂ was higher than it was today as well as average temperatures. I definitely agree that increased water vapor is a big culprit in affecting temperatures and I more so support that water vapor drives temperature regimes. 

I'll have to read through your thread.  

 

CO2 molecules re-radiate infrared in controlled lab experiments, but this is the first time that co2 could "potentially" initiate the warming. So, there is no perfect formula to gauge sensitivity. 

[Sundog]

"It's just a theory." I really, really, hate that line.

[Snow_Miser]

Interesting analogy. Are you aware that the earth is absorbing energy at a rate of four Hiroshima bombs every second?

 

You forgot to mention that this figure has an error margin of +/-117 Hiroshima bombs every second.

 

[f2tornado]

Interesting analogy. Are you aware that the earth is absorbing energy at a rate of four Hiroshima bombs every second?

 

The bulk of this analogy presented by John Cook (the same guy who put out the often misinterpreted 97% study) is based on discussion from one paper (Church et al. 2011). That's right, one paper. Cook even goes so far as to explain the Hiroshima bomb analogy is effectively a propaganda campaign (and I'll argue is not necessary and potentially counterproductive with good science, see Gore, Al). http://skepticalscience.com/4-Hiroshima-bombs-worth-of-heat-per-second.html  As has been discussed here previously, we don't have a lot of OHC data prior to around the mid 80s and Argo floats didn't get launched in earnest until the early part of the last decade. Further, data from NOAA’s Pacific Marine Environmental Laboratory do not show the magnitude of trend the paper did. As such, I take the analogy with a grain of salt.

[Snow_Miser]

The bulk of this analogy presented by John Cook (the same guy who put out the often misinterpreted 97% study) is based on discussion from one paper (Church et al. 2011). That's right, one paper. Cook even goes so far as to explain the Hiroshima bomb analogy is effectively a propaganda campaign (and I'll argue is not necessary and potentially counterproductive with good science, see Gore, Al). http://skepticalscience.com/4-Hiroshima-bombs-worth-of-heat-per-second.html  As has been discussed here previously, we don't have a lot of OHC data prior to around the mid 80s and Argo floats didn't get launched in earnest until the early part of the last decade. Further, data from NOAA’s Pacific Marine Environmental Laboratory do not show the magnitude of trend the paper did. As such, I take the analogy with a grain of salt.

 

This is a great point. A lot of people on this forum accept OHC data at face value without even bothering to question how reliable such a dataset is. The dataset is incredibly spotty, and we shouldn't have much confidence in OHC measurements. The image below shows the total number of measurements of the deep ocean in 1985. A dataset with virtually no data in the Indian and Pacific ocean, is questionable to put it lightly.

 

[Snow_Miser]

CO2 molecules re-radiate infrared in controlled lab experiments, but this is the first time that co2 could "potentially" initiate the warming. So, there is no perfect formula to gauge sensitivity. 

 

I don't think anyone denies that when you add CO2, you get warming. But I think some are taking this as evidence that CO2 caused all of the warming we saw during the 20th Century. Given that the LIA featured some of the coldest temperatures seen in thousands of years, it is very likely that at least some of the warming is a natural recovery from the LIA, likely solar induced.

[Geos]

I don't think anyone denies that when you add CO2, you get warming. But I think some are taking this as evidence that CO2 caused all of the warming we saw during the 20th Century. Given that the LIA featured some of the coldest temperatures seen in thousands of years, it is very likely that at least some of the warming is a natural recovery from the LIA, likely solar induced.

 

Definitely agree that most of the warming was the bounce back from the LIA and that was driven by solar activity. Holocene Maximum and Medieval warm period are good examples of warming during higher solar activity.

[skierinvermont]

You forgot to mention that this figure has an error margin of +/-117 Hiroshima bombs every second.

 

 

You are a liar. I have already explained to you why this is false. Even modern fairly precise OHC measurements support his statement that the earth is absorbing 4 Hiroshimas of energy every second. In addition, you have provided little evidence for your aspersions regarding historical estimates of OHC. Both Will and I have asked you to address the actual methods and data in the many papers regarding historical OHC and you have provided little evidence, other than linking to maps of float data from the 80s which is not a direct rebuttal. You actually have to read and find fault with the existing science on the matter.

 

It's a moot point anyways. There is no other way to explain the 8" rise in sea level over the last century, other than a dramatic increase in OHC.

[Snow_Miser]

You are a liar. I have already explained to you why this is false. Even modern fairly precise OHC measurements support his statement that the earth is absorbing 4 Hiroshimas of energy every second. In addition, you have provided little evidence for your aspersions regarding historical estimates of OHC. Both Will and I have asked you to address the actual methods and data in the many papers regarding historical OHC and you have provided little evidence, other than linking to maps of float data from the 80s which is not a direct rebuttal. You actually have to read and find fault with the existing science on the matter.

It's a moot point anyways. There is no other way to explain the 8" rise in sea level over the last century, other than a dramatic increase in OHC.

There's no need for the accusations. You coming off as extremely hostile does not bode well for your argument to the layperson, so why need for the remarks like "you're a liar?" I could easily bring up your epic fail about the Douglas 1997 paper, and said that you lied when you said it was an obscure denier paper, but I'll choose not too.

Also, I've never stated that Heat Content did not rise over the 20th Century. I'm questioning the robustness of the Heat Content trends. That being said, it should also be noted that the link between anthropogenic forcing and sea level rise during the 20th Century is weak at best.

From the paper:

"Semiempirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of the authors' closure of the budget is that such a relationship is weak or absent during the twentieth century."

The only timeframe in which we truly have accurate data is since 2003, which is when the ARGO floats started recording data. The ARGO team themselves have stated that this is too far of a short timeframe to draw robust conclusions from the data.

Before that, we had XBT instruments that were used to record the temperatures, and as you can see from the CPC graph that I posted, the OHC dataset is extremely sparce. You throw red herring after red herring to try and avoid this point, but it still stands.

Since when did the North Atlantic represent temperature trends for the rest of the world?

[Snow_Miser]

Definitely agree that most of the warming was the bounce back from the LIA and that was driven by solar activity. Holocene Maximum and Medieval warm period are good examples of warming during higher solar activity.

As van Loon et al. 2012 note:

(http://nldr.library.ucar.edu/repository/assets/osgc/OSGC-000-000-010-628.pdf)

"It is commonly assumed that the second rise was owing principally to increasing greenhouse gases in the atmosphere. However, at the same time, solar activity...rose from a longer period of low solar activity to one of higher activity, and it would be unwise to ignore or disparage this fact."

[f2tornado]

In addition, you have provided little evidence for your aspersions regarding historical estimates of OHC.

 

This is a reasonable point though snow's concern over data quantity is quite valid as there will be far greater uncertainly in the estimates. Labeling it "aspersions" is a bit harsh. That implies slander and I don't see it. Further, in 2007, NOAA acknowledged a problem http://www.nodc.noaa.gov/OC5/XBT_BIAS/xbt_bias.html with XBT sensor data and researchers have scrambled over the past five years to find ways to sort out the biases in the data...

 

"Gouretski and Koltermann (2007) shows statistics from Expendable Bathythermograph (XBT) vs. Conductivity-Temperature-Depth (CTD)/reversing thermometer instrument comparisons which reveal a warm bias in XBT temperatures. This bias varies over time and over depth. The bias may be due to both errors in the calculation of depth and in measurement of the temperature. An important deviation from the majority of existing correction schemes is that depth correction varies with depth".  This is adequately discussed in the summary paper below including the various ways researchers tackle the problem.

 

I took a good half hour or more to plod through this extremely informative and recent summary paper on the instruments used to measure the data and the papers that assessed the data. This summary paper gets my highest recommendation as it is certain to educate. There are a number of reasons to approach the historical data with some skepticism, most notably data from XBTs and how it is corrected. http://www.pmel.noaa.gov/people/gjohnson/Ocean_Temp_Review.pdf While the summary paper leaves little doubt on ocean warming to 700m, the authors state, "By 2005 the ocean observing system had reached new capabilities, providing regular temperature soundings of the upper 2000 m, giving considerably greater confidence in the OHC assessment. However, the pre-Argo and Argo eras may not be compatible for inventory analysis in determining changes over time. Other observing systems in place can nominally measure the major storage and flux terms, but owing to errors and uncertainty, it remains a challenge to track anomalies with confidence".

 

Like just about everything else in climate change, the uncertainly is on the magnitude: "However, estimates of OHC trends above 700 m from 2005-2012 range from 0.2 to 0.4 W m2, with large, overlapping uncertainties, highlighting the remaining issues of adequately dealing with missing data in space and time and how OHC is mapped, in addition to remediating instrumental biases, quality control, and other sensitivities".

[LakeEffectKing]

"It's just a theory." I really, really, hate that line.

I know...right?  It really is just a HYPOTHESIS that (depending on what faction of it is stated) is really quite untestable.  Actually, it's more of a prediction that can ONLY be tested, if we wait the full amount of time until 2100.