Guest Post by Willis Eschenbach
In 2006, I lived for a year in Waimea, on the Big Island of Hawaii. From my house I could see the Mauna Loa Observatory (MLO). This observatory is the home of the longest continuous series of CO2 measurements we have. The recording station was set up by Dave Keeling in 1959, and has operated continuously ever since.
Figure 1. Mauna Loa Observatory ( 19.536337°N, 155.576248°W)
Here’s a view of the observatory:
Every time the subject of CO2 measurements comes up, people raise all kinds of objections to the Mauna Loa measurements. So I thought I’d start a thread where we can discuss those objections, and perhaps dispose of some of them.
Here are the objections that I hear the most:
1. The Mauna Loa results don’t measure the background CO2 levels.
2. You can’t get accurate CO2 measurements from samples taken on the side of an active volcano that is outgassing CO2.
3. The measurements from Mauna Loa are not representative of the rest of the world.
4. What about the Beck data, doesn’t it contradict the MLO data?
5. Keeling chose a bad location.
Before we get into those issues, let’s start by looking at the local meteorological conditions at the site. Mauna Loa is at an elevation of 3397 metres (11,140 ft) on the side of a 4,170 metre (13,680 ft) volcano way out in the middle of the Pacific Ocean. Because it is on an island, it gets the “sea breeze” in the daytime, and the “land breeze” in the nighttime.
These winds are caused by the differential heating of the land and the sea. Land heats up much faster than the ocean. So during the day, the warmer land heats the air, which rises. This rising air is replaced by air moving in from the surrounding ocean, creating the “sea breeze”.
At night, the situation is reversed. The land is cooler than the ocean. This cools the air. The cool air runs downhill along the slopes of the island and out to sea, creating the “land breeze”. Here’s a drawing of the situation:
Figure 2. Day and night breezes at Mauna Loa.
Now that we understand what is happening at Mauna Loa, let’s look at the objections.
1. The Mauna Loa results don’t measure the background CO2 levels. As you might imagine from Fig. 2, the CO2 measurements are taken only at night. Thus, they are measuring descending air that is coming from thousands of feet aloft. This air has traveled across half of the Pacific Ocean, so it is far from any man-made CO2 sources. And as a result, it is very representative of the global background CO2 levels. That’s why Keeling chose the site.
2. You can’t get accurate CO2 measurements from samples taken on the side of an active volcano that is outgassing CO2. This seems like an insuperable objection. I mean, Mauna Loa is in fact an active volcano that is outgassing CO2. How do they avoid that?
The answer lies in the fact that the volcanic gasses are very rich in CO2. At night, they are trapped in a thin layer near the ground by a temperature inversion.
To detect the difference between volcanic and background CO2, the measurements are taken simultaneously from tall towers and from near the ground, at intervals throughout the night. Background CO2 levels will be around 380 ppmv (these days), will be steady, and will be identical at the top and bottom of the towers. Volcanic gasses, on the other hand, will be well above 380 ppmv, will be variable, and will be greater near the ground than at the top of the towers.
This allows the scientists to distinguish reliably between volcanic and background CO2 levels. Here is a description of the process:
Air samples at Mauna Loa are collected continuously from air intakes at the top of four 7-m towers and one 27-m tower. Four air samples are collected each hour for the purpose of determining the CO2 concentration. Determinations of CO2 are made by using a Siemens Ultramat 3 nondispersive infrared gas analyzer with a water vapor freeze trap. This analyzer registers the concentration of CO2 in a stream of air flowing at ~0.5 L/min. Every 30 minutes, the flow is replaced by a stream of calibrating gas or “working reference gas”. In December 1983, CO2-in-N2 calibration gases were replaced with the currently used CO2-in-air calibration gases. These calibration gases and other reference gases are compared periodically to determine the instrument sensitivity and to check for possible contamination in the air-handling system. These reference gases are themselves calibrated against specific standard gases whose CO2 concentrations are determined manometrically. Greater details about the sampling methods at Mauna Loa are given in Keeling et al. (1982) and Keeling et al. (2002).
Hourly averages of atmospheric CO2 concentration, wind speed, and wind direction are plotted as a basis for selecting data for further processing. Data are selected for periods of steady hourly data to within ~0.5 parts per million by volume (ppmv); at least six consecutive hours of steady data are required to form a daily average. Greater details about the data selection criteria used at Mauna Loa are given in Bacastow et al. (1985). Data are in terms of the Scripps “03A” calibration scale.
There is a more detailed description of the measurement and selection process here.
As a result, the Mauna Loa record does accurately measure the background CO2 levels, despite the fact that it is on an active volcano. The samples that are identified as volcanic CO2 are not thrown away, however. They are used for analyses of the volcanic emission rates, such as this one (pdf).
3. The measurements from Mauna Loa are not representative of the rest of the world. Well, yes and no. The concentration of atmospheric CO2 varies by month, and also by latitude. Here is a “carpet diagram” of the changes by time and latitude.
Figure 3. A “carpet diagram” of CO2 distributions, by time and latitude.
Note that the swings are much greater in the Northern Hemisphere. Presumably, this is from the plants in the much larger land area of the Northern Hemisphere. However, the difference between the annual average of the Northern and Southern Hemispheres is small. In addition, there are smaller daily variations around the planet. An animation of these is visible here, with day by day variations available here.
Figure 4 shows is a typical day’s variations, picked at random:
Figure 4. Snapshot of the variations in tropospheric CO2. Note that the range is small, about ±1% of the average value.
In general, the different global records match quite closely. In addition to the Mauna Loa observatory, NOAA maintains CO2 measuring stations at Barrow, Alaska; American Samoa; and the South Pole. Here is a comparison of the four records (along with two methane records):
Figure 5. Comparison of the CO2 records from the four NOAA measuring sites.
As you can see, there is very little difference between the CO2 measurements at the four stations – two in the Northern Hemisphere, two in the Southern, two tropical, and two polar.
4. What about the Beck data, doesn’t it contradict the MLO data? In 2007, Ernst-Georg Beck published a paper called “180 Years Of Atmospheric CO2 Gas Analysis by Chemical Methods” (pdf). In it, he showed a variety of results from earlier analyses of the atmospheric CO2. In general, these were larger than either the ice core or the MLO data. So why don’t I believe them?
I do believe them … with a caveat. I think that the Beck data is accurate, but that it is not measuring the background CO2. CO2 measurements need to be done very carefully, in selected locations, to avoid contamination from a host of natural CO2 sources. These sources include industry, automobiles, fires, soil, plants, the list is long. To illustrate the problems, I have graphed the Beck data from his Figure 13, against the Law Dome ice core data and the MLO data.
Figure 6. CO2 data from a variety of sources. White crosses are MLO data. Three separate ice core records are shown. Photo is of Mauna Loa dusted with snow (yes, it snows in Hawaii.) PHOTO SOURCE
There are several things to note about this graph. First, there is good agreement between the Law Dome ice core data and the MLO data over the ~ two decade overlap. Second, there is good agreement between the three separate Law Dome ice core datasets. Third, both the ice cores and the MLO data do not vary much from year to year.
Now look at the various datasets cited by Beck. Many of them vary quite widely from one year to the next. The different datasets show very different values for either the same year or for nearby years. And they differ greatly from both the ice core and the MLO data.
Because of this, I conclude that the Beck data, while valuable for showing ground level CO2 variations at individual locations, do not reflect the background CO2 level of the planet. As such, they cannot be compared to the MLO data, to the ice core data, or to each other.
5. Keeling chose a bad location. I would say that Keeling picked a very good location. It not only allows us to measure the background CO2 in a very accurate manner, it provides invaluable information about the amount of CO2 coming from the volcano.
My conclusion? Most of the records in the field of climate science are short, spotty, and not very accurate. We have little global historical information on ocean temperatures, on land temperatures, on relative humidity, on atmospheric temperatures, on hurricane occurrence and strength, or on a host of other variables. By contrast, the Mauna Loa CO2 records are complete since 1959, are very accurate, and are verified by measurements in several other locations.
I’m about as skeptical as anyone I know. But I think that the Mauna Loa CO2 measurements are arguably the best dataset in the field of climate science. I wouldn’t waste time fighting to disprove them, there are lots of other datasets that deserve closer scrutiny.
[UPDATE] A reader below has added another question, viz:
6. What about Jaworoski’s claim that the ice core data has had its age “adjusted”?
Jaworoski argues that the age of the air in the ice cores has been “adjusted” to make it align with the modern data. He says, for example, that the Siple ice core data has been moved forwards exactly 83 years to make them match the Mauna Loa data.
Dating the ice core data is problematic. We can date the ice itself pretty accurately, through counting layers (like tree rings) and through studying various substances such as volcanic dust that is trapped in the ice. However, dating the air is harder.
The difficulty is that the air is not trapped in the ice immediately. The pores in the “firn”, the snow that falls annually on top of the ice are open. Air can flow in and out.
As more and more snow falls over the years, at some point the pores close off and the air is trapped. So how long does it take for the pores in the firn to seal off?
Unfortunately, as in so many areas of climate science, the answer is … “depends”. It depends inter alia on how much snow falls every year, how much of that snow sublimates (changes from a solid to a gas) every year, and even the shape and size of the individual snowflakes.
The end result of all of this is that we end up with two ages for any given thin slice of an ice core. These are the “ice age” (how old the ice itself is), and the “air age” (how old the air trapped in the ice is). The ice is always older than the air.
The main variable in that is thought to be the annual snowfall. Unfortunately, while we know the current rate of annual snowfall, we don’t know the historical rate, particularly tens of thousands of years ago. So we use the concentration of an isotope of oxygen called “d18O” to estimate the historical snowfall rate, and thence the firn closing rate, and from that the air age.
Sounds a bit sketchy? Well … it is, particularly as we go way back. However, for recent data, it is much more accurate.
So to bring this back to real data, in the ice core data I showed in Fig. 5, the air is calculated to be 30 years younger than the ice for cores DEO8 and DEO8-2, and 58 years younger for the DSS core. Is this correct? I don’t know, but I do know that there are sound scientific reasons for the “adjustment” that Jaworowski objects to .
Finally, the existence of a thirty to sixty year difference in air and ice age doesn’t make much difference in the pre-industrial levels of CO2. This is because prior to about 1800, the level is basically flat, so an error in the air age dating doesn’t change the CO2 values in any significant manner.
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Theo Goodwin says:
June 5, 2010 at 3:40 pm
No, that is the figure from the satellite image shown as Fig. 3. The range of values shown on the earth there is from about 383 to 393 ppmv … which is about ±1%.
w.
Willis Eschenbach says:
June 5, 2010 at 12:57 pm
“….For me, it’s never a waste of time to put out a clear explanation of what I see as the “truth” (a relative term, yes, I know). While there are lots of folks out there who are in the “My mind is made up, don’t bother me with the facts” headset, there are also large numbers of people who are seriously trying to understand what is going on. I think that they are what might be called the “forgotten majority”, they get all of this nonsense from the pro-AGW side (and some from skeptical side as well), and they are not clear on what is valid and what isn’t.”
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Willis, I do appreciate you efforts. In my case I am bringing to the table decades of trauma from sampling nonuniform mixes and fighting with very unhappy foremen trying to meet a schedule. “Is it Mixed? – HECK NO – sample it again please”
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On another note:
Tony says:
June 5, 2010 at 10:56 am
Does CO2 adsorb onto snow and ice surfaces? If so, does it do it at high altitude? (where the CO2 is supposed to do the warming?)
Willis Eschenbach answers:
June 5, 2010 at 12:47 pm
See here for what the adherents of this theory say.
“Sea ice in the Arctic basin is formed from sea-water with salinity of about 30‰ to 32 ‰. Sweet water freezes right through, and the sea salts brine remains in the ice, it partly flows down towards the bottom of ice surface and partly comes into the upper layers of the Ocean, and partly remains in the closed ice cavities. Calcium ions in the saline solution interact with dissolved acetic acid. As a result of such a reaction, calcium carbonate, water and carbonic acid gas are produced, at that carbonic acid gas together with the brine gets into the upper water layer under the ice and into the atmosphere through microfissures in the ice. In March and April, the air above the Arctic ice is calm, and carbon dioxide is accumulated in the bottom layer of subpolar atmosphere, thus increasing the winter concentration maximum above the frozen ocean.
In summer, ice is thawing together with the snow covering it. On the glacial surface, snowy puddles with cold sweet water appear, where poorly soluble calcium carbonate is suspended. At the zero temperature, lime water reacts with CO2, thus forming dissoluble calcium bicarbonate. Carbon dioxide dissolves excellently in cold water, therefore its summer concentration in the atmosphere decreases not only due to chemical reaction. It is absorbed by desalinated water on the surface of patches of ice-free water, cracks and channel. In summer, plankton life activates in the top water layer, and photosynthesis is taking place, which also requires CO2. As a result of all these processes, summer minimum of carbonic acid gas occurs in the air above the ice and in the water layer under the ice.
Genryh Alekseyev, Doctor of Science (Geography), Head of the department of the ocean and atmosphere interaction , St. Petersburg , Arctic and Antarctic Research Institute, Russian Academy of Sciences
http://www.informnauka.ru/eng/2008/2008-03-21-8-012_e.htm
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The English is horrible and it is a theory not proven but if I am not mistaken they are indicating there are processes that remove the CO2 captured in the ice! This could explain the discrepancy between ice core CO2 data and plant stomata CO2 data. It would also explain why the CO2 ice core data is so uniform.
old construction worker says:
June 5, 2010 at 4:36 pm
From Geiger again:
Distance from surface (m), Distance from surface (ft), Contribution to ghg radiation hitting surface87, 285, 72%
176, 577, 78.4%
269, 883, 82.4%
368, 1207, 86.1%
470, 1542, 88.4%
578, 1896, 89.6%
So 90% of the downwelling radiation hitting the surface comes from the first 580 metres (1900 ft) of the atmosphere.
In passing, anyone who is seriously interested in these questions should get a copy of Geiger. The current version is the sixth edition. The first edition came out in 1950, back when scientists actually measured things. Fascinating stuff, details, measurements, chapter after chapter.
This is an excellent post and one with which I fully agree.
When NOAA assigned me to write a book on the history of the Mauna Loa Observatory (where I have just completed a day on sun photometer and other instrument calibrations), I was instructed to write a full and honest account. The result will be a book of some 800 pages and 150+ color plates and B&W photos. A few of the photos are posted on my main web site (see below).
I looked very hard at the two CO2 records from MLO, the first beginning in November 1958 and the second more than a decade later by NOAA. Though there were the inevitable debates and disagreements between Dr. Keeling and NOAA, the two data sets are virtually a perfect match.
Last week I taught a short course in atmospheric science to students from some 14 nations. I openly discussed the various debates about climate change and the human impact on climate. We covered how regional weather and climate can be significantly affected by biomass smoke, land use changes, industrial pollution, forest fires and so forth. There was an exam question about the vital role played by skepticism in science.
Based on 4 years of research writing the MLO book and a very close look at the data record and the processing employed to remove data contaminated by volcanic emissions, I am not skeptical about the Mauna Loa CO2 record. It’s a stunning example of good science.
Skepticism might best be directed at the global climate models that are as yet unable to fully account for the impact of cloud cover, aerosols, water vapor feedback and, yes, solar cycle variations.
Forrest M. Mims III
http://www.forrestmims.org
Jbar says:
June 5, 2010 at 4:46 pm
Once again let me request that people not hijack this thread for a discussion of whether humans are the cause of the rise in CO2. That’s another question for another thread. This one is about whether we can trust the Mauna Loa dataset.
Fig 4 shows a very linear increase in CO2 concntrations between 1975 and 2007. However, I very much doubt that the global consumption of fossil fuels during this period is simarly linear. It would be interesting to plot MLO observations from 1959 to date with global consumption of fossil fuels over the same period to see whether the shape of the graph(s) matches. I bet it does not. If it does not, it would strongly suggest that the burning of fossil fuels is not the explanation behind the MLO measurments.
Perhaps someone knows of the comparative data for this period and can refeence a link.
Thank you for the explainer, Willis, but I have to say that I still object to the siting.
Here’s why; the methodology of detecting and omiting volcanic gasses is flawed. The reason is that it only omits large influxes, but if you have a slight amount of contamination, it won’t omit it.
The downflow of air at night is good, but flawed RE volcanic gasses; the observatory is downslope from the summits, so you can still get mixing and contamination.
I’ll agree that the Mona Loa record is pretty good, but for the life of me I can’t see why they don’t use Mona Kea ant its observatory instead. Mona Kea is as high (actually a bit hither) and is extinct, and far enough away from Mona Loa and Kilauea so that contamination would not be such an issue).
I think it would be an interesting experiment to have C02 sampling at Mona Kea, and see what the differences are over time (vs. Mona Loa).
Malcolm Miller says:
June 5, 2010 at 3:35 pm
A small apology – I did find one good reference to the Cape Grim station, with a graph of some results. I wonder why their data differs from that of other staions if the atmosphere is really fully mixed?
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Anna V may have an explanation for that in an earlier comment.
” anna v says:
June 5, 2010 at 12:56 pm
Hi Willis:
I am amazed with the 1,2,3 ,4 statements you are quoting.
Are they making a dress from a pattern? Talk about cherry picking data.
particularly
4. In keeping with the requirement that CO2 in background air should be steady, we apply a general “outlier rejection” step, in which we fit a curve to the preliminary daily means for each day calculated from the hours surviving step 1 and 2, and not including times with upslope winds. All hourly averages that are further than two standard deviations, calculated for every day, away from the fitted curve (“outliers”) are rejected. This step is iterated until no more rejections occur.
On the lines:” you will obey me, or else”
They have a preconceived notion of what the curve should be and they impose it, is my conclusion from this series.
You say there are independent measurements. Once I had managed to find a link and publications for those measurements. The were all Keeling and another fellow,possibly the graduate student going through the loops. I do not call that independent.
Here are the locations I find:
http://scrippsco2.ucsd.edu/data/atmospheric_co2.html
something like 14, and practically all the publications are Keeling et al
There is a map too
http://scrippsco2.ucsd.edu/research/atmospheric_co2.html
Do you believe that these 14 or so stations are representative enough so that the measurements could produce the amount of CO2 in the atmosphere?
I hope that helps.
dr.bill says:
June 5, 2010 at 3:44 pm
The fundamental distinctions are between ‘whole-molecule processes’ and ‘electron-transition processes’.
For the key CO2 IR absorption at the 667 cm^-1 wave number (15 micrometer wavelength), energy is stored in the vibrational bending mode (see chart 16 here).
Phil. says:
June 5, 2010 at 4:29 pm
“Since the measured annual accumulation in the atmosphere is about half the amount released into the atmosphere by fossil fuel combustion it’s impossible for it to be otherwise!”
Complete and total non sequitur.
Willis Eschenbach says:
June 5, 2010 at 5:23 pm
“Once again let me request that people not hijack this thread for a discussion of whether humans are the cause of the rise in CO2.”
My apologies. My note to Phil is not really arguing the point, just pointing out bad logic.
Bart (and others) –
Slioch said: “There has been more than enough CO2 emitted from human burning of fossil fuels to account for all the increase in atmospheric CO2 in recent centuries.”
Bart queried: “Why do people think this constitutes evidence that the CO2 increase is man-made?
The very first lesson in chemical engineering 101 is the “mass balance”. It is:
In – Out = Accumulation
Simple in theory, but often very difficult in practice.
It is reflexive thinking to chem engineers and chemists, but I have to assume not to the general public.
This principle also applies to the “energy balance”, and to eating:
In(food, drink, calories) – Out(exercise, metabolism, vomiting) = Accumulation(weight gain[or loss])
Applied to atmospheric CO2 on a per-year basis (“basis” – another Chem Eng 101 lesson),
Accumulation = 2/1,000,000 (i.e. “ppmv”)* mass of the atmosphere * molecular weight factor = 3 gigatons
In = “natural” emissions + human emissions = VeryBigNumber(natural) + 7 gigatons(human)
Out = VeryBigNumber + 4(human emissions absorbed by nature)
So putting it all together
(VBN + 7GT) – (VBN + 4GT) = 3 GT
If humans suddenly disappeared from the planet, then we would have to subtract 7 gigatons from both sides of the equation due to lack of fossil fuel emissions. A sudden human mass extinction should therefore result in atmospheric CO2 declining for some decades (initially by 4 GT/year) to a new equilibrium. (The “equilibrium” lesson is taught in Chemistry 101.)
That is how people think that fossil fuel emissions account for the CO2 increase in the atmosphere.
People don’t like to think that their weight gain comes from eating too much either, but when they actually add up the calories, that’s where it comes from. If “Out” is too low, you must either increase it or reduce “In”.
(IMPORTANT health tangent – Every extra 100 calories a 200 lb person consumes per day will turn into 10 pounds of weight over 5 to 10 years. This is GOOD news. If you want to lose 10 lbs, you don’t have to give up much – just about half a soda. Cut down from 3 regular to 1 regular soda a day and you’ll lose 34 pounds!!! Eventually. The catch – you must do it EVERY DAY!)
I have a few questions:
Is there a FTP site where we can download the raw data? I would also like the see the calibration data and the CO2 calibration bottle data sheets.
I would also like to know what instruments (specifically) were being used to measure the CO2 in the past and what instrument is being used today.
Oh…and I would also like to see the interference checks for all those monitors.
Anyone?
More questions:
What methodology is being used to correct for positive or negative bias? What is the acceptable calibration error %?
Phil.: June 5, 2010 at 4:24 pm
Your statement that is rather puzzling. CO2 is no different than any other molecule. If it happens to be hit by photons that it can absorb, then it will do so, and in very short order, as with any other molecule, but it doesn’t ‘reach out and grab them’.
If you calculate the mean time between collisions for a CO2 molecule at sea-level and 20°C, it comes out to about 0.4nsec. This would certainly give it lots of chances to collide with another molecule before an excited electron could drop back spontaneously (which generally takes 5 to 10nsec). The only outcome I would expect from such a collision, however, is that the electron would be stimulated to drop back immediately, thus restoring the molecule to its former state. I don’t see at all how it would change the speed of the molecule any more than would be the case of non-excited molecules bumping into each other ‘business as usual’.
/dr.bill
On The Air Vent a while back, Dr. Beck responded to the Errren/Engelbeen critics in a convincing manner.
I agree with that. It’s another example of how to temporarily store energy without changing the translational speed of the molecule as a whole, and is thus not involved in temperature-related effects (well, not in first order, anyway). Perhaps I should also have mentioned bending, stretching, and rotational modes in my note to Hank, but I didn’t want to get overly complicated. Mea culpa. 🙁
/dr.bill
In order to get a truer idea of atmospheric concentration anomalies, don’t we need sensors at desert bands as well as in green bands and at the poles? The AIRs data demonstrated that CO2 concentration is not well mixed in the atmosphere. It clumps into bands, one in the upper and one in the lower hemisphere. Therefore, one should be measuring all the bands (the CO2 bands as well as the “not CO2” bands). The NH Arctic, 45th parallel, desert band, equator, SH desert band, lower parallel, and Antarctic. As it stands, we can only say what the concentration is doing in the bands it prefers to circle in.
I’ve often wondered how ice cores can be dated accuratedly so many years back considering the story of the WWII P38 Lightning fighter plane was found 250 feet down in the ice.
http://p38assn.org/glacier-girl-recovery.htm
Willis Eschenbach says:
June 5, 2010 at 5:21 pm
Geiger says: … Contribution to ghg radiation hitting surface
You say: So 90% of the downwelling radiation hitting the surface comes from the first 580 metres (1900 ft) of the atmosphere.
In both this reference and your 12:24pm reference, you don’t use a qualifier like “downwelling longwave radiation” I figured you weren’t including shortwave radiation (i.e. visible +/-), but your description was unclear.
I agree with crosspatch @June 4, 2010 at 11:52 pm.
Good measurements; glad somebody’s doing something right. But, So What?
Let’s focus on those bogus, jet-engine influenced “global” temperatures. Right off the bat, one can say that the reason there hasn’t been any “global warming” in the last umpteen years (what was that number of years, Phil?) is because the preponderant number of measuring stations are now in more or less the same thermal environment – sitting on asphalt at an airport. The results, unless there truly is warming, will flat line or, if there isn’t warming, decline more or less. Thus, further “global” warming can come only from manipulations made in the computers of the measuring organizations. Thus every “update” from GISS or HadCRUt needs to be handled like a rattlesnake. Every update should result in a blizzard of FOIA requests for exactly what and why they are “improving” the actual data.
In essence, I think it’s “game over” for the would be global warming tyrants.
bubbagyro says:
June 5, 2010 at 10:27 am
Mt. Washington in my estimation would be a horrible place for CO2 monitoring. We get winds from almost any direction:
NW: Montreal lights are visible from MWN. Last week forest fires in Quebec brought so much smoke here that people were calling fire departments and hospitals had an increase in ER traffic. In the winter, this can be very dry “continental polar” air.
SW: Ozone air quality alerts due to all the industrial and transportation emissions between here and the Gulf of Mexico.
E: Clean ocean fetch. pretty rare, but does happen.
NE: Lots of air sources tangled into nor’easter that will cover the air sampler with a foot of rime ice.
For a first CO2 station, steady trade winds sounds awfully good!
——-
Mauna Loa that has increased in activity in the last 50 years – Okay, so Keeling didn’t consult fortune tellers or other crystal balls. His bad, but someone should’ve have warned him about the next 50 years.
——-
Peruvian Andes where we have great telescopes – I don’t think there were many telescopes there in 1959. I’d have to do some reading, but I think the building boom was in the 1980s
——
I think I read somewhere that Keeling wanted to spend some time in Hawaii.
Some other considerations:
1) CO2 concentration in the atmosphere correlates negatively with altitude, consistent with generation near the earth’s surface, and diffusing upward and becoming diluted.
2) Atmosphere becomes rarer with altitude. Although percentage composition is similar, the absolute composition is less of each component. There are lower amounts of each oxygen, and nitrogen, and so on. This is why percent by volume, or parts per million by volume, does not quantify the numbers of molecules in a given volume. In other words, there may be a similar percentage of CO2 both at sea level and 10,000 feet, but there is less CO2 in absolute amounts. We have to keep this in mind, that at 10,000 feet, there are less molecules to measure than at one atmosphere (sea level). This is why climbers of Mt. Everest need oxygen masks. The percentage of oxygen is still around 20%, but much fewer molecules.
3) partial pressures of gas, under ideal conditions of infinite dilution, are independent of other gases present until a higher concentration is reached (non-ideal state) and then the gases become interactive.
Willis, a couple of questions, thedata out of spec is not used to average. Why would there be over 20 days lost in one month. How can we know that there are enough readings in a month to make a decent guess at the average.
You say reading the background is important. In respect to AGW and the Greenhouse Effect, wouldn’t the amount of CO2 in the 50 feet, or even less, above the surface and the amount in the upper trop be most important to determining the amount of heating that will happen? CO2 in the Strat really doesn’t matter to heating the earth etc.
Reading the ice core data is about as useful as reading chicken innards after the purposeful mishandling of the ice cores. These come from the plastic area and leaving them to decompress allow major changes to the cores leaving data that is a smear at the best.
JimF: June 5, 2010 at 7:04 pm
At the risk of getting swatted by Willis for going off-topic, let me compliment you on your analysis of the ‘Limits to Warmth‘. ☺ ☺ With most of the thermometers sitting in jetwash and the ‘benefits of anomalies’ so fervently promoted, there’s not much room left for them to cry disaster. Well put!
/dr.bill