Via Eurekalert, from the NGO Partnership for Observation of the Global Oceans (POGO), a press release that says, “panic! please send money”. Here’s the punch line:
The Foundation says the average level of pH at the ocean surface has dropped from 8.2 to 8.1 units, “rendering the oceans more acidic than they have been for 20 million years,”
Note that any pH lower than 7.0 is considered “acidic”. Distilled (pure) water has a pH of 7.0. Right now the ocean with a pH of 8.1 is considered “basic”.
Even more interesting is this map below from WikiMedia showing the change in global ocean pH over the last two hundred years. The map information says:
Estimated change in annual mean sea surface pH between the pre-industrial period (1700s) and the present day (1990s). Δ pH here is in standard pH units. Calculated from fields of dissolved inorganic carbon and alkalinity from the Global Ocean Data Analysis Project climatology and temperature and salinity from the World Ocean Atlas (2005) climatology using Richard Zeebe’s csys package . It is plotted here using a Mollweide projection (using MATLAB and the M_Map package). Note that the GLODAP climatology is missing data in certain oceanic provinces including the Arctic Ocean, the Caribbean Sea, the Mediterranean Sea and the Malay Archipelago.
So, with accuracy like this, and such small pH changes obviously measurable, and the pH not yet anywhere near acidic, why do we need a global $15 billion pH measurement system again? It seems all they need is a few places covered to infill some data.
Here’s the press release:
Speed installation of system to monitor vital signs of global ocean, scientists urge
‘It is past time to get serious about measuring what’s happening to the seas around us’
The ocean surface is 30 percent more acidic today than it was in 1800, much of that increase occurring in the last 50 years – a rising trend that could both harm coral reefs and profoundly impact tiny shelled plankton at the base of the ocean food web, scientists warn.
Despite the seriousness of such changes to the ocean, however, the world has yet to deploy a complete suite of available tools to monitor rising acidification and other ocean conditions that have a fundamental impact on life throughout the planet.
Marine life patterns, water temperature, sea level, and polar ice cover join acidity and other variables in a list of ocean characteristics that can and should be tracked continuously through the expanded deployment of existing technologies in a permanent, integrated global monitoring system, scientists say.
Caption: A mooring with a suite of ocean acidification and other environmental sensors at Heron Island on the Great Barrier Reef is the latest tool in an expanding global network of ocean measurements, informing scientists of changes in ocean chemistry.
Credit: Dr. Bronte Tilbrook, CSIRO, Australia
The Partnership for Observation of the Global Oceans (POGO), representing 38 major oceanographic institutions from 21 countries and leading a global consortium called Oceans United, will urge government officials and ministers meeting in Beijing Nov. 3-5 to help complete an integrated global ocean observation system by target date 2015.
It would be the marine component of a Global Earth Observation System of Systems under discussion in Beijing by some 71 member nations of the intergovernmental Group on Earth Observations.
The cost to create an adequate monitoring system has been estimated at $10 billion to $15 billion in assets, with $5 billion in annual operating costs.
Some 600 scientists with expertise in all facets of the oceans developed an authoritative vision of characteristics to monitor at a 2009 conference on ocean observations, (www.oceanobs09.net).
Furthermore, as documented in the forthcoming proceedings of the 2009 conference (to be published shortly by the European Space Agency), the value of such information to the world’s financial interests and to human security would dwarf the investment required.
“Although the US and European Union governments have recently signaled support, international cooperation is desperately needed to complete a global ocean observation system that could continuously collect, synthesize and interpret data critical to a wide variety of human needs,” says Dr. Kiyoshi Suyehiro, Chairman of POGO.
“Most ocean experts believe the future ocean will be saltier, hotter, more acidic, and less diverse,” states Jesse Ausubel, a founder of POGO and of the recently completed Census of Marine Life. “It is past time to get serious about measuring what’s happening to the seas around us.”
The risks posed by ocean acidification exemplify the many good reasons to act urgently.
Caption: Scientists explore on and beneath polar ice. Their aircraft remotely sense animals through properties of scattered light. Marine animals themselves carry tags that store records of their travels and dives and communicate with satellites. Fish carry tags that revealed their migration past acoustic listening lines. Sounds that echoed back to ships portray schools of fish assembling, swimming, and commuting up and down. Standardized frames and structures dropped near shores and on reefs provide information for comparing diversity and abundance. Manned and unmanned undersea vehicles plus divers photograph sea floors and cliffs. Deep submersibles sniff and videotape smoking seafloor vents. And nets and dredges catch specimens, shallow and deep, for closest study.
Credit: E. Paul Oberlander / Census of Marine Life
POGO-affiliated scientists at the UK-based Sir Alister Hardy Foundation for Ocean Science recently published a world atlas charting the distribution of the subset of plankton species that grow shells at some point in their life cycles. Not only are these shelled plankton fundamental to the ocean’s food web, they also play a major role in planetary climate regulation and oxygen production. Highly acidic sea water inhibits the growth of plankton shells.
The Foundation says the average level of pH at the ocean surface has dropped from 8.2 to 8.1 units, “rendering the oceans more acidic than they have been for 20 million years,” with expectations of continuing acidification due to high concentrations of carbon dioxide in the atmosphere.
Because colder water retains more carbon dioxide, the acidity of surface waters may increase fastest at Earth’s high latitudes where the zooplankton known as pteropods are particularly abundant. Pteropods (see links to images below) are colorful, free-swimming pelagic sea snails and sea slugs on which many animals higher in the food chain depend. Scientists caution that the overall global marine impact of rising carbon dioxide is unclear because warming of the oceans associated with rising greenhouse gases in the air could in turn lead to lower retention of carbon dioxide at lower latitudes and to potential countervailing effects.
Says Foundation Director Dr. Peter Burkill: “Ocean acidification could have a devastating effect on calcifying organisms, and perhaps marine ecosystems as a whole, and we need global monitoring to provide timely information on trends and fluxes from the tropics to the poles. Threatened are tiny life forms that help the oceans absorb an estimated 50 gigatonnes of carbon from Earth’s atmosphere annually, about the same as all plants and trees on land. Humanity has a vital interest in authoritative information about ocean conditions and a global network of observations is urgently needed.”
Ocean conditions that require monitoring can be divided into three categories:
- Chemical – including pollution, levels of oxygen, and rising acidity;
- Physical / Geological – including sound, tide and sea levels, as well as sudden wave energy and bottom pressure changes that could provide precious minutes of warning before a tsunami; and
- Biological – including shifts in marine species diversity, distribution, biomass and ecosystem function due to changing water conditions.
Benefits of the comprehensive ocean system envisioned include:
- Improved short-term and seasonal forecasts to mitigate the harm caused by drought, or by severe storms, cyclones, hurricanes and monsoons, such as those that recently put one-fifth of Pakistan temporarily underwater and left 21 million people homeless or injured. International lenders estimate the damage to Pakistan’s infrastructure, agriculture and other sectors at $9.5 billion. Improved weather forecasting would also enhance the safety of the fishing and shipping industries, and offshore operations such as wind farms and oil drilling. Sea surface temperature is a key factor in the intensity and location of severe weather events;
- Early identification of pollution-induced eutrophication that spawns algal blooms responsible for health problems in humans and marine species, and harm to aquaculture operations;
- Timely alerts of changes in distributions of marine life that would allow identification of areas needing protective commercial re-zoning, and of immigration by invasive species;
eadler. In the continental US, the primary stress on native fish species is introduced piscavorous game fishes. This is followed by a distant second of structural changes such as damming. As for your precious lake trout, PH had nothing to do with their decline. Any study that you might be referencing that claims such (and there are quite a few, greenies are always busy concocting spin) is bogus. Salvelinus namaycush can tolerate an enormous range of water chemistry. The only real constraints is on O2 and temperature. If I remember correctly, they are found in waters with PH’s that range from 5.0 to 8.5! The primary factors related to population declines is over harvesting, as they have a min population doubling time of 4.5 years to 15 years depending on the phenotype. Just for your info, my field is not botany, but I do have some knowledge where it impacts aquatic habitats. One often deliberately ignored fact is that many tree species tend to die off in groves. Ever wonder were mountain meadows come from? Beavers don’t do all the work. The primary culprit in your spruce are beetles which have periodic population explosions. In some areas this might be exasperated by particulates.
Ric Werme says:
November 1, 2010 at 8:02 pm
“No. Only 10,000,000 percent _as_ acidic, 9,999,900 percent _more_ acidic.”
=============
Yes, I did realize this shortly after I posted the initial figure, and my own correction appears just a couple of posts above yours, coinciding with what you say. I suppose you did not see it.
The point remains entirely valid that the much advertised “30 percent more acidic” mantra looks idiotic and deceitful (because it is *meant* to be deceitful) if we start expressing acidity variations by that method, whereby Kool-Aid would be 10 million percent more acidic than ocean water, and the full range of the pH scale from 14 to 0 would cover a ten thousand trillion (10^16) percent increase in “acidity”. I have never seen acidity variations expressed in this grotesque fashion, other than in the depressing field of climate charlatanism, where the “30 percent more acidic” phrase is enthusiastically repeated tens of thousands of times all over the web like a universal braying contest.
eadler said:
November 1, 2010 at 1:57 pm
“The account of pH given by the above poster is his own invention and totally wrong.”
Just what part of:
ie 100% H+ = pH 0
—-50% H+= pH 7
—– 0% H+ = pH 14
is wrong?? I certainly did not invent the standard expression of pH. Obviously, you are comfortable with greater than 100% of a total. I am not. There is not one incorrect statement in my comment. It is merely stated in a simpler format, than what you are used to. For what it’s worth… I would like to see the whole globe instrumented, but I doubt, whether I could sell the expense, to the public. Of course this may be because I cannot give 110%, like you. GK
eadler says:
November 1, 2010 at 8:17 pm
The point I am making, and it needs to be made, is that the request for $15B is for a comprehensive system to monitor all aspects of ocean phenomena, not just pH. So a lot of people are getting their knickers all twisted up for no reason.
So, it’s entirely OK with you that they spend $15B on KoolAid science, as long as they promise to throw in some other stuff as well, to make it look like they are doing actual science. Got it.
DesertYote says:
November 1, 2010 at 10:18 pm
“eadler. In the continental US, the primary stress on native fish species is introduced piscavorous game fishes. This is followed by a distant second of structural changes such as damming. As for your precious lake trout, PH had nothing to do with their decline. Any study that you might be referencing that claims such (and there are quite a few, greenies are always busy concocting spin) is bogus. Salvelinus namaycush can tolerate an enormous range of water chemistry. The only real constraints is on O2 and temperature. If I remember correctly, they are found in waters with PH’s that range from 5.0 to 8.5! The primary factors related to population declines is over harvesting, as they have a min population doubling time of 4.5 years to 15 years depending on the phenotype. Just for your info, my field is not botany, but I do have some knowledge where it impacts aquatic habitats. One often deliberately ignored fact is that many tree species tend to die off in groves. Ever wonder were mountain meadows come from? Beavers don’t do all the work. The primary culprit in your spruce are beetles which have periodic population explosions. In some areas this might be exasperated by particulates.”
The science you quote comes out of your imagination. The science behind the death of red spruce at high altitudes is very clear. Acid clouds have caused it. The tips of branches die in a uniform mode around the circumference of the entire tree. Juvenile trout are killed off first as the pH of the water decreases. Lakes that have no limestone to buffer the acid, are the places where the trout disappear. It has nothing to do with overfishing or predators. Your figures on the tolerance of trout agree with what the table shows for the maximum pH of trout, but the pH of acid rain can be as low as 4.3. In addition, the prey of trout like mayflies will die off at higher pH.
http://www.epa.gov/acidrain/measure/index.html
http://www.epa.gov/acidrain/effects/surface_water.html
Recently spruce beetles have been killing off trees in the western US in huge numbers because winters have been milder due to climate change, and more beetles survive the winter.
All of this is off topic.
chris y November 1, 2010 at 11:22 am:
That’s why I agreed with most of what you said, but where you say-
… some money should be spent … to at least provide enough understanding to thoroughly debunk the climate alarmist claims.
and-
Right now the alarmists depend on lack of reliable observations to enable nonsensical adjustments that always favor a pending catastrophe.
there are more important things to do with “our” money than disprove alarmist claims, such as your suggestion to enhance the ARGO system for a few million. Great idea! And yes, we need continued funding for other more accurate data gathering systems. But even the “A-Train” of satellites, as mentioned here in other posts, is questionable (or should have been) or I would even say marginal comparing the total cost to actionable data that we hope to derive therefrom. In other words, spending money on data gathering for the sake of data gathering (or just for the sake of proving someone else “data” wrong) or on a “hope and a prayer” that it’ll mean something is – – A. Stupid, B. Wasteful, C. Killing people, D. Non-scientific, E. All of the above.
Your choice.
Some coments by physicist Denis Rancourt on the “acidification” industry, old and new.
http://tinyurl.com/24wftd6
[…] This has in turn led to tenuous proposals (and an associated research industry) that the mean ocean water has been acidified by 0.1 pH units and that this postulated acidification alone may cause ecological change putting certain shell-forming organisms at risk. To date there has been no direct experimental validation of a change in ocean pH, nor has there been a conclusive demonstration that ecological damage arises from increased ocean acidity.
This ocean acidification side show on the global warming science bandwagon, involving major nation research centers and international collaborations, is interesting to compare with the 1970s-1980s hoax of boreal forest lake acidification.
[…]
http://tinyurl.com/2cq2gqa
Acid Rain on the Boreal Forest
In the seventies it was acid rain. Thousands of scientists from around the world (Northern Hemisphere) studied this “most pressing environmental problem on the planet.” The boreal forest is the largest ecosystem on Earth and its millions of lakes were reportedly being killed by acid from the sky.
Coal burning plants spewed out sulphides into the atmosphere causing the rain to be acidic. The acid rain was postulated to acidify the soils and lakes in the boreal forest but the acidification was virtually impossible to detect. Pristine lakes in the hearts of national parks had to be studied for decades in attempts to detect a statistically significant acidification.
Meanwhile the lakes and their watersheds were being destroyed by the cottage industry, agriculture, forestry, mining, over fishing and tourism. None of the local and regional destruction was studied or exposed. Instead, scientists turned their gaze to distant coal burning plants, atmospheric distribution, and postulated chemical reactions occurring in rain droplets. One study found that the spawning in aquarium of one fish species was extremely sensitive to acidity (pH). Long treatises about cation charge balance and transport were written and attention was diverted away from the destruction on the ground towards a sanitized problem of atmospheric chemistry that was the result of industrialization and progress rather than being caused by identifiable exploiters.
As a physicist and Earth scientist turned environmental scientist, I personally read virtually every single scientific paper written about acid rain and could not find an example of a demonstrated negative impact on lakes or forests from acid rain. In my opinion, contrary to the repeated claims of the scientist authors, the research on acid rain demonstrates that acid rain could not possibly have been the problem.
This model of elite-forces-coordinated exploiter whitewashing was to play itself out on an even grander scale only decades later with global warming.
[…]
Have they not heard? NASA is now a muslim outreach. NOAA soon to be running soup kitchens. Good luck with that $15 Billion.
Francisco says:
November 1, 2010 at 7:25 pm
That comment made my day 🙂
Mike says:
November 1, 2010 at 8:23 am
When the annual and daily changes in pH are on a much larger scale than the supposed changes since the 1700s, and the fact that most of these organisms have been around for thousands of years and seen much greater changes, it is simply not logical to fall for the alarmist propaganda that “ocean acidification” poses any real problem what so ever.
The crux of Lubchenko’s demonstration is that corals and shellfish can thrive in ordinary tap water; including its deliberate Chlorination and Fluoridation; so long as you dye it blue with an ordinary laboratory blue dye; but they will not grow in ordinary tap water, if you chill it by adding lots of dry ice to it and dye it yellow with an ordinary laboratory yellow dye.
Her experiment would have been a lot more convincing if instead of ordinary chlorinated fluoridated tap water, she had used some actual sea water flown in from The Great Barrier Reef; where it is well known that corals, and shell fish will in fact survive quite nicely even without the need for an ordinary laboratory blue dye.
And I suggest that she finds herself a different brand of ordinary Laboratory blue dye; That Phenolpthalene is notorious for turning yellow when you chill it with dry ice.
And I was under the impression that she does have a degree in oceanography.
Her demo is only slightly less fraudulent, than the dumb experiments that people including the so-called science guy do with synthetic air samples; one with a ton more CO2 than the other, with thermometers in them which you expose to the roughly 2800 K Radiation from an incandescent light bulb which has its peak spectral radiance at about one micron wavelength; which the human body detects as “heat” largely because of the significant water absorption band at about 0.94 microns. Such a lamp also puts out a large amount of radiation at 2.7 7 microns, where CO2 has a significant absorption band (the assymmetrical stretch mode); and it would also put out a very large amount of 15 micron LWIR thermal radiation if the lamp glass could transmit it. But the glass will heat up to some high Temperature; but not 2800 K, and then the glass will radiate lots of 4.0 and also 15 micron Radiation which CO2 can absorb.
To do the experiment properly, you need to carefully set the amounts of CO2 in your air samples to perhaps 280 and 560 ppm comprising one doubling of the CO2, and then you need to use something like an ordinary garden brick which you chill to about 15 deg C in your refrigerator before using it to irradiate the air samples with 390 W/m^2 LWIR thermal radiation with a 10.1 micron spectral peak.
You should get a temperature rise of 3.0 +/-50% for the 560 ppm CO2 sample over the 280 ppm sample.
Don’t forget to put about 1% mole percent of H2O in with each of those air samples. The only difefrence should be 280 ppm extra CO2 in one of them.
G. Karst says:
November 2, 2010 at 12:06 am
eadler said:
November 1, 2010 at 1:57 pm
“The account of pH given by the above poster is his own invention and totally wrong.”
Just what part of:
ie 100% H+ = pH 0
—-50% H+= pH 7
—– 0% H+ = pH 14
is wrong?? I certainly did not invent the standard expression of pH. Obviously, you are comfortable with greater than 100% of a total. I am not. There is not one incorrect statement in my comment.
Actually all of it is wrong, it doesn’t contain a single correct statement!
To illustrate 10^-7 H+ = pH 7
0% H+ = pH infinity!
Phil. said:
November 2, 2010 at 4:49 pm
“0% H+ = pH infinity”
0% – 100% H+ references the pH scale ranging of 0 to 14 it does not reference a scale of 0 to infinity. But then… you already knew that so why did I bite? It won’t happen again. GK
Frank says:
November 2, 2010 at 10:24 am
When the annual and daily changes in pH are on a much larger scale than the supposed changes since the 1700s, and the fact that most of these organisms have been around for thousands of years and seen much greater changes, it is simply not logical to fall for the alarmist propaganda that “ocean acidification” poses any real problem what so ever.
————
You are presuming quite a lot. While pH does fluctuate shell formation occurs over time so the average pH is relevant. Keep in mind we aren’t just talking about fish and crabs and clams, but zooplankton. Effects of lower pH aren’t fully understood and will likely be mixed. Some sea animals grow faster with lower pH. But will their food supply match? We are making a very serious chemistry experiment and there is no going back if it goes wrong.
You are wrong that these organisms have seen much greater pH changes in the past – and survived.
“Payne said humans may not ultimately release as much carbon dioxide as the Siberian traps, but we may be doing it at a faster rate. The end-Permian extinction could be viewed as a “worst case scenario” for what we could be facing as we burn more fossil fuels and increase ocean acidity, he said.
“We won’t necessarily end up with a world that looks as bad as it did after the end-Permian extinction, but that event highlights the fact that things can go very, very wrong,” Payne said.
The National Resource Council recently reported that the ocean’s chemistry is changing faster than it has in hundreds of thousands of years, because carbon dioxide is being released into the atmosphere and absorbed into the oceans, making them more acidic. Studies have shown increased ocean acidity decreases photosynthesis, nutrient absorption, growth and reproduction of marine organisms.”
http://www.physorg.com/news191605233.html
“This study concludes that acidification has the potential to trigger a sixth mass extinction event and to do so independently of anthropogenic extinctions that are currently taking place. ”
http://www.springerlink.com/content/085g2151l3nlt871/
“It is more acidic now than it has been for at least 500,000 years…”
http://news.bbc.co.uk/2/hi/science/nature/7936137.stm
You are free to ignore what the scientists are finding. You are free to substitute your own naive judgment or what you pick up in blogs for expert opinion and analysis. But is this wise?
G. Karst says:
November 2, 2010 at 8:20 pm
Phil. said:
November 2, 2010 at 4:49 pm
“0% H+ = pH infinity”
0% – 100% H+ references the pH scale ranging of 0 to 14 it does not reference a scale of 0 to infinity. But then… you already knew that so why did I bite? It won’t happen again. GK
Presumably you bit for the same reason you messed it up in the original post, you don’t know what pH is!
For your education pH=-log([H+]) (log(0)=-infinity)
The reason the range is usually stated as 1-14 is because at 25ºC [H+][OH-]=10^-14
As stated before none of your statements were correct.
And percentage does not care for the “reasons” of the range. It only cares that it is referenced to a specified range, in this case pH 0-14 calibrated as a 100%-0% signal H+. Bye GK
G. Karst says:
November 2, 2010 at 9:07 pm
And percentage does not care for the “reasons” of the range. It only cares that it is referenced to a specified range, in this case pH 0-14 calibrated as a 100%-0% signal H+. Bye GK
Which is a chemical ( & mathematical) absurdity.
The oceans can never become permanently acidified no matter what the amount of atmospheric CO2, which in the Jurassic was some 5-10x current levels where delicate aragonite corals evolved in the first place. The fact that the oceans constantly brush against alkaline shores is also missed by these rent-seekers.
Some say jailing “deniers” is a bit harsh, but when CAGWists themselves become the deniers (No.. we didn’t misappropriate anything..), I find renaming them to criminals and jailing very appropriate.
Phil. says:
November 2, 2010 at 9:57 pm
G. Karst says:
November 2, 2010 at 9:07 pm
And percentage does not care for the “reasons” of the range. It only cares that it is referenced to a specified range, in this case pH 0-14 calibrated as a 100%-0% signal H+. Bye GK
Which is a chemical ( & mathematical) absurdity.
To elaborate, if pH 1 is defined as 100% (as shown above 0 is impossible), then pH 3 is 1%!
@ur momisugly Olaf Koenders says:
November 2, 2010 at 11:31 pm …
———–
It takes tens of thousands of years for ocean pH to return to normal.
“”””” Phil. says:
November 2, 2010 at 8:46 pm
G. Karst says:
November 2, 2010 at 8:20 pm
Phil. said:
November 2, 2010 at 4:49 pm
“0% H+ = pH infinity”
0% – 100% H+ references the pH scale ranging of 0 to 14 it does not reference a scale of 0 to infinity. But then… you already knew that so why did I bite? It won’t happen again. GK
Presumably you bit for the same reason you messed it up in the original post, you don’t know what pH is!
For your education pH=-log([H+]) (log(0)=-infinity)
The reason the range is usually stated as 1-14 is because at 25ºC [H+][OH-]=10^-14
As stated before none of your statements were correct. “””””
I’m a total idiot on this stuff; but I am under the impression (some sort of impression) that at STP conditions even the purest of water; containing no molecule that is not H2O, is naturally dissociated giving a Hydrogen (+) ion concentration of 10^7 or so; and hence arises the pH scale centered on -7.
From my now somewhat dated Semic-conductor processing days; we used to talk about (good) clean water as being
“18 megOhm water”. And for water to be conductive, it would have to contain ions; and H+ and OH- would seem to be the logical candidates.
Now you math whizzes out there should be able to connect a 10^7 H+ ion concentration to the 18 megOhms; which I would take a wild guess is the simple assed one dimensional resistance of any cube of water measured between two opposite faces with perfectly conducting end electrodes. I’d take a wild guess, that we would use Platinum electrodes in the instruments we used to measure the water to see how “clean” it was.
If pH relates to something else, then please forget I even mentioned this.
Is it only me? Or do other bloggers here think this hypothetical scientific back and forth claptrap needs some ACTUAL measurements so that their OPINIONS can be verified?
I know, why doesn’t someone build a comprehensive measurement system of the oceans so that we can base our debates around precise OBSERVATIONS. Considering, of course, the magnitude mankind will face if we leave a festering sore – like ocean acidification — not only untreated, but unnoticed.
George E. Smith says:
November 3, 2010 at 4:20 pm
I’m a total idiot on this stuff; but I am under the impression (some sort of impression) that at STP conditions even the purest of water; containing no molecule that is not H2O, is naturally dissociated giving a Hydrogen (+) ion concentration of 10^7 or so; and hence arises the pH scale centered on -7.
Correct George, 10^-7 mol/l of H+ and the same of OH- at 25ºC. That gives a conductivity of 0.0548 µS/cm. (not sure what resistivity that works out to but you can’t do better than that). If the water is in contact with air the pH will drop to about 5.6 because of dissolved CO2, more than 10 times the number of ions and therefore a conductivity above 1 µS/cm.
From my now somewhat dated Semic-conductor processing days; we used to talk about (good) clean water as being
“18 megOhm water”. And for water to be conductive, it would have to contain ions; and H+ and OH- would seem to be the logical candidates.
Now you math whizzes out there should be able to connect a 10^7 H+ ion concentration to the 18 megOhms; which I would take a wild guess is the simple assed one dimensional resistance of any cube of water measured between two opposite faces with perfectly conducting end electrodes. I’d take a wild guess, that we would use Platinum electrodes in the instruments we used to measure the water tosee how “clean” it was.
Exactly.
If pH relates to something else, then please forget I even mentioned this.
pH is related to the H+ ions mentioned above and can be measured in a similar fashion using a glass electrode and applying the Nernst equation.
I looked it up George, 0.1 μS/cm = 10 MΩ-cm, so 0.0548 μS/cm=18.2 MΩ-cm
“”””” Phil. says:
November 3, 2010 at 7:48 pm
I looked it up George, 0.1 μS/cm = 10 MΩ-cm, so 0.0548 μS/cm=18.2 MΩ-cm “””””
Thanks Phil; Funny how different disciplines think about the same phenomena in different ways. I think I may have got some signs wrong in my pH model; and it looks like our 18 megOhm water was pretty good stuff.