Guest Post by Willis Eschenbach
Anthony recently discussed a recent paper called “The Role of Atmospheric Nuclear Explosions on the Stagnation of Global Warming in the Mid 20th Century” (PDF, author’s version). It advances the claim that nuclear tests changed the temperature in the period 1945-1980, in a sort of mini-“nuclear winter”. Here’s their main graph:
ORIGINAL CAPTION: Fig. 1 Anomaly in global-mean surface temperature [GST] between 1880 and 2008. Black line: original data and their trend (the broken line). Red triangles: eruptions whose VEI (volcanic explosivity index) is equal or greater than 5 (source). Green vertical bars: annual yield of atmospheric nuclear explosions (UNSCEAR, 2000). Blue line: corrected GST (0.3K was added to GST data of 1945 and later) based on Thompson et al. (2008) and its trend (the broken line). Red line: re-corrected GST anomaly based on effects of atmospheric nuclear explosion (∆t was set at 3 years) and Thompson et al. (2008), and its trend (the broken line). Green line: imaginary linear global warming trend. Gray line: sunspot number (source)
Something caught my eye about this graph, something that generally makes me curious.
What I found odd was the logarithmic scale on the right, for the green bars showing the “Annual yield of atmospheric nuclear explosions (MT/y).” I don’t like logarithmic scales unless there’s a good reason for them. In this case, obviously, a good reason would be if the temperature cooling effect of the bombs was proportional, not to the total yield of the explosions, but to the log of the total yield. However, this would mean that smaller explosions would cause more cooling per megatonne than large explosions, which seemed unlikely.
And in fact, their Figure 6 shows that the amount of fine dust injected into the atmosphere goes up, not logarithmically with total yield, but linearly with total bomb yield. In addition, their Figure 5 shows that the total temperature drop varies linearly with the dust concentration. Which means that the temperature drop varies linearly with the total bomb yield. So the logarithmic display is deceptive.
I got to thinking about the question of how I might falsify their claim. I realized that a) the lifetime of dust in the troposphere isn’t very long, months rather than years or decades; b) there’s only a slow exchange of air between the Northern and Southern Hemispheres; and c) the overwhelming majority of the tests were conducted in the Northern Hemisphere. The Brits blew a few off in Australia, and that was about it. China, Russia, and the US did most of the atmospheric testing, and it was virtually all north of the equator.
This means that if their theory is true, the atom bomb tests should have cooled the Northern Hemisphere more than the Southern Hemisphere.
And that, we can say something about. Figure 2 shows the HadCRUT3 Northern and Southern Hemisphere data, along with a non-logarithmic view of the annual yield of the nuclear and thermonuclear bomb tests:
Figure 2. Temperature anomalies for the Northern (blue) and Southern (red) Hemispheres. Orange circles show annual total yield of all atmospheric (above-ground) nuclear and thermonuclear bombs. Yield data from Figure 1. Vertical gray lines show the start and end of atmospheric tests and bombs, 1945-1980. Fine dust in the lower troposphere has a half-life of days/weeks, and in the upper troposphere, a few months. Stratospheric dust lasts longer, but not much of the dust made it that high.
Immediately, we can see problems. In no particular order these are:
• More than half of the total bomb yield comes from just two years, 1962 and 1963.
• The first big temperature drop takes place in the period 1945-1950, during which time there was little testing.
• During the time when most of the fine dust was injected into the atmosphere, from 1951-1963 (94% of total bomb yield), the temperature was not falling.
So it’s not looking good for the hypothesis.
However, we still haven’t examined what I set out to examine. This was the difference between the Northern and Southern Hemisphere temperatures. Figure 3 shows that difference. We would expect the line to drop if the Northern Hemisphere actually were being cooled by dust injected into the atmosphere.
Figure 3. Difference between the Northern Hemisphere and Southern Hemisphere temperatures (North minus South).
At first glance it looks like they might have something. There is a big drop in the period 1964-72. But there’s a couple of problems with that.
First, if we look at Figure 2, we see that the reason for the drop is the Southern Hemisphere is warming. The Northern Hemisphere is not cooling during that period,. False alarm.
Second, they identify the period of “stagnation of global warming as being 1945-1975. But the relative change between the two hemispheres didn’t happen until 1965.
Overall, I’d say that their explanation of the “stagnation” simply doesn’t hold water. The timing is not right, the size is not right, and the pattern of cooling is not right.
Note that the same arguments apply for the usual culprit advanced for the “stagnation”, which is aerosols, particularly sulfates. As with the bombs, the main sulfate and other aerosol sources were predominantly in the Northern Hemisphere at that time, and they last no longer in the atmosphere than does fine dust from bombs. So the lack of NH cooling argues against the sulfate/aerosol hypothesis as well.
Best to all,
w.
PS – Before you ask, yes, I know that the Partial Test Ban Treaty (PTBT) went into effect in 1963. But the Chinese and the French didn’t pay any attention to that, did they? After all, we’re talking China and France, and besides we were asking them not to do something we’d done over a hundred times.
I call “bull” on this silly nuclear explosion report and must agree with Willis.
Willis has a very short memory . This Wall Street Journal piece
http://www.textfiles.com/survival/nkwrmelt.txt
notes that ‘nuclear winter’ s foremost critic was none other than Steve Schneider , whose
‘Nuclear Winter Reappraised ‘ appeared in Foreign Affairs; CF
http://adamant.typepad.com/seitz/2006/12/preherein_honor.html
Their claim is no better than the pirate claim.
More pirates = lower temps
Less pirates = higher temps
Luckily we have some East Africans bringing pirating back in a big way that’s why temps have fallen on hard times of late.
This post looks like a good rebuttal paper that you should publish.
Another excellent clinical analysis.
I bet there was an explosion in pixie’s magically coming into existence between 45 and 82, and then a subsequent drop in population.
Hey – Pixie dust is every bit as plausible a cooling cause as the tripe espoused in this paper.
<>
This is a new item of information for me. And very interesting.
Isn’t the lion’s share of man-made CO2 released in the NH? If so how long does it take NH CO2 to mix with the SH?
Ranger Rick,
Willis falsified the Yoshiaki paper. He’s not putting out a new hypothesis here. But it sounds like you are.
Hi Willis
The French conducted 41 atmospheric nuclear tests near or over the South Pacific atoll Moruroa between 1966 and 1974. I’m a Kiwi and remember the ruckus well. Are they factored into the calculations?
Hey, look … all those atmospheric nuclear detonations caused the sun spot number to go down. That by itself deserves a peer-reviewed paper.
I still haven’t seen one to explain why CO2 on Earth made the Earth and many of the other planets and some moons in the solar system warmer.
Willis
I would echo James Allison. As a Kiwi i remember that the atmospheric French testing caused rather a lot of strain between the NZ and French governments. NZ even sent naval vessels into the French exclusion zone in protest and in support of civilian craft. This might have contributed to the French shifting to underground testing (but who can tell with the French).
Given that these tests were over atolls or ocean there might not have been much dust put into the atmosphere in any case. Must of the American testing would be similar.
James Allison says:
April 6, 2011 at 6:35 pm
Indeed they were. And as Rob R points out, the over-the-sea tests provided less fine dust than over the land. The authors take all of that into account.
w.
As I recall from fifty years ago in chem e classes, a logarithmic scale flattens the curve, and wouldn’t form the hockey stick. Am I misremembering?
What ratio is the dust supposedly kick up by the nuc’s vs the 40m tonnes of dust is swept up from north Africa and whistled across the Atlantic Ocean, a distance of over 5,000km, before finally coming to rest in the Amazon basin in South America.
http://www.guardian.co.uk/weather/2009/mar/26/weatherwatch-weather
Yes Willis, but the French and Chinese tested VERY few bombs compared to the US and Russia. The US is responsible for more than 60% of all bomb tests and Russia is responsible for another 30% or so. The rest are divided between Britain (tested in the US), France, India, China, North Korea, and Pakistan. And yes, while some nations were not signatories to the treaty, pretty much everybody observed the treaty when they realized the environmental/health issues involved. The Nuclear Winter hypothesis for the mid century cooling is a scam, capitalizing on the Fukushima disaster for hype factor.
So I guess it just destroyed the ozone layer instead 😛
This paper is extremely silly. What some folks are willing to do, to keep the money spigot open, is amazing.
The cooling precedes the outset of weapon testing, and warming recommences before the cessation of weapon testing: therefore, (post hoc, ergo propter hoc) a cooling climate causes nuclear explosions. Well, either that, or the Earth is sentient.
This new science is marvelous, isn’t it?
Willis,
Thanks again for a great post.
I think you were on to something, but didn’t quite go far enough.
Please try charting the ‘rate of change’ of temperature differential.
It’s the rate of change, and timing of, between the two hemispheres that is relevant to the argument.
Thanks Willis. I read the press release and decided it was not worth any further effort on my part. Wondering Aloud call it “extremely silly”. I think WA is all to kind. Your discomfort with log scales is shared. Sometimes they are very useful as they do make a straight line of things. Grain size distributions in sediment samples comes most to my mind. The straight lines help greatly in comparing large numbers of the things. As you rightly point out, when used for other kinds of comparisons great care is need and they will more often then not give a false impression. This is simply another example of trying to force the facts to conform to your hypothesis then in using the facts to test which one of several is most likely correct. We geologists call it the multiple working hypothesis.
Like a velvet wrapped wrecking ball, you smoothly demolished the hypothesis of ‘nuclear cooling’ of the atmosphere, Willis, with concise clarity and little residual ‘dust’.
Nice!
One might as well write a paper correlating UFO sightings with Climate Change.
Guaranteed to rake in the dough if you can get a book deal with it.
This is sort of like the theory that Carl Sagan pushed about the flaming Kuwait oil wells causing the equivalent of a localized nuclear winter.
Didn’t happen as I recall.
I assume that the big Mt yield spike, is the effect of the “Tsar Bomb” ?
Volcanic dust has to be injected a long way into the atmospheric column to have a significant effect on climate. To have any effect then the dust must remain in the atmosphere for a considerable time so height of injection is a vital factor, as far as the stratosphere would be ideal. Explosive eruptions have a higher eruptive column than effusive ones and this depends on magma type and gas content. This can change during an eruptive run or between eruptions so a particular volcano cannot be labeled as climate changing simply because it once caused a problem.
The mistrustful amongst us are surely thinking that the intent of the original paper is to bolster AGW by explaining an inconvenient global temperature decline between 45 and 75 . . . . Waste of time either way since the Earth doesn’t have a fixed temperature. It’s part of a constantly changing system that’s still beyond our comprehension and control. And even if the temperature keeps on rising for the next several generations, that in itself won’t prove the AGW hypothesis – if that’s not too grand a term for it. All the evidence of the last 600,000 years points towards irregular rebound rises in temperature after each ice age until the next one is precipitated, though there are clearly no guarantees that another one will occur since the pattern isn’t precisely repeated – meaning there is no irresistible patterned causative factor. The trigger might be something local to part of the northern hemisphere but persistent over the course of a single year’s “weather”. Or something quite different. Seems to me that the science is so far from being settled that it’s barely survived the conception stage.
rbateman says:
April 6, 2011 at 10:37 pm
“One might as well write a paper correlating UFO sightings with Climate Change.
Guaranteed to rake in the dough if you can get a book deal with it.”
I like the idea. How about a collaboration with von Daniken? Maybe title it “Climate Change Chariots of the Gods?”
So this was a peer reviewed paper that took only a matter of minutes to be shot through with big holes.
Thanks, Willis, for your usual immaculate deconstruction, but one thing puzzles me. The paper is such obvious lightweight nonsense, why did you bother, or was it a rainy Sunday afternoon and you had nothing else to do. 🙂
Willis,
I seem to recall some DoD studies indicating that at around 110
megatons there was the beginning of a “fall off” on the rate of
destructive effectiveness of any given weapon. By the time the
weapon reached 175 megatons, the rate of a weapon’s destructive
effectiveness flattened out.
High (70+)megaton atomic devices weren’t easy to deliver,
but the more efficient hydrogen bombs of the same size
or larger were feasible payloads for our missles back then.
But, they could only blow up so much with a single weapon.
This, together with a desire to confound Soviet and the later
Chinese antimissile systems, brought us MIRVed nuke delivery
vehicles.
These MIRV systems were tested in an unannounced
fashion somewhere.
Where’s Hank Kissinger when you need him ?
Willis says ‘ Note that the same arguments apply for the usual culprit advanced for the “stagnation”, which is aerosols,’
Nuff said.
All the discussion is on dust – but my fading recollection of high school science says that mushroom clouds are white from water vapour not dust. Isn’t that water vapour being sent miles into the atmosphere going to act like a “forcing” mechanism – to create warming not cooling? Are they clutching at straws to explain the last cooling cycle and in the process arguing against one of the very basic tenets of AGW?
When you look at the awesome movies of thermonuclear tests, you see saturated layers of the atmosphere condense as the ionising radiation forms nuclei for water droplets to form upon, soon to be evaporated as the heat from the initial blast raises those regions temperature above the dew point again.
Once the initial heat, and shock waves have dissipated, thick clouds often form unnaturally fast, in some super Svensmark event, as all the secondary radiation and radioactive fusion product particles, gases and vapours, free neutrons and tritium etc escape the initial scene, and start interacting with the atmosphere, converting N14 to C14, for instance.
It’s not the dust that affects the change in cloudiness, it’s the radioactive atmospheric content.
If you can stand the music and Bill Shatner’s voice, watch the footage in “Trinity and Beyond, The Atomic Bomb Movie” and the sequel, “Nukes in Space -The Rainbow Bombs” or extracts on Youtube to see it in action.
I’m not surprised we cooled during that period, but not for the reasons in the paper Willis has countered above. The early bombs were very dirty compared to their destructive power. Thermonuclear are in a different league altogether. The actual radiation levels – classified, and probably conveniently lost forever. They couldn’t have been in safer hands, even at the CRU.
Actually, this reminds me of another debate from a couple of decades back. Although the most recent evidence has really put a nail in the coffin of the CFC/Ozone Hole connection, there is still dewbate about the source of free radical halogens in the stratosphere.
Back in the day many argued that sea spray was a likely source. The anti-CFC crowd claimed (correctly) that airborne particles of salt from the ocean are born wrapped in an organic shell that prevents them ending up in the stratosphere. But then the action of OH in the atmosphere was found to scrub the organic layer off the nanoparticles and the debate was back on.
But now I’m beginning to wonder if atmospheric testing of atomic weapons over the southern oceans didn’t have a significant impact on atmospheric halogen concentration.
I wonder if I’ll find time to look at that. What a fantastic irony if this latest attempt to blame global warming on the “evil West” turns out to answer the ozone hole question and the Montreal Protocol is proved yet again to be ill-conceived.
Adam Gallon says:
April 7, 2011 at 1:51 am
I assume that the big Mt yield spike, is the effect of the “Tsar Bomb” ?
More likely the ‘Castle series of tests in 1954. The Americans discovered the secret to making dry fuelled thermonuclear weapons. Castle Bravo was far more powerful than they thought it would be and forced the evacuation of the Marshall Islands
Willis:
Excellent and elegant piece of analysis. Have you contacted the authors with your analysis?
What truly makes me wonder is how come the reviewers did not push the authors to do something along the lines that you did in order to verify their hypotheses. After all, and this is not to diminish your analysis, you have simply asked, “If X is true, then Y1 and Y2 should be true.” I can understand researchers getting excited by a potential finding, but is not the purpose of the peer review at a minimum to check the quality of the researchers’ critical thinking, i.e., their application of scientific reasoning?
Smokey,
I’ll use the same argument for your comment as the AGW folks.
Prove me wrong!
The nuclear testing argument fails spectacularly. I swear this paper is nothing more than a new form of high-brow humor. Why do I say this? Because volcanoes spit up more fine dust and use more explosive power than decades of nuclear testing, and they do it in the span of a few days.
Mt St Helens 1980:
“..equivalent to 1,600 times the size of the atomic bomb dropped on Hiroshima…”
Pinatubo was orders-of-magnitude stronger, and backended their period of presumed cooling. Yet these guys laughingly conclude that atmospheric nuclear testing directly contributed, with a nearly instantaneous response mind you, to global temperature changes?
They can’t be serious, this is a new form of comedy.
Ranger Rick,
You need to get up to speed on the scientific method: skeptics have nothing to prove.
It is the alarmist crowd’s falsified hypothesis claiming that CO2 causes catastrophic global warming [CO2=CAGW] that has been repeatedly debunked.
Skeptics are asking questions – very embarrassing questions – that the alarmist contingent is unable to answer. Willis easily falsified the latest warmist bunkum in this article, and your lame “pixie dust” comment at 6:16 pm above was the best response you could come up with.
The Tsar bomb was about one-third of the total nuclear power released in 1962. Check AW’s more detailed plot at Climate Craziness of the Week. The spike in the current post appears to represent 1961-1962 following two years of very little testing.
Smokey – Ever heard of sarcasm? Wow, how easily inflamed one can become!
Ranger Rick,
If it was sarcasm all is forgiven.☺
Thanks Willis. Nicely done.
It looks simpler than that to me (if I’m reading the graph correctly). Looking at the raw data (ignore the trend lines that fool the eye), the first half of the data is roughly identical to the second half.
1880-1920 shows a downward trend, just like 1940 to 1980.
1910-1940 shows an upward trend, just like 1980 to present.
Is the last decade the start of another downward trend?
What I want to know is how those explosions managed to alter sunspot activity? Or did the change in sunspot activity cause us to test nuclear bombs?
You distort we deride says:
April 6, 2011 at 5:52 pm
“Willis has a very short memory . This Wall Street Journal piece
http://www.textfiles.com/survival/nkwrmelt.txt
notes that ‘nuclear winter’ s foremost critic was none other than Steve Schneider”
Willis has not said anything about Schneider, so what’s your problem?
Willis
“I got to thinking about the question of how I might falsify their claim. I realized that a) the lifetime of dust in the troposphere isn’t very long, months rather than years or decades; b) there’s only a slow exchange of air between the Northern and Southern Hemispheres; and c) the overwhelming majority of the tests were conducted in the Northern Hemisphere. ”
Problem. they are not talking about dust in the troposphere. They are talking about fine dust in the STRATOSPHERE. the average drop time I believe they put at 3 years or so. I’m pretty sure this exceeds the interhemispheric exchange times by a couple of years.
so, a falsification that depends upon and assumption of
1. short drop times in the troposphere
2. short interhemisphere exchange rates.
Really doesnt address the problem, since they are talking about fine dust that makes it into the stratosphere and which has longer drop times and thus more time to mix from hemisphere to hemisphere.
It’s in the paper you linked. stratosphere. not troposphere.
Falsifying nothing. Just found it interesting …
A Time-Lapse Map of Every Nuclear Explosion Since 1945 – feel free to come to any apropriate conclusion..
http://donnafleischer.wordpress.com/2011/03/12/a-time-lapse-map-of-every-nuclear-explosion-since-1945-by-isao-hashimoto/
RusQ.
Very nice. Interesting to see how many were “technically” in the Nhemisphere but close to the equator and how many were in the southern hemisphere. To asses it properly I suppose one has to eliminate the blasts which they did. And blasts under water or blasts in the air were eliminated. only blasts which could have created ‘fine dust’ were used.
Then you’d have to look at the likelihood of these particles staying aloft long enough to mix uniformly from “north” ( prolly about 30 latitude) to south. spliting the data by latitude bands might be a better idea than just doing a north south hemisphere split.
more than the back of an envelop is required
Just caught your Heartland Inst lecture on our thunder storm throttle.
I never thought of it like that. Has this been reviewed or published?
From:
http://www.physorg.com/news91820684.html
“U.S. researchers have determined typhoons and hurricanes are the dominant cause of mixing between the Earth’s troposphere and stratosphere.”
From:
http://webphysics.iupui.edu/webscience/physics_archive/hurricanes.html
“Hurricanes are among the most powerful of all natural phenomena, and by far the most powerful storms. At its peak, a severe storm may have a total power near to 1015 Watts: about 3,000 times the total electrical power generated in the world. This is equivalent to exploding 500,000 atomic bombs per day (the little ones that were used at the end of WWII).”
Thanks for your thoughts as always, Mosh.
steven mosher says:
April 7, 2011 at 12:10 pm
Well … no. That’s not what the paper says. It says:
So they are talking about three things – first, fine dust in the troposphere, with a very short (one month or less) removal times.
Next, fine dust that makes it to the tropopause, which lasts longer, but which stays in the same hemisphere.
Finally, fine dust that makes it to the stratosphere. This varies in removal time from three months to 3.5 years.
Now, the dust starts out at ground level. According to the paper, on average about three quarters of it makes it to the stratosphere.
OK. A quarter has a residence time of one month. Three quarters of it have a residence time from 3 months to 3.5 years.
Average stratospheric residence time, therefore, seems to be 3.75/2 = 1.8 years. This is in agreement with other estimates, viz:
So overall, we’re looking at a residence time for the whole thing of a year or a bit more … which is what I said.
However, and most curiously, the paper uses a residence time of 5 years … I find no explanation of that.
Next, the testing through differential warming should still be valid even if the residence time is longer … because with new dust being constantly added in the north and only slow interchange between hemispheres, the majority of the dust will be in the Northern Hemisphere.
In addition, while there is more interchange between hemispheres in the stratosphere than the troposphere, the “Brewer-Dobson” circulation generally circulates the stratosphere from the Equatorial region to the extra-tropics, viz:
This, of course, tends to keep the stratosphere in the two hemispheres separated.
Finally, the inter-hemispheric temperature difference is only part of the reason why bombs don’t explain the 1945-70 temperature plateau. Neither the timing nor the size of the global temperature changes match up with the yield of the bombs.
All the best,
w.
Alexander K says:
April 7, 2011 at 2:50 am
It’s lightweight, but it has gotten quoted all over the web. Gotta fight them where they live.
w.
mike restin says:
April 7, 2011 at 3:48 pm
It was peer-reviewed and published in Energy and Environment, the journal that AGW folks love to hate … see here for a bit more.
w.
Not so sure about what your claiming.
The model they used looks like it put dust in the strat.
The emprical test they propose puts dust in the strat.
The geoengineering they reference, in the strat.
Then comes the issue raised by the video of how many explostions were in the SH,
the large number at the equator an the large number within 30 deg of the equator.
One of The models they consulted did the estimation for the strat.
5
The other model looks like it was sued to estimate the trop effect
Residence time?
You wrote “Finally, fine dust that makes it to the stratosphere. This varies in removal time from three months to 3.5 years.” No. HALF removal time. Plus, you cannot just
average 3 months and 3.5 years. Why, because 3 months looks like what you get at the poles. 3.5 years is for the equatorial stratophere. Thats from 0 to 30degrees.
see the report they site which defined the polar strat as 30-90degrees. It also shows the circulation. Then look at the explosions and where they actually happen. figure 4
page 163 of the source they site for half removal time will show you some interesting NH versus SH. not what you expect.
Your temperature graph, like most others, shows World War Two as a heat wave and cooling that starts in 1950. This is complete BS. Cooling started in the winter of 1939/1940 when the Finnish Winter War was fought in the bitter cold of minus 40 Celsius. When Hitler invaded Russia a year later the bitter cold caused many casualties and helped the Russian cause. And GIs had to fight their way from the Battle of the Bulge to the German border in the coldest winter that West Europeans could remember. My theory is that due to the war records were screwed up and later everyone just copied each other from unreliable sources that did not relate to reality.
steven mosher says:
April 7, 2011 at 11:24 pm
Yes, and I said they put dust in the stratosphere, and I quantified it. The paper says about three quarters of the dust made it to the stratosphere.
Yes, half removal time, or half-life. Pardon my error.
Actually, they were about what I expected. You need to learn to mistrust log scales like I do, Mosh, you’ve mis-read Figure 4 completely. Log scales are teh suxxor. I digitize log data and convert it back to real numbers. According to the numbers in their Figure 4, the concentrations in the two hemispheres were as follows (without the log scale):
Note a couple things. First, note that the levels drop fast from the 1963 peak. In one year they’ve dropped by just about half — what does that say about the half-life?
Notice also that the corresponding peak in the Southern Hemisphere occurs in 1964.
Finally, note that the NH peak is NINE TIMES AS LARGE as the SH peak.
So despite all of your theories, the observations show that the time constant is short, far from the 5 year half-life claimed in the paper. We also see that concentrations are much higher in the north than the south. Finally, we see that despite certainly making it to the stratosphere, only a fraction of the fallout made it to the SH. This is also confirmed by the cumulative totals shown in Figure 5 of the same paper. NH totals are about seven or eight times SH totals.
All the best,
w.
Willis,
Unfortunately, you cant use the strontium 90 distribution to talk about the distribution of the fine dust. The fine dust was only created by a selection of
all explosions. So it still takes more than the back of an envelope to determine
the distribution of fine dust into the hemispheres. Look again at the video of the
explosions, or again at the table of which explosions they used. Even in the NH
you are seeing dust injected at 30-40N at the most. Given the half removal time
of 3.5 years for dust in this zone, its not clear that this will not be mixed into
the SH. That’s why I’d suggest looking at latitude bands rather than hemispherical
figures.
Willis, plus there is a reason to use a log scale. Especially when you are talking about the obscuring effects of particles. So, you want to leave it in log scale because the effect
(blocking) is going to have a log response, depending of course upon the size of the particles in question. I’d waste some time and go look at scattering to get some more clarity
steven mosher says:
April 9, 2011 at 2:34 pm
Thanks, Mosh. Whether you are looking at “most” atmospheric explosions (what the original paper did) or “all” explosions (what the USCEAR Report did) is not a large difference. And in fact, your point works against you — many of the equatorial explosions were over the Pacific, so there would have been strontium, but little dust. So we’d expect less dust in the SH, proportional to the NH, than strontium
My point is, however, that the proportions will be not too far different. If about a quarter of the strontium made it to the south, about a quarter of the dust is very likely to have done the same.
So if so much dust is making it into the SH as you claim … why isn’t the strontium doing the same? And why did they put the graph of the strontium in there, if not to show where the fallout was falling out … which turns out to be, as I said, in the NH. Only 25% of the Strontium made it to the SH, so we can assume that even less of the dust made it to the SH.
You also say:
steven mosher says:
April 9, 2011 at 2:37 pm
While that log-relationship is certainly true for medium and high concentrations, we’re talking about very, very low concentrations which are principally in the lower stratosphere. At that level, the log and linear will only be trivially different, because both will be about linear. The log relationship is because when you get lots of particles, they start to interfere with each other. But when the numbers are tiny, it’s not a large effect. And as I mentioned above, the people who wrote the original article agree with me, they show the temperature deviation to be linear with dust, not logarithmic.
Does some of the dust make it into the SH? Sure … but as the strontium data shows … not much. There just isn’t a whole lot of interchange between the atmospheres of the two hemispheres. Even a long-lived molecule like CO2 takes a while to move from the NH to the SH.
w.
Mosh, I’d also like to know why the paper uses 5 years as the half-life of the dust in the atmosphere … do you happen to have any clues on that one? Because all of the numbers that both you and I have estimated have been well below that.
w.
Also, Mosh, according to the UNSCEAR report, the majority of the explosion ends up in the lower stratosphere. You say regarding this zone:
However, the UNSCEAR paper says:
‘
So it seems your numbers are still too high.
And in section 31, p 165, it gives two estimates of the average half-life for bomb debris in the atmosphere, which are 1.3 and 1.1 years … remember that my estimate was one year.
It also shows in Table 8 the hemispheric and zonal distribution, about which they say:
w.
Chronology of all above ground nuclear tests. http://www.johnstonsarchive.net/nuclear/atest00.html
USA popped off 216. USSR did 214, but their combined yield was nearly double the American bombs, with the Tsar Bomba contributing quite a lot.
A bit of irony, if you’ve seen “Dr. Strangelove”. The USSR actually did contemplate building a giant nuclear doomsday bomb, which would have been built into a ship cruising the north sea. Detection devices spotted around Russian territory would automatically set it off should they be attacked with nuclear bombs. Pretty much exactly the ending of the movie, but Stanley Kubrick could not then have known about the real doomsday bomb plan – which fortunately the Soviets weren’t crazy enough to actually go ahead and build.