Guest Post by Willis Eschenbach
It’s been a while since I played “Spot The Volcano”. The premise of the game is that the decrease in temperatures from volcanic eruptions is nowhere near as large as people claim. So I ask people to see if they can identify when a volcano erupted based on the temperature records of the time.
Now, I say that the main reason the temperature drop from volcanic eruptions is so small is that when we get a reduction in downwelling radiation from any cause, the equatorial oceans start to cool. When that happens the clouds form later in the day, allowing in more sunshine. And the net result is that any cooling from the volcanic eruption is mostly offset by the increase in incoming solar energy.
With that in mind, I thought I’d take a look to see what records we have for the largest volcanic eruption in modern times. This was the eruption of the Indonesian island of Tambora in April of 1815. To my surprise, I found that we have no less than forty-two temperature records from that time. As you might imagine, most of these are from Europe. The list of the forty-two stations is appended in the end-notes.
So I took the records for the period during which the Tambora eruption occurred, and I “standardized” them so that they all had an average value of zero and a standard deviation of one. Then I plotted them all on one graph. Here is that result.
Figure 1. Temperature records of forty-two temperature stations for a period during which the Tambora eruption occurred. Seasonal variations have been removed from the data, leaving only anomalies. DATA SOURCE
As you can see, there is good agreement between the various records, with the cold and warm years affecting most if not all of the records. And if that’s too fuzzy for you, here is the same data with the average of all forty-two of the stations overlaid in red on the individual station records.
Figure 2. As in Figure 1, but with the average overlaid in red.
You can see the problem. The largest eruption in modern times, and it is absolutely not obvious when it happened …
So when was the eruption? Well, it’s not where you’d expect, which would be just before one of the two biggest drops in temperature, shown on the left-hand side of the graph. Nor is it where the big temperature drop is on the far right of the graph. Nope. It’s in a very generic area where you’d never expect it to be found …
Figure 3. As in Figure 1, but with the years added.
Now, there are a couple things of note here. First, there are a number of temperature drops even in only this short record which are much larger than the temperature drop after the Tambora eruption.
Second, there are a number of cold temperature excursions even in this short record, some of which are much colder than during the period after the eruption.
My conclusion from this? Yes, there were likely areas in Europe and the US which were somewhat colder than usual after the Tambora eruption. But temperatures somewhat colder than usual occur every few years …
And overall, despite the size of the eruption, despite the megatonnes of sulfur dioxide that the eruption sent up into the stratosphere, despite the reduction in sunlight from that stratospheric dimming … despite all of that, the effect on temperature was indistinguishable from natural fluctuations in other parts of the record.
My very best to everyone,
w.
PS—As is my custom, I ask that when you comment you quote the exact words you are discussing, so that we can avoid at least some of the misunderstandings that plague the intarwebs.
DATA NOTES:
The following records were used in this analysis:
Basel Binningen, Switzerland
Berlin-Dahlem, Germany
Berlin-Tempel, Germany
Bologna Borgo, Italy
Budapest, Hungary
Chalons, France
De Bilt, Netherlands
Edinburgh Royal Obs., UK
Gdansk-Wrzeszcz, Poland
Geneve-Cointr, Switzerland
Gordon Castle, UK
Greenwich Maritime Muk, UK
Hohenpeissenb, Germany
Innsbruck University, Austria
Karlsruhe, Germany
Kobenhavn, Denmark
Kremsmuenster, Austria
Leobschutz, Czech Republic
Madras Minamb, India
Manchester Ai, UK
Milano Linate, Italy
Montdidier, France
Munchen Riem, Germany
New Haven Tweed, United States
Nice, France
Palermo, Italy
Paris Le Bourget, France
Praha Ruzyne, Czech Republic
Regensburg, Germany
St.Peterburg, Russia
Stockholm, Sweden
Strasbourg, France
Stuttgart, Germany
Torino Casell, Italy
Torneo, Finland
Trondheim Tyholt, Norway
Udine Campoformido, Italy
Vilnius, Lithuania
Warszawa-Okec, Poland
Wien Hohe War, Austria
Woro, Finland
Wroclaw Ii, Poland
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Willis if all human co2 emissions stopped today when would we see an impact on temps and co2 levels?
Your NAS and the Royal Society joint report tells us that temps would take a thousand years to decrease and co2 levels wouldn’t drop much for thousands of years.
Nic Lewis thinks that temps wouldn’t take a thousand years to respond, but co2 levels would be much slower. Just asking?
We wouldn’t see any difference ever, temperature wise, because there is no forcing, theres nothing there excepting conjecture.
Sorry OT, but I just saw this and wanted to park it somewhere (’cause I’ll lose track of it).
Spot the landscape containing 2 #shale drilling pads, 16 wells & a #natgas pipeline…
https://twitter.com/DWBerkley/status/641443786695045120
Apparently you’re no sorry you posted it anyway.
Well I am sorry, but not terribly sorry. Well, not even that sorry, really. Just formally sorry in a sorry kind of way. Sorry if I’m being sorry for not being really and truly sorry. I’m just sorry, I guess.
I’m sorry. “Sorry if I’m being sorry” should be “Sorry if I’m not being sorry enough”
Willis, I’m agreed with your basic position that volcanoes are over rated. Feedbacks in climate, quite possibly the ones you suggest, react to ensure increase solar input which compensates for the lost energy. The degree-days of lost input get made up in the following 4-5 years.
Following Bob Tisdale’s recent article on NODC ‘averaged temperature’ of the ocean depths, I decided to look at top 100m vs 100-700m by subtracting the datasets provide. By inverting the 100m data we can see the heat flowing in and out of the thermocline and general see-sawing of the two reservoirs.
Here is a ‘spot the correction’ challenge , in the same spirit as your article.
I suspect someone has had their finger on the scales at one point , see if you can spot it.
There were quite a few VEI 4 or greater leading up to Tambora:
“Mystery eruption” somewhere in the South Pacific, 1808 or 1809 estimated at VEI-6
La Soufrière St. Vincent (in the Caribbean) 1812
Mount Awu Indonesia 1812
Suwanose-jima Japan volcano eruptions 1813-1814
Mayon Phililpines eruption Feb 1 1814
As tty pointed out the mystery eruption left a sulfate signature in glacier cores. It is similar to the signature of Tambora, with the same peak but narrower width. Tambora was a VEI-7. With all of that activity, I’m not sure you could single out one extra volcano.
the efolding time is on the order of 2 years
Eyeball observation.
After Tambora there is a slope down in temperature and it looks like the joint slowest drop.
That is: the rate of fall is slower than all other periods where the temperature falls (except possibly one other like it).
It may be that volcanoes cause a different cooling effect with a different signature. A lesser signature, sure, but still real.
There is an initial dip but within few years it recovers. This implies that volcanoes do not induce a permanent cooling effect, just a temporary one.
How can it be temporary? Well, the climate modellers would have AGW causing warming which counters the volcanic cooling and this kinda fits the late 20th c. , if you don’t look too closely.
The problem with that is Tambora does just the same thing and there was no significant AGW back then ! This would imply that there are climate feedbacks which compensate for changes in downward radiation and that the models attempting to balance AGW and volcanic forcing are doing the wrong thing.
This is why they are over sensitive post Y2K since they no longer have volcanoes to counter the exaggerated AGW.
Willis,
I am a big fan of your thunderstorm thermostat model!
You said: “Ben, I suspect that the main effect of volcanic eruptions is not a cold spike, but a lack of hot spikes …”
Is this what you meant Willis?
The large equatorial eruptions of the second half of the 20th Century were:
Mount Agung – March 17th (VEI 5) + second weak eruption May 16th, 1963.
El Chichon – March 28th (VEI 5) + 2nd weaker eruption March 30th and 3rd stronger eruption April 4th, 1982.
Mount Pinatubo – June 15th (VEI 6), 1991
Which just happened to closely followed by the onset of moderate to strong El Nino events:
1963/64 – moderate El Nino – starting around August 1963
1982/83 – very strong El Nino – starting in May 1982
1991/92 – strong El Nino – starting in Jun 1991
Normally, you would expect a noticeable increase in the world temperatures in the year following these El Nino events.
According to the Quinn El Nino index, there were:
a strong (index 4) El Nino event in 1814
and moderate+ (index 3) events in 1812 and 1817.
The expected post-warmings following the 1812 and 1817 El Nino events are evident in your temperature data, however, the post-warming expected after the 1814 El Nino event should have occurred in 1815. Maybe the volcanic cooling of the 1814 eruption was just counterbalanced by the El Nino post-warming just like the three large eruptions in the late 20th century.
[N.B.: The 1819 warming in your temperature record occurs just before a moderate (index 3) El Nino event in 1820, so it is not explained by this hypothesis].
Hi Ian, there is such a warming in the extra-tropical SH oceans:
Part of a full article on tropical feedbacks :
https://climategrog.wordpress.com/2015/01/17/on-determination-of-tropical-feedbacks/
It’s not an easy because of the natural noise in temperature series. It’s like in finance to try and find if a particular indicator can predict the future of stock prices. Lots and lots of if history is needed to find the relationship due to all the noise.
Of course there’s a lot of noise, but it’s hard to stop people shouting on the floor of a stock exchange.
It would be so much easier to just model this stuff.
modelling it is hard because the effect is also a function of the size of the aerosols
That’s not a problem, it means you have a few more unconstrained variable you can play with to ensure you get an exaggerated climate sensitivity from the model.
This is exactly the problem with the whole game. We do not have “basic physics” for some of the key phenomena that drive climate. Thanks for pointing that out.
Willis,
Sorry, but I misread Quinn El Nino index table at:
http://research.jisao.washington.edu/data_sets/quinn/
The Quinn index says that there was a moderate+ in 1819, not 1820, so the warming in your data set in 1819 could be associated with this event.
American farmers and fishermen noticed the effects of Pinatubo, which were indeed dramatic:
https://www.tandfonline.com/doi/abs/10.1577/1548-8675(2002)022%3C1014%3AWDMPHT%3E2.0.CO%3B2
The eruption of Mt. Pinatubo in the Philippine Islands during June 1991 was followed by a global temperature decline of 1°F through 1993. May to July temperatures in Minnesota during 1992 and 1993 were 3°F below the 1979–1998 average. The 1992 and 1993 year-classes of walleyes Stizostedion vitreum from Minnesota’s nine largest walleye lakes, which are gillnetted annually, were the two weakest since 1979. Mean June temperature explained more than 40% of the variation in year-class strength. Mean statewide walleye gill-net catch per unit effort (CPUE) from lake surveys increased at a rate of 1.3% annually after 1979 and was positively related to rising June temperatures, which explains 57% of the variation from lakes in glacial drift and 28% of the variation from Precambrian shield lakes. Walleye fry stocking was also positively related to increased walleye gill-net CPUE, but fingerling stocking was not. Chaotic events, such as large volcanic eruptions, may negatively affect walleye recruitment, and these effects may be evident to anglers several years later.
“The Year Without a Summer” isn’t a quaint anecdote. It’s a scientific fact, a global observation.
The effects of even the largest tropical eruptions however are fleeting.
My comment on the obvious effects of the Pinatubo eruption on North American agriculture and even fisheries is still missing. Maybe because it included a link.
I think the affect of volcanoes on temperatures and subsequent climate disturbances is a research field still in diapers. Data sets are still being adjusted as more eyes get on the ice cores.
http://www.antarctica.gov.au/magazine/2011-2015/issue-27-december-2014/science/new-ice-core-records-rewrite-volcanic-history
err, more data is availble than willis considers.
but yes, just start reading the literature and you will see that it is core complex than a simple look
at a few temperature stations and more complex than reaidng a few diaries.
There is a rcih pile of literature that no one here bothers to read before opining
Another recent article re ice core variability at the local single core level.
https://www.clim-past.net/12/103/2016/cp-12-103-2016.pdf
Thanks Willis.
Knowing this series of yours, I did not bite,
just kept reading. Ha.
~ ~ ~ ~ ~
The weather in the region was documented.
Here is a link to historical accounts:
New England Historical Society
This was a time of transport by cart, walking, or horse. Information about the regional problems did not easily get out, and doing much about it was not possible.
It became a serious issue, unlike it would if it happened in 2019. We could flood the area with food and clothing in 2 days via Amazon dot com, UPS, Fed X, and the USPS.
Similarly, read Timothy Egan’s “The Worst Hard Time” about the Dust Bowl years – before, during, after.
There were extreme hot summers, cold winters, and strong winds. The dust itself is easily explained, the weather not so much.
w. ==> Judith Curry included a paper on Tambora in her weekly review.
https://sci-hub.tw/10.1029/2018GL081018
Mr. Mosher, you disappoint me. The “study” you linked to is only an exercise in model fitting, AFAICT. I’m sure you realize, in fact you may have been one of the ones to point out, model output is not data. If I have mischarcterized the study, please define how, don’t give me one of your typical, “You got it all wrong…” type of comments.
First lets see what willis claims
‘It’s been a while since I played “Spot The Volcano”. The premise of the game is that the decrease in temperatures from volcanic eruptions is nowhere near as large as people claim. ”
Really? well HOW LARGE do they claim it is? since he gave no cite, you have to start looking for the folks he is trying to counter.
The paper is not MODEL FITTING. I suspect you dont know what model fitting is.
Here is what you should have learned.
1. It tells you what the important uncertainties are.
2. It indicates that the climate response may be driven more by the initial conditions
than the forcings
3. It tells you that summer response may be larger than winter response.
Model output is of course data, the key is knowing HOW to use it.
So, reading this paper, I would be inclined to check the observations in summer as a seperate analysis.
From the conclusions some more hints about what to look for
“Our results demonstrate that uncertainties in initial conditions can prevail or even dominate
the impact of (realistic) choices on the eruption’s magnitude on the surface temperature
response to such a large eruption. Especially for winter, the inter-ensemble overlap of posteruption temperature anomalies hinders conclusive assessments about the forcing magnitude
and response pathways compatible with a certain volcanic signature on certain regional
surface climates. Otherwise stated, different realistic combinations of volcanic forcing and
initial conditions lead to indistinguishable temperature responses. This implies that improved
constraints on the Tambora forcing would not allow for better understanding of the
temperature response to this eruption within current modelling frameworks, unless this is
accompanied by substantial progress in the constraint of initial conditions. Accounting for
volcanic forcing uncertainty seems nonetheless necessary, as the use of just a current best
estimate can bias the interpretation of reconstructed responses. This was exemplified for the
European “year without a summer” as the cluster yielding the best correspondence between
reconstructed and simulated features mainly contains realizations from an ensemble using the
low-end estimate of volcanic forcing. In this sense, the classical truth-centered approach for
ensemble analysis, where the ensemble mean and spread are regarded as forced response and
uncertainty due to internal climate variability, respectively, may bring to misleading
conclusions in reconstruction-simulations comparisons. On the other hand, certain continental
and subcontinental regions appear to be particularly sensitive to the magnitude of volcanic
forcing especially in boreal summer (e.g., North America in MPI-ESM-LR), which may
provide guidance on identifying locations where climate proxies are most sensitive to the
direct radiative impacts of volcanic eruptions.
The general validity of these conclusions stands beyond the single climate model used here,
as different models currently used in paleoclimate applications share similar ranges of
internal variability and climate sensitivity (e.g., PAGES2k-PMIP3 group, 2015).
Generalization of our conclusions must consider that the forcing uncertainty used here
accounts only for uncertainty in the volcanic stratospheric sulfur injection, not uncertainties
related to the translation of sulfur injection into aerosol and radiative properties as performed
here by the EVA module. Such uncertainties result from, e.g., the poorly constrained aerosol
size distribution for eruptions larger than those recently observed (Toohey et al., 2016), and
variations in the spatio-temporal evolution of the forcing due to differences in atmospheric
circulation and sulfur injection height. Furthermore, the estimate of uncertainty in volcanic
stratospheric sulfur injection for Tambora is smaller than most eruptions of the past 2500
years (Toohey and Sigl, 2017): Robust quantitative analysis for specific eruptions thus
requires an ad-hoc design”
Most importantly the paper gives you a START at seeing what the ACTUAL SCIENCE says about volcanic reponse.
Remember Willis’ first uncited claim
“It’s been a while since I played “Spot The Volcano”. The premise of the game is that the decrease in temperatures from volcanic eruptions is nowhere near as large as people claim. ”
WELL, how large do they claim it is? Willis never says. so you need to start
researching what the science says about this volcano. RIGHT?
or do you just wave your arms and say “The science says the effect is huge!!! but look here
I say its small!”
So a reading list..
Stoffel, M. et al. (2015), Estimates of volcanic induced cooling in the Northern Hemisphere
over the past 1,500 years. Nature Geoscience 8:784–8. doi:10.1038/ngeo2526
Swingedouw, D., Ortega, P., Mignot, J., Guilyardi, E., Masson-Delmotte, V., Butler, P.G., &
Khodri, M. (2015), Bidecadal North Atlantic ocean circulation variability controlled by
timing of volcanic eruptions. Nature Communications 6:6545. doi:10.1038/ncomms7545
Swingedouw, D., Mignot, J., Ortega, P., Khodri, M., Menegoz, M., Cassou, C., & Hanquiez,
V. (2017), Impact of explosive volcanic eruptions on the main climate variability modes.
Glob. Planet. Ch., 150: 24-45
Timmreck, C. (2012), Modeling the climatic effects of large volcanic eruptions. WIREs Clim
Change. 2012;3:545–64. doi:10.1002/wcc.192.
Toohey, M. & Sigl, M. (2017) Volcanic stratospheric sulfur injections and aerosol optical
depth from 500 BCE to 1900 CE, Earth Syst. Sci. Data, 9, 809-831,
https://doi.org/10.5194/essd-9-809-2017
Toohey, M., Stevens, B., Schmidt, H., & Timmreck, C. (2016) Easy Volcanic Aerosol (EVA
v1.0): an idealized forcing generator for climate simulations, Geosci. Model Dev., 9, 4049–
4070, https://doi.org/10.5194/gmd-9-4049-2016
Zanchettin, D., Bothe, O., Graf, H. F., Lorenz, S. J., Luterbacher, J., Timmreck, C., &
Jungclaus, J. H. (2013), Background conditions influence the decadal climate response to
strong volcanic eruptions. J. Geophys. Res. Atm. 118(10):4090–106. doi:10.1002/jgrd.50229
Zanchettin, D., Bothe, O., Lehner, F., Ortega, P., Raible, C. C., & Swingedouw, D. (2015),
Reconciling reconstructed and simulated features of the win
Thank you, Mr. Mosher, now I have an idea what you’re talking about.
I didn’t want to quote the whole thing you quoted even though it does give a detailed analysis, but I think that one sentence sums up what I’m getting out of this, i.e., the impact of a volcano may be less than natural variability and/or uncertainty. In other words, it ain’t no big deal. I like this paper, it does a better job than most of admitting what they could prove and what they still don’t know. Having said that, it still is, IMHO, way too much time spent straining at gnats. Models have been shown to be unfit for purpose of predicting long-term climate. Now the model these authors have spent so much time dissecting, bisecting and fine-tuning may be intended solely to model a volcano’s impact on the world weather (it’s not getting anywhere near 30 years, they freely acknowledge, so don’t call it climate) and in the end it appears they concede it can’t be done, the choice of initial conditions completely overwhelms the response from the volcano. So overall, this study supports Willis’ conclusion, a volcano doesn’t have a significant impact on GST.
What gets the most noise from people who publish headlines, and therefore I conjecture may be what Willis is responding to, is papers like this: http://advances.sciencemag.org/content/4/6/eaao5297 where the entire intent of the paper seems to be the-only-reason-we’re-not-warming-the-way-we-predicted-is-an-evil-conspiracy-by-the-sun-and-those-damn-volcanoes-so-you-can’t-relax-yet-CO₂ -will-get-you-in-the-end-anyway!!! (But reveals 3 significant climb-downs: 1st there has been nearly a decade of denying a “pause”, now it seems there is one; 2nd a decade ago greenhouse gas forcing was going to overwhelm natural variability in 10 years, but now this paper admits it hasn’t; and 3rd the BBC said the science was settled in 2005 and there was no sun link to climate change, now there is; these are all paraphrased from David Whitehouse.) So Willis seems to be right, the effect from a volcano is overwhelmed by natural cycles and uncertainty, so don’t blame every cooling, or even every failure to warm, on volcanoes.
I would be interested to see Figure 3 compared against PMO and/or AMO, and maybe for good measure graph the El Niño’s and La Niñas.
Which has led me to cogitate this: The “anomalies” are calculated solely from an average of a 30 year set of years. To truly plot “anomalies” one should know what the natural cycle of weather would have been, so rather than a flat-line average, there should be a sine wave (maybe rising or falling) or even double sine waves added together. Then subtract that from the current temperature to possibly hope to begin to see if we might be able to tell if something is changing, and whether or not it might be significant.
Looks like I forgot to say, “…and ENSO…” Some other commenters not only thought of that, they’re producing the graphs. I like it. Both DWR54 and ALLAN MACRAE (seem to) show that, with a 5-month offset, ENSO is good predictor of temperature except for a couple of years immediately after a significant volcanic eruption. Now we’re getting somewhere.
It seems to make sense that some type of natural variation would be in play at the time of eruption. If a minor warming was occurring the eruption may do nothing more than limit any increase (dampen) and may not be identifiable because one couldn’t know how much warmer it was going to be owing to other natural causes. If the natural variability was a temperature decrease an eruption would enhance a temperature decline, but one could never know how low the temperature would have gone anyway. The question then becomes one of does an eruption spew enough material into the atmosphere to over-ride other drivers of natural variation in temperature. I guess I’m the fourth frog on the log with this issue.
Maybe all this shows is how doctored the surface datasets are.
Willis,
Why are all your records (the 42) from the Northern Hemisphere? I know Tambora is on the Equator or thereabouts but there should be the same effect in Southern Hemisphere, shouldn’t there be (or similar lack of)
I have not read all the comments so maybe this is redundant.
Very interesting paper, and as you say, surprising.
Old Woman, the reason is that there are not many temperature records from the Southern Hemisphere in general, and none from that early a time.
w.
Calendar dates of several major volcanos are co-plotted on HadCRUT4 temperature graph starting 1850 in Figure 10 at http://globalclimatedrivers2.blogspot.com . Consistent with Willis’ assessments: “No consistent AGT [Average Global Temperature] response is observed to be associated with these.”
It would be interesting to see the weather effects of a Toba type eruption (75,000 years ago), thought to be 30 x the size of Tambora, but the effect on humans would be rather severe.
I assisted David Ludlum on the publishing of the Nantucket Weather Book. One of his series and meticulously researched.
“The Year Without a Summer” is well documented.
June, July and August all recorded below freezing temperatures on the Island with “ice in the water pails each month.”
Crop failures drove many islanders to the Midwest.
Much as warmer, drier conditions drove Indians from Arizona to Colorado 600 years ago.
(Moved from Nantucket to Arizona two years ago. My on island tomatoe plants did not do well that year 🙂
Do you have a reference to the July ice? Amazon has the book available for about $100, there are less expensive used books.
The diary of Mrs. Kezia Fanning:
June 15
Remarkable cold weather for the season. Ice was on water pail in the morn this week. Vegetation almost destroyed.
Thomas Rodman’s record at New Bedford gave an indication of departures from normal.
June -5.1, July -5.8, August minus 2.1, September-3.4
There are no temperature records
On Nantucket till 1886.
Hope this helps,
Bruce
The June freeze is well documented in New Hampshire, I can find but a single reference to frost in July, and that was in the White Mountains.
June in NH:
http://notrickszone.com/wp-content/uploads/2016/04/Volcanic-Dust-Injections-and-NH-Temperatures-1880-1970-Oliver-1976.jpg
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0450%281976%29015%3C0933%3AOTROHM%3E2.0.CO%3B2
“A period of several decades existed (~1915-1945) in which volcanic activity was unusually light and, as mentioned earlier, the temperatures were higher than the preceding [1880s to 1910s] or, in fact, the subsequent (current) [1950s-1970s] period. … Numerous possible causes of climate change have been discussed in the literature, including both anthropogenic and natural factors. Two principal anthropogenic sources are often considered: changes in atmospheric carbon dioxide and changes in tropospheric dust. … Mitchell (1975) concluded that neither tropospheric particulates [anthropogenic pollution] nor atmospheric CO2, in concert or separately, could have accounted for the major part of the observed temperature changes of the past century.”
—
http://www.nature.com/articles/srep24331
“There are 54 large explosive volcanoes during 501–2000 AD in total, and the strongest one is the Samalas volcano in 1257–1258, which is followed by three smaller eruptions in 1268, 1275 and 1284. These strong volcanoes do not allow the climate to recover, and might have triggered the Little Ice Age.”
https://www.nature.com/articles/srep24331/figures/2
—
https://hal-amu.archives-ouvertes.fr/hal-01457247/document
“Climate simulations using single and cumulative forcings suggest that the ocean surface cooling trend from 801 to 1800 CE is not primarily a response to orbital forcing but arises from a high frequency of explosive volcanism. Our results show that repeated clusters of volcanic eruptions can induce a net negative radiative forcing that results in a centennial and global scale cooling trend via a decline in mixed-layer oceanic heat content.”
99 records in GHCN v4
probably more in berkeley earth. I have to check
Here are the best sources if you have the time. The source files you used have not been updated since
we lost our access to the lawrence livermore supercomputer. I’ll see if I can get them updated
but its a huge task on a deskside system
look here:
1. Spatial http://berkeleyearth.lbl.gov/auto/Global/Gridded/Complete_TAVG_LatLong1.nc
2. Station data: QC applied http://berkeleyearth.lbl.gov/downloads/TAVG/LATEST%20-%20Quality%20Controlled.zip
3. Predicted station data
http://berkeleyearth.lbl.gov/downloads/TAVG/LATEST%20-%20Breakpoint%20Corrected.zip
predicted station data is this. during the estimating process every station/segement is assigned a quality
score. The quality score is a weight that is used to create the final field.
After completing the final feild, we can then subtract the station from the feild. This diference
is the “adjustment” the station would need to bring it into alignment with the field prediction.
Some people called this “adjusted data”, however for us adusted data is an OUTPUT of the process and not an input.
Steven Mosher January 26, 2019 at 6:00 pm
Thanks for the link to the data, Steve. I took a look. Of the 99, only 61 have over 120 valid observations during the period of my graphs … and the additional 19 stations make no difference to the results.
All the best,
w.
Willis:
The Tambora eruption occurred during the on-going 1814 “ENSO warm event”, which is why the climate record doesn’t show a deep drop in temperatures immediately associated with the eruption. You have to look at the ENSO temperatures at the time of an eruption. Had it occurred during a La Nina, its climatic effect would have been even more severe.
The same happened with the Pinatubo eruption, which also occurred during an El Nino. Smaller eruptions in non-El Nino years have exhibited more initial cooling than Pinatubo, though it eventually did end the El Nino, and temperatures dropped–but not as much as they would have done otherwise–it did not cause a La Nina, as is often seen after even smaller eruptions.
yup.
The bigger issue is the uncertainty ( monthly) during this time period
on the order of 2-3C which could swamp any signal
Steven Mosher January 26, 2019 at 7:00 pm
Mosh, when I plot up the 61 datasets covering the time, in actual degrees as anomalies, I get the following:
Not seeing the monthly uncertainty … what am I missing?
w.
what are you missing?
Brohan’s data.
https://sci-hub.tw/10.5194/cp-8-1551-2012
Thanks
I looked at Brohan’s data … still not seeing the “monthly uncertainty”. Also, his graph of “Northern Hemisphere temperatures from observations” in Figure 9 is totally unlike the GHCN data …
Fascinating stuff nonetheless, thanks for the link.
w.
Burl Henry January 26, 2019 at 6:11 pm
Thanks, Burl. I’ve never seen an ENSO record that went back to 1814 … link, please?
w.
Willis
You’ll find the data here:
http://research.jisao.washington.edu/data/quinn/quinn15251987.dat
Thanks, Burl and Bindidon. Can’t say I’m impressed with that Quinn El Nino Index. It overlaps with the NINO34 Index from 1870 to 1987. Here’s how they compare. I averaged the NINO34 index for all the years where the Quinn Index was 0, 1, 2, etc. Here’s the result:
As you can see, a Quinn Index of 5 is not statistically different from a Quinn Index of 0. Both of them translate into a negative NINO34 value. the Quinn Indexes of 1, 4, and 6 all translate into high NINO34 values. Go figure.
And given that the Quinn Index does that badly in modern times, the idea that it is accurate in 1815 is … well … let me just call it “very doubtful” and let it go at that.
Best to you both,
w.
Willis, I’m afraid you did not choose the best approach when yearly averaging a monthly time series like ENSO.
Simply because the El Nino signals are concentrated around a peak mostly located near year begin. Averaging the monthly values into years instead of doing that around the peaks often will dilute the El Nino information, especially where it is immediately followed by a strong La Nina.
Some similarities exist, but in many places it gets a bit silly.
I don’t want to search for the NINO3+4 stuff on the disk, but MEI for 1871-2017 I have a hand.
Here is the monthly data:
https://drive.google.com/file/d/1Fg9vsUoSkvyVcnG4t3GY4mxslS2LE2bi/view
and here is its yearly average:
https://drive.google.com/file/d/1ICmCex43tAr-AdtyYVTEDo_EJZbWJe6d/view
Nevertheless I suppose like you that Quinn’s accuracy is somewhat questionable.
Bindidon January 27, 2019 at 3:56 pm
Bindidon, the Quinn data is annual averages. If I use anything but annual averages to compare them to, I’d be comparing apples and oranges … no bueno.
Regards,
w.
Willis:
The book “El Nino in History” by Cesar N. Caviedes has a Table of El Ninos and La Ninas from 1800-1999, which includes an El Nino in 1814.
However, he does discuss the Quinn, et al chronologies, which span the years 1541-1983. and states that it is considered “the yardstick against which the effects of past El Ninos on the entire Pacific as well as on distant continents are gauged”. Quinn;s list integrated the findings of an Emil Taulis (1934) on El Nino conditions in Chile, and Caviedes had produced a separate list in 1991,(which I have not seen, as yet). I am sure that they had facts which identified an El Nino in 1814.
Burl Henry
With Google’s usual help I found a free copy of César N. Caviedes book on the Persian Met Agency server:
El Nino in History
Storming through the Ages
http://www.kermanshahmet.ir/myfiles/admins/xabar/file/cavi0813020999.pdf
This is imho one of the most competent books concerning ENSO events.
1814 is indeed referenced therein as El Nino year. But it certainly wasn’t a very strong one: all heavy El Ninos appeared als yearly duos.
Bindidon January 29, 2019 at 10:48 am
I looked at it. I also took the next step, which it appears you didn’t take. I listed off all of the years he says are El Nino and La Nina years, and compared the modern ones to his list … bad news. He doesn’t do much better than just picking at random.
Not impressed …
w.
Willis:
Links are:
sharpy.org/1739-1816.html
research.jisao.washington.edu/data_sets/quinn
So much for the sulphur injection into the upper atmosphere geoengineering idea, than.
https://iopscience.iop.org/article/10.1088/1748-9326/11/2/024001#erlaa0d97s2