Researchers match modern ocean temperature records to those of the 1870s

Using the Argo array of automated buoys, oceanographers were able to calculate the warming that has occurred since the HMS <i>Challenger</i> circled the globe taking similar measurements in 1872.

<a href='http://meincmagazine.com/science/news/2012/04/modern-ocean-temperatures-compared-to-challenger-expedition-data.ars'>Read the whole story</a>

 

[dsmooth]

This is a joke... ...right?

 

[helel ben shachar]

Oh, this will be lively. [grabs the proverbial popcorn] I'll share.

 

[deet]

The researchers note that the sub-surface measurements are useful in calculating the past contribution of thermal expansion to sea level rise.

Like how? This sounds interesting but I'm not sure I'm making sense of it.

 

[linnen]

For those interested in the ARGO system;

 

[ScottJohnson]

The researchers note that the sub-surface measurements are useful in calculating the past contribution of thermal expansion to sea level rise.

Like how? This sounds interesting but I'm not sure I'm making sense of it.

In terms of putting together timelines of sea level rise and parsing the various contributors- what were the initial conditions, when did they change and by how much...

 

[jandrese]

Oh nice, I can't wait to see another 15 page thread of trolls trolling other trolls.

I really like the elegant simplicity of the ARGO system though. That has to be a real wealth of data with the number of probes they have deployed.

 

[jvillain]

This is just sad. First the accuracy of thermometers has changed drastically between the two time periods. Second the way the temperatures were taken has changed drastically and if you look at long term data for when they changed from using pails lowered in the water to tubes on the hull for measurements in ships you will see a large sudden change in temperature measurements. Beyond that one ship is indicative of exactly nothing.

B8ut lets not let science get in the way of a really good scare story. Republicans have terrorists to scare the public and Democrats have global warming/change/disaster.

 

[Wheels Of Confusion]

For those interested in the ARGO system;
image

And they're currently distributed like so.
The Argo data is also freely available on the web in almost real-time, but it takes some knowledge to make it useful.

 

[beeba]

" its crew of over 200 (at the start, that is)"

how many survived? that's the most thrilling part...

 

[Sailirish_7]

I'm no climate denier, but all this does is prove what we already know. Sealevel is rising, and the oceans are warming. What we need is indisputable proof of *WHY*...

 

[issor]

B8ut lets not let science get in the way of a really good scare story. Republicans have terrorists to scare the public and Democrats have global warming/change/disaster.

I don't think anyone intelligent believes that the globe isn't warming. The scientific community as a whole has moved beyond that, and anyone in the public with average intelligence or above should be beyond that as well. The debate has more to do with why, as there is a solid history of warming and cooling without human intervention, and also science showing that man's activities can contribute significantly to these swings.

 

[ScottJohnson]

" its crew of over 200 (at the start, that is)"

how many survived? that's the most thrilling part...

Only a few died, but about a quarter of the crew bailed before the end.

 

[AndrewZ]

This is just sad. First the accuracy of thermometers has changed drastically between the two time periods. .

Actually, thermometers in 1870 were pretty accurate, what has changed is precision. But precision isn't the issue here.

 

[AndrewZ]

" its crew of over 200 (at the start, that is)"

how many survived? that's the most thrilling part...

Only a few died, but about a quarter of the crew bailed before the end.

I'm sure they were 'bailing' well before the end...

 

[Sailirish_7]

This is just sad. First the accuracy of thermometers has changed drastically between the two time periods. .

Actually, thermometers in 1870 were pretty accurate, what has changed is precision. But precision isn't the issue here.

Yeah I am willing to bet that their data was analyzed statistically to account for the change/lack of precision equipment in that era.

 

[Bad Monkey!]

This is just sad. First the accuracy of thermometers has changed drastically between the two time periods. .

Actually, thermometers in 1870 were pretty accurate, what has changed is precision. But precision isn't the issue here.

Yes, thermometers at the time *could be* pretty accurate, but were these particular thermometers on the Challenger accurate? More importantly, was the method in which they were employed (was there frequent calibration, was the thermometer stored in ambient conditions on deck while in use, was the thermometer read properly in all conditions) and the way samples were taken (a bucket thrown from the ship and recovered on a line for surface samples, a weighted pipe with spring-loaded openings for samples from depth), all along with the fact that we're talking about less than 300 samples spread out over a vast distance and a long period of time, is all that truly conducive to producing data that can honestly be compared to modern data?

 

[potato44819]

This is a good article.

Points in its favor:

1. Proper conversions
2. Definitions
3. No political bullshit

 

[fferitt25]

The researchers note that the sub-surface measurements are useful in calculating the past contribution of thermal expansion to sea level rise.

Like how? This sounds interesting but I'm not sure I'm making sense of it.

In terms of putting together timelines of sea level rise and parsing the various contributors- what were the initial conditions, when did they change and by how much...

Still do not see how the 1870 expedition gives an accurate baseline reading. Since - even as you state near the ned of the article that their methods for measuring would have been flawed. Additionally their sense of geographic orientation would not necessarily be correct either. General area - but by no means accurate.

The analogy can be applied to modern maps vs maps from 100+ years ago. Accuracy differences. Granted they had a basic shape of landmarks on a global scale - but the distortions are obvious when you compare the maps of both eras.

So how would their concept of accurate temperature measurements be any more precise in order to give a true baseline ?

 

[melquiades]

This is a good article.

Points in its favor:

1. Proper conversions
2. Definitions
3. No political bullshit

True that. And clarity about the purpose of the experiment.

Some commenters seem to have missed that purspose, saying, "Why do we care? We already know the Earth is warming." The point is that having multiple measurements of _where_ and _how much_ is critically important to developing models. And this study was about where and how much — not about why or what to do about it.

Much sadder are the commenters obviously hostile to the whole notion of climate change, who nit-pick details of the methodology but obviously have not actually read the paper, where said nit-picks might be addressed.

 

[ScottJohnson]

The researchers note that the sub-surface measurements are useful in calculating the past contribution of thermal expansion to sea level rise.

Like how? This sounds interesting but I'm not sure I'm making sense of it.

In terms of putting together timelines of sea level rise and parsing the various contributors- what were the initial conditions, when did they change and by how much...

Still do not see how the 1870 expedition gives an accurate baseline reading. Since - even as you state near the ned of the article that their methods for measuring would have been flawed. Additionally their sense of geographic orientation would not necessarily be correct either. General area - but by no means accurate.

The analogy can be applied to modern maps vs maps from 100+ years ago. Accuracy differences. Granted they had a basic shape of landmarks on a global scale - but the distortions are obvious when you compare the maps of both eras.

So how would their concept of accurate temperature measurements be any more precise in order to give a true baseline ?

It's not "more precise". It's not a gold standard survey of the planet. It's just additional data that's unique for the time period.

 

[daedalus169]

" This is just sad. First the accuracy of thermometers has changed drastically between the two time periods. Second the way the temperatures were taken has changed drastically and if you look at long term data for when they changed from using pails lowered in the water to tubes on the hull for measurements in ships you will see a large sudden change in temperature measurements. Beyond that one ship is indicative of exactly nothing.

Late-19th century thermometers were pretty accurate, though one of the scientific goals of the Challenger expedition was to test how deep sea conditions could affect readings. There were various methods of either locking a specialized deep sea thermometer by inverting it when hauling it back up to the deck, or by securing an insulated sample of seawater and bringing the "ordinary thermometer" up for a reading inside the sample. The Challenger's naturalists were all obsessive about accuracy, typical of Victorian biologists, and this Nature paper's authors are pretty confident in the consistency of the Challenger's readings at least. You can read the original 1885 discussion of methods here: http://19thcenturyscience.org/HMSC/HMSC ... oc083.html

Also, it's worth remembering that the whole point of the Challenger expedition was to see what deep sea organisms were like as a way of testing Darwin's relatively new theory, and to check to see if any were munching on the trans-oceanic telegraph cables being laid out at the time. The final expedition report was a really amazing, 12-year long publishing effort, with 3 summary volumes, 2 volumes on botany, 1 volume each on physics and ocean chemistry, 1 volume on geological findings, and *32* volumes describing the zoology.

" its crew of over 200 (at the start, that is)"

how many survived? that's the most thrilling part...

Almost all of the crew survived, and of the scientific staff only one died. Sea travel was pretty safe by 1873. There were more losses from desertion at port by underpaid crewmen, and several of the officers were promoted to other posts.

 

[AnObfuscator]

Much sadder are the commenters obviously hostile to the whole notion of climate change, who nit-pick details of the methodology but obviously have not actually read the paper, where said nit-picks might be addressed.

I'd love to read it, and I'm no denier, but I don't really have the time... and I am curious how they accounted for the margin of error in the Challenger instrumentation. Can you give a summary of how they addressed that?

 

[SydBarrett]

A couple of things. The most interesting piece of info that's not very clear in the article is that we have about 100 years of good oceanic temperature data to compare this new (old) data with. So the comparisons are between 1871-4 and 1910. It's that range that shows warming as well that from what I read looks to be linear.There's lots of articles in Canadian news about this because the person who put the voyage together was born in Canada.

 

[SydBarrett]

double post

 

[siliconaddict]

Yes, thermometers at the time *could be* pretty accurate, but were these particular thermometers on the Challenger accurate? More importantly, was the method in which they were employed (was there frequent calibration, was the thermometer stored in ambient conditions on deck while in use, was the thermometer read properly in all conditions) and the way samples were taken (a bucket thrown from the ship and recovered on a line for surface samples, a weighted pipe with spring-loaded openings for samples from depth), all along with the fact that we're talking about less than 300 samples spread out over a vast distance and a long period of time, is all that truly conducive to producing data that can honestly be compared to modern data?

Oh good lord. If they are willing to finance a three year journey around the globe, which at that time wasn't exactly crossing the street for a gallon of milk easy, I'm pretty sure they had the best equipment that a country can afford on board. This data is useful as another data point, that is all. You don't make a conclusion based on this, but when you start to assemble a picture from multiple sources things start to get a little clearer from the standpoint of temperatures. Cause is another matter altogether.

 

[crhilton]

I'm no climate denier, but all this does is prove what we already know. Sealevel is rising, and the oceans are warming. What we need is indisputable proof of *WHY*...

There's no such thing as indisputable .

 

[Wheels Of Confusion]

There's no such thing as indisputable .

Yes there is!

 

[ManWithHat]

There's no such thing as indisputable .

Yes there is!

Inconceivable!

 

[iregisteredjusttosaythis]

There's no such thing as indisputable .

Yes there is!

I dispute that.

 

[NicoleC]

This is a good article.

Points in its favor:

1. Proper conversions
2. Definitions
3. No political bullshit

Ditto. This is about the 8th article I've read on this and the only one that strikes the proper balance between how important the Challenger data set is (very) but also what the data is NOT.

Headlines elsewhere are making idiotic and completely inaccurate statements like, "data proves ocean has been warming for 135 years!"

 

[Sailirish_7]

There's no such thing as indisputable .

Yes there is!

Inconceivable!

I do not think that means what you think it means....

 

[Kestrel]

There's no such thing as indisputable .

Yes there is!

Inconceivable!

I do not think that means what you think it means....

...prepare to die.

 

[A314InTheSky]

There's no such thing as indisputable .

Yes there is!

Inconceivable!

I do not think that means what you think it means....

...prepare to die.

Infallible

 

[gmerrick]

<quote>These numbers may underestimate the warming for a number of reasons relating to the Challenger measurements. For example, the crew worked under the assumption that the line holding the thermometer extended downward perfectly perpendicular to the surface. In reality (as they knew), it was likely to trail behind the motion of the ship, which couldn’t be kept completely stationary. That means the thermometer would measure at a depth a bit shallower than intended, yielding a warmer temperature. </quote>

So the question is did the modern researchers take measurements the same way, or did they use sippican XBT to take the the measurements? I presume that they did the latter. The followup question is which is more precise and repeatable?

 

[pipe13]

Precision in Measurement -- the title of first our Chemistry 201 laboratory session back in the day, though the Physics department had something similar -- has been with us for quite a while. What the (allegedly) modern era brings us is the internet, wherein can type "thermometer calibration" into Wikipedia's search bar and learn more than one could possibly wish about the Ancient's' (nee Fahrenheit and Celsius) care with calibration. Also the invention of the registering thermometer by James Six in 1782. From
http://en.wikipedia.org/wiki/Thermometer

For many purposes reproducibility is important. That is, does the same thermometer give the same reading for the same temperature (or do replacement or multiple thermometers give the same reading)? Reproducible temperature measurement means that comparisons are valid in scientific experiments and industrial processes are consistent. Thus if the same type of thermometer is calibrated in the same way its readings will be valid even if it is slightly inaccurate compared to the absolute scale...

According to British Standards, correctly calibrated, used and maintained liquid-in-glass thermometers can achieve a measurement uncertainty of ±0.01 °C in the range 0 to 100 °C, and a larger uncertainty outside this range: ±0.05 °C up to 200 or down to −40 °C, ±0.2 °C up to 450 or down to −80 °C.[34]

For those who have questioned the accuracy of 19th century navigation and cartography, I cordially suggest both Daniel Boorstin's "The Discoverers", and (for more immediate gratification)
http://en.wikipedia.org/wiki/Ship's_chronometer_from_HMS_Beagle

Enjoy!

 

[Kalessin]

So the question is did the modern researchers take measurements the same way, or did they use sippican XBT to take the the measurements? I presume that they did the latter.

They use Argo, not XBTs. Argo floats have pressure sensors.

 

[potato44819]

If only someone who won the lotto had a leaning to reproduce the challenger journey...

 

[RichardJames13]

The Argo system is amazing, especially the coverage over the globe.

 

[Zarko]

Yeah I am willing to bet that their data was analyzed statistically to account for the change/lack of precision equipment in that era.

Unlike on CSI, you can't just 'zoom in' on information that wasn't there in the first place. While the comparisons between the modern temperature readings and the historical record from the 1870s is an interesting bit of trivia, it's scientific validity is essentially nil at the level of precision of the Argo measurements.