KICKING THE BUCKET

Cut and paste data splicing is a scientific norm in palaeoclimatology, where temperatures antedating the development of the thermometer  must be inferred from proxies as various as tree rings ,coral. and wine vintages. The lack of an ancient instrumental temperature  record has led to much recrimination,  like the Hockey Stick fracas, but  it is often assumed that the modern record stands in contrast as a sterling example of the hard data  science prefers as the basis for theory.

Not quite. One of the most conspicuous glitches in the slow-changing record of global climate is the .3 degree downturn in the record of global warming that the literature records for 1945. It has been unconvincingly attributed to everything from the Hiroshima bomb to postwar chaos in Pacific weather reporting, homeward bound fleets having somehow missed an El Nino event en route.

A new paper by David Thompson and othe NOAA atmospheric scientists in  Nature reports a different explanation .Most of the wartime measurements of sea temperatures factored int the global average  came from US warships, which unlike the British navy tended to log engine room  water intake thermometer readings  as representing the temperature of the sea. 

The hardy jack tars who returned to meteorological duty as the war wound down instead relied as always on the time honored method of throwing a bucket over the side ,hauling it in , and putting it on deck for  a  thermometer wielding chief or officer to measure . The  late Victorian change from  oaken buckets to galvanized steel   was  compounded before World War II,  when not just British, but Dutch and Japanese hydrographers were issued porous and hence cooling-prone canvas seawater scoops , a Bad Idea since the wind is generally brisk on a moving vesse.  Inevitably,  the seawater sampled tended to cool - evidently measurably, in the time it took to present it on deck  for measurement.

Between this newly detected  bias and  the already known disparity between  modern ships ' intakes ( warm)  and ocean measurement buoys (cold)  expect a lot of  dithering as the record is massaged in the year to come.As  to the Royal Navy,  it ultimately solved the problem- behold the wondrous evolution of  the New Model Navy Insulated Thermometer Bucket --

Comments

[Neil Frandsen]

Folks:

I am a retired Seismic Surveyor, with experience in Western Canada, the Arctic, and the High Arctic, plus once in the Republic of Niger, and once in Tanzania.
I took air temperature every time I did a Sunshot, or a Starshot.
Now, the theory, about metal, or canvas buckets, causing differences in the water-temperature, is not quite what my own farm-boy experiences were, with water in metal buckets. And I do remember how long it took the olden days big canvas water-bottles, that cooled their contents by means of evaporation of the small part that oozed thru the canvass.
The theory smacks of summat that Snopes is going to shoot down.
By the by, _I_ have taken a sponge bath in -40° temperatures, standing on a scrap of cardboard, on the lee side of the Snow-Melter. Some of the Urb-raised ideas about outdoor temperatures, and how they affect people and things, are wrong....

[Brian H]

It would seem to be an obvious thing to do to take measurements at a few locations, in different temperature and wind conditions, with simultaneous scoops using oaken, steel, canvas, and insulated buckets, plus at the intake ports, and tabulate the differences. That would provide meaningful fudge factors to apply retroactively.