On 8 Jul 2015 11:26:23 GMT
"Norman" wrote:

Eskimo Will wrote:


"Norman" wrote in message
...
Metman2012 wrote:

snip

No doubt there have been changes which may have been
significant, but then don't the climatologists make allowances
for this. I know that even such mundane things as SST
measurement had to be adjusted by the method and material of
actually measuring the sea temp - the buckets used to get the
water had different characteristics and work was done to
homogenize the results.

Just my 2 pennyworth


As you imply, the sea surface temperature measurement can vary
significantly dependent on what method is used for the
measurement. Unfortunately, the method used is not usually
recorded. For example, on the Ocean Weather Ships (at least on
the British ones) any one of the following could be used:

- canvas bucket (usually used only in relatively benign
weather)
- rubber bucket (usually used only when under way)
- thermistor loctated somewhere in the engine-room sea
water intake - direct measurement of the engine-room sea
water intake (turn on a tap and stick a thermometer
into the water)

The first 2 methods sampled the water at, or very close to the
surface. The other 2 sampled the water a few metres below the
surface. It was up to the individual observer to decide which
method was used at each observation. I don't know if any
comparative tests were ever made. I can't recall any during my
time on the Weather Ships.


So the years of research put into homogenizing the SST dataset was
a waste of time as vital information would be missing?

Will

I don't know how the homogenisation could be done if the method used
for each SST temperature measurement was not known.


I'm trying to recall whether the method for each measurement was
recorded in the ships' log books. I'm failing miserably but then it was
nearly fifty years ago that I last saw one. If the data was in the
books, I don't know that it would have been included in the machinable
data.

I do recall that the use of engine-room intakes instead of buckets
tended to be -
(a) when the seas were too high or -
(b) when the observer couldn't be arsed to chuck a bucket over the side.

In case (a) any error would be small but (b) might occur in calm
conditions with a large temperature gradient near the surface.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
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