Someone mentioned recently that North Sea temperatures in winter are
today about 2 degrees higher than they were some 60 years ago.

Currently, the North Sea is around 7 to 8 degrees. This would seem to
suggest that cold easterly weather cannot be anything like as severe as
it might have been in the middle of the last century.

Does anyone have data for North Sea temperatures in the mid 20th
century?

Jack

wrote in message
oups.com...
Someone mentioned recently that North Sea temperatures in winter are
today about 2 degrees higher than they were some 60 years ago.

Currently, the North Sea is around 7 to 8 degrees. This would seem to
suggest that cold easterly weather cannot be anything like as severe
as
it might have been in the middle of the last century.

Does anyone have data for North Sea temperatures in the mid 20th
century?

We discussed this a couple of years ago, when I scanned a page as under
..... this is for *February* (the coldest of the series): January shows 6
to 7 degC central & western North Sea, but well below 5 for coastal
waters near Denmark & NW Germany.

Not quite the mid-20th century, but a mean for the period 1854-1958,
taken from the "Weather in Home Waters" publication.

http://homepage.ntlworld.com/booty.w...t_historic.gif

If anyone is interested in other times of the year, let me know and I'll
try and find time to put up a composite through the year.

Martin.


--
FAQ & Glossary for uk.sci.weather at:-
http://homepage.ntlworld.com/booty.weather/uswfaqfr.htm
and
http://booty.org.uk/booty.weather/metindex.htm

Thanks Martin. The current end January temperatures are 1 to 2 degrees
warmer than that "February" graphic providing some correlation with
earlier thoughts.

Jack

wrote in message
oups.com...
Thanks Martin. The current end January temperatures are 1 to 2
degrees
warmer than that "February" graphic providing some correlation with
earlier thoughts.

.... I managed to locate my original post from a couple of years ago: I
think the data are still pertinent.


quote
Following some comments regarding the changes in sea surface
temperatures in recent years, I thought I would dig out the maps
published in the 'Weather in Home Waters' series and compare with
current values (actually 15th February ... roughly in the coldest point
of the annual cycle).

The averaging period used in that publication is based on period: 1854
to 1958 (punched card dataset: US Navy); There is always a problem doing
this exercise in that the data are not homogenous, and with SST
measurement in particular, arguments surround how accurate or otherwise
the data are; indeed the publication I took the long-period averages
from discuss the differences between the 'bucket' method (recommended)
and the 'intake' method.

These maps are apparently based primarily on *intake* temperatures,
which the author states had (at this time) been found to be on average
some 0.5degC *warmer* than 'real' surface SST values (intake water is
taken some way below the waterline, but is subject to warming on being
drawn through & past the ship's internal pipework, into the engine-room
area). Taking the worst case scenario then, the 'historic' map might be
regarded as a little too warm, and the differences found below perhaps
greater. That of course assumes that current values are accurate!

However, remembering these problems, the figures appear to confirm the
warming - quite significantly so in some cases.

Using some 'fixed' points: (change, degC)
60N10W: +1.5
60N00W: +1.5
50N10W: +1.0
50N00W: +2.0

Generally, across the 'Shipping Forecast' domain, +1 to +1.5degC, but
some places around +2degC, for example, large areas in the North Sea
(where data coverage should be pretty good both 'then' and 'now') &
fairly generally offshore Norwegian coastal waters. This year (Feb.2004)
in particular, the waters of the Skagerrak appear to be particularly
warm (5 or 6degC from 5-day mean, as opposed to 1 to 3 degC from
averages). Anomalies not quite so high Irish and Celtic Seas (circa +1)
or the western English Channel.

Strong patterns are there - albeit with higher values, so no sign of the
North Atlantic Drift disappearing just yet! Even the little bulge of
warmer water running southward across west Forties from the Northern
Isles is still very pronounced; also the broad 'front' of warm water
from 60N25W to north Hebrides.

The maps can be found on my web site at:-

http://homepage.ntlworld.com/booty.w...st_current.gif
(ex. Met Office for 15th Feb, 5-day mean)
http://homepage.ntlworld.com/booty.w...t_historic.gif
(ex. Weather in Home Waters, Meteorological Office, 1975)

/quote


--
FAQ & Glossary for uk.sci.weather at:-
http://homepage.ntlworld.com/booty.weather/uswfaqfr.htm
and
http://booty.org.uk/booty.weather/metindex.htm

While the extra warmth of the North Sea might mean that rain rather
than snow would be the more frequent scenario today, given a REALLY
cold blast, those higher SSTs would result in deeper and more
impressive convection than in the past - and heavier snow
perhaps.......

Or am I talking rubbish?

Jack

In article . com,
writes:
While the extra warmth of the North Sea might mean that rain rather
than snow would be the more frequent scenario today, given a REALLY
cold blast, those higher SSTs would result in deeper and more
impressive convection than in the past - and heavier snow
perhaps.......

Or am I talking rubbish?

Sounds plausible.

Another factor is that, unlike the Atlantic, the North Sea can cool down
fairly quickly during a cold spell, I believe. So it might only need a
week or so of a cold Easterly to knock a degree off the SST.
--
John Hall "Never play cards with a man called Doc.
Never eat at a place called Mom's.
Never sleep with a woman whose troubles
are worse than your own." Nelson Algren

In message , Martin Rowley
writes
... I managed to locate my original post from a couple of years ago: I
think the data are still pertinent.


quote
Following some comments regarding the changes in sea surface
temperatures in recent years, I thought I would dig out the maps
published in the 'Weather in Home Waters' series and compare with
current values (actually 15th February ... roughly in the coldest point
of the annual cycle).

The averaging period used in that publication is based on period: 1854
to 1958 (punched card dataset: US Navy); There is always a problem doing
this exercise in that the data are not homogenous, and with SST
measurement in particular, arguments surround how accurate or otherwise
the data are; indeed the publication I took the long-period averages
from discuss the differences between the 'bucket' method (recommended)
and the 'intake' method.

These maps are apparently based primarily on *intake* temperatures,
which the author states had (at this time) been found to be on average
some 0.5degC *warmer* than 'real' surface SST values (intake water is
taken some way below the waterline, but is subject to warming on being
drawn through & past the ship's internal pipework, into the engine-room
area). Taking the worst case scenario then, the 'historic' map might be
regarded as a little too warm, and the differences found below perhaps
greater. That of course assumes that current values are accurate!

On the Weather Ships there were 3 ways of measuring sea temperatu

1. The canvas bucket method.
2. A tap on a pipe in the engine room. You turned on the tap and held
a thermometer bulb in the flow.
3. A thermistor somewhere in the intake pipework connected to a
readout in the Met Office at the stern of the ship.

They all gave different readings, with the bucket usually being the
lowest. There was a theory that the water in the bucket was cooled by
evaporation before the reading settled. I was never convinced by that.

The "rule" was that the bucket method should be used whenever possible
but stormy weather often precluded that. Also, some observers were less
keen than others about using the bucket method every hour on a filthy
wet night in December :-). What often happened, but not always, was that
the bucket method was used at a main synoptic hour and a thermistor
reading was taken at the same time. Thermistor readings, adjusted by the
difference found at the main synoptic hour, were then used at the
intervening hours until the bucket method was used again at the next
main synoptic hour. In stormy weather, when it was not feasible to use
the bucket method, the thermistor readings were used unadjusted.

The manual readings using the tap in the engine room were logged once
daily but were not normally used in the SYNOPs.

Sea temperatures in the weather ship archive are therefore a random mix
of bucket and intake figures.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England

Felly sgrifennodd
Norman Lynagh :
On the Weather Ships there were 3 ways of measuring sea temperatu

1. The canvas bucket method.
2. A tap on a pipe in the engine room. You turned on the tap and held
a thermometer bulb in the flow.
3. A thermistor somewhere in the intake pipework connected to a
readout in the Met Office at the stern of the ship.

They all gave different readings, with the bucket usually being the
lowest. There was a theory that the water in the bucket was cooled by
evaporation before the reading settled. I was never convinced by that.

Might the reason be that the bucket was filled by dangling it over the side
into the very top of the surface of the sea, whereas the others came from
pipework a little further below the surface?

Adrian
--
Adrian Shaw ais@
Adran Cyfrifiadureg, Prifysgol Cymru, aber.
Aberystwyth, Ceredigion, Cymru ac.
http://users.aber.ac.uk/ais uk

In message , Adrian D. Shaw
writes
Felly sgrifennodd
Norman Lynagh :
On the Weather Ships there were 3 ways of measuring sea temperatu

1. The canvas bucket method.
2. A tap on a pipe in the engine room. You turned on the tap and held
a thermometer bulb in the flow.
3. A thermistor somewhere in the intake pipework connected to a
readout in the Met Office at the stern of the ship.

They all gave different readings, with the bucket usually being the
lowest. There was a theory that the water in the bucket was cooled by
evaporation before the reading settled. I was never convinced by that.

Might the reason be that the bucket was filled by dangling it over the side
into the very top of the surface of the sea, whereas the others came from
pipework a little further below the surface?

Adrian

That could obviously explain why the readings were different but not why
the bucket was almost always cooler. As Martin said earlier in the
thread the intake water was probably warmed slightly before its
temperature was read.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England