On 26 June, 19:40, Robin Nicholson
wrote:
On Fri, 26 Jun 2009 17:25:37 +0100, "Nick Gardner"

wrote:

*Current SST is 17.3°C.

I have always wondered where that is measured - a standard distance
from the shore? Who does the measuring?

R

There are no real standards.

There are are number of sights where you can get SST data. Many marine
buoys e.g. Sevenstones off Land's End
www.ndbc.noaa.gov/station_page.php?station=62107 and sites like
http://www.channelcoast.org/data_man...e_data/charts/
Just click on Penzance & you get http://www.channelcoast.org/data_man...arts/?chart=75

It's best to be a bit cautious with the results. E.g temperatures at
the Penzance buoy can drop 2-3C in a few hours when an onshore wind
switches to offshore. In quiet calm conditions readings can become
very high. I've seen 21C in mid summer out at Severnstones after 3
calm days, 2 days of rough weather and it's 17C. In fact, the common
belief that SSTs change slowly is far from the case. The top few feet
can flutuate quite dramatically, especially close to the shore. So in
Penzance, swimming off the Battery Rocks may be a very pleasant
pleasant experience with an air temperature of 18C in an onshore
breeze, when the SST may well also be 18C. The next day the wind's
switched offshore with an air temperature of 22C, but the upwelling of
cold water may be no more than 15C.

The MetO charts seem to give a reasonable account of SSTs, though the
drawing of the isotherms can leave a bit to be desired. A similar
pattern emerges virtually every summer, with warmest water around the
the Thames estuary east channel, and around Cornwall SW Devon
(currently 16C, 17C close in), with a cool patch just west of the Isle
of Wight (currently 14-15C). I suspect it's due to some tidal mixing
in mid channel.

Graham
Penzance