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Old February 5th 18, 03:44 PM posted to uk.sci.astronomy
N_Cook
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Posts: 86
Default Of moon and tides

On 05/02/2018 09:01, Martin Brown wrote:
On 04/02/2018 09:50, N_Cook wrote:
On 01/02/2018 08:45, N_Cook wrote:
On 31/01/2018 20:29, Martin Brown wrote:
On 31/01/2018 18:03, N_Cook wrote:
On 31/01/2018 16:17, Martin Brown wrote:

I = Inex ~29y and S = Saros ~18y

They are the fundamental periodicities that allow you to catalogue
eclipse cycles. It will be interesting to see if the strong tides
this
year drive any climatic effects from deep ocean mixing.

http://www.staff.science.uu.nl/~gent...ipsecycles.htm

Inex gives you an eclipse about the same longitude but opposite
latitude
and 3x Saros gives you about the same eclipse conditions in about the
same place on the Earth. Or for an overviews and better explanation

https://eclipse.gsfc.nasa.gov/SEsaro...riodicity.html

Ta for that, I'll let the local NOC academic oceanographers know, to
avoid too much head-scratching.
Next stop Milankovitch cycles

Checking there was also a nice juicy total lunar eclipse in 1942 Mar 3
which is midway between the one you quoted and now (ie every 2I+S).

https://en.wikipedia.org/wiki/March_1942_lunar_eclipse

Any interesting tides observed back then?


[snip]

From one of the NOC experts on deep-sea oceanography
"I would be very surprised if the tides have any significant effect on
deep ocean mixing."
"tides" in this context referring the recent anomolous tides as
exemplified at Dover last week


I know it is out of fashion at the moment but I think the Keeling tides
paper PNAS 1997 August, 94 (16) 8321-8328 was actually onto something
(although some of the analysis is flawed and the MEM spectrum (fig 4) is
over fitted causing peak splitting of the 18y Saros peak to 15y & 21y.

They see a strong peak at 58y (2x Inex but fail to comment on it).

http://www.pnas.org/content/94/16/8321

My contention is that there is evidence in their analysis despite them
having removed a fair amount of the longer periodicities for tidal
forcing at 2xInex = 58 years. HADCRUT also shows periodic positive
excursions around 2000, 1940 and 1880 separated by about the Inex
period. You would also expect something at ~54 years which is a period
for about the same eclipse at about the same longitude and especially
when the eclipse is at or near perigee.

My email address is valid so if you would be kind enough to your NOC
expert to get in touch I would be interested to discuss with them why
they would dismiss the possibility of tidal forcing out of hand.


I'll tell him of your recent post and "newspam"@... em address, remove
both " ?

My interest is a bit more parochial.
I wonder if the "sotonisation" of the pompey tides
https://www.admiralty.co.uk/Admiralt...20stan ds.pdf
and multiple high-waters for Soton also since the end of 2015,
(correspondence with Southampton Hydrographic office confirming this
phenomenom but no insight as to cause, from them)
change in Lymington tide times, growth of a spit at Pagham Harbour are
all connected.
Perhaps connected to whatever tidal harmonic constituents are close to
syncing together for 2 or more years , along with the super-blue-blood
moon, and all these local effects might drop out again after 2 more years.

Myself and 3 proper NOC oceanographers are intrigued about this local
effect, so far tentatively "blamed" on dredging for aggregates in the
English channel, but an astronomic cause is much more interesting.