[LEAPSECS] long interval predicted

[John Sauter]

On Sat, 2020-08-08 at 15:28 +0000, Michael Deckers via LEAPSECS wrote:
>     On 2020-08-08 10:46, John Sauter via LEAPSECS wrote:
> 
> 
> > UT2 captures the seasonal change in the length of day, so it can be
> > ignored for long-term estimates.  The important number, therefore,
> > is
> > -0.00010, which I will call the UT1 slope.
> 
>      Perhaps "slope of UT2 - UTC (as predicted by the IERS)" would be
> a 
> better
>      name, as the formula of Bulletin A implies (by taking the
> derivative
>      after adding the implied units):
> 
>                  d(UT2)/d(UTC) = 1 - 0.10 ms/d.
> 
>      But anyway, UT2 still contains known short period (<= 35 d) 
> fluctuations,
>      and currently, the combined amplitude of these fluctuations
> exceeds
>      by far the indicated secular trend of UT2 during their periods.
> 
>      Another observation, namely the increase in the uncertainty of
> UT1 
> - TAI
>      as given in the long term EOP parameters (published by the IERS
> in
> [
> https://datacenter.iers.org/data/latestVersion/38_EOP_C01.1900-NOW_V2013_0138.txt
> ])
>      from 4 µs to 30 µs since J2020.40 = 2020-05-26.6 may be a
> related 
> effect.
> 
>      Michael Deckers.

Thank you for your feedback, Michael.  I have improved the chart based
on your suggestions and also worked on the format.  I attach the
result.
    John Sauter (John_Sauter at systemeyescomputerstore.com)

-- 
PGP fingerprint E24A D25B E5FE 4914 A603  49EC 7030 3EA1 9A0B 511E

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