On 28/11/2020 15:54, N_Cook wrote:

Global Sea Level rise from satellite altimetry from the latest
aviso.altimetry.fr data release, from datafile at

ftp://ftp.aviso.altimetry.fr/pub/oceano/AVISO/indicators/msl/MSL_Serie_MERGED_Global_AVISO_GIA_Adjust_Filter2m. txt

Processing below is for my preferred time-span of 2003.0 to latest
2020.702868 (13 September 2020 ), output to the public this morning
,28 November 2020.

Using 651 datapoint subset, avoiding early Jason and Mount Pinatubo
problems and being able to choose x=0 for year 2000 and y is cm of
global SLR in Aviso terms.

The following curve-fits ranked in terms of R^2 goodness of fit and
curve-forms with, second differentials; zero acceleration, increasing
acceleration, constant acceleration and the indicial form with
decreasing acceleration again as the best fit.

Linear
r*r = 0.97374
y= 0.376521*x + 1.34
SLR to 2100= 40.0cm

In Aviso terms, 3.77mm/year of GSLR . Bear in mind that gradient is
based on 2003 to 2020 data. If/when Aviso sorts out the javascript
problem on their site, myself and others have enquired but no change for
months, I'll redo with the full dataset 1993 to 2020 . But without their
linear "fit", little point in me doing so, the previous such comparisons
of the gradient have agreed.

The tide gauge at Battery Park in New York has recorded a linear rise in
sea level there since before the American civil war. How does this
differ from modern satellite observations, and how would any differences
be accounted for?

If the Battery Park historical observations do not need to be
readjusted, the data suggests a SLR there to 2100AD as being in the
region of 21cm, rather less than your various analyses suggest.

--
Spike