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Old March 15th 20, 05:15 PM posted to uk.sci.weather
N_Cook N_Cook is offline
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Default [CC] Sea level to rise 70 cm by 2100

On 15/03/2020 16:06, Alastair B. McDonald wrote:
The BBC have reported that "Greenland and Antarctica ice loss [is] accelerating" https://www.bbc.co.uk/news/science-environment-51846468

"In the [IPCC]panel's 2014 assessment, its mid-range simulations (RCP4.5) suggested global sea-levels might rise by 53cm by 2100. But the Ambien team's studies show that ice losses from Antarctica and Greenland are actually heading to much more pessimistic outcomes, and will likely add another 17cm to those end-of-century forecasts." I wonder if that includes any increase in acceleration.


It may even have been picked up by the radar altimeters floating around
aloft.
http://www.aviso.altimetry.fr/en/data/products/ocean-indicators-products/mean-sea-level/products-images.html
With ENSO neutral for about 2 years, there's been little perterbation to
the plot , so the recent gradient rise in the Jason3 curve, may well be
reflecting that.
More info on curve-fitting/future projection to their data on my page
http://diverse.4mg.com/slr.htm
Which reminds me I've not updated that page with this latest data and
agreement with this thread heading of SLR to 2100 , in range 81 to 88 cm

624 datapoints from year 2003.002659 to year 2019.9699 ,data from
aviso.altimetry.fr
output to the public 29 Feb 2020.
Starting from 2003 to avoid the earlier altimeter drift problem and
false flattening of the curve for approx 10 years after the 1993 Mount
Pinatubo eruption

x=year minus 2000
y = Aviso sea level
ranking by r^2
linear
y=1.364 +0.373531*x
SLR to year 2100 38.7cm
r*r = 0.983499

exponential
y=2.254 -3.878231*(1-e^(0.051999*x))
SLR to 2100 701cm or 7metres
r*r = 0.983499

quadratic
y=2.446+0.143071*x + 0.010034*x^2
SLR to 2100, 117cm
r*r = 0.983912

indicial
y=2.681+ 0.05599*x^1.592718
SLR to 2100, 88.5cm
r*r = 0.984025

Change from previous is the R^2 ranking , reverting to indicial as best
fit to the data , so dropping back to 88 cm SLR from the previous such
assessment


For completeness, processing the full 991 datapoint set from 1993 to
near end of 2019, similarly 81.5cm SLR to 2100
x = year minus 1990
ranked by goodness-of-fit r^2
Linear
y= -1.59 + 0.339733+x
(rounds to 0.340 cm/yr or 3.40mm/yr of the Aviso Reference plot as
confirmation of no silly errors to this stage of linear only)
r*r = 0.985297
SLR to year2100= 32.4cm

Indicial
y=-0.592 +0.118672*x^1.289997
r*r = 0.989438
SLR to year 2100= 45.7cm

Quadratic
y= -0.869 + 0.227209*x +0.003410*x^2
r*r = 0.990111
SLR to year 2100=56cm

Exponential
y= -0.892 -11.162847*(1-e^(x*0.021255))
r*r = 0.990392
SLR to year 2100= 81.5cm



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Monthly public talks on science topics, Hampshire , England
http://diverse.4mg.com/scicaf.htm