An interesting read here

https://www.nasa.gov/feature/goddard...sea-level-rise
-accelerating


I suppose it's no great surprise but it certainly is very worrying and
is potentially far more important than all the political shenanigans
that fill the news media. I wonder if there's a backroom team somewhere
in Whitehall trying to devise a plan for an orderly abandonment of
Central London before the end of the century. It might eventually come
to that. There's only so much water that can be kept out. I won't be
around to see the potential problem becoming reality but my
grandchildren might well be.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

On Sunday, February 18, 2018 at 1:15:37 PM UTC, Norman Lynagh wrote:
An interesting read here

https://www.nasa.gov/feature/goddard...sea-level-rise
-accelerating


I suppose it's no great surprise but it certainly is very worrying and
is potentially far more important than all the political shenanigans
that fill the news media. I wonder if there's a backroom team somewhere
in Whitehall trying to devise a plan for an orderly abandonment of
Central London before the end of the century. It might eventually come
to that. There's only so much water that can be kept out. I won't be
around to see the potential problem becoming reality but my
grandchildren might well be.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

Probably a good time to be living where the land is rising after the last ice age. Anyone for Norway?

Out on Scilly the land's sinking. It's very interesting, from an archaeological point of view, looking through the shallow clear waters to see all the old remains, including stone walls and buildings, now around or just below the low tide mark. Such as here http://www.cismas.org.uk/images/sams...s/image010.jpg

Graham
Penzance

Graham Easterling wrote:

On Sunday, February 18, 2018 at 1:15:37 PM UTC, Norman Lynagh wrote:
An interesting read here

https://www.nasa.gov/feature/goddard...nds-sea-level-
rise -accelerating


I suppose it's no great surprise but it certainly is very worrying
and is potentially far more important than all the political
shenanigans that fill the news media. I wonder if there's a
backroom team somewhere in Whitehall trying to devise a plan for an
orderly abandonment of Central London before the end of the
century. It might eventually come to that. There's only so much
water that can be kept out. I won't be around to see the potential
problem becoming reality but my grandchildren might well be.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

Probably a good time to be living where the land is rising after the
last ice age. Anyone for Norway?

Out on Scilly the land's sinking. It's very interesting, from an
archaeological point of view, looking through the shallow clear
waters to see all the old remains, including stone walls and
buildings, now around or just below the low tide mark. Such as here
http://www.cismas.org.uk/images/sams...s/image010.jpg

Graham
Penzance

The environment always looks so permanent, except it isn't:-)

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr

On 18/02/2018 13:15, Norman Lynagh wrote:
An interesting read here

https://www.nasa.gov/feature/goddard...sea-level-rise
-accelerating


I suppose it's no great surprise but it certainly is very worrying and
is potentially far more important than all the political shenanigans
that fill the news media. I wonder if there's a backroom team somewhere
in Whitehall trying to devise a plan for an orderly abandonment of
Central London before the end of the century. It might eventually come
to that. There's only so much water that can be kept out. I won't be
around to see the potential problem becoming reality but my
grandchildren might well be.


That reminds me I must get back to
https://www.aviso.altimetry.fr/en/da...sea-level.html
unfortunately the Jason-2 satellite had to have its orbit shifted
outwards and public outputting of data has still not recommenced, but it
looks as though Jason-3 output now has enough output to concattenate to
the previous Jason2 data, seemingly compatible.
As it stood before abandoning that curve-fitting.
For Aviso/Jason-2 data as of 20 Dec 2016, public access 13 March 2017,
from a suite of a few hundred curve types to try, the best R^20.998
fit was for exponential curve type (soon gets alarming not so far into
this century)
Aviso plot (y cm as in Aviso plots and scaling, and years where x=0 for
year 2000)
y=2.1465 - (2.00209)*(1 - e^(+0.07779*x))

The situation has apparently improved since end of 2016, all those nasty
El-Nino effects etc producing a very bumpy plot, ie not so steeply
exponential.

Tide gauges also problematic as they may as well be mounted on a
water-bed , as the ground is not fixed. Currents and gyres , salinity
etc change in the oceans , also , upsetting local land-bordering
mean-sea levels.
From BODC data for Lerwick , between 1957 and 1999 mean sea level has
only risen 30 mm relative to their rising land , isostatic rebound
there. But for Portsmouth between 1962 and 2002 , sea level relative to
sinking Portsmouth then 170mm a rise (contra-rebound to compensate for
rising Scotland).

May as well add a link, as relevant.
An expert on this stuff , next month Southampton, giving a talk in the
open-to-public series of science talks I run
http://www.diverse.ip3.co.uk/scicaf.htm

In message , Norman Lynagh
writes
An interesting read here

https://www.nasa.gov/feature/goddard...sea-level-rise
-accelerating

I suspect that the space after "rise" in the url shouldn't be there.
--
John Hall
"Hegel was right when he said that we learn from history
that man can never learn anything from history."
George Bernard Shaw (1856-1950)

On 18 Feb 2018, Norman Lynagh wrote
(in article ):

An interesting read here

https://www.nasa.gov/feature/goddard...sea-level-rise
-accelerating

I suppose it's no great surprise but it certainly is very worrying and
is potentially far more important than all the political shenanigans
that fill the news media. I wonder if there's a backroom team somewhere
in Whitehall trying to devise a plan for an orderly abandonment of
Central London before the end of the century. It might eventually come
to that. There's only so much water that can be kept out. I won't be
around to see the potential problem becoming reality but my
grandchildren might well be.

Couldn’t countries invest in solar powered coastal desalination plants, and
use solar powered pumps to move the water inland, and irrigate crops?

Given the amount spent by arid countries on military spending, a few billion
diverted to environmental issues might be worthwhile.

On Sunday, February 18, 2018 at 6:30:18 PM UTC, johnny-knowall wrote:
snip
Couldn’t countries invest in solar powered coastal desalination plants, and
use solar powered pumps to move the water inland, and irrigate crops?
snip

Or even refill some of those aquifers they(we) have been emptying steadily over the past 50 years.

I've not seen any figures on how much water has been abstracted or, more to the point, how much it may have contributed to sea levels. Even if it's not much, given a long enough programme it would at least very usefully remove from the oceans some water on a semi-permanent basis but still make it available to our children, should they become desperate for it in the future..

As things stand, we're so consumed with using everything we can find that we fail to think ahead in anything we do.

That reminds me I must get back to
https://www.aviso.altimetry.fr/en/da...sea-level.html

unfortunately the Jason-2 satellite had to have its orbit shifted
outwards and public outputting of data has still not recommenced, but it
looks as though Jason-3 output now has enough output to concattenate to
the previous Jason2 data, seemingly compatible.
As it stood before abandoning that curve-fitting.
For Aviso/Jason-2 data as of 20 Dec 2016, public access 13 March 2017,
from a suite of a few hundred curve types to try, the best R^20.998
fit was for exponential curve type (soon gets alarming not so far into
this century)
Aviso plot (y cm as in Aviso plots and scaling, and years where x=0 for
year 2000)
y=2.1465 - (2.00209)*(1 - e^(+0.07779*x))

The situation has apparently improved since end of 2016, all those nasty
El-Nino effects etc producing a very bumpy plot, ie not so steeply
exponential.

Tide gauges also problematic as they may as well be mounted on a
water-bed , as the ground is not fixed. Currents and gyres , salinity
etc change in the oceans , also , upsetting local land-bordering
mean-sea levels.
From BODC data for Lerwick , between 1957 and 1999 mean sea level has
only risen 30 mm relative to their rising land , isostatic rebound
there. But for Portsmouth between 1962 and 2002 , sea level relative to
sinking Portsmouth then 170mm a rise (contra-rebound to compensate for
rising Scotland).

May as well add a link, as relevant.
An expert on this stuff , next month Southampton, giving a talk in the
open-to-public series of science talks I run
http://www.diverse.ip3.co.uk/scicaf.htm

Ignoring the first and last six months of Jason 1,2 and 3 plots,
scaling, hovering transparent at the joins. The central parts of the
overlap curves agree, but with a vertical displacement of about 2mm .
Seems odd querying 2mm when dealing with the slippery commodity that is
sea level. From one of the team on the Jason project, they use
land-locked lakes like Windermere in Cumbria, other such lakes around
the world and also active transponders they can place anywhere before
overpasses, for calibrating and therefore cross-calibrating different
satellite outputs. So I assume the end result is that there is smooth
transition in the outputted results from J1 to J3 and the jumps have
some technical justification. Anyway concattenating the 3 plots from
the Aviso site , ignoring the transistion steps , continous from 2003 to
end 2017 and 46 datapoints for curve-fitting .
At least exponential is no longer the best fit in the rankings from
Linear, Exponential, Quadratic and Fractional Indicial, any other
curve-type suggestions?
Linear
Y= cm of sea-level as per Aviso output and x=0 for year 2000
Y = 1.446098 + 0.331877*x
R^2= 0.978086
RMS Error = 0.244821
projecting into the future
year 2030 11.402 cm SL rise
2050 18.04 cm
2100 34.63cm

Exponential
Y = 1.948854 -6.880730*(1-Exp(0.033013*x))

R^2 = 0.981571
RMS Error = 0.227110
projections
2030 13.593 cm
2050 30.919 cm

Quadratic
Y = 2.023609 + 0.204265*x + 0.005656*x^2
R^2 = 0.981740
RMS Error = 0.226064
projections
2030 13.242cm
2050 26.377cm

Indicial, approx 4/3 fractional indicial power
Best fit on R^2 and RMS
Y = 2.252107 + 0.104773*x^1.355666

R^2 = 0.981919
RMS Error = 0.224954
2030 13.058cm
2050 23.313 cm
2100 , 56.15 cm (21.5cm more than linear , the official standpoint)

Then staying with indicial curve type , chopping off later data and
curve-fitting for an idea of trend over time.
The fractional index to near end of 2017 ,1.355666
to mid 2017 , 1.378523
to 2017.0 , 1.571937
to 2016.0 , 1.730158
to 2015.0, 1.449256
to 2014.0, 1.428276
so knocked back from the year 2016, when things looked to be going fully
exponential.

My Jason1 + Jason2 + Jason3 concattenated graphical plot
http://diverse.4mg.com/jason1+2+3r.jpg
2003 to Nov 2017
retaining as much as possible of the 3 separate images, 2mm
discontinuities, linear "fit" segments etc.

Other such long-term plots

http://www.kpress.info/images/Jan_20...level_rise.jpg

https://www.aviso.altimetry.fr/filea... rence_sm.png

Anyone doubt a curve is a better fit than linear, then just a matter of
what sort of curve is the optimal fit.

On Tuesday, 20 February 2018 12:43:52 UTC, N_Cook wrote:
My Jason1 + Jason2 + Jason3 concattenated graphical plot
http://diverse.4mg.com/jason1+2+3r.jpg
2003 to Nov 2017
retaining as much as possible of the 3 separate images, 2mm
discontinuities, linear "fit" segments etc.

Other such long-term plots

http://www.kpress.info/images/Jan_20...level_rise.jpg

https://www.aviso.altimetry.fr/filea... rence_sm.png

Anyone doubt a curve is a better fit than linear, then just a matter of
what sort of curve is the optimal fit.

There is another plot he
https://cires.colorado.edu/council-f...r-steven-nerem
but I am doubtful since parts of the plot show sea level falling.