Guest essay by Albert Parker
Just in case somebody could be interested in understanding if the climate scientists are telling us the truth about sea level acceleleration, there is still the opportunity to verify by using the tide gauge data in the PSMSL data base.
The tide gauges measure the relative sea level in many locations worldwide, mostly in northern Europe and North America, in the best cases since the mid-late 1800s, and are therefore the best source of information to understand what is going on…
The PSMSL data base include the time series of the monthly average mean sea levels recorded by every tide gauge…
· Go to http://www.psmsl.org/products/trends
· Use as start year 1900 and end year 1975 and then zoom and window over one selected area, for example Europe (but the United States and Canada or Australia and New Zealand work fine as well …)
· These were the relative sea level rates of rises about Europe in 1975 – this is a print screen of today 17 March 2016
· The above relative rates of rise are obtained by linearly fitting all the monthly average mean sea level data 1900 to 1975. The relative rate of rise is the slope of the fitting line.
· Now, let see what happened during the last 40 years …. Just move the end year to 2014 …
· These are the relative sea level rates of rises about Europe in 2014 – this is a print screen in March 2016
· The above relative rates of rise are obtained by linearly fitting all the monthly average mean sea level data 1900 to 2014.
· Surprise, surprise, no major changes …..
· Do you spot any significant change?
· Those that are claiming the sea levels are rising sharply than ever before at an accelerating rate are simply not telling the truth.
· This may realize (for now) downloading and analyzing the PSMSL data, or even analyzing the data online.
· In a few years’ time, also this data base will be corrupted and the truly measured data will be replaced by computations or reconstructions.
· Below same results for the US and Canada, plus Australia and New Zealand … just in case …
So, tide gauges restricted almost entirely to N. Europe and USA coasts give us a reliable indication of GLOBAL sea level change do they?
How about using satellite-based instruments with global coverage instead?
“So, tide gauges restricted almost entirely to N. Europe and USA coasts give us a reliable indication of GLOBAL sea level change do they?”
It is more or less the same countries that express the most concern, so it is fair to look at the gauges in these countries.
I can recommend this site: http://www.psmsl.org/data/obtaining/
I don’t care if the oceans contain more or less water, but i care about the level at the shores, especially my shore. I live close to the shore in Danmark as most does, but think of the time involved. How many houses may be rebuild/mowed before it is a problem.
For a host of technical reasons, satellites (TOPEX/Poseidon & Jason) are NOT capable of giving accurate sea level data (its only accurate to ±25mm),
Tide Gauge Data is accurate to ±3mm. http://tinyurl.com/pfgj8sm
Explanation of tide measurement problems – Failed Experiments in Measuring Global Sea Level Change. Willie Soon – Start at 15min http://tinyurl.com/k49aaja
Worth watching all of it.
The satellite measurements are made from satellites in orbits 1336 kilometers above the oceans’ surfaces. The measurements are used to report annual changes in sea level to a precision of 0.1 millimeters, or one part in 13.36 billion. Arguably, since the measurements are based on the time for microwave signals to travel from the satellite to the ocean surface and return, 0.1 millimeter precision might actually represent one part in 26.72 billion, since the microwaves travel 26.72 billion millimeters from the satellite to the ocean surface and back to the satellite.
Do satellites provide any usable information?
No real news here, but a nice way to present things, and alerting people to PSMSL availability is a real plus!!!
In areas that have remained tectonically inert, neither sinking nor uplifting since the middle 1800s, while CO2 has shown a 40% increase, the inert zones clearly show an unchanging linear rise of about 1.2mm/yr.
No acceleration in the rate of sea-level rise whatsoever. (repeat the last sentence 3X!!!). For isostatic background, etc., if you have a chunk of time available, check out the first 30 minutes of this January 26, 2016 National Press Club presentation – the whole event runs 2hrs + with Q&A:
But the UK Met Office says it is.
“How about using satellite-based instruments with global coverage instead?”
Because the coasts are all that matter to folk that live on land?
Um, the two maps of Australia look the same ‘cos they are the same…
The linked site contains this caveat:
“Note that these measured trends are not corrected for local land movement. Furthermore, no attempt has been made to assess the validity of any individual fit, so results should not be treated as a publication quality values suitable for use in planning or policy making.”
Tide guages have two problems. One is isotatic rebound from the last glaciation. Visible along western Europe and NA east coasy. Two is tectonics, very visible along PNW north America (especially Alaska). Both are correctile by finding the long term tide guage subset that is reasonably geostationary. That can be done using differential GPS over some years. Answer is about 1.8-2.0 mm/ yr rise measurement/ geostationary uncertainty), and no SLR acceleration in the last 45.
Interestingly, this number does not give rise to the so called divergence problem. The sat altimetry valuess do. Suggests the sat altimetry has reasonable precision but not reasonable accuracy. Especially since explicitly not measuring shorelines.