Munging The Sea Level Data

[rangerrebew]

Munging The Sea Level Data
2 years ago Willis Eschenbach
Guest Post by Willis Eschenbach

Guest Post by Willis Eschenbach

mung
/mənj/ [pronounced “munge”]
verb
INFORMAL•COMPUTING
gerund or present participle: munging
to manipulate (data)
EXAMPLE: “you could do what anti-spammers have done for years and mung the URLs”

For more than a decade now, I’ve been wondering about a couple of questions.

First, why does the satellite-based sea-level data show that the sea level is rising so much faster than the rise measured at tidal stations on the coastlines around the world? Records from tidal stations show a rise on the order of a couple of mm per year, a rate which is little changed over the century or so for which we have adequate records. But the satellite record (Figure 1) shows a rise of 3.3 mm/year. Why the large difference?

Second, why does the satellite-based sea-level show such significant acceleration? As mentioned above, the sea-level records from tidal stations, which are much longer, show little or no acceleration. But the satellite record claims that the rate of sea-level rise is increasing by about a tenth of a millimeter per year. That amount of acceleration would double the rate of sea-level rise in about thirty years. Again, why the large difference?

To start with, here’s what the satellite data says, according to the University of Colorado Sea Level Research Group.

https://wattsupwiththat.com/2021/02/21/munging-the-sea-level-data/

[rangerrebew]

Science Catches Up With WUWT
20 hours ago Willis Eschenbach 100 Comments
Guest Post by Willis Eschenbach

Those who read my work may recall my post called “Munging the Sea Level Data“. In it, I showed that the apparent acceleration in the satellite sea level was merely an artifact of the combining of the four satellite records, viz:


Original Caption: NOAA sea level data, showing the trend of each of the full individual satellite records and the overall trend. SOURCE: NOAA Excel Spreadsheet

Despite the obvious differences between the first and last halves of the record, scientists merely spliced them together and obscured the splice. My conclusion in that post was:

There’s no evidence of any acceleration in the rate of sea-level rise in either the tide gauge or the shabbily-spliced satellite records.

So today I stumbled across a paper published in Nature magazine entitled A revised acceleration rate from the altimetry-derived global mean sea level record. Care to guess what the paper says?

Yep. You’re right. They conclude that once they took a hard look at the satellite records, the problem was disagreement between the satellites … and once they applied their correction methods to the TOPEX satellite records, they found:

Based on four different weighting methods used in a tide-gauge comparison it is determined that TOPEX is drifting and not ERS. Therefore, we suggest to calibrate the TOPEX GMSL record with the crossover of ERS1&2 after the removal of cal-1. The calibration reduces the observed acceleration in GMSL, so that it becomes statistically equivalent to zero at the 95%-confidence level.

The observed acceleration in satellite-observed GMSL (global mean sea level) is “statistically equivalent to zero” … go figure.

https://wattsupwiththat.com/2022/12/29/science-catches-up-with-wuwt/