KevinNM
Contributor
Could be. Or land subsidence, usually due to ground water removal. Or errors. Given the tidal effects are typically on the order of feet and there are larger cycles around the tides, and I somehow doubt the satellite passes are tide synchronous, the whole idea of trying to determine the accuracy of the ocean mean surface height to an accuracy of a tenth of a mm with a measurement tool has a margin of error of plus or minus 33mm seems somewhat doubtful to me.Perhaps due to salinity, temperature, currents, and wind?