In a previous post, I explored the connection between ENSO ((El Niño/La Niña Southern Oscillation) and sea-levels at Darwin and Fremantle on the west coast of Australia, in particular, the remarkably close correlation between smoothed monthly average levels and a smoothed, trended multiple of the SOI (Southern Oscillation Index).
It had already occurred to me that if the correlation was so convincing, that perhaps it might be possible to adjust monthly average data by the multiple of SOI to remove its effect and reveal the underlying pattern and trend of sea-level change at such strongly-affected locations. First attempts showed that the tenfold multiple I'd used to show correlation was too high, and that a multiple of 7 was "just right" for ENSO adjustment. Lower multipliers didn't reduce the variability ("lumpiness") sufficiently, and too high a value increased variability in the opposite direction. Lucky 7 turned out to be the "Goldilocks" factor. Here's my revised chart for Darwin:
The revised chart for Fremantle for the same period
High rates of rise in the western Pacific (as shown by satellite sea-level maps) have been a thorn in the side of some sceptics for some time. They conveniently ignore the fact that sea-levels along the Pacific coasts of the Americas show low or negative rates on the maps, supported by tide-gauge data, and that the high rates in the west are also supported by tide-gauge data, when exactly the same time-spans as the satellite maps are compared. They also ignore the reasoned, researched and informed voices which explain that both phenomena are effects of ENSO.
The island of Pohnpei (Federated States of Micronesia) is in that western "hotspot", and using PSMSL data for the two tide-gauges covering the period I've been able to recreate the record from 1974-2012.
latest data to June 2013 for Majuro from the South Pacific Sea Level and Climate Monitoring Project.
Pago Pago, American Samoa, shows a less-satisfactory correlation overall, but it's still reasonably convincing. It also shows the sharp recent uptick.