Further Exploration of Historical Sea Level Rise Acceleration
22 hours ago Guest Blogger 38 Comments
by Chris Hall
Introduction
This article builds on a previous posting of mine entitled “Sea Level Rise: Hockey Stick or Roller Coaster”. See:
In that article, I outlined an approach that I used to tease out signs of acceleration in the rate of rise of sea level in the historical tidal gauge provided by the Permanent Service for Mean Sea Level or PMSL (Holgate et al., 2013; PSMSL, 2022). The posting was inspired by the peer reviewed article Nerem et al. (2018), herein referred to as PNAS2018. In that article, the authors estimated the current rate of change of the rate of sea level rise (i.e., sea level acceleration) and they argued that the historical tidal gauge record was inadequate for measuring sea level acceleration of the past. I wanted to see what the tidal gauge record had to say about historical sea level rise acceleration.
Briefly, I explored many different avenues to calculate prior sea level rise acceleration to see if I could determine whether modern acceleration found in PNAS2018 was a novel and new phenomenon, or whether this sort of acceleration ebbed and flowed throughout the 20th century. I wound up picking a subset of data from the most complete tidal gauge records over the period from 1925 to 2015, a kind of top 100 sites on the “Tidal Gauge Hit Parade”. Using that subset, the best method that I found to combine acceleration signals, in a manner that did not produce artifacts caused by missing data points, was to first calculate an acceleration record for each site and then combine the acceleration data using an area-weighted average. See the previous post for details on the method used.
Since posting that article of WUWT, I realized that I could use a similar technique to cast a wider net and exploit data from a much larger subset of the 1548 sites recorded in the PMSL dataset. The results of that effort are outlined in this posting and it represents the maximal amount of historical sea level acceleration information that I can derive.
Where The Data Are
https://wattsupwiththat.com/2023/02/21/further-exploration-of-historical-sea-level-rise-acceleration/
