Reconstruction of changes in sea level in the tropical Pacific, the Mediterranean Sea and the Arctic Ocean

 

This work of reconstruction of changes in sea level in the tropical Pacific, the Mediterranean Sea and the Arctic Ocean is part of the thesis of Benedict Meyssignac and focuses on:

  1. the analysis of observations on the regional variability in sea level rise;
  2. a reconstruction of the regional variability since 1950 (i.e. before the advent of satellite altimetry);
  3. the study of the causes and origins.

 

General context

During the 20th century, tidal measurements were used to estimate the global sea level rise at 1.7 mm/year. In the last two decades, observations by satellite altimetry indicate a faster rise in sea level of 3.2 mm/year over the period 1993-2011. Due to their quasi-global coverage, satellite observations also revealed a strong regional variability in the sea level rise that far exceeds the average overall rise in many parts of the earth. The regional component that adds to the overall rise to give the total local sea level is key when studying the impacts of sea level rise on coastal and low-lying islands.

 

Reconstruction of changes in sea level since 1950

The regional variability of the sea level in the past (prior to the altimetric period) can be reconstructed by combining tide gauge data with spatial structures specific to the oceans derived from global ocean models. This method makes it possible to reconstruct the sea level in 2 dimensions since 1950, for most of the world, with a resolution close to that of satellite altimetry.

 

Satellite altimetry sea level trends over 1993–2009 and reconstructed past sea level trends over 1950–2010. (a) Trends computed from the weekly AVISO sea level dataset. Time series have been averaged to annual time series. A global averaged sea level trend of 3.3mmyr−1 has been removed. (b) Reconstructed sea level trends over 1950–2010 (the reconstruction total time span). A global averaged sea level trend of 1.76mmyr−1 has been removed. Time series have been averaged to annual time series. Cliquer sur la figure pour l'agrandi

 

This reconstruction method is also used to estimate the regional variability of past sea level rise in three regions vulnerable to climate warming: the tropical Pacific, the Mediterranean and the Arctic Ocean.

 

To find out more:

  • Benedict Meyssignac whose thesis defence is scheduled for October 19, 2012 at LEGOS, Toulouse.
     

References

 

Last updated: 12/12/2012

Further reading about the reconstruction of tide gauge records:

List of programs, projects and reconstructions of tide gauge data