Estimating the distribution of the mass component of sea level trends using tide gauges, altimetry and steric reconstructions

Bellingham, Clare Estimating the distribution of the mass component of sea level trends using tide gauges, altimetry and steric reconstructions. PhD thesis, University of Liverpool.

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Abstract

The recent global mean sea level rise is dominated by the addition of water to the oceans, accounting for around two thirds of the increase. In contrast, altimetry trends from 1993 to 2010 reveal that the local trends are dominated by the steric contribution, involving density expansion from warming and freshening. We explore an intermediate view between the global and local reconstructions based upon zonal averaging. By combining altimetry or tide gauges along with steric reconstructions, we provide two independent estimates of the zonal average of the mass component of sea level trends. We find that the trend in the increase of mass is spatially dependent and can be partly explained using mass redistribution predictions from gravitational fingerprints. Our two estimates, though, have different zonally averaged patterns. We find that the mass contribution implied by altimetry results in a higher rate of sea level rise in the southern hemisphere and the tropics, while the tide gauges imply a higher rate of rise within the tropics. These different views can be reconciled by the sparse tide gauge data in the southern hemisphere and the tropics. We show that while various land movement corrections at each gauge can alter the magnitude of the trend, this does not impact on the general shape of their latitudinal distributions.

Item Type:	Thesis (PhD)
Additional Information:	Date: 2015-06 (completed)
Uncontrolled Keywords:	Sea level, ocean mass, climate change, steric height, gravity fingerprints, tide gauges, altimetry
Subjects:	?? Q1 ??
Depositing User:	Symplectic Admin
Date Deposited:	30 Jul 2015 11:57
Last Modified:	17 Dec 2022 01:07
DOI:	10.17638/02013819
URI:	https://livrepository.liverpool.ac.uk/id/eprint/2013819