The sea level fingerprint of recent ice mass fluxes

J Bamber,R Riva

doi:10.5194/tc-4-621-2010

J Bamber, R Riva

Open Access

https://doi.org/10.5194/tc-4-621-2010

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Abstract

Abstract. The sea level contribution from glacial sources has been accelerating during the first decade of the 21st Century (Meier et al., 2007; Velicogna, 2009). This contribution is not distributed uniformly across the world's oceans due to both oceanographic and gravitational effects. We compute the sea level signature for ice mass fluxes due to changes in the gravity field, Earth's rotation and related effects for the nine year period 2000–2008. Mass loss from Greenland results in a relative sea level (RSL) reduction for much of North Western Europe and Eastern Canada. RSL rise from this source is concentrated around South America. Losses in West Antarctica marginally compensate for this and produce maxima along the coastlines of North America, Australia and Oceania. The combined far-field pattern of wastage from all ice melt sources, is dominated by losses from the ice sheets and results in maxima at latitudes between 20° N and 40° S across the Pacific and Indian Oceans, affecting particularly vulnerable land masses in Oceania. The spatial pattern of RSL variations from ice mass losses used in this study is time-invariant and cumulative. Thus, sea level rise, based on the gravitational effects from the ice losses considered here, will be amplified for this sensitive region.

Highlights

It has been suggested that the ocean dynamic response to future climate change will result in enhanced sea level rise for the northeast coastline of the United States (Yin et al, 2009) and that steric anomalies, due to increased melt from the ice sheets, will result in long-lived local relative sea level (RSL) variations (Stammer, 2008)
Consistency between different approaches is being achieved, for Greenland at least, providing greater confidence in the results. We use these detailed observations of the spatial pattern of mass loss to examine the signature of relative sea level resulting from changes to the gravity field, true polar wander (TPW) and shoreline migration
Mountain glacier and ice cap (MG&IC) sources from elsewhere are, individually, considerably smaller than the three regions mentioned, and combined they contribute about 27% of the total for the period 2000–2008 (Meier et al, 2007; Hock et al, 2009; Chen et al, 2007, 2009; Wouters et al, 2008)

Summary

Introduction

It has been suggested that the ocean dynamic response to future climate change will result in enhanced sea level rise for the northeast coastline of the United States (Yin et al, 2009) and that steric anomalies, due to increased melt from the ice sheets, will result in long-lived local RSL variations (Stammer, 2008). This updated theory has been used to examine the spatial pattern in relative sea level for a hypothetical wastage of large ice masses and to infer the mean rate of loss from Greenland over the 20th Century (Mitrovica et al, 2001).

Results

Conclusion