A benchmark study of numerical implementations of the sea level equation in GIA modelling

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10384964" target="_blank" >RIV/00216208:11320/18:10384964 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1093/gji/ggy280" target="_blank" >https://doi.org/10.1093/gji/ggy280</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/gji/ggy280" target="_blank" >10.1093/gji/ggy280</a>

Result language

angličtina

Original language name

A benchmark study of numerical implementations of the sea level equation in GIA modelling

Original language description

The ocean load in glacial isostatic adjustment (GIA) modelling is represented by the so-called sea level equation (SLE). The SLE describes the mass redistribution of water between ice sheets and oceans on a deforming Earth. Despite various teams independently investigating GIA, there has been no systematic intercomparison among the numerical solvers of the SLE through which the methods may be validated. The goal of this paper is to present a series of synthetic examples designed for testing and comparing the numerical implementations of the SLE in GIA modelling. The 10 numerical codes tested combine various temporal and spatial parametrizations. The time-domain or Laplace-domain discretizations are used to solve the SLE through time, while spherical harmonics, finite differences or finite elements parametrize the GIA-related field variables spatially. The surface ice-water load and solid Earth&apos;s topography are represented spatially either on an equiangular grid, a Gauss-Legendre or an equiarea grid with icosahedron-shaped spherical pixels. Comparisons are made in a series of five benchmark examples with an increasing degree of complexity. Due to the complexity of the SLE, there is no analytical solution to it. The accuracy of the numerical implementations is therefore assessed by the differences of the individual solutions with respect to a reference solution. While the benchmark study does not result in GIA predictions for a realistic loading scenario, we establish a set of agreed-upon results that can be extended in the future by including more complex case studies, such as solutions with realistic loading scenarios, the rotational feedback in the linear-momentum equation, and by considering a 3-D viscosity structure of the Earth&apos;s mantle. The test computations performed so far show very good agreement between the individual results and their ability to capture the main features of sea-surface variation and the surface vertical displacement. The differences found can often be attributed to the different approximations inherent in the various algorithms. This shows the accuracy that can be expected from different implementations of the SLE, which helps to assess differences noted in the literature between predictions for realistic loading cases.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10500 - Earth and related environmental sciences

Project

<a href="/en/project/GA17-03689S" target="_blank" >GA17-03689S: Ocean flows and their magnetic signatures on global and regional scales</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Geophysical Journal International

ISSN

0956-540X

e-ISSN

—

Volume of the periodical

215

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

26

Pages from-to

389-414

UT code for WoS article

000448242600025

EID of the result in the Scopus database

2-s2.0-85054064116