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A benchmark study on mantle convection in a 3-D spherical shell using CitcomS

Zhong, Shijie and McNamara, Allen and Tan, Eh and Moresi, Louis and Gurnis, Michael (2008) A benchmark study on mantle convection in a 3-D spherical shell using CitcomS. Geochemistry, Geophysics, Geosystems, 9 (10). Q10017. ISSN 1525-2027. http://resolver.caltech.edu/CaltechAUTHORS:ZHOggg08

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Abstract

As high-performance computing facilities and sophisticated modeling software become available, modeling mantle convection in a three-dimensional (3-D) spherical shell geometry with realistic physical parameters and processes becomes increasingly feasible. However, there is still a lack of comprehensive benchmark studies for 3-D spherical mantle convection. Here we present benchmark and test calculations using a finite element code CitcomS for 3-D spherical convection. Two classes of model calculations are presented: the Stokes' flow and thermal and thermochemical convection. For Stokes' flow, response functions of characteristic flow velocity, topography, and geoid at the surface and core-mantle boundary (CMB) at different spherical harmonic degrees are computed using CitcomS and are compared with those from analytic solutions using a propagator matrix method. For thermal and thermochemical convection, 24 cases are computed with different model parameters including Rayleigh number (7 × 10^3 or 10^5) and viscosity contrast due to temperature dependence (1 to 10^7). For each case, time-averaged quantities at the steady state are computed, including surface and CMB Nussult numbers, RMS velocity, averaged temperature, and maximum and minimum flow velocity, and temperature at the midmantle depth and their standard deviations. For thermochemical convection cases, in addition to outputs for thermal convection, we also quantified entrainment of an initially dense component of the convection and the relative errors in conserving its volume. For nine thermal convection cases that have small viscosity variations and where previously published results were available, we find that the CitcomS results are mostly consistent with these previously published with less than 1% relative differences in globally averaged quantities including Nussult numbers and RMS velocities. For other 15 cases with either strongly temperature-dependent viscosity or thermochemical convection, no previous calculations are available for comparison, but these 15 test calculations from CitcomS are useful for future code developments and comparisons. We also presented results for parallel efficiency for CitcomS, showing that the code achieves 57% efficiency with 3072 cores on Texas Advanced Computing Center's parallel supercomputer Ranger.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/2008GC002048DOIArticle
ORCID:
AuthorORCID
Moresi, Louis0000-0003-3685-174X
Gurnis, Michael0000-0003-1704-597X
Additional Information:© 2008. American Geophysical Union. Received 5 April 2008; Revised 14 August 2008; Accepted 5 September 2008; Published 31 October 2008. SZ was supported by NSF EAR-0711366 and David and Lucile Packard Foundation. AKM was supported by NSF-0510383. ET and MG were supported by NSF EAR-042271. We thank Scott King, Paul Tackley, and Peter van Keken for their constructive reviews and Teresa Lassak for going through equations and finding out two typos in two equations. Part of the calculations was performed on TACC's Parallel Supercomputer Ranger.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR-0711366
David and Lucile Packard FoundationUNSPECIFIED
NSFEAR-0510383
NSFEAR-042271
Subject Keywords:mantle convection; benchmark
Record Number:CaltechAUTHORS:ZHOggg08
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:ZHOggg08
Official Citation:Zhong, S., A. McNamara, E. Tan, L. Moresi, and M. Gurnis (2008), A benchmark study on mantle convection in a 3-D spherical shell using CitcomS, Geochem. Geophys. Geosyst., 9, Q10017, doi:10.1029/2008GC002048.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12500
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:11 Dec 2008 17:38
Last Modified:24 Oct 2017 18:18

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