Contours of the radial velocity at the equator in a spherical shell simulation of convection in the Earth’s core subject to a large lower mantle heterogeneity. A coherent downwelling that forms beneath the Atlantic in a mildly driven convection (left panel) switches over to Asia in strongly driven convection (right panel). These simulations may explain the eastward migration of the magnetic North Pole, observed in the present-day geomagnetic field.
Prof. Binod Sreenivasan’s Lab at Centre for Earth Sciences (CEaS) studies magnetic fields of Earth and planets.The magnetic fields of Earth and planets are generated by dynamo action in their fluid cores. The numerical simulation of the planetary dynamo problem involves the solution of the nonlinear magnetohydrodynamic (MHD) equations on massaively parallel computers. “The problems solved by us on SERC’s supercomputer SahasraT in 2019 are devoted to understanding (a) the preference for the axial dipole in rotating planetary dynamos, and (b) the effect of large lower-mantle heterogeneity on the geodynamo”, says Prof. Sreenivasan. The computations are performed in a spherical shell geometry, with MPI parallelization in the radial and latitudinal grid points and run on more than 2160 cores and tens of runs for each simulation.
Outcomes
- S. Sahoo and B. Sreenivasan, Convection in a rapidly rotating cylindrical annulus with laterally varying boundary heat flux, Journal of Fluid Mechanics, v883, A1, 2019. doi:10.1017/jfm.2019.803.
- Indo-French Centre for the Promotion of Advanced Research, Grant No. 5307-1