Basic Science

SAMIL3 Operates on ‘Tianhe’ Supercomputer

SAMIL3, the latest in the series of global atmospheric general circulation models developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), successfully achieved two groups of simulations with more than 10,000 cores on “Tianhe-1A” supercomputer platform at the National Supercomputer Center in Tianjin, China. SAMIL3 has been tested with 12.5km and 6.25km respectively in horizontal resolutions. That is the first attempt in China to perform the simulation of atmospheric general circulation model on more than 10,000 cores supercomputer. Along with the previous successful experiments of 10km resolution LICOM on 1,000+ cores, accomplishment of 10,000+ core scale simulation of SAMIL3 indicates that the climate model has the capability to compete with other high resolution model research groups, and lays the foundation of ultra-high resolution climate model development in China.

New Insights of Europa's Internal Structure

Europa is the smallest one of the Jupiter’s four Galilean satellites. It has a thick ice shell on the surface, smooth but striated by cracks and streaks. Beneath its surface there might exist a ocean which could probably serve as an favorable environment for life. The research group at Purple Mountain Observatory, leading by Prof. Ji Jianghui, modeled the internal structure of Europa. In their models, they have considered a solid core composed by Fe or FeS, and they also proposed a new scenario of a core as mixture of Fe and FeS. In the Fe-FeS core model, Europa has a 571 km Fe-FeS core, an 832 km silicate mantle, and a 166 km water-ice shell, conformed with the observed 1569 km mean radius of Europa. The mass fraction of the core, the mantle and the water-ice shell is 12%, 78% and 10%. Prof. Ji and his PhD student Jin Sheng show that Europa is possibly differentiated into a metallic core surrounded by a rock mantle and a water-ice shell, and the mixture of Fe and FeS could be a new possible core material. The work was published in Science China Physics, Mechanics and Astronomy in January 2012.