Submitted as: development and technical paper
| 23 Jan 2023
Status: this preprint is currently under review for the journal GMD.
A parallel implementation of the confined-unconfined aquifer system model for subglacial hydrology: design, verification, and performance analysis (CUAS-MPI v0.1.0)
Yannic Fischler1,Thomas Kleiner2,Christian Bischof1,Jeremie Schmiedel4,Roiy Sayag4,Raban Emunds1,2,Lennart Frederik Oestreich1,2,and Angelika Humbert2,3Yannic Fischler et al.Yannic Fischler1,Thomas Kleiner2,Christian Bischof1,Jeremie Schmiedel4,Roiy Sayag4,Raban Emunds1,2,Lennart Frederik Oestreich1,2,and Angelika Humbert2,3
Received: 22 Dec 2022 – Discussion started: 23 Jan 2023
Abstract. The subglacial hydrological system affects the motion of ice sheets, the ocean circulation by freshwater discharge, as well as marginal lakes and rivers. For modelling this system a porous medium model has been developed, representing a confined-unconfined aquifer system (CUAS) with evolving transmissivity. To allow for realistic simulations, we developed CUAS-MPI, an MPI-parallel C/C++ implementation, which employs the PETSc infrastructure for handling grids and equation systems. We describe the CUAS model and our software design and validate the numerical result of a pumping test using5 analytical solutions. We then investigate the scaling behavior of CUAS-MPI and show, that CUAS-MPI scales up to 3840 MPI processes running a realistic Greenland setup. Our measurements show that CUAS-MPI reaches a throughput comparable to the throughput of ice sheet simulations, e.g. the Ice-sheet and Sea-level System Model (ISSM). Lastly, we discuss opportunities for ice-sheet modelling, future coupling possibilities of CUAS-MPI with other simulations, and consider throughput bottlenecks and limits of further scaling.
Water underneath ice sheets affects the motion of glaciers. This study presents a newly developed code CUAS-MPI that simulates subglacial hydrology. It is designed for supercomputers and is hence a parallelized code. We measure the performance of this code for simulations of the entire Greenland ice sheet and find that the code works efficient. Moreover we validated the code to ensure the correctness of the solution. CUAS-MPI opens new possibilities for simulations of ice sheet hydrology.
Water underneath ice sheets affects the motion of glaciers. This study presents a newly...