Accelerating the Lagrangian Particle Tracking in Hydrologic Modeling to Continental-Scale

Unprecedented climate change and anthropogenic activities have induced increasing ecohydrological problems, motivating the development of large-scale hydrologic modeling for solutions. Water age/quality is as important as water quantity for understanding the terrestrial water cycle. However, scientific progress in tracking water parcels at large-scale with high spatiotemporal resolutions is far behind that in simulating water balance/quantity owing to the lack of powerful modeling tools. EcoSLIM is a particle tracking model working with ParFlow-CLM that couples integrated surface-subsurface hydrology with land surface processes. Here, we demonstrate a parallel framework on distributed, multi-Graphics Processing Unit platforms with Compute Unified Device Architecture-Aware Message Passing Interface for accelerating EcoSLIM to continental-scale. In tests from catchment-, to regional-, and then to continental-scale using 25-million to 1.6-billion particles, EcoSLIM shows significant speedup and excellent parallel performance. The parallel framework is portable to atmospheric and oceanic particle tracking models, where the parallelization is inadequate, and a standard parallel framework is also absent. The parallelized EcoSLIM is a promising tool to accelerate our understanding of the terrestrial water cycle and the upscaling of subsurface hydrology to Earth System Models.

Automated summary

Unprecedented climate change and anthropogenic activities have led to increasing ecohydrological problems, prompting the development of large-scale hydrologic modeling for solutions. However, scientific progress in tracking water parcels at large-scale with high spatiotemporal resolutions is lacking due to the absence of powerful modeling tools. In this study, a parallel framework for the particle tracking model EcoSLIM is demonstrated, showing significant speedup and excellent parallel performance. This parallel framework can be applied to other particle tracking models and is a promising tool for accelerating our understanding of the terrestrial water cycle and upscaling subsurface hydrology to Earth System Models.