1:45 PM - 2:00 PM
[AAS02-01] Exploring global 1-km hydrological simulations using the Integrated Land Simulator
★Invited Papers

Keywords:global terrestrial water cycle, hyper-resolution terrestrial hydrological simulations, Integrated Land Simulator, general-purpose coupler
During our presentation, we will initially describe the computational methods employed by each module. Subsequently, we will address the challenges faced in executing hyper-resolution simulations and the strategies to overcome them. The original coupling system was designed for lower-resolution models, where the computational demand was sufficiently extensive compared to the coupling processes. This system required adjustments for our high-resolution study, which involves considerable computational loads around the coupling interface. Following these modifications, we achieved a setup that allows for completing a 1-year simulation within a practical time frame of 12.8 hours using the Fugaku supercomputer.
A global 1-km experiment, with 1-km resolution land parameters (land cover, soil classification, leaf area index, etc.) and 0.5-degree meteorological data, showed that the canopy interception, which has a significant impact from LAI, can be represented at 1-km. We evaluated the impact of high-resolution land parameters on various variables by comparing the ratio of the mean of standard deviations within each 0.5-degree grid cell to the overall 0.5-degree mean. This analysis revealed that snow cover-related variables were minimally impacted, whereas soil moisture, canopy intercepted water, and latent and sensible heat fluxes experienced more substantial effects.
