Grid Resolution & Routing Resolution Best Practices

[Alfred Zhong]

Hello All,

I have a question about best practices for selecting LSM grid resolution and routing grid resolution.

1) How do I select the Land Surface Model grid resolution? In most examples I see online, I see that it is set anywhere from 1km to 15km depending on the use case. Apart from the obvious downside in increased computation costs, is there any other reason it isn't usually set lower than 1k. For my particular model run, I plan to use GFS forcing data which is 13km resolution. Would having a LSM grid resolution that is much greater than the forcing data resolution be problematic?

2) Once I've settled on a LSM coarse grid resolution, what's the best practice for selecting a regridding factor for the higher resolution routing grid? I plan on using a DEM that has a resolution of ~25meters. Should the routing grid resolution try to match that?

3) Would it make sense to use the GFS forcing data (13km resolution) when my DEM resolution (25m resolution) is so much higher? Should I try to use something like HRRR for higher resolution forcing data?

Thanks!