Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

Further downscaling from wrf results

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


New member

I am aware that many scientists are running tons of simulations for different domains at the same time. Projects like CORDEX seem to harmonize such experiments by giving several standards for running the simulations so that everyone can utilize and benefit from these results.

However, some people may downscale from a GCM upto 50 km or 25 km using WRF. Is there any way to use these model results or any intermediate file to further downscale upto 5 km or less using WRF? This would reduce the computation cost of bringing GCM resolutions of scale 100 km to 5 km.

Any ideas or suggestion would be greatly appreciated.

The answer is yes. You can downscale GCM outputs to finer scale. This is a quite general answer. If you have a specific case, you are welcome to provide more information for further discussion.
Hi Ming Chen

Thank you for your response. My question to be exact is whether it is possible to use a wrfout file from one simulation to be used as the input for WPS or as an intermediate data for further downscaling using WRF to a finer resolution.

For example, lets say that I have a set of wrfout results downscaled to 50 km resolution from a GCM boundary and lateral conditions. Can I use this product to downscale again to 5 km using WRF rather than computing again from GCM lateral and boundary conditions. By doing so, the intention is to reduce the computation.

I came across ndown.exe which seems to be one possible option for this task.

Coordinated research program CORDEX uses WRF as an RCM to downscale certain GCM data and I am wondering if it is possible to use their results which are at 50 km to further downscale to 5 km.

Your suggestions and advice are most welcome.

I would suggest you run ndown to downscale the 50-km WRF results. However, I am a little bit concerned of the ratio (50/5=10), which is way too large. You probably should have a large enough 5-km domain in this case.
Hi Minh Chen

Thanks for your response. yes I agree 50 to 5 is too large of a ratio. Maybe 50 - 25 - 5 would be better. Anyway, thanks again.