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Estimating roughness length from canopy height

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New member
Hey there WRF experts,

I'm running simulations where I increase tree height in a specific land use category. However, I'm having trouble figuring out how to change Z0MIN and Z0MAX in VEGPARM.TBL to reflect the increased canopy height. I read a general rule of thumb that roughness length is about one-tenth of canopy height, but I can't find information on the units used in the VEGPARM table or how adjustments are made for seasonal growing patterns in Z0MIN and Z0MAX. Could someone direct me to where I might find this information?


I am sorry that I have no answer to your question. I talked to our land model expert and he told me the values are mostly empirical. They derive these values based on in-situ observations and satellite remote sensing. We use them as is and never really explore how they are specified.