reflectivity in WRF is different from the NCL calculation

[huihuojia]

I am planning to use the reflectivity.

WRF could write reflectivity dataset in the output file under the variable name "REFL_10CM", and NCL could calculate the reflectivity based on WRF output using the function "wrf_dbz".

But it turns out that the two are quite different. Which is the correct one?

Jia