# Calculating layer thickness in python

I have calculated the $$∂θ_\varepsilon/∂z$$ with 'Height', 'Latitude', 'Longitude' dimensions.

import numpy as np
import xarray as xr
from wrf import (getvar)

eth = np.array(getvar(ncfile, "eth", timeidx=time))
z = np.array(getvar(ncfile, "z", timeidx=time, units="km"))


I would like to plot the horizontal depth or thickness (in km) of the dthdz. It is a bit similar to this question. But when I do dthdz.sum(dim='Height'), I get very low depth values. I just want to know where I'm doing it wrong. Thank you!