I have a 2-D latitude-time zonal wind netCDF dataset (such as this small sample from ERA-Interim) from which I want to find all local maxima of the zonal wind as a function of latitude, for each time step. The output should be a list of latitudes (possibly empty) for each time step.
I would prefer to use mostly python, cdo and/or nco, if possible. I can use the derivative function in python xarray and specify the latitude dimension, for example, and then find roots of this new function subject to a condition on the second derivate, but I've not come across a function for finding zeroes/roots of a 2-D array along a specific dimension. Is there a more efficient, preferable way of going about this task?
Please let me know if this is not appropriate for the Earth Science Stack Exchange and where I should rather post the question if so.