IMI directory contents

This page describes the contents of various file directories generated and populated by the IMI in the course of an inversion.

Inversion directory

The inversion directory is where the IMI computes the Jacobian, obtains the optimal estimate of emissions, and saves the results.

It is located at /home/ubuntu/imi_output_dir/{YourRunName}/inversion.

In addition to a shell script and several Python scripts used in the inversion, you will find the following items in the inversion directory after completing an inversion:

data_converted/	Directory of Python .pkl files containing TROPOMI observations virtual TROPOMI observations of the GEOS-Chem reference simulation elements of the Jacobian matrix for each TROPOMI orbit relevant to the inversion. All quantities have been “converted” to 1D fields indexed by latitude and longitude.
data_converted_posterior/	Directory of Python .pkl files containing TROPOMI observations virtual TROPOMI observations of the GEOS-Chem posterior simulation for each TROPOMI orbit relevant to the inversion. All quantities have been “converted” to 1D fields indexed by latitude and longitude.
data_geoschem/	Directory of .nc files containing daily GEOS-Chem SpeciesConc output from the reference simulation. These files are used to generate virtual TROPOMI observations for comparison with the true observations.
data_geoschem_posterior/	Directory of .nc files containing daily GEOS-Chem SpeciesConc output from the posterior simulation. These files are used to generate virtual TROPOMI observations for comparison with the true observations.
data_sensitivities/	Directory of .nc files containing daily 4-D GEOS-Chem sensitivities to perturbations in the state variables of the inversion (i.e., in the emission elements being optimized). The data have dimensions (element, lev, lat, lon), where element is the emission element id (state variable id) and lev is the vertical dimension. These files are used to compute the Jacobian matrix by application of the TROPOMI operator.
inversion_result.nc	File containing the raw output of the inversion (invert.py) as vectors (posterior emission estimate) and matrices (posterior error covariance matrix, averaging kernel matrix).
gridded_posterior.nc	File containing the posterior emission estimate, posterior error covariance matrix, and averaging kernel matrix projected onto the 2-D inversion grid.
visualization_notebook.ipynb	Jupyter notebook for quickly visualizing key results of the inversion.