Structure of Output History Files
=================================
.. _output:
NetCDF Output Files (:term:`netCDF`)
------------------------------------
TIEGCM history files are output in `netCDF `_,
a self-describing platform-independent data format written and maintained by the UCAR
`Unidata `_ program.
Each netCDF file contains one or more :term:`histories `, i.e., the state of the
model output fields at a discrete instant in :term:`model time`. Here is an example of the
metadata content of a sample primary history file: :download:`primary.ncd <_static/primary.ncd>`.
This example file contains six daily histories (days 355 to 360 of 2002).
This metadata is obtained via the "ncdump" command in the netCDF utilities. This example
ncdump file contains data values for scalar and singly-dimensioned vectors only.
TIEGCM history files are "CF compliant", i.e., they conform to the
`NetCDF Climate and Forecast (CF) Metadata Convention `_.
Primary and Secondary History Files
-----------------------------------
"Primary" history files contain the "prognostic" fields necessary to restart the model.
They can be specified in namelist input as the :ref:`SOURCE