Overview: x4c as a CESM Diagnostic System

Overview: `x4c` as a CESM Diagnostic System#

x4c provides a high-level diagnositc system for CESM output analysis and visualization. In this tutorial, we show some simple examples to give a quick glance of the major features, including:

The Timeseries case system
The spell magics
Adding new diagnostic variables

More detailed explainations of each feature can be found in later sections.

Example Datasets: Zhu, F. & Zhu, J. Long simulations of the Miocene Climatic Optimum, DOI: 10.5065/3QFN-GN70 (2025). https://rda.ucar.edu/datasets/d010026/.

[1]:

%load_ext autoreload
%autoreload 2

import os
import x4c
import datetime

os.chdir('/glade/u/home/fengzhu/Github/x4c/docsrc/notebooks')
print(x4c.__version__)
print(f'Last Update: {datetime.date.today()}')

2026.3.9
Last Update: 2026-03-09

[ ]:

dirpath = './b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.Miocene.3xCO2.005'
case = x4c.Timeseries(dirpath, grid_dict={'atm': 'ne16np4'}, cesm_ver=1)

>>> case.root_dir: /glade/u/home/fengzhu/Github/x4c/docsrc/notebooks/b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.Miocene.3xCO2.005
>>> case.path_pattern: comp/proc/tseries/*/casename.hstr.vn.timespan.nc
>>> case.grid_dict: {'atm': 'ne16np4', 'ocn': 'g16', 'lnd': 'ne16np4', 'rof': 'ne16np4', 'ice': 'g16'}
>>> case.casename: b.e13.B1850C5.ne16_g16.icesm131_d18O_fixer.Miocene.3xCO2.005
>>> case.paths["atm"]["cam.h0"] created
>>> case.paths["ocn"]["pop.h"] created
>>> case.paths["lnd"]["clm2.h0"] created
>>> case.paths["rof"]["rtm.h0"] created
>>> case.paths["ice"]["cice.h"] created
>>> case.vns["atm"]["cam.h0"] created
>>> case.vns["ocn"]["pop.h"] created
>>> case.vns["lnd"]["clm2.h0"] created
>>> case.vns["rof"]["rtm.h0"] created
>>> case.vns["ice"]["cice.h"] created

Now let’s load the surface temperature (TS).

[3]:

case.load('TS')
case.ds['TS']

>>> case.ds["TS"] created

Note that the same variable name could exist for multiple history strings (h-strings). In which case we should specify the component and h-string:

[4]:

case.load('TS', comp='atm', hstr='cam.h0a')
case.ds['TS']

>>> case.ds["TS"] already loaded; to reload, run case.load("TS", ..., reload=True).

All derived variables should follow the same idea of specifying component and h-strings if the underlying variables exist for multiple h-strings:

[5]:

case.load('LST', comp='atm', hstr='cam.h0a')
case.ds['LST']

>>> LST is a supported derived variable.
>>> case.ds["TS"] already loaded; to reload, run case.load("TS", ..., reload=True).
>>> case.ds["LANDFRAC"] created
>>> case.ds["LST"] created

[ ]:

Overview: x4c as a CESM Diagnostic System

Overview: x4c as a CESM Diagnostic System#

Overview: `x4c` as a CESM Diagnostic System#