Concatenate model time-slices

In this example we have the surface temperature files for HadCM3 in our directory, which are provided in six time-slices for the historical experiment, as the files:

• ts_Amon_HadCM3_historical_r1i1p1_185912-188411.nc
• ts_Amon_HadCM3_historical_r1i1p1_188412-190911.nc
• ts_Amon_HadCM3_historical_r1i1p1_190912-193411.nc
• ts_Amon_HadCM3_historical_r1i1p1_193412-195911.nc
• ts_Amon_HadCM3_historical_r1i1p1_195912-198411.nc
• ts_Amon_HadCM3_historical_r1i1p1_198412-200512.nc

To join them we can use the cat_exp_slices() function from cmipdata:

import cmipdata as cd
ens = cd.mkensemble('ts_Amon_HadCM3*')
ens = cd.cat_exp_slices(ens)

The result is one unified file in our directory, which has been appropriately named. By default the individual time-slice fields will be deleted, and only the joined file is left in our directory. We can change this by passing the delete=False option to cat_exp_slices(). We were also returned an updated ensemble object, the structure of which we can view as follows:

ens.fulldetails()

HadCM3:
    historical
            r1i1p1
                    ts
                            ts_Amon_HadCM3_historical_r1i1p1_185912-200512.nc

Note that the joined file has been named in such a way that the start and end dates cover the full range of the input files.

This example shows only one model, but the method works equally well for a large ensemble consisting of multple models, each with multiple realizations and hundreds of files. For example, using:

ens = cd.mkensemble('ts_Amon_*')

would build an ensemble consisting of all files in the present directory starting with ts_Amon, and join_exp_slices would, on a per-realization basis, do the joining, when necessary.