Slice each field in the list, returning a new list of fields. Slicing by indices or by coordinate values are both allowed.
Examples
>>> fl
[<CF Variable: air_temperature(73, 96)>,
<CF Variable: air_temperature(73, 96)>]
>>> fl.subspace[0,0]
[<CF Variable: air_temperature(1,1)>,
<CF Variable: air_temperature(1,1)>]
>>> fl.slice(longitude=0, latitude=0)
[<CF Variable: air_temperature(1,1)>,
<CF Variable: air_temperature(1,1)>]