nco man page

NCO — netCDF Operators


operator [ options] input-files output-file


The netCDF Operators, or NCO are a suite of programs known as operators. Each operator is a standalone, command line program which is executed at the UNIX shell-level like, e.g., ls or mkdir. The operators take netCDF (<…>) files as input, then perform a set of operations (e.g., deriving new data, averaging, hyperslabbing, or metadata manipulation) and produce a netCDF file as output. The operators are primarily designed to aid manipulation and analysis of gridded scientific data. The single command style of NCO allows users to manipulate and analyze files interactively and with simple scripts, avoiding the overhead (and some of the power) of a higher level programming environment. The NCO Users Guide illustrates their use with examples from the field of climate modeling and analysis.

The available operators are:

ncap2, netCDF Arithmetic Processor

ncatted, netCDF Attribute Editor

ncbo, netCDF Binary Operator (includes ncadd, ncsubtract, ncmultiply, ncdivide)

nces, netCDF Ensemble Averager

ncecat, netCDF Ensemble Concatenator

ncflint, netCDF File Interpolator

ncks, netCDF Kitchen Sink

ncpdq, netCDF Permute Dimensions Quickly, Pack Data Quietly

ncra, netCDF Record Averager

ncrcat, netCDF Record Concatenator

ncrename, netCDF Renamer

ncwa, netCDF Weighted Averager.

(Note that the "averagers" are misnamed because they perform many non-linear operations as well, e.g., total, minimum, maximum, RMS).

The operators are as general as netCDF itself: there are no restrictions on the contents of the netCDF file(s) used as input. NCO's internal routines are completely dynamic and impose no limit on the number or sizes of dimensions, variables, and files. NCO is designed to be used both interactively and with large batch jobs. The default operator behavior is often sufficient for everyday needs, and there are numerous command line (i.e., run-time) options, for special cases. NCO works well on all modern operating systems.


NCO manual pages written by Charlie Zender and originally formatted by Brian Mays.

Reporting Bugs

Report bugs to <>.

See Also

The full documentation for NCO is maintained as a Texinfo manual called the NCO Users Guide. Because NCO is mathematical in nature, the documentation includes TeX-intensive portions not viewable on character-based displays. Hence the only complete and authoritative versions of the NCO Users Guide are the PDF (recommended), DVI, and Postscript versions at <>, <>, and <>, respectively. HTML and XML versions are available at <> and <>, respectively.

If the info and NCO programs are properly installed at your site, the command

info nco

should give you access to the complete manual, except for the TeX-intensive portions.

ncap2(1), ncatted(1), ncbo(1), ncclimo(1), nces(1), ncecat(1), ncflint(1), ncks(1), nco(1), ncpdq(1), ncra(1), ncrcat(1), ncremap(1), ncrename(1), ncwa(1)


The NCO homepage at <> contains more information.

Referenced By

ncap(1), ncap2(1), ncatted(1), ncclimo(1), ncecat(1), nces(1), ncflint(1), ncks(1), ncpdq(1), ncra(1), ncrcat(1), ncremap(1), ncrename(1), ncwa(1).