---
name: "nc4tonc3"
section: "1"
platform: "linux"
package: "python3-netcdf4"
version: "1.7.2-1+b4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/nc4tonc3"
---

# nc4tonc3(1)

a program to convert a classic netCDF 4 file to netCDF 3 format

## NAME

nc4tonc3 - a program to convert a classic netCDF 4 file to netCDF 3 format

## SYNOPSIS

**nc4tonc3** \[**-h**\] \[**-o**\] \[**--chunk**\] *netcdf4filename* *netcdf3filename*\

## DESCRIPTION

This manual page documents briefly the **nc4tonc3** command.

**nc4tonc3** is a program that converts a netCDF 4 file (in NETCDF4\_CLASSIC format) to netCDF 3 format.

## OPTIONS

These programs follow the usual GNU command line syntax, with long options starting with two dashes (\`-'). A summary of options is included below.

- **-h**

  Shows a summary of the available options.

- **-o**

  Overwrite destination file (default is to raise an error if output file already exists).

- **--quiet=(0\|1)**

  If set to 1, don't print any diagnostic information.

- **--format**

  Choose the netcdf3 format to use. NETCDF3\_64BIT is used by default, or it can be set to NETCDF3\_CLASSIC.

- **--chunk=(integer)**

  The number of records along unlimited dimension to write at once. The default is 10. It is ignored if there is no unlimited dimension. If chunk=0, this means write all the data at once.

## SEE ALSO

[**ncinfo**(1)](/ncinfo/1.md), [**nc3tonc4**(1)](/nc3tonc4/1.md).\

## AUTHOR

This manual page was written by Ross Gammon \<rossgammon@mail.dk\> based on the options displayed by nc3tonc4 -h.