MARS

Specifies the packing method used in the target GRIB messages. 

packing=<value>

Valid values for latitude/longitude output are simple (si) or second order (so). Valid values for spectral fields are complex packing (co) or simple packing (si). In order to preserve the packing of the archived data one would specify archived value (packing = av).

Dissemination

Member States and Cooperating states can request Second Order packing

packing = so;