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Selects the representation of the archived data if more than one are availbleis available, e.g. the ERA-15 archive contains surface data as Gaussian and latitude/longitude grid, fields on pressure levels are archived as both spherical harmonics and Gaussian grid. As this is no longer common practice, this keyword can in general be ignored. Valid values are sh for spherical harmonics, gg for Gaussian grid or ll for latitude/longitude. If nothing set, repres will default to sh.
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