The answer from ESRL PSD data about precision and least_significant_digit: Hi Least significant digit is in the original grib files. Precision is calculated here and is related to the packing. The precision may be a little sloppy with regards to our packing. We hope to be transitioning to netCDF4 at some point soon, which is what we use for other datasets. It does not need scale/offset packing as it packes internally. Cathy Smith answering for PSD data
netcdfgroup
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