The GOZCARDS Merged Data for Hydrogen Chloride 1 month L3 10 degree Zonal Averages on a Vertical Pressure Grid product (GozMmlpHCl) contains zonal means and related information (standard deviation, minimum/maximum value, etc.), calculated as a result of a merging process that ties together the source datasets, after bias removal and averaging. The merged HCl data are from the following satellite instruments: HALOE (v19; 1991 - 2005), ACE-FTS (v2.2u; 2004 - onward), and Aura MLS (v3.3; 2004 - onward). The vertical pressure range for HCl is from 147 to 0.5 hPa. The input source data used to create this merged product are contained in a separate data product with the short name GozSmlpHCl. The GozMmlpHCl merged data are distributed in netCDF4 format.