The merged-satellite Solar Backscattered Ultraviolet (SBUV) Level-3 monthly zonal mean (MZM) product (MSO3L3zm5) contains 1 month zonal means for profile layer and total column ozone based on v8.6 SBUV data from the Nimbus-4 BUV, Nimbus-7 SBUV, and NOAA-9 through NOAA-18 SBUV/2 instruments. The v8.6 SBUV algorithm estimates the ozone nadir profile and total column from SBUV measurements, and differs from the v8.0 SBUV algorithm via the use of 1) the Brion-Daumont-Malicet ozone cross sections, 2) an OMI-derived cloud-height climatology, 3) a revised a priori ozone climatology, and 4) inter-instrument calibration based on comparisons with no local time difference.

The MSO3L3zm5 product is stored as a single HDF5 file, and has a size of 0.4 MB. The MZM product contains 5.0-degree-wide latitude zones with data between latitude -80.0 and 80.0 degrees. The data cover the time period from May 1970 through July 2013. Data coverage during the BUV mission from 1970 - 1977 contains many gaps after October 1973, and there are no data between November 1976 and November 1978. Continuous data coverage begins with SBUV and SBUV/2 missions starting November 1978.