View all of the Arctic Hemisphere monthly-mean maps of total ozone for April. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone.
Click any map image to bring up a new page with a high-resolution map.
Missing areas (bad orbits and polar night) are filled using assimilated ozone data from the Modern-Era Retrospective analysis for Research and Applications (MERRA and Version 2 (MERRA-2) assimilations, produced by the Goddard Earth Observing System Data Assimilation System (GEOS DAS). MERRA and MERRA-2 use a version of the GEOS model with the Gridpoint Statistical Interpolation (GSI) atmospheric analysis developed jointly with NOAA/NCEP/EMC. Data are also filled using the GEOS FP data are produced by the Goddard Earth Observing System data assimilation system (DAS). The GEOS FP system integrates forefront versions of the GEOS atmospheric general circulation model with advanced data assimilation techniques, using a broad range of satellite observations.
The following links will provide you with bulk access to the images, animations, and raw satellite data.
Missing years are indicated with a plain gray globe.
Monthly averages (1979–current)