Total Column Ozone from EP-TOMS and MERRA-2 GMI

The ozone layer is Earth’s protection from harmful ultraviolet radiation. NASA has a long history of measuring total column ozone using a variety of instruments, typically with polar orbiting satellites measuring backscattered solar radiation. This produces near global coverage over the course of a day over the sunlit portion of Earth. Some missing data occurs between swaths, over the polar region during winter, and during satellite outages. This animation shows the evolution of daily composites of total column ozone as observed with Earth Probe Total Ozone Mapping Spectrometer (EP-TOMS), on the right panel, from July 1, 2002 to Oct. 31, 2002. On the left panel is the total column ozone from the MERRA-2 GMI simulation, with hourly time resolution over the same time period. MERRA-2 GMI is a Goddard Earth Observing System version 5 (GEOS-5) “replay” simulation at 0.5° (~50km) horizontal resolution, driven by MERRA-2 reanalyzed winds, temperature, and pressure, coupled to the comprehensive Global Modeling Initiative (GMI) stratosphere-troposphere chemical mechanism. This animation shows the onset of the Antarctic ozone hole formation during austral winter of the dynamically active 2002 season and its breakdown during spring. In September 2002, the Antarctic polar vortex split into 2 lobes following the first and only observed major stratospheric warming in the Southern Hemisphere over our observational record. By combining NASA’s observations and chemistry simulations we have a clearer view of the evolution of Earth’s ozone layer over the recent past.