MERRA2 Global Atmosphere Forcing Data

The MERRA2 was introduced to replace the original MERRA dataset because of the advances made in the assimilation system that enable assimilation of modern spectral radiance and microwave observations, along with GPS Radio Occultation datasets.

It also uses NASA's ozone profile observations that began in late 2004. Additional advances in both the GEOS model and the GSI assimilation system are included in MERRA2.