The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) is the latest atmospheric reanalysis of the modern satellite era produced by NASA’s Global Modeling and Assimilation Office (GMAO). MERRA-2 incorporates observation types not available to its predecessor, MERRA, and includes updates to the Goddard Earth Observing System (GEOS) model and analysis scheme to provide an advanced product suite suitable for weather and climate applications.

MERRA-2 is a long-term record of global atmospheric analyses, beginning in 1980. It was introduced to replace the original MERRA dataset because of the advances made in the assimilation system that enable use of modern hyperspectral radiance and microwave observations, among other data types. Additional advances in both the Goddard Earth Observing System (GEOS) model and the Gridpoint Statistical Interpolation (GSI) analysis technique are included. MERRA-2 takes some significant steps toward the GMAO’s target of an Earth System reanalysis. With its assimilation of the long-term observational record of atmospheric aerosols, MERRA-2 is the first long-term global reanalysis to represent aerosol impacts on other physical processes in the climate system. MERRA-2 sustains GMAO’s commitment to having an ongoing near-real-time climate analysis.

The six square data images shown below and on the data cube illustrate the cubed sphere grid used in the GEOS model that helps improve the representation of the polar regions compared to traditional latitude-longitude grids. On the back of the printed card are overviews of the six different data sets shown here.