Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2)
NASA’s Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), is an atmospheric reanalysis designed to provide an intermediate dataset and bridge between the first MERRA reanalysis and the project’s long-term goal of producing a coupled Earth system reanalysis. MERRA-2 incorporates system changes and fundamental developments in modeling and data assimilation, including 1) assimilation of aerosol observations that can interact with atmospheric radiative processes; 2) constraining mass conservation even with the analysis of water vapor, allowing a global balance between evaporation and precipitation; 3) use of a cube sphere to reduce the effect of gridpoint singularities at the pole, allowing for improved polar circulation; 4) an updated radiative transfer model to permit the assimilation of data from many more instruments than could have been included in MERRA; and 5) inclusion of new observational forcing for the land model to provide more stable land feedback processes. This special collection documents the performance of MERRA-2 and addresses key research questions in large-scale climate and weather.
An overview article of the MERRA-2 project can be found here.
Dr. Michael G. Bosilovich, NASA Goddard Space Flight Center