1. Global Earth Science Community
  2. Community Data System Programs
  3. REASoN Projects
  4. MERRA: Modern Era Retrospective-analysis for Research and Applications

MERRA: Modern Era Retrospective-analysis for Research and Applications

Recent research has shown that assimilating remotely sensed rain rates improves not only precipitation predictions, but also the outgoing long wave radiation of the planetary energy budget. This yields improved short-term forecasts, including hurricane tracks and threat scores. Previous long-term reanlyses of the Earth's climate had unacceptable levels of uncertainty in precipitation and inter-annual variability. The improved diagnostics of the water cycle developed by NASA's Global Modeling and Assimilation Office (GMAO), combined with the ever-advancing art of large-scale computation, will enable Modern-Era Retrospective Analysis for Research and Applications (MERRA) to produce data products which directly address the variability and predictability of the hydrological cycle.


Beyond the focus of the hydrological cycle, there are numerous other potential uses for reanalysis data. The disseminated data products will provide much improved initial conditions for predicting weather and other subseasonal variability that is strongly linked to tropical moisture. Studies of climate variability rely on reanalysis data sets. Limited domain models use reanalyses to provide the boundary forcing and initial conditions for mesoscale and regional climate simulations. The reanalysis data can be used in applications driven projects. For example, the precipitation, evaporation and runoff can drive river flow models and help to study sensitive ecosystems, such as estuaries. Transport models can use the reanalysis winds to evaluate aerosols.

The educational component of the MERRA project will involve college students running simplified versions of the assimilation infrastructure to study climate change. MERRA data products will conform to ESE standards, and will be disseminated over the Internet. The MERRA dataset will be a cornerstone of the collective data developed for addressing the NASA Earth Science mission.

With the current keen interest of the scientific community and society on climate and predictability, MERRA will answer the call for a 21st century reanalysis product that capitalizes on state-of-the-art assimilation and modeling techniques and the incorporation of NASA's remotely sensed observations. MERRA is funded by a NASA Cooperative Agreement Notice (CAN): Earth Science Research, Education, and Applications Solutions Network (REASoN).


Siegfried D. Schubert - PI, Goddard Space Flight Center (GSFC)
Michael Bosilovich - co-PI, GSFC

Last Updated: Nov 15, 2017 at 10:30 AM EST