Impact on energy efficiency assessment: WEEK 2

The first dataset was published in 2009 by NASA’s Global Modelling and Assimilation Office (GMAO). It is based on a version of the GEOS-51 atmospheric data assimilation system that was frozen in 20082. Due to apparent limitations and deficiencies, production of the MERRA reanalysis dataset ended on February 29, 2016.

Incorporating the latest advances in atmospheric modeling and data assimilation, the MERRA-2 program was developed to replace the original MERRA product. The water cycle was a major consideration in the development of the first data assimilation system. Over time, use of the original water balance equation revealed inconsistencies in terms of mass conservation.

It was therefore necessary to develop a more reliable model. The MERRA-2 data assimilation system differs from its predecessor in that the data system includes many additional observations (mainly satellite data), as well as a preferred cubic-spherical grid, instead of the initial latitude-longitude grid. In addition, certain modifications have been made to the forecast model, as well as to the assimilation procedure.

Sources :

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-16-0758.1
https://gmao.gsfc.nasa.gov/reanalysis/MERRA/

By Perrine Bugeat – Asset Manager