GEO on Continuing Reanalyses

GEO has published an article supporting the reanalyses development and international collaboration and coordination. Reanalyses represent a significant confrontation between the models and observations, and can be used to improve both, and produce a research quality value-added data product. While CFSR, Interim, 20CR and MERRA are all being released about the same time, they were not planned that way. So, there is a unique opportunity to have a community-wide check on our technological development in the models, assimilation, observations quality and computational resources (which affect the resolution and numerics). Generally, there will be advantages and disadvantages to each of these, which will take some time and effort to sort out. While they will be different, the important point will be is if they are making improvements on the representation of the Earth system.

In order to make progress, continuity and traceability in the system development will be crucial, but can only be attained if the respective centers have regular plans to produce the next round. If too many years go by, the next systems will be so different isolating and understanding the reasons for differences will not be possible. To little time, and the next reanalysis will not represent much difference, and the community will begin to feel the workload updating to the latest. Ideally, the next reanalyses should utilize all the information gained on the quality of the observations from the previous reanalyses, while advancing the representation of physical processes and data assimilation.