MERRA began production in March 2008. After data is produced, the GMAO examines the data files in several ways to test the quality of the data. When we are confident that the data files are within the tolerance of the uncertainty we have seen in our validation experiments, we release it to the MDISC. At that point, they provisionally release it for download. We are not holding the data for any substantial length of time, before it can be accessed by the community.
When will my case study be produced and available? Or, when will X number of continuous years be available?
Each stream is moving forward at ~10 days/real day, slightly faster for the early period as there are less observations to deal with. So, let's say ~2 months each week, so maybe in 7 months we can have 5 years.
These are best case conditions that will not happen over long periods. The computers go down from time to time, scheduled and unscheduled. We estimate more than a year to finish any one stream, and likely 18 months to finish it all. Also, there is a chance that a severe bug may occur that affects the scientific integrity of the data. In this case, any time period may need to reprocessed delaying overall production. Check: http://gmao.gsfc.nasa.gov/operations/merra_status_production.gif for the current progress of the data streams. This provides the current date of each stream. Use 10 days per day, and add 25-50% slack to estimate when the date you are interested in will be produced.
