AMS Annual Meeting - MERRA Short Course

Today, January 11, we hosted the short course on MERRA and data access. We had 15 attendees from a variety of backgrounds, research and applications, universities and government. Also, there were a range of experiences, some familiar with reanalyses some no prior experience. Our objective was to provide the basic understanding of the system, how we validate and use the data in research and how to access the data (with traditional methods, and newer online software access).

The day started with and overview of the project and the GEOS5 data assimilation system by Michele Rienecker. Michael Bosilovich presented an overview of the validation prior to starting the reanalysis and the current description of the hydrological cycle and global energy budget. Steve Berrick described the access to the data and the various portals at the MDISC. Arlindo da Silva gave a wide ranging presentation on how many different software packages can access MERRA online data.

We were pleased to have Alan Betts give a lunch time presentation covering much of the work he has done over the last 10 years working with ECMWF reanalyses data. The afternoon was reserved for some hands on data analysis and processing activities. We provided digital handouts including many of the presentations but also some software and data that the attendees could run on rented laptops (or their own).

The first hands-on exercise was reproducing some of Alan's figures of ERA land atmosphere interactions except with MERRA data. Next Arlindo da Silva discussed the regridding and reformatting of reanalyses data with the theme of "Look-Alike" imitation. In other words, making MERRA look like NCEP reanalyses (or any other reanalysis) for comparison or reading into existing software applications.

One theme of the meeting was processing data online, not downloading data, but producing the answer with online utilities. This was primarily through GrADS Data Servers (GDS) . The Look-Alike hands-on activity included a walkthrough where participants created MERRA data files from the online data servers using a command line utility (lats4d). Following that, Michael Bosilovich showed examples of using serverside calculations to improve the efficiency of online GDS calculations.

Lastly, Dana Ostrenga of the GSFC MDISC demonstrated the Giovanni access and evaluation of MERRA data, including the along track (satellite track) utility soon to be released. This will allow comparison of MERRA vertical sections compared to A Train data, such as Cloud Sat.

We are currently preparing the materials (including software and presentations) for WWW distribution and will post a message here when they are ready. The networking and online data servers performed well during these exercises.