Giovanni for Quick look and data download

Recently a question about some regional climate data came in, it needed to be independently checked. It seemed like a good opportunity to make use of the Giovanni portal into the MERRA data. Many of the MERRA data collections are available to Giovanni, even 2D one hourly data. MERRA data is directly linked through the Giovanni page, but also from the MERRA data holdings page, which may be more desirable since there is more documentation about what is in each MERRA collection.

Once at the MERRA/Giovanni page, there are options to choose variable(s), region, level and time. There are several hardwired calculation/visualization options in which the data can be presented. Depending on the size of the request, there may be a few minutes before the results are available. However, once they are there is options to download the visualizations, or the data. Both source data and processed data can be retrieved. At this time, HDF, NetCDF and ASCII formats are supported for download.

The FTP Subset is the best way for large requests, and OpenDAP/GDS still serves a purpose for some on the fly live calculation jobs needing flexibility. However, Giovanni fills the middle ground in data visualization and retrieval. It certainly is worth a test drive, and may be a useful option in many cases. Given the range of what can be done with MERRA data, the wide array of ways to access the data should fit most needs.