GPM-IMERG
work in progress !
Integrated Multi-satellitE Retrievals for GPM
IMERG is an algorithm that combines information from the GPM satellites to estimate global precipitation. IMERG is the continuation of TRMM. The latest Version 06 combines the precipitation estimates collected by the TRMM satellite (2000 - 2015) with the estimates from the GPM satellite (2014 - present).
More information is available on the NASA GPM website.
We download the data from their hyrax server, using the opendap protocol, so we can get it in netcdf4 format instead of the original HDF5.
GPM-IMERG at NCI
The GPM data is available, as part of the Precipitation datasets collection, in:
/g/data/ua8/Precipitation/GPM
The original data is divided in folders by year
<yyyy>/3B-HHR.MS.MRG.3IMERG.<yyyymmdd>-S<hhmmss>-E<hhmmss>.<time-fo-day-in minutes>.V06B.nc4
Where S<hhmmss> is the start timestamp, E<hhmmss> is the end timestamp, these are followed by the time of the day expressed as minutes starting form 0000.
As an example:
2019/3B-HHR.MS.MRG.3IMERG.20191231-S233000-E235959.1410.V06B.nc4
We also provide a concatenated version with monthly files:
/GPM/concat/gpm_3imerg_v06b_<yyyymm>.nc
This is produced using cdo to concatenate the original files