Upgrade to IMERG Early and Late Runs
The upgrade of GPROF and the Combined Radar-Radiometer Algorithm (CORRA) code to Version 07 as of 0 UTC on May 9, 2022, while IMERG continues at V06 until August, requires the Early and Late Runs to change slightly and be given the version number 06C. Specifically, the V07 GPROF and CORRA data must be used in V06 IMERG, and the GPCP climatological calibration has been recomputed to account for the change in CORRA. In addition, the GMI-other sensor calibrations will shift over the next month as V07 data are incorporated into the accumulation files. We expect the Early and Late time series to be relatively consistent across this data boundary.
IMERG was upgraded to V06C when the May 9 data became available for the Early Run. At that point the Late Run only had V06 input available, but the new GPCP-adjusted CORRA calibration started being applied. After about 10 hours the Late also shifted to V07 input at 00 UTC 9 May. We expect the changes to be modest, and think that users desire a continuous record of data, so the additional small inhomogeneity in the Late record is accepted. All Late files with V06C before May 9 are affected.
Starting on May 9, 2022, 0 UTC, a gridding problem prevented the use of GPROF-AMSR2 input in IMERG Early and Late. The problem was rectified around 16 UTC and data started flowing into IMERG.
The last month of V06 IMERG Final available is September 2021. The full June 2000-to-present data record will be reprocessed once IMERG Final moves to V07, which is scheduled to occur in August 2022
Thank you for your patience during this transition.