The IMERG development team has become aware that a small number of isolated bad Level 2 GPROF orbit granules leaked into V07A IMERG Final Run processing.  The team is working with PPS to identify a more-complete list of such instances and trace them back to the Level 1C microwave data.  Additional testing is being done and might reveal a few more cases. 

Image

We are providing this information now in case the times happen to impinge on a detailed study that you are performing.  The above image is an example of one of the worse cases (from F16 SSMIS); most cases are less severe or shorter in duration and a few are more severe or longer in duration.  As you can see, the spatial coverage of the artifacts varies with case (details on request).  In the regions affected by the bad granules, in addition to the half hour of IMERG, the IR calibration and adjustment to gauges (over land) will be affected across the month.  The severity of these impacts is being evaluated.

We are working to address the problem, but it may take a while for the data to be corrected because PPS has several high-priority items to address first.

Please contact us for any questions.