Hello, I am trying to run simulations using FLEXPART v11, but have been running into a number of issues that I was hoping somebody would be able to help with. I am running my simulations using the NCEP Climate Forecast System Version 2 (CFSv2) 6-hourly Products<https://rda.ucar.edu/datasets/d094000/dataaccess/>, which I have done successfully using previous versions of FLEXPART. I am running approximately 1500 simulations using slurm on a HPC here at PNNL. Roughly 2/3 of them complete without an issue, but the remaining 1/3 fail with a segmentation fault. There are also a few simulations that fail with a HF5 error, but they are definitely in the minority. I have attached a couple folders of the input folders, one for a simulation that worked and one that didn’t. From debugging, it appears that the issue is coming from interpol_mod, specifically the function hor_interpol_4d. The failure comes when ix and jy are very large and negative (-2171xxxxx, something like that). Interpret this as some sort of memory access issue, but this is coming to my limits of fortran and computer science. I have tried restarting the simulations at the point where, or just before where they failed. The runs complete at this point, but the partoutput files (what I am primarily interested in) are empty. Do you have any insight into why this might be happening, or advice about how to fix the issue? Thanks for your help. Best, Gavin Gavin Cornwell Earth Scientist Pacific Northwest National Laboratory Earth and Biological Sciences Directorate gavin.cornwell@pnnl.gov<mailto:gavin.cornwell@pnnl.gov> 509-375-6364 [failed.tar](/uploads/5a720f0cd2fdf21f611e064227cf8e83/failed.tar) [successful.tar](/uploads/1792ee4b7cbbd244779941fdc9291e7d/successful.tar)