id summary reporter owner description type status priority milestone component version resolution keywords cc 245 particles below ground are reflected ZhenhuaHao "hi there, I reaslise that in subrountine 'advance.o', all the particles that below the ground are reflected which means they are moved back to the altitude above ground. I could understand this setting for gas, but maybe not for some particles, and it make no sense for my case when I am simulating seed dispersions. So I would suggest to set up a switch to do reflection or not. If I want to fix in my own version, could you comment on how to fix it in the most simple way? " New feature closed major FP coding/compilation FLEXPART-WRF worksforme altitude