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?

[pesei]

There are two arguments for the way how it is coded (in both FLEXPART and FLEXPART-WRF):

1. Particles can be reflected physically as well. The probability that deposition occurs is properly taken care for. Maybe there are some slight improvements possible, because maybe a calculational particle does not enter the dry depo layer before reaching the ground. But this does not justify to let all mass associated with a particle reaching the ground be deposited.

2. Computational particles are terminated only at the lateral or top domain or if they reach the maximum age.

I would not advise you to modify this behaviour. If you have direct evidence of too weak dry deposition, please let us know.