HYSPLIT Forum: hysplitbbs.arl.noaa.gov

I'm trying to calculate concentration of volcanic ash by using NOAA's HYSPLIT modeling on PC version; hysplit4. However, the calculations always have been failed. *ERROR*
The numbers of Deposition Set-up must be wrong.
Deposition velocity (m/s), Pollutant molecular weight (Gram/Mole), Surface Reactive Ratio, Diffusivity Ratio, Effective Henry's Constant are suggested numbers in Table 1 in "Help" but the values for calculation of volcanic ash is not suggested.

Although Pollutant molecular can be given as SiO2, the others are difficult to detect the numbers.
Please give me advice.

We don't know exactly what is in the ash, so approximations are made. In that GUI section, first do a run choosing Particle, and no wet, no dry deposition. Save the CONTROL file for reference. Then add dry deposition, which will give a value for the deposition velocity. Then add wet deposition.

Thank you for replying. I'll try it!