If your simulation includes precipitation, you need to specify how the concentration of the State Variables, which are transported by Advection-dispersion, shall change due to precipitation. There are two different ways to do this:
· You may in the combo-box choose the type "Ambient Water", in which case the concentration of the precipitated water mass is set equal to the concentration of the ambient sea water; or
· You may specify the value of the concentration in the precipitated water mass through the types "Constant", "Type 0 File" or "Type 2 File". The constant value will be applied to all points in the model, at all time steps. The type 0 and type 2 data files must cover the whole simulation period and have the same number of items as there are State Variables, which are transported by Advection-dispersion, in the simulation. The type 2 data file must match the spatial extent of the main area.
If you have chosen the net-precipitation option, then the selected Precipitation concentration will be used when the specified net-precipitation is positive. When the net-precipitation is negative, an "evaporation concentration" of zero is applied. If evaporation occurs as part of the optional heat exchange facility, an "evaporation concentration" of zero is similarly applied.