Computes the monthly mean values of discharge, concentration, flux, flow-normalized concentration and flow-normalized flux (Q, Conc, FNConc, Flux, and FNFlux) in SI units
If WRTDSKalman has been run the outputs are averages for Q, Conc, GenConc, FNConc, Flux, GenFlux, and FNFlux.
Note that the Flux, GenFlux, and FNFlux values are average flux values (not totals). For discharge the units are in m3/s, concentration is mg/L, and flux is kg/day.
It returns a data frame containing month, year, decimal year, and mean values of DecYear, Q, Conc, GenConc, FNConc, Flux, GenFlux, and FNFlux.