Question about post-processing and model evaluation

[stwcn1]

Hello. I have some questions about post-processing and model evaluation，which are as follows. I would appreciate it if you could help me in your free time.
1.In the Chemical Transfer section (13.5) of the model evaluation section of the Technical Documentation, it is mentioned that "To remove any differences due to the species background, the cross plume concentration perturbations are compared,  where the perturbation is the difference between the actual plume concentration and the background or ambient  concentration. ", I want to get the simulated perturbation concentration from the model simulation results and compare it with the observed values to evaluate the model. And then in sciDOSpost inp, I specify the keyword is plume (calculate plume ), is that right?
 2.I changed the simulation time for the "Four corners" case in tutorials to two days and used the SCICHEM GUI to view the simulation results, when I select the output surface ozone concentration of the 48hr average, plot choice and fig as shown in Figure 1. I want to output the same graph using the sciDOSpost program, so i use sciDOSpost program output grd file, and using surfer to plot (Fig 2:plume,Fig 3:total) .Gui view the result(fig 1) is not consistent with the fig 2 or fig 3, the peak value is different too.How to get a grd file or pst file with  O3 surface concentration averages over a period of time by using sciDospost program?  Relevant keywords in sciDOSpost are specified as follows:

Spec Units RecSet Space Time Period Statistic FType Filename con o3 ppm coarse AllRec 1st 48 hr Average GRD o3_48hr.grd