CONUS404 radiation (GLW and SWDOWN) no data for first time step

[amsnyder]

I noticed that two of the radiation variables (GLW and SWDOWN, I did not check the others) have no data on the first hour of the CONUS404 simulations (1979-10-01 00:00). I understand that accumulated variables like PREC_ACC_NC do not have any data on the first hour, because it represents a sum of the precipitation over the last hour; because the model just started, there is no previous hour to sum. However, I think the radiation variables that I mentioned are instantaneous measures of the radiation hitting the surface at that particular point in time, and the other instantaneous variables that I've worked with in the dataset do have data on the first timestamp of the model simulation. Do you know why these variables would be missing the first hour of data?

@aubreyd could you help tag in someone who might be able to help answer this?

[aubreyd]

Tagging @lulinxue

[lulinxue]

@amsnyder Many fields in the WRF output of the initial time directly reflect the values in the wrfinput file. For fields that are not part of the initial conditions, they are associated with specific physics prescribed in the namelist. The physics is not integrated at the very first initial time which leads to zero values in the wrfout. Radiation is called every 5 mins or so, therefore, non-zero values will show up at least 5 mins into the simulation. Let me know if this helps.