Without lat and lon information in ideal case, how to calculate the local time?

[Shaofeng Hua]

For example, assume we set the time as 0000 UTC in an ideal case (such as em_quarter_ss or em_les), because both lat and lon are 0, how can we know
the local time?
0000 UTC is midnight? or morning?

 

[Ming Chen]

Most of the ideal cases don't provide lat/long information because these cases are not run on grids with specific map projection. In these cases some physics options like radiation are not activated. Therefore 'local time' doesn't really matter.

 

[Shaofeng Hua]

Thank you for your reply, but I have to activate the radiation process, so the "local time" is important.

 

[Ming Chen]

In this case, you need to modify the initialization code for the ideal case you are interested. For WRF version earlier than WRV4.0, each ideal case has its own initialization code, for example module_initialize_quarter_ss.F for quarter_ss. Since WRFv4, the initialization of all ideal cases are put in the same code module_initialize_ideal.F.
Please take a look at the initialization for seabreeze2d_x, in which xlat and xlong are explicitly specified. Note that they don't correspond to realistic location of the grid on earth and no map-projection is specified.