Dear All,

I’m running the RegCM-4.1.1. At first, I set the frequency of ATM and RAD outputs at 6 hours and SRF output at 3 hours. And I use CDO to postprocess the data at daily means. I name the output as o and opost respectively. Then I rerun the model, setting the frequency at 24 hours for all of them. I name its output as odaily.

My questions are as follows.

1. I find that the tpr (total precipitation) written in odaily are daily mean values, while the tg (surface temperature) are instant values. I only compared these two variables, and I don’t know what is about for other variables. Why the model writes them in the two different ways? Besides, if the monthly outputs can be derived straightly from the model?

2. I find that every opost has one additional time slice for all of the variables. It is because that the last time in o is recorded at 0:00 in the next month. When the CDO computes their daily or monthly means, it will not include the last time slice. So the daily or monthly means of opost will ignore the last time of the variables for every month. Although the differences for the last day between the opost and the Fortran processed daily means are small, I think some errors will be caused when using the opost to run another model if I ignore the last time slice of variables. I’m not sure if I’m right.

I hope your help.

Regards,

Miao