swint_opt=1,swint_opt=2

[yx06]

Help me, this problem has been bothering me for a long time. I would like to ask, when I set swint_opt=1, my SWDOWN does not match with the SWDOWN when swint_opt=2. But according to the official website, the Fast All Sky Radiation Model (FARMS) scenario for solar applications can be activated by setting swint_opt = 2. FARMS calculates the surface irradiance for each model time step and stores the value in SWDOWN2, what is the difference between the output SWDOWN and SWDOWN2 at this point? I am not sure which variable I should use as a result of the total irradiance.
I would like to get the answer and appreciate it in advance.

 

[Ming Chen]

With swint_opt = 1, short-wave radiation is interpolated between the calls of SW scheme.
With swint_opt = 2, the Fast All-Sky Radiation Model for Solar applications is called at every time step.

Because of the different approaches used in these two options, it is understandable that the results are not identical.

 

[yx06]

Thank you for your reply, I understand it now and am very grateful