Hi

I have a question about running the CMAQ model. We have WRF output in 1-hour time step. How CCTM interpolate MCIP output to run the model? because the max sync time step is 300 sec.

Thank you

I/O API routine `INTERP3`

: see https://www.cmascenter.org/ioapi/documentation/all_versions/html/INTERP3.html

Hi Carlie

Thank you for your reply. Suppose we have meteorology for 1 and 2 o’clock. Could you guide me on how to interpolate data for 1:05, 1:10, 1:15, 1:20, …, 1:45, and 1:55 from data of 1 and 2 o’clock?

I saw the link you sent, but I couldn’t solve my problem. Could you help me, please?

Thank you

`INTERP3`

maintains double buffer arrays for this variable (let’s call it `V`

) and (for this example) times 1:00 and 2:00 – `V1`

at 1:00 and `V2`

at 2:00, respectively. Then at 1:05, let

`P = (2:00-1:05)(2:00-1:00) = 55.0/60.0`

and

`Q = 5.0/60.0`

be the linear-interpolating-fraction coefficients to interpolate from 1:00 to 2:00 (note that `P+Q=1`

). To get `V`

at 1:05, do the array-arithmetic `P*V1 + Q*V2`

.

And similarly, at 1:10, `P = 50.0/60.0`

and `Q = 10.0/60.0.`

etc.