Dear Olson I am a user of cesm1.2.2. I am interested in simulating global precipitation for Sept, 2016 - Jan, 2017 with CAM-SE 1deg set up. I am following the step (#3) in https://bb.cgd.ucar.edu/node/1001566 for generating the ICs. 1. I spun up the land from 2010/01 - 2016/02. Now I've land ICs and atmospheric startup file for 2016/03. 2. I regridded the ERA-Interim data for 2016-03-01:00:00:00 to SE 1 deg. I did not fully understand the next step:For spin up of atmosphere, 6-hourly runs are suggested for one model month replacing with ECMWF values after every 6-hourly interval. Does it mean that I replace the state variables with ERA-Interim for 2016-03-01:00 and stop it after first 6-hours (with inithist='6-hourly'). Then again replace with ERA-Interim 2016-03-01:06 values and run again for next 6 hours and so on. Do this until 2016-03-31:18. a. Is my understanding correct?b. why this exercise has to be done for 1 month (= [31 days x 4 timesteps] times)?c. What way will it effect if I just do this for the first timestep i.e, 2016-03-01:00 and let it run until jan 2017?