Arctic Sea Ice Phenology in CMIP6

The seasonal timing of summer sea ice retreat (sea ice concentration falls below 15%) and fall sea ice advance (sea ice concentration rises above 15%) is recorded annually, as are the annual sea ice minimum, day of minimum, and the length of the open-water (i.e., ice-free) period. Data input is daily sea ice concentration from CMIP6 models that were run under four experiments: historical, ssp126, ssp245, and ssp585. The first ensemble member for each model and experiment is included. A single-model ensemble (MPI-ESM1-2-LR) with 10 members is also included for each experiment. All data are stored in NetCDF4 files on the same grids as the original model output.