Figure 4 requires intermediary files created from Large Ensemble simulations output.
These scripts are all in ncl. For each script, change name and location of source
data directory and output directory then
> ncl script.ncl

The necessary files use the following scripts:

1. create statistics for ice surface heat flux variables fswabs_ai, fsens_ai, flat_ai, flwup_ai, flwdn_ai and fswthru_ai:
     netCDF_aice_stats.LE.ts_bymonth.ncl
will need to change variable name for each of these variables
This script is also used for figure 3 and hence in f03 directory.

2. create statistics for ocean heat flux variables MELTH_F and SHF:
     netCDF_ocn_stats.LE.ts_bymonth.ncl
will need to change variable name for each of these variables 

3. create statistics for surface temperature (atmospheric variable tas):
     netCDF_monthly_stats_tas.CMIP5_MMLE.ncl
will need to change directories, file names accordingly

4. create area averaged time series (to calculated AA) using pre_proc_hem_avg_tas_LE.ncl


Edit file directories, etc and run f04.cont_ndiff_SHF.ncl