ISIMIP2b protocol changes

We have a few important protocol changes and corrections that we'd like you to be aware of:

• All sectors: In order to ensure a smooth transition between the pre-industrial and historical periods, the pre-industrial CO2 concentration needs to be set to 286ppm (not the previously announced 278ppm!). This has been corrected in the CO2 concentration files that can be found online. If you have already conducted the pre-industrial runs using the original CO2 concentration value of 276ppm and do not intend to repeat the runs, please let us know, and include this information in the metadata of your NetCDF output files.
  
• Biomes & Permafrost: two new output variables are now requested: N20 emissions into the atmosphere (n2o) & CH4 emissions into the atmosphere (ch4). These variables can now be found in the output-variable tables for the biomes and permafrost sectors (Tables 11 and 18 of the protocol).
• Water: five new output variables have been added to the water-sector output-variable table (9):
  
• total water storage (tws),
• total actual water consumption (atotuse),
• total actual water withdrawal (atotww),
• groundwater runoff (qg),
• groundwater recharge (qr).
• Water: The definition of the variables surface runoff (qs) and subsurface runoff (qsb) have been added:
  
• qs: "Water that leaves the surface layer (top soil layer) e.g. as overland flow / fast runoff"
• qsb: "Sum of water that flows out from subsurface layer(s) including the groundwater layer (if present). Equals qg in case of a groundwater layer below only one soil layer"

Please note that all these changes are documented in the protocol change log, which can be found at Protocol>ISIMIP2b Protocol Changes on the website.