Objective

library(hector)

Here are some notes about how to add a new species that will effect Hector’s radiative forcing budget in order to answer the question “how much impact does this newly discovered forcer X have”.

Here are some notes as to how to do this

• option 1: add the estimated radiative forcing values to the miscellaneous radiative forcing variable
• option 2: add a new component to Hector and pass the appropriate information to Hector’s forcing components

Option 1

Use Hector’s miscellaneous radiative forcing variable to read additional radiative forcing values. This approach requires little to no code experience but does require that the users have radiative forcing values readily available. Users can read in the new radiative forcing values via the ini file with the Fmisc variable. Alternatively using the R hector package, users can read in miscellaneous forcing to a hector core with RF_MISC() and the setvar() functions.

Option 2

Adding a new component to Hector will required changes to the cpp code. Start by creating a new Hector component, using the dummy_model_component as the template. Use this component to read in the emissions. If the forcer being added is a GHG then use the appropriate method to convent from emissions to concentrations and expose the concentrations so that they may be passed to other Hector components. Next modify the forcing_compoent.cpp, add the equation that to convert the emissions or concentration time series to radiative forcing values. The new values should be added into the forcing map so that these new values will be incorperated into the total radiative forcing calculation.