Model setups for SimplyC for Nordic boreal headwater catchments

This is accompanying model setups for the paper Norling M.D., Jackson-Blake L.A., de Wit H.A. *Modelling long-term and seasonal variations in organic carbon export from Nordic boreal headwater catchments using the widely applicable SimplyC model.* (to appear). See the paper for description of the sites and model setups. Usage Install and get started with Mobius2 [following the description on its home page](https://nivanorge.github.io/Mobius2/gettingstarted/gettingstarted.html). Open the setups using MobiView2 and Mobius2/models/simplyc_model.txt or Mobius2/models/super_easy_c_model.txt . The latter one should be used if there is a lake in the catchment. If you are in doubt, open the .dat file with a text editor to see what model it expects in the first line. (You will also get an error if you open it with the wrong model). For each site, the following model setups (.dat files) can be opened: - calib_all_data.dat : Here, the DOC parameters are calibrated against all available stream DOC samples.- calib_1997_2003.dat : (not available at all sites). Here, DOC parameters are calibrated against stream samples in the years 1997-2003. Used for validation of predictivity of the model on later data.- calib_after_2000.dat : DOC is calibrated on all available data after the year 2000.- doc_regressed.dat : DOC parameters are determined based on regression against the other sites.- doc_one_sample.dat : As above, but baseline DOC is determined based on one autumn sample. Further description of the setups is found in the paper. Data source attributions and acknowledgements For each catchment, daily temperature and precipitation were derived from the Norwegian Meteorological Institute Nordic Gridded Climate Dataset, version 19.09, with a spatial resolution of 1 × 1 km (met.no) using area-weighted catchment means, were obtained. SO4 deposition data was obtained from NILU (Blake Lewis et al. 2023). These gave values with approximately 5-year intervals, which were linearly interpolated to construct a full daily series. This work was funded by the Research Council of Norway, with co-funding from the FRIPRO project QUANTOM (Grant 314957), FESTiVAL (Grant ES742317) and NorSink (Norway's carbon sink under climate change, Grant 352474). The FESTiVAL project is part of the EU's Horizon Europe Programme under the 2023 Joint Transnational Call of the European Partnership Water4All. The collation of water chemical data, discharge and catchment metadata for the 16 catchments was funded through BIOWATER, a Nordic Centre of Excellence under the Nordic Programme of Bioeconomy (NF Project Number 82263). In particular, we’d like to acknowledge the role of Hannu Marttila, Martyn Futter and Ahti Lehpistö during the data collation. National agencies (Naturvårdsverket, Miljødirektoratet, Finnish Environment Institute SYKE) are acknowledged for their support of long-term surface water monitoring.