For the Helsinki Commission (HELCOM), annual waterborne basin inflows of total nitrogen (N) and total phosphorus (P) were compiled for the seven main Baltic Sea sub-basins (Sect. 1.1). In order to allow the utilization within a regional Earth System or ocean modelling framework, we redistributed these nutrient loads spatially and temporally using a dataset of bias corrected discharge that was generated with the Hydrological Discharge (HD) model (Sect. 1.2). Following the spatial and temporal downscaling procedure described in Sect. 1.3, we generated a dataset of daily riverine and annual direct nutrient loads (N and P) into the Baltic Sea at 1/12° resolution from 1901-2019. Detailed information you can find in the specified sections of the attached PDF https://www.wdc-climate.de/ui/entry?acronym=HELCOM_HD_info

                In November 2023, the bias corrected discharges were improved after a bug was found (see "Bias corrected high resolution river runoff over Europe (Version 1.0)", https://doi.org/10.26050/WDCC/Biasc_hr_riverro_Eu). 
                Consequently, the redistributed HELCOM loads of nitrogen (N) and phosphorus (P) were also updated using the improved bias corrected discharge dataset. However, changes in the N and P loads into the Baltic Sea are marginal. The annual basin sums are the same, only daily values may have slightly changed.