Project: coastDat - Regional Water and Matter Fluxes at the Land-Ocean Interface - In order to better understand the global coastal systems and the dangers and risks associated with them, it is important to examine the atmosphere, the land, hydrology, the ocean and especially their interactions and feedbacks. In this project, we provide data on water and matter transport at the land surface. Currently, contributions were made by Umweltforschungszentrum Leipzig (UFZ) and the “Regional Land and Atmosphere Modeling” department of the Institute of Coastal Systems - Analysis and Modeling at Helmholtz-Zentrum Hereon as well as from NIOZ and IOW. Our aim is to quantify the associated cycles of water and matter and their changes, mainly for the transition from land to the ocean. Our work contributes to GCOAST (Geesthacht Coupled cOAstal model SysTem) --> https://www.hereon.de/institutes/coastal_systems_analysis_modeling/research/gcoast/index.php.en Summary: 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.
