Modeling pathways of riverine nitrogen and phosphorus in the Baltic Sea

摘要: [1] A better understanding of the fate nutrients entering Baltic Sea ecosystem is an important issue with implications for environmental management. There are two sources nitrogen and phosphorus: riverine input atmospheric deposition. In case nitrogen, fixation dinitrogen by diazotrophic bacteria represents a third source. From analysis stable isotope ratios it was suggested that most sequestered in coastal rim, specifically along southern coast its coarse sediments, whereas from dominates central basins. However, pathways timescales between their arrival different basins difficult to obtain direct measurements. To elucidate this problem, we use source attribution technique three-dimensional model, ERGOM, track originating various rivers. An “age” variable attributed marked elements indicate propagation speeds residence times. paper, investigate spreading phosphorus discharges Oder, Vistula, Neman Daugava. We demonstrate which regions they transported how long remain ecosystem. The model results show good agreement estimations observedδ15N values sediments. suggest 95% lost denitrification after average time 1.4 years nitrogen. much longer exceeds our simulated period 35 years.