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Uncertainty in the future nitrogen load to the Baltic Sea due to unknown meteorological conditions. Jerzy Bartnicki Norwegian Meteorological Institute. Background. Eutriphication due to nitrogen load is a serious and expensive problem for the Baltic Sea
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Uncertainty in the future nitrogen load to the Baltic Sea due to unknown meteorological conditions Jerzy Bartnicki Norwegian Meteorological Institute
Background • Eutriphication due to nitrogen load is a serious and expensive problem for the Baltic Sea • Atmospheric part of nitrogen load is 25-30% • In the frame of agreement between HELCOM and EMEP, atmospheric load of nitrogen is calculated every year based on updated emissions and meteorological data • EMEP Unified model is used for calculation of nitrogen depositions to the Baltic Sea, as well as source receptor matrices • The Source receptor matrix gives the contribution of each of more than 50 emission sources (EMEP countries, ship emissions etc.) to the deposition • What about the future?
Practical problem • Following Gothenburg Protocol and EU NEC Directive, the nitrogen emissions will be reduced in 2010 for most of the sources • How will it affect atmospheric deposition of nitrogen to the Baltic Sea and its sub-regions in 2010? • Which sources will contribute most to the deposition in 2010? • Request from HELCOM to EMEP • What about uncertainty of the prediction? What will be uncertainty due to unknown meteorological conditions?
Simple solution • Compilation of 2010 nitrogen emissions in the model grid system following Gothenburg Protocol and EU NEC Directive (+ 2 additional scenarios) • Runs of EMEP Unified model using meteorological data for: 1996, 1997,1998, 2000 • Computation of nitrogen deposition for each of available meteorological year • Computation of source receptor matrices for each of available meteorological year
HELCOM CP’s Denmark Estonia Finland Germany Latvia Lithuania Poland Sweden Russian Federation + Europan Commision
EMEP Unified model • Eulerian, 170 × 133 grids, Δx=50 km • 20 vertical layers up to 10 km • Topography and land use included • Meteorological data every 6 hour (300TB – 1 year) • 150 chemical reactions also in clouds • Dry deposition processes • Wet deposition with in cloud and below cloud scavenging • 1 year simulation – 2 hours execution time
2010 deposition maps N oxidized N reduced
2010 deposition maps N dry N wet
Main sources for total nitrogen deposition to the Baltic Sea
Conclusions • More model runs with the same emissions and different meteorological years necessary to have a better idea about the probability distribution • A longer period than one year is necessary to evaluate the effects of nitrogen emission reductions. • The results of this project had an impact on the plans for the future emission reductions of nitrogen oxides and ammonia in Europe