Spatial variation of atmospheric deposition in Europe in 2014

The evaluation of the atmospheric deposition of major inorganic ions emitted into the atmosphere from natural sources and human activities is needed to quantify ion fluxes within the forest ecosystem. In this report we focus on acidifying, buffering, and eutrophying compounds in deposition collected under forest canopy (throughfall deposition). High deposition of N-NO3 deposition was mainly found in Central Europe, while the lower values (below 1 kg ha-1 y-1) were found in Finland, Bulgaria and on the Alps. The Central European area of high deposition (> 8 kg ha-1 y-1) of N-NH4 is larger, covering parts of Belgium, the Netherlands, Germany, the Czech Republic, Austria, Slovenia and Serbia. Other plots with high N-NH4 deposition are also found in Poland, Italy, France and Spain. Low values, below 1 kg ha-1 y-1, were found again in Finland and Bulgaria, but also in Switzerland and France. High deposition of S-SO4 deposition is spread over all Europe, partly due the contribution of marine aerosol. After sea-salt correction, the area with higher S-SO4 deposition in Central Europe is smaller than for N-NO3 and N-NH4 deposition, but high values are also found in Southern and Eastern Europe, partly due to the input of Saharan dust. The lowest values of S-SO4 deposition are found in the Swiss Alps. High values of Ca deposition are recorded in almost all plots in Southern Europe, from Spain to Romania, probably due to the relevant contribution of Saharan dust. Isolated plots with high Ca deposition are also found in Belgium, Germany, Denmark, the Czech Republic, Poland and Lithuania, probably related to local mineral sources. Low values of Ca deposition (below 2 kg ha-1 y-1) were mainly found in Northern Europe. The correction for the marine contribution does not affect the spatial pattern of Ca deposition. On the contrary, Mg deposition is mainly related to the marine aerosol. After sea-salt correction, values below 1.5 kg ha-1 y-1 are found in most of Europe, while the highest values are reported in Eastern Europe and on isolated plots in Italy, Germany and the Czech Republic.