1 Department of Atmospheric Environment, National Environmental Research Institute, Aarhus University, Aarhus University2 unknown3 Department of Environmental Science - Atmospheric modeling, Department of Environmental Science, Science and Technology, Aarhus University4 Department of Environmental Science - Atmospheric modeling, Department of Environmental Science, Science and Technology, Aarhus University
Recent trends in nitrogen and sulphur compounds in air and precipitation from a range of Arctic monitoring stations are presented, with seasonal data from the late 70s to 2004 or 2005. Earlier findings of declining sulphur concentrations are confirmed for most stations, while the pattern is less clear for reduced and oxidized nitrogen. In fact there are positive trends for nitrogen compounds in air at several stations. Acidity is generally reduced at many stations while the precipitation amount is either increasing or stable. Variability of sulphate concentrations in air for the period 1991-2000 is reasonably well reproduced at most stations using an Eulerian, hemispherical model. Results for nitrogen compounds are weaker. Scenario studies show that even if large sulphur emission reductions take place in important source regions in South-East Asia in the coming decades, only small changes in Arctic deposition can be expected. This is because South-East Asian emissions have small influence north of the Arctic circle.
Atmospheric Environment, 2009, Vol 43, Issue 4, p. 928-939