Trajectory analysis of atmospheric transport of fine particles, SOsub2/sub, NOsubx/sub and Osub3/sub to the SMEAR II station in Finland in 1996–2008

摘要

Trajectory statistical methods that combine in situ measurements of trace gasor particle concentrations and back trajectories calculated for correspondingtimes have proven to be a valuable approach in atmospheric research;especially in investigating air pollution episodes, but also in e.g. tracingthe air mass history related to high vs. low concentrations of aerosolparticles of different sizes at the receptor site. A concentration fieldmethod was fine-tuned to take the presumable horizontal error in calculatedtrajectories into account, tested with SO₂ and validated by comparisonagainst EMEP (European Monitoring and Evaluation Programme) emission data. Inthis work we apply the improved method for characterizing the transport ofatmospheric SO₂, NO_x, O₃ and aerosol particles of different sizemodes to a Finnish measurement station located in Hyyti?l?(61°51' N, 24°17' E). Our method did not reproduce the EMEPemission soures, but proved useful for qualitative analysis on where themeasured compounds come from, from one measurement station point of view. Weapplied it to study trends and seasonal variation in atmospheric pollutanttransport during 13 yr at the SMEAR II (Station for Measuring Ecosystem-Atmosphere Interactions) station.