2005), Long-range transport to Europe: Seasonal variations and implications for the European ozone budget

• Main Authors: M. Auvray, I. Bey
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.144.3363; http://www-as.harvard.edu/chemistry/trop/publications/auvray_2005.pdf

[1] We use a chemical transport model (GEOS-CHEM) to quantify the contribution of long-range transported pollution to the European ozone (O3) budget for the year 1997. The model reproduces the main features observed over Europe for O 3, carbon monoxide and nitrogen dioxides, as well as two events of enhanced O3 of North American origin over the eastern North Atlantic and over Europe. North American O3 fluxes into Europe experience a maximum in spring and summer, reflecting the seasonal variation in photochemical activity and in export pathways. In summer, North American O3 enters Europe at higher altitudes and lower latitudes because of deep convection, and because the flow over the North Atlantic is mostly zonal in that season. The low-level inflow is only important in spring, when loss rates in the boundary layer over the North Atlantic are weaker. Asian O3 arrives mainly via the westerlies, and usually at higher altitudes than North American O3 because of stronger deep convection over Asia. In addition, Asian O3 fluxes are at a maximum in summer during the monsoon period because of enhanced convection over Asia, increased nitrogen oxides sources from lightning and direct transport towards Europe via the monsoon easterlies. Over Europe, total background