Increasing ozone in marine boundary layer inflow at the west coasts of North America and Europe

摘要: Abstract. An effective method is presented for determining the ozone (O3) mixing ratio in onshore flow of marine air at North American west coast. By combining data available from all boundary layer (MBL) sites with simultaneous wind data, decadal temporal trends MBL O3 seasons are established high precision. The average springtime trend over past two decades 0.46 ppbv/yr a 95% confidence limit 0.13 ppbv/yr, and statistically significant found except autumn, which does have significantly smaller than other seasons. mean annual 0.34±0.09 ppbv/yr. These coast present striking comparison contrast reported European Mace Head, Ireland. winter, spring summer compare well locations, while Head greater autumn. Even though similar, absolute ratios differ markedly, arriving Europe containing 7±2 ppbv higher America. Further, show no indication stabilizing as has been Head. In larger historical context background 130 years covered by increased substantially (by factor to three), this increase continues present, least Pacific region reproduction increasing decades, difference between coastal regions will challenge global chemical transport models. ability models semi-quantitatively reproduce longer-term, may an even challenge.