Ozone Source Apportionment to Quantify Local-to-Continental Source Contributions to Episodic Events in Northern Iberia

We present here a study of a number of ozone episodes in Northern Iberia (NIB) during the warm season of 2010 (April 1-September 30) using WRF and CAMx models. The episodes were selected after a detailed analysis of the ozone concentrations registered by the Air Quality Monitoring Network of the Basque Country (AQNBC), and rural background stations of the European Air Quality Database AirBase located in Northern Iberia. Preliminary results of the analysis of an early summer episode (24-26 June) are shown. For the first time during this type of episodes, it is shown that in the stations where the EU information threshold is exceeded frequently, there is an important contribution from local and regional sources, but the causative factor of high levels of ozone is the transport from medium-long range sources (France and Central Europe). Ozone production is mainly NOx limited.