Geographical sources of surface ozone in five Spanish EMEP stations are stu
died using the air mass trajectories that arrive at the stations together w
ith the CPFs (Conditional Probability Functions). Results show that regions
with strong NOx emissions placed far away the stations are the main source
s of ozone in Spain. So, the center of Europe and the middle Mediterranean
area are the two main geographical sources of surface ozone in Spain. (C) 1
999 Elsevier Science Ltd. All rights reserved.