Assessment of HONO Measurements: The FIONA Campaign at EUPHORE

HONO is an important source of OH-radicals, the major oxidant in the atmosphere during daytime that participates in ozone formation and can lead to photo-smog. Nevertheless, there are still many open questions about its formation and role as a source of OH-radicals. A better knowledge of HONO processes is highly desirable for the improvement of air pollution models, many of which do not currently include heterogeneous HONO production mechanisms. One reason for the uncertainties in the atmospheric role of HONO is the difficulty in measuring this species.