This volume comprises the results of atmospheric measurements obtained during the field campaign POPCORN (Photo-Oxidant Formation by Plant Emitted Compounds and OH Radicals in North-Eastern Germany) which was carried out to investigate the role and impact of biogenic trace gases on tropospheric chemistry. The text describes meteorological situations and origins of air masses during the campaign, and presents measurements of a variety of trace gases, solar radiation and photolysis frequencies. Special attention is given to OH radical measurements and the in-situ comparison of the two OH measurement techniques.
