Polluted Troposphere TORCH1: Tropospheric ORganic CHemistry Experiment (TORCH1) Ground-based Atmospheric Components Measurements Collection at Writtle College as part of the Polluted Troposphere Programme

The Polluted Troposphere Programme was a 5-year NERC thematic research programme which was centred upon the study of polluted boundary layer air and its transport to the free troposphere. The programme focussed on the regional scale, defined as intermediate between urban and hemispheric. This dataset collection contains measurements of O3, CO, NO, NO2, C2-C8 hydrocarbons, C1-C4 oxygenated hydrocarbons, PAN, Peroxides (Organic and Inorganic), Organic nitrates, OH and HO2 radicals, Sum of RO2 + HO2 radicals, OH chemical lifetime, Photolysis frequencies (e.g. j(O1D), j(NO2), j (HCHO), Aerosol number and size distribution, Aerosol composition, Local meteorology, and 5 and 10 day back trajectories. Many of the instruments are also part of the Universities Facility for Atmospheric Measurement (UFAM). TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. The goals were to provide both a detailed data set on organic composition in the polluted atmosphere, and to develop theoretical and modelling tools which may be used in defining future air quality policy.