Ionisation as a precursor to Aerosol Formation (also known as IONS) was a NERC Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00150 - Duration 2002 - 2005) and was led by Dr RG Harrison, University of Reading. Formation of ultrafine particles from molecular cluster ions in the atmosphere has been shown to occur in urban air, from both experimental findings and theoretical considerations. Ion-induced (or mediated) aerosol formation is currently neglected, despite the considerable variability known in atmospheric ions. Ionisation in the atmosphere is ubiquitous, arising from cosmic rays and natural radioactivity, with a further contribution from nuclear reprocessing. The efficiency of ion to particle conversion was sensitive to gas composition and condensable vapour supply. The work measured ion-induced ultrafine particle production in surface air, combining ion and aerosol data. Existing ion-aerosol theory will be extended to include particle production from ions, to assess the significance for clouds of additional condensation nuclei. This dataset collection contains surface level atmospheric measurements of background ion production rates and small ion concentrations. Data from the TORCH2 campaign are also included as used by the project participants. 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.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. This dataset contains hygroscopicity tandem aerosol differential mobility analyser measurements.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. This dataset contains model outputs.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 2 took place in April and May 2004 at Weybourne Atmospheric Observatory, on the north Norfolk coast. This dataset contains O3 measurements from a 49C Analyser.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. This dataset contains formaldehyde measurements from a formaldehyde analyser.

Ionisation as a precursor to Aerosol Formation (also known as IONS) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00150 - Duration 2002 - 2005) and was led by Dr RG Harrison, University of Reading. This dataset contains solar radiation, ground heat flux, air temperature, wind, dew point and relative humidity measurements at the Weybourne Atmospheric Observatory (WAO), Norfolk.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. This dataset contains NO and NO2 measurements from a trace level chemiluminsence analyser.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 2 took place in April and May 2004 at Weybourne Atmospheric Observatory, on the north Norfolk coast. This dataset contains condensation nuclei counter measurements.

Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex. This dataset contains CH3CHO, CH3COCH3, HCHO-NR, HCHO-R, HONO, NO2 and JO1D measurements from a spectral radiometer.

Ionisation as a precursor to Aerosol Formation (also known as IONS) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00150 - Duration 2002 - 2005) and was led by Dr RG Harrison, University of Reading. Data consist of surface level measurements of background ion production rates and small ion concentrations. This dataset contains aerosol geiger counter measurements at the University of Reading Atmospheric Observatory.