This dataset contains hourly averaged 4-pi filter radiometer measurements of the rate constant of NO2 photolysis, j(JNO2) from both downwelling radiation (direct and diffuse radiation from the above atmosphere) and upwelling (diffuse radiation from the atmosphere below). Data are reported in s^-1.

Measurements made at Auchencorth Moss (55ᵒ47’36” N, 3°14’41” W), for more information see http://www.auchencorth.ceh.ac.uk/. The instrument was situated in a clear section of the site, 3 m above ground level. The surface cover consisted of long grasses (~15 cm), often covered by frost/snow in the winter months (December - February). Data were collected between 2018/11/21 12:00 - 2019/11/20 23:00, using a j(NO2) 4-pi filter radiometer manufactured by Meteorologie Consult GmbH (MetCon) measuring broadband actinic flux between ~310-420 nm. The instrument was operated and data were collected by staff at the UK Centre for Ecology & Hydrology. Most of the missing data are between 2019/06/13-25, due to the instrument being relocated for calibration. Other incidences of missing data occur due to power cuts at the site and problems with the data collection. This data comprises the start of a long-term time series of filter radiometer measurements at Auchencorth Moss, in order to provide data access to evaluate j-values in current radiation models and parameterisations.

The ongoing operation of the j(NO2) filter radiometer is supported by the UK Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability.