A long-term quality assured dataset of the three-dimensional distribution of pollutants (gaseous nitrogen dioxide, ozone, sulphur dioxide and fine mode (PM2.5) aerosol) collected over southern UK, from August 2019 to April 2022, using the instrumented Met Office Atmospheric Survey Aircraft (MOASA). It includes 60 flights (totalling over 153 hours of atmospheric sampling), across 8 repeatable sorties made for the MOASA Clean Air project.

Data are presented as one NetCDF file per flight, containing quality assured, time synchronised, three-dimensionally geo-located time-series of observed pollutants.

To ensure optimal traceability and transparency of data, comprehensive metadata is included for each flight, detailing any calibration constants and/or corrections applied to data alongside general information about the data and instruments.

A full list of NetCDF variables can be found in “Long-term airborne measurements of pollutants over the United Kingdom to support air quality model development and evaluation”, A. Mynard et al, 2023. This paper also provides a technical introduction to the MOASA measurement platform, information on instrumentation, flight strategies and data, as well as example case studies comparing flight observations to the Met Office Air Quality in the Unified Model (AQUM) and the ground based Automated Urban and Rural Network. This paper should be referenced in any research/publications pertaining from this dataset.