MAX-DOAS retrievals of formaldehyde (HCHO) and nitrogen dioxide (NO2) vertical profiles over Central London

Compressed zipped files of MAX-DOAS measurements at the Central London University College London monitoring site from 1 July to 30 September 2022. 

Includes three compressed files of daily MAX-DOAS observations of HCHO, NO2, and O4 in NetCDF format. Each compressed file is the collection of measurements for the three optimized azimuth angles. 

Data variables in each NetCDF file are:

NO2 vertical profiles and error estimate in ppbv
HCHO vertical profiles and error estimate in ppbv
Aerosol extinction and error estimate at 360 nm in (1/km)
Qualitative cloud flag

Variables dimensions and units are specified in each file. 

Additional details of retrieval of trace gas profiles and cloud detection are in Ryan et al. (2022), submitted for review to Copernicus' Atmospheric Chemistry and Physics journal Measurement Report stream.

NetCDF file of hourly isoprene concentrations at the London Marylebone Road monitoring site from 1 July to 30 September 2022. The file includes isoprene concentrations in ug/m3 and ppbv directly measured and derived using the strong linear relationship bewteen hourly isoprene at Marylebone Road and the London Eltham site. 

UCL MAX-DOAS photo credit: Robert G Ryan.