ABSTRACT
Mobile DOAS (Differential Optical Absorption Spectroscopy) circular measurements of tropospheric nitrogen dioxide (NO2) were performed on a number of days in 2012 and 2014–2016 around St.Petersburg. These observations figured out an evolution of urban pollution plume, released from the megacity. The HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectories) model was configured to simulate the observed NO2 dispersion, taking into account the municipal inventory database of urban nitrogen oxides (NOx = NO+ NO2) emission. The simulation results were found consistent with the data of mobile measurements, allowing to fit an estimate of integral NOx emission rate from St.Petersburg (about 60 kt year−1 on the average). Coincident satellite measurements the Aura Ozone Monitoring Instrument (OMI) of tropospheric NO2 mostly agree with the data of simulation on the days of mobile observations. In general, presented results demonstrate the capabilities of joint interpretation of disparate tropospheric NO2 data in the vicinity of a megacity.
Acknowledgments
The instrument used for DOAS mobile measurements belongs to the Centre for Geo-Environmental Research and Modelling (GEOMODEL), St.Petersburg State University. The data analysis of this study was partly supported by the Russian Foundation for Basic Research under Grant number 14-05-00897. The numerical model simulation was supported by the Russian Science Foundation under Grant number 14-17-00096. We would like to thank the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) for supplying the OMI tropospheric NO2 vertical column density data.
Disclosure statement
No potential conflict of interest was reported by the authors.