Potential sources of tropospheric nitrogen dioxide for Western Moscow Region, Russia

A.M. Obukhov IAP of RAS performs regular measurements of the integral content of tropospheric nitrogen dioxide (NO2) by the MAX-DOAS method at the Zvenigorod Scientific Station (ZSS) since 2009. ZSS is located to the West from Moscow and is in background air mass of Central Russian about 80% of time, while polluted air of Moscow megacity cover it in about 20% of time. We calculate the fields of the average contribution of potential sources on the integral content of NO2 on ZSS using the concentration weighted trajectory (CWT) method. The NO2 measurements performed in cloudless sky were used for the analysis. Five-day backward trajectories of air particles arriving into the convective boundary layer of the atmosphere above ZSS were calculated using the NOAA HYSPLIT_4 trajectory model and the NCEP GDAS1.0 meteorological variables data fields. The differences of the fields of contribution of potential sources in warm (April-September) and cold (October-March) seasons of the year are analyzed.