measured O 4 dscd [10 43 molecules 2 cm -5 ] measured NO 2 dscd [10 15 molecules cm -2 ] frequency Supplement for Vertical profiles of NO 2, SO 2, HONO, HCHO, CHOCHO, and aerosols derived from MAX-DOAS measurements at a rural site in the central-western North China Plain and their relation to emission sources and effects of regional transport Yang Wang 1, Steffen Dörner 1, Sebastian Donner 1, Sebastian Böhnke 1, Isabelle De Smedt 2, Russell R. Dickerson 3, Zipeng Dong 4, Hao He 3, Zhanqing Li 3,4, Zhengqiang Li 5, Donghui Li 5, Dong Liu 6, Xinrong Ren 3,7, Nicolas Theys 7, Yuying Wang 4, Yang Wang 4, Zhenzhu Wang 6, Hua Xu 5, Jiwei Xu 6, Thomas Wagner 1 1 Max Planck Institute for Chemistry, Mainz, Germany 2 Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium 3 Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park, Maryland, USA 4 College of Global Change and Earth System Sciences, Beijing Normal University, Beijing, China 5 Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences 6 Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China 7 Air Resources Laboratory, National Oceanic and Atmospheric Administration, College Park, Maryland, USA Correspondence to: Yang Wang (y.wang@mpic.de) (a) (b) 20% 15% 10% 5% 0% WNW W NW NNW N NNE NE ENE E wind speed [m/s] >= 10 8-10 6-8 4-6 2-4 0-2 5% 10% WSW ESE 15% SW SE 20% SSW S SSE Figure S1: Wind roses (a) and averaged diurnal variations of local winds (b) derived from a local weather station during the measurement period of MAX-DOAS. The arrows point to the direction to which wind blows; the length of the arrows represent the wind speed. 5 4 R 2 =0.99 y=1.01x-0.025 200 150 R 2 =0.99 y=1.02x-1.44 3 2 100 1 50 0 0 1 2 3 4 5 modelled O 4 dscd [10 43 molecules 2 cm -5 ] 0 0 50 100 150 200 modelled NO 2 dscd [10 15 molecules cm -2 ]
measured HCHO dscd [10 15 molecules cm -2 ] measured SO 2 dscd [10 15 molecules cm -2 ] measured HONO dscd [10 15 molecules cm -2 ] 300 200 R 2 =0.99 y=1.01x-0.65 12 8 all data: R 2 =0.91, y=1.12x-0.44 measured dscd>1: R 2 =0.91, y=0.99x+0.05 100 4 0 0 100 200 300 modelled SO 2 dscd [10 15 molecules cm -2 ] 0 0 4 8 12 modelled HONO dscd [10 15 molecules cm -2 ] 100 80 R 2 =0.94 y=1.00x-0.55 60 40 20 0 0 20 40 60 80 100 modelled HCHO dscd [10 15 molecules cm -2 ] Figure S2: Scatter plots of measured dscds against modelled dscds (simulated by the RTM SCIATRAN for the retrieved profiles) during the whole measurement period for retrievals of aerosols, NO 2, SO 2, HONO, and HCHO. The squares of the correlation coefficients (R 2 ) and the slopes derived from the linear regressions (red lines) are given in each subplot. For HONO, R²and the slopes are also given for the measured dscd larger than 1 10 15 molecules cm -2 in order to minimise the effect of measurements close or below the detection limit.
Figure S3: Results from MAX-DOAS measurements, trajectories, meteorology data, and independent measurements of pollutants during the whole measurement period. See Fig. 10 in the main manuscript.
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(d) Figure S4: Average reproduced maps of VMRs of NO 2 (a), SO 2 (b), HCHO (c), and aerosol extinctions (d) based on MAX-DOAS results and backward trajectories at different altitudes (different columns of subfigures) with different backward times (different rows of subfigures).
Figure S5: Nighttime (0-6h) and daytime (7-18h) contributions (colorbar) of air mass from different locations into the measurement area along the 6h backward trajectories in the three groups of days during the whole measurement period. The days are sorted into the three groups based on the dominant directions (southerly, north-westerly, and easterly) of trajectories. The white areas represent no trajectories passing the areas.