1 / 18

HONO retrievals in Beijing and Xianghe

HONO retrievals in Beijing and Xianghe. F. Hendrick 1 , K. Clémer 1,* , C. Fayt 1 , C. Hermans 1 , Y. Huan 1,2 , T. Vlemmix 1 , P. Wang 2 , and M. Van Roozendael 1. 1 Belgian Institute for Space Aeronomy (IASB-BIRA), Brussels, Belgium 2 Institute of Atmospheric Physics, Beijing, China

john
Télécharger la présentation

HONO retrievals in Beijing and Xianghe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HONO retrievals in Beijing and Xianghe F. Hendrick1, K. Clémer1,*, C. Fayt1, C. Hermans1, Y. Huan1,2, T. Vlemmix1, P. Wang2, and M. Van Roozendael1 1Belgian Institute for Space Aeronomy (IASB-BIRA), Brussels, Belgium 2Institute of Atmospheric Physics, Beijing, China *Now at Institute of Astrophysics, KU Leuven, Belgium NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 1

  2. Nitrous acid (HONO) in the troposphere • HONO is a source of OH radicals through its photolysis, especially in the early morning: • HONO + h → OH + NO • HONO sources and sinks: Li et al., ACP, 2012 NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 2

  3. Why it is important to measure HONO ? • Formation mechanisms not well understood and poorly quantified, especially during daytime • Realistic simulations of HONO levels are difficult • Measurements can contribute to improve the modeling of the HONO and OH chemistry • HONO measurements are sparse in time because mainly resulting from field campaigns Continuous MAX-DOAS measurements of HONO can be highly valuable NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 3

  4. Observation sites Institute of Atmospheric Physics (06/2008 - 04/2009) (03/2010 till now ) NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 4

  5. DOAS settings • The following settings are used for the DOAS analysis: • Fitting window: 337-375 nm • Fitted species: HONO, NO2, O3, O4, BrO, HCHO, Ring effect • HONO XS: Stutz et al. (2000) at 296 K • For each scan, DSCDoff-axis = SCDoff-axis – SCDzenith of the scan used by the profiling algorithm NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 5

  6. MAX-DOAS retrieval algorithm MAXDOAS measurements LIDORT Apriori Atm: P,T Surface albedo Trace gas: , profile Aerosol: optical prop. DOAS HONO DSCD O4 DSCD DI DSCD DI Weighting functions Optimal estimation Aerosol vertical extinction profiles Clémer et al., AMT, 2010 Tropospheric HONO vertical profiles NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 6

  7. Aerosol extinction profile retrieval Beijing 21/01/2009 AM NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 7

  8. Comparison with AERONET data NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 8

  9. HONO vertical profile retrieval Beijing 21/01/2009 AM A priori: with SH = 0.5 km NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 9

  10. Impact of SH on the retrieval (1) Beijing 21/01/2009 AM A priori Retrieval NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 10

  11. Impact of SH on the retrieval (2) Beijing 21/01/2009 NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 11

  12. HONO VCD time-series NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 12

  13. Tropospheric NO2 VCD (geometrical approximation) HONO VCD time-series HONO VCD NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 13

  14. HONO and NO2 VCD correlation Beijing Xianghe NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 14

  15. Diurnal variation of surface HONO vmr (1) NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 15

  16. Comparison to CAREBeijing2006 data (1) NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 16

  17. Comparison to CAREBeijing2006 data (2) CAREBeijing2006 HONO measurements at Yufa: in-situ long-path absorption photometry (LOPAP); see Lu et al., ACPD, 2012 NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 17

  18. Concluding remarks • First HONO retrievals from MAX-DOAS observations at Beijing and Xianghe show promising results • HONO columns larger at Beijing • Good correlation between HONO and NO2 tropospheric columns, especially in the afternoon • Diurnal variation of HONO vmr in the 0-200m altitude range; Good agreement with CAREBeijing2006 data • On-going work: • NO2 profiles retrieval; correlation HONO and NO2 vmr in the 0-200m altitude range • Investigation of the [HONO]/[NO2] ratio • Estimation of the OH production from [HONO] and photolysis rate NORS/NDACC UV-VIS meeting, Brussels, 3-4 July 2012 18

More Related