Preprints
https://doi.org/10.5194/amt-2021-400
https://doi.org/10.5194/amt-2021-400

  02 Dec 2021

02 Dec 2021

Review status: this preprint is currently under review for the journal AMT.

A comparison of the impact of TROPOMI and OMI tropospheric NO2 on global chemical data assimilation

Takashi Sekiya1, Kazuyuki Miyazaki2, Henk Eskes3, Kengo Sudo4,1, Masayuki Takigawa1, and Yugo Kanaya1 Takashi Sekiya et al.
  • 1Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
  • 2Jet Propulsion Laboratory/California Institute for Technology, Pasadena, CA, USA
  • 3Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands
  • 4Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan

Abstract. This study gives a systematic comparison of the Tropospheric Monitoring Instrument (TROPOMI) version 1.2 and Ozone Monitoring Instrument (OMI) QA4ECV tropospheric NO2 column through global chemical data assimilation (DA) integration for the period April−May 2018. DA performance is controlled by measurement sensitivities, retrieval errors, and coverage. The smaller mean relative observation errors by 16 % in TROPOMI than OMI over 60° N−60° S during April−May 2018 led to larger reductions in the global root mean square error (RMSE) against the assimilated NO2 measurements in TROPOMI DA (by 54 %) than in OMI DA (by 38 %). Agreements against the independent surface, aircraft-campaign, and ozonesonde observation data were also improved by TROPOMI DA compared to the control model simulation (by 12−84 % for NO2 and by 7−40 % for ozone), which were more obvious than those by OMI DA for many cases (by 2−70 % for NO2 and by 1−22 % for ozone). The estimated global total NOx emissions were 15 % lower in TROPOMI DA, with 2−23 % smaller regional total emissions, in line with the observed negative bias of the TROPOMI version 1.2 product compared to the OMI QA4ECV product. TROPOMI DA can provide city scale emission estimates, which were within 10 % differences with other high-resolution analyses for several limited areas, while providing a globally consistent analysis. These results demonstrate that TROPOMI DA improves global analyses of NO2 and ozone, which would also benefit studies on detailed spatial and temporal variations in ozone and nitrate aerosols and the evaluation of bottom-up NOx emission inventories.

Takashi Sekiya et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on amt-2021-400', Anonymous Referee #1, 04 Jan 2022
  • RC2: 'Comment on amt-2021-400', Anonymous Referee #2, 04 Jan 2022

Takashi Sekiya et al.

Takashi Sekiya et al.

Viewed

Total article views: 389 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
299 84 6 389 1 4
  • HTML: 299
  • PDF: 84
  • XML: 6
  • Total: 389
  • BibTeX: 1
  • EndNote: 4
Views and downloads (calculated since 02 Dec 2021)
Cumulative views and downloads (calculated since 02 Dec 2021)

Viewed (geographical distribution)

Total article views: 363 (including HTML, PDF, and XML) Thereof 363 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 15 Jan 2022
Download
Short summary
This study gives a systematic comparison of TROPOMI version 1.2 and OMI QA4ECV tropospheric NO2 column through global chemical data assimilation (DA) integration for April–May 2018. DA performance is controlled by measurement sensitivities, retrieval errors, and coverage. Due to reduced errors in TROPOMI, agreements against assimilated and independent observations were improved by TROPOMI DA compared to OMI DA. These results demonstrate that TROPOMI DA improves global analyses of NO2 and ozone.