Intercomparison of MAX-DOAS, FTIR and direct sun HCHO vertical columns at Xianghe, China

Pinardi, Gaia; Friedrich, Martina M.; Vigouroux, Corinne; Langerock, Bavo; De Smedt, Isabelle; Fayt, Caroline; Hermans, Christian; Beirle, Steffen; Wagner, Thomas; Zhou, Minqiang; Wang, Ting; Wang, Pucai; De Mazière, Martine; Van Roozendael, Michel

doi:10.5194/amt-19-1259-2026

Articles | Volume 19, issue 4

https://doi.org/10.5194/amt-19-1259-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/amt-19-1259-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 4

Research article

|

19 Feb 2026

Research article |

| 19 Feb 2026

Intercomparison of MAX-DOAS, FTIR and direct sun HCHO vertical columns at Xianghe, China

Gaia Pinardi, Martina M. Friedrich, Corinne Vigouroux, Bavo Langerock, Isabelle De Smedt, Caroline Fayt, Christian Hermans, Steffen Beirle, Thomas Wagner, Minqiang Zhou, Ting Wang, Pucai Wang, Martine De Mazière, and Michel Van Roozendael

Data sets

Formaldehyde (HCHO) groundbased remote sensing data from the FTIR instrument CAS.IAP001 at Xianghe, version RD Minqiang Zhou et al. https://doi.org/10.60897/ndacc.xianghe_ftir.h2co_cas.iap001_rd

Xianghe HCHO MAX-DOAS MMF and MAPA data from the FRM4DOAS processing system, 2018-2021 (Version 1) Martina Friedrich et al. https://doi.org/10.18758/79K62VRM

Xianghe HCHO MAX-DOAS MMF data with monthly CAMS model profiles as a priori (Version 1) Gaia Pinardi et al. https://doi.org/10.18758/6ULMAD6R

Xianghe HCHO MAX-DOAS MMF data with monthly TM5 model profiles as a priori (Version 1) Gaia Pinardi et al. https://doi.org/10.18758/EX6DPIFK

Xianghe HCHO direct sun data (Version 1) Michel Van Roozendael and Gaia Pinardi https://doi.org/10.18758/S4A40K11

CCI+P HCHO tropospheric column L3 data from OMI, v1 (Version 1) Isabelle De Smedt et al. https://doi.org/10.18758/H2V1UO6X

CCI+P HCHO tropospheric column L3 data from OMI, v2 (Version 2) Isabelle De Smedt et al. https://doi.org/10.18758/BF145884

Short summary

We evaluate ground-based remote-sensing measurements of formaldehyde from three techniques at a suburban site in China. A systematic −20 % bias in Multi-AXis Differential Optical Absorption Spectroscopy compared to direct-sun ultraviolet and infrared data is linked to limited sensitivity above a few kilometers and simplified vertical profiles assumptions. Using model-based priors and accounting for vertical sensitivity removes these differences, improving consistency for satellite validation.