Vertical distribution characteristics and potential sources of atmospheric pollutants in the North China Plain basing on the MAX-DOAS measurement

Environmental Sciences Europe

Table 1 DOAS retrievals settings used for NO₂, O₄, HCHO, and CHOCHO DOAS spectral analysis

parameter	Data source	Fitting internal (nm)
parameter	Data source	O₄	NO₂	HCHO	Glyoxal
Wavelength range		338–370	338–370	322.5–358	431–461
NO₂	298K,I0 correction (SCDs of 1017 molecules cm⁻²) Vandaele et al. [37]	√	√	√	√
NO₂	220K,I0 correction (SCDs of 1017 molecules cm⁻²), pre-orthogonalized; Vandaele et al. [37]	√	√	×	√
O₄	293K; Thalman and Volkamer [38]	√	√	√	√
HCHO	297K; Meller and Moortgat [39]	√	√	√	×
CHOCHO	296K; Volkamer et al. [40]	×	×	×	√
Ring	Ring spectra calculated with QDOAS according to Chance and Spurr [41]	√	√	√	√
Polynomial degree		Order 3	Order 3	Order 5	Order 5
Intensity offset		Constant	Constant	Constant	Constant
Wavelength calibration	Based on a high-resolution solar reference spectrum (SAO2010 solar spectra); Chance and Kurucz [41]