Retrievals of Stratospheric O3 and NO2 Columns from the Ground-Based Twilight Zenith Sky Observations
地基曙暮光光谱观测反演平流层O3和NO2柱含量

Stratospheric O 3 and NO 2 columns are retrieved from the ground\|based twilight zenith sky observations by using DOAS method Our moderate resolution spectrometer has the 0 6 nm resolution with 1200 g mm -1 grating, which is suitable for O 3 and NO 2 measurements It is seen from the simulated retrievals that the DOAS method is accurate if the wavelength calibration and the cross section are accurate The AMF is calculated with the DISORT radiative trasfer model We have also calculated the errors in linear and nonlinear square fittings In O 3 and NO 2 retrievals the nonlinear error is not important at the wavelength used In validation, the bias between the DOAS O 3 and Dobson O 3 column is about 10% The NO 2 column difference between DOAS and SAGE II is about 20% in monthly average values But the residual spectra are still large, which is another cause for the bias The measurement and retrieval algorithm should be improved later