Retrieval of atmospheric visibility from multi-axis differential optical absorption spectroscopy

The multi-axis differential optical absorption spectroscopy (MAX-DOAS) technique is being widely used in the monitoring of trace gases column density. In this paper, a retrieval method of visibility from O-4 slant column density measured with MAX-DOAS is present. O-4 slant column density is sensitive to the change of aerosol properties, and aerosol properties determine the atmospheric visibility. The relationship of atmospheric visibility and O-4 slant column density is analyzed, and a retrieval algorithm to convert the O-4 differential slant column density into visibility is described. MAX-DOAS observation is carried out, and atmospheric visibility is retrieved successfully. The visibility measured with MAX-DOAS shows good agreement with the result obtained with visibility meter, proving the feasibility of the retrieval method. This research presents a simple and effective monitoring method of visibility with MAX-DOAS, expands the application of MAX-DOAS technique.