Multiple axis DOAS measurements for the retrieval of nitrogen dioxide and ozone vertical profiles in the Presidential Estate of Castel Porziano (Rome)

In this paper we present a methodology for the retrieval of the vertical profile of atmospheric gas pollutants in the boundary layer from ground based remote sensing measurements. Nitrogen dioxide (NO(2)) and ozone (03) slant column amounts have been obtained with the Differential Optical Absorption Spectroscopy (DOAS) technique used in the multiple axis configuration (the so called MAX-DOAS). The measurements have been carried out in the Presidential Estate at Castel Porziano (Rome) in the period from September to November 2006 in the frame of a programme started in 1994 for studying and monitoring the Estate's environment. The retrieval of information on the vertical profile of trace gases from their slant column amounts requires: (1) the simulation of the radiative transfer in the atmosphere for Air Mass Factor (AW) calculation; (2) the application of inversion schemes. In this paper the vertical profiles of NO(2) and O(3) obtained from multiple axis DOAS measurements and their daily evolution are presented and discussed. The day under study is the 29(th) of October, 2006.