Remote sensing of stratospheric O3 and NO2 using a portable and compact DOAS spectrometer

MARCELO RAPONI, RODRIGO JIMÉNEZ, ELIAN WOLFRAM, JORGE O. TOCHO, EDUARDO QUEL.

Journal of Physics: Conf. Series

IOP Science

Año: 2011 vol. 274 p. 12094 - 12103

1742-6588

The use of passive and active remote sensing systems has largely contributed to advance our understanding of important atmospheric phenomena. Here we present a compact and portable passive DOAS (Differential Optical Absorption Spectroscopy) system, developed for measuring the vertical column density (VCD) of multiple atmospheric trace gases. We highlight the main characteristics of the system components: a mini-spectrometer (HR4000, Ocean Optics), two optical fibers (400 μm of core, 6 m and 25 cm of longitude), an external shutter and the control/data processing software. Nitrogen dioxide (NO2) and ozone (O3) VCDs are derived from solar spectra acquired during twilights (87° - 91° zenithal angles) using the DOAS technique. The analysis is carried out by solving the Beer-Lambert-Bouger (BLB) law for the main atmospheric absorbers at selected wavelength ranges. The algorithm minimizes the fitting residuals to the BLB law, having as unknown the slant column density (SCD) of the species to determine. We present measurements carried out at the Marambio Antarctic Base (64° 14? 25?? S; 56° 37? 21?? W, 197 m asl) during January - February 2008. In addition, we compare our results with co-located measurements performed with EVA, a visible absorption spectrometer of Instituto Nacional de Técnica Aeroespacial (INTA, Spain), a Dobson spectrophotometer of Servicio Meteorológico Nacional (SMN, Argentine) and the Ozone Monitoring Instrument (OMI), on board AURA satellite.