SPIRALE: A multispecies high vertical resolution in-situ instrument for stratospheric chemistry”, 2003, 5, 11344 – Communication orale
Résumé
SPIRALE (French acronym for Spectromètre Infra Rouge pour l’étude de l’Atmosphère par diodes Laser Embarquées) is a balloon-borne instrument devoted to in-situ measurement of stratospheric trace species from the tropopause up to 40 km. The measurement technique is based on the quantified absorption of light emitted by tunable diode lasers in the infrared. Absorption is increased by the use of a deployable multipass cell, enabling absorption length of up to 550 meters. Since the absorption detection limit is of the order of 10-5, species of concentrations higher than 0,01 ppb can be detected. Species are detected simultaneously every second, i.e giving a vertical resolution of a few meters, which is necessary for the study of small scale processes. Up to now, 3 successful flights have provided vertical profiles of several species : O3, CO, HCl, NO, NO2, HNO3, N2O, CH4, COF2, HOCl, H2O2, CO2, H2O. A new flight is projected at the end of January 2003. The prominent results on the detected species involved in the stratospheric chemistry are presented. They highlight the excellent performances of the instrument which are also discussed.