NEW DIFFERENTIAL ABSORPTION LIDAR FOR STRATOSPHERIC OZONE MONITORING IN PATAGONIA, SOUTH ARGENTINA.

E A WOLFRAM, J SALVADOR, R DELIA, C CASICCIA, N PAES LEME, A PAZMIÑO, J PORTENEUVE, S GODIN-BEEKMAN, H NAKANE AND E J QUEL.

Journal of Optics A: Pure and Applied Optics

IOP PUBLISHING LTD

Año: 2008 vol. 10 p. 104021 - 104027

As part of environmental studies concerning with measurements of the stratospheric ozone layer, the CEILAP developed a new Differential Absorption Lidar (DIAL) instrument. Since the early construction of the first DIAL instrument, Lidar Division has been made important financial and scientific investments to improve this initial prototype. The new version has a bigger reception system formed by 4 newtonian telescopes of 50 cm diameter each one and a higher number of detection channels: four different wavelengths are detected simultaneously and six digital channels record the Rayleigh and Raman backscattered photons emitted by an ClXe Excimer laser at 308 nm and third harmonic of Nd-YAG laser at 355 nm. A number of different changes have been made to increase the dynamical range of this lidar: a mechanical chopper was installed together with gated photomultiplier in the high energy detection channels to avoid strong signals from lower atmospheric layers. This new version was installed inside a shelter given the possibility to make field campaigns outside CEILAP laboratories as SOLAR Campaign made in Argentine Patagonian region during 2005-2006 springs. In this paper a full description of instrument update is given. Intercomparisons with ozonesonde and satellite platform instrument are presented. The results show agreement better than 10% in 16 – 38 km range when same airmasses are sampled. The comparison with five quasi coincident sondes launched in Punta Arenas during spring 2005 shows good agreement between both type measurements, with relative differences inside 1s deviation of lidar measurement. The comparison of the   integral of completed-lidar profiles with total ozone column measured with Brewer sunphotometer shows good agreement with relative differences less than 10%.