E. Wolfram^1,2, P. D’Aulerio³, F. Fierli³, A. Pazmiño^1,4, D. Lazarte^1,6, F. Congeduti³, J. Porteneuve⁵ and E. Quel¹.

¹Centro de Investigaciones en Láseres y Aplicaciones (CITEFA-CONICET), Villa Martelli, Argentina
²Fellow of CONICET
³Istituto di Science dell’Atmosfera e del Clima – ISAC, Rome, Italy
⁴Fellow of Estenssoro Grant of Repsol-YPF Foundation
⁵SA, Université Pierre et Marie Curie, Paris, France.
⁶Fellow of Universidad Nacional de General San Martín (UNSAM)

A new Raman backscatter Lidar for the detection of atmospheric water vapor was developed at CEILAP (Centro de Investigaciones en Láseres y Aplicaciones) in Buenos Aires, Argentina. This instrument uses an Excimer laser (XeCl), with pulse energy of 400 mJ @ 308 nm, and a repetition rate of 100 Hz. The backscatter photons of inelastic Raman scattering of nitrogen and water vapor molecules are simultaneously collected by four 50-cm Newtonian telescopes. All this system will be inside a mobile laboratory and will permit to make measurements in different sites. In this work we present a detailed description of the planned instrument, and the modeling of expected backscatter signal for typically water vapor contents at Buenos Aires city. Moreover we present some examples of analysis performed from the Rome water vapor lidar measurements, in order to assess the interest of such instrumentation for dynamical studies of the upper Troposphere- Lower Stratosphere in South America. In particular, water vapor can be used as tracer of Stratosphere-Troposphere exchanges; to illustrate this we present the analysis made on stratospheric air intrusion issued from polar filament in the Northern hemisphere during the MAP campaign.