Raul D'Elia

Study of cloud enhanced surface UV radiation at the atmospheric observatory of Southern Patagonia, Río Gallegos, Argentina

Ozone and ultraviolet (UV) radiation are two important issues in the study of Earth’s atmosphere. The anthropogenic perturbation of the ozone layer has induced change in the amount of UV radiation that reaches the Earth’s surface, mainly through the Antarctic ozone hole. Also clouds have been identified as the main modulator of UV amount over short time scales. While clouds can decrease direct radiation, they can produce an increase in the diffuse component, and as a consequence the surface UV radiation may be higher than during an equivalent clear sky scenario. In particular this situation can be important when a low ozone column and partially cloud coverered skies occur simultaneously. These situations happen frequently in southern Patagonia, where the CEILAP Lidar Division has established the Atmospheric Observatory of Southern Patagonia, an atmospheric remote sensing site near the city of Rio Gallegos (51°55’S, 69°14’W). In this paper, the impact of clouds on UV radiation is investigated by the use of...

New Differential Absorption Lidar for Stratospheric Ozone Monitoring in Argentina

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 give...