The Latin American Lidar Network (LALINET) is the aerosol lidar network operating over South America. LALINET is now an operative network performing a schedule of routine measurements and, currently, is composed by 9 stations distributed over South America. The main objective of LALINET is to generate a consistent and statistically relevant database to enhance the understanding of the particle distribution over the continent and its direct and indirect influence on climate. The creation of an un-biased spatiotemporal database requires a throughout review of the network on two pillars: instrumentation and data processing. Because most of the LALINET systems are not series-produced instruments and, therefore, present large differences in configuration and capabilities, attempts for network harmonization and, consequently, optimization are mandatory. In this study a review of the current instrumental status of all LALINET systems is done and analyzed in detail in order to assess the potential performance of the network and to detect networking weaknesses.
With the aim of contribution to the study of atmospheric ozone layer, a new sensitive radiometer for atmospheric minor
constituents has been installed in the Observatorio Atmosférico de la Patagonia Austral, División LIDAR, CEILAP
(CITEDEF-CONICET), in October 2010. This observatory is established in the city of Rio Gallegos (51° 36' S, 69° 19'
W), Argentina, close to the spring ozone hole. The millimeter wave radiometer was developed in STEL (Solar
Terrestrial Environment Laboratory), Nagoya University, Japan. This passive remote sensing instrument is able to
measure the ozone (O3) amount in the high stratosphere and mesosphere continuously and automatically with a high time
resolution. The millimeter wave radiometer ozone profiles will be supplemented with the ozone profiles obtained from
the DIAL system existent in the observatory.
The millimeter wave radiometer is based on the spectral signal detection from the atmosphere due to the molecular
rotational transition of molecules under study. The operation is based on a superheterodyne system which uses a
Superconductor-Insulator-Superconductor (SIS) mixer receiver operating at 203.6GHz. The SIS mixer junction consists
of a sandwich structure of Nb/AlOx/Nb, and is cooled to 4.2K with a closed cycle He-gas refrigerator. Two additional
heterodyne-mixed stages are realized with the aim to shift the measured spectral line until a frequency around of 500
MHz. A FFT (Fast Fourier Transform) spectrometer system is used as a back end.
The aims of this work are to show the potential of the millimeter wave radiometer installed in the subpolar latitudes close
to the polar ozone hole and to present the preliminary result of the first measurements.
As part of environmental studies of the southern atmosphere, the CEILAP Lidar Division in collaboration with the Service d'Aeronomie has developed a mobile differential absorption lidar capable of making precise and accurate measurements of the stratospheric ozone. The XeCl excimer laser emission at 308 nm is used as absorbed line in the DIAL technique and an Nd-YAG laser 355 nm third harmonic is employed as a reference wavelength. Six detected channels are used for stratospheric ozone retrieval, four of them in the high and low energy of the elastically backscattered signal of the emitted wavelengths and two corresponding to the first Stokes nitrogen Raman of the emitted wavelengths. Tropospheric Water Vapor profiles using Raman channels and Aerosol Backscatter profiles are also obtained. In this paper we present a detailed description of the instrument, a discussion of data analysis and the results of the first lidar-satellite inter-comparison of stratospheric ozone profiles measured with this instrument. We also present a description of the SOLAR campaign that will be held in the 2005 southern winter-spring period in Rio Gallegos (51° 55'S, 69° 14'W) with the objective of studying the ozone layer when the polar vortex crosses over the continental part of Argentina. This campaign will be supported by JICA (Japan International Cooperation Agency).
The solar radiation at Earth surface is measured usually with instruments of narrow or large wavelengths bands. However, for different applications like the determination of irradiances related to biological actions and substance and material degradations, it is needed to know the spectrum at all wavelengths with reasonable resolution. In CEILAP (CONICET - CITEFA) placed at the Gran Buenos Aires suburbs (34° 33' S, 58° 30' W, 20 m asl), we made measurements of solar UV irradiance in clear sky days in the UV range (300 - 400 nm) range with a spectroradiometer Monospec 27 of National University of Rosario. The data represented in a 3D diagram show the variations in the solar spectrum along the day as function of the solar zenith angle. From the comparison with the results obtained employing the TUV program developed by Madronich/NCAR that solves the radiative transfer equation, it is possible to determine the influence of the ozone and aerosol atmospheric components on this irradiance. The spectra were calibrated against the absolute measurements made with an instrument GUV 541 at wavelengths of 305, 320, 340 and 380 nm, which is placed in the same building and was recently calibrated.
The lidar systems contribute with privileged information to study environmental pollution due to its capacity to discriminate different atmospheric parameters in time and space. In this work, three of those system were developed at CEILAP laboratory in Argentina (34° 33' S, 58° 30' W): 1) a Multiwavelength lidar to characterized the atmospheric boundary layer and tropospheric aerosols using a Nd:YAG laser (10 Hz, 650 mJ @ 1064 nm); 2) a Raman lidar to measure night-time water vapor profiles, useful as a tracer of air parcel and in understanding energy transport within the atmosphere. This system utilizes an excimer laser (XeCl) (100 Hz, 300 mJ @ 308 nm), and 3) a differential absorption lidar (DIAL) to measure the stratospheric ozone profile. Two laser are used, the same excimer laser of Raman lidar and a Nd:YAG laser (30 Hz, 950 mJ @ 1064 nm). Complementary in situ measurements are also performed with a sun-photometer (AERONET-NASA); UVA, UVB and GUV radiometers (Argentina Solar Monitoring Network), pyranometer and a pyrgeometer. Recent results and the synergy between the actives and passives instruments are showed.