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Santiago de Cuba, Cuba

Gouveia D.A.,University of Sao Paulo | Barbosa H.M.J.,University of Sao Paulo | Barja B.,Institute Meteorologia Of Cuba
Optica Pura y Aplicada

In 2011 a UV Raman-Lidar station become operational in the central Amazon region. The instrument is installed 30 km up-wind from Manaus-AM and remotely senses the troposphere using a 95 mJ Nd-Yag laser at 355 nm. Receiving optics consists of a cassegrain telescope with 400 mm and 4000 mm focal length. During the first year of operation, a narrow field of view was used to allow a reasonable signal to noise ratio near the tropopause. This study focuses on the characterization of tropical cirrus clouds observed during the first year of operation (February to December 2011). A cloud detection algorithm developed by Barja and Aroche (2001) was adapted for this system and used to determine the cloud base and top heights, and cloud thickness. The method based on the lidar transmittance factor was used to derive the cirrus optical depth. The occurrence of cirrus clouds is about 63% of the total observation time, and these are located between 10 and 16 km height typically. This result agrees with those derived by Sassen et al (2008) from Calipso data. We also found that around 26% of all cirrus were subvisual cirrus ( <0.03), 43 % were thin cirrus (0.03< <0.3) and 31% were cirrus stratus ( >0.3). © Sociedad Española de óptica. Source

Barbosa H.M.J.,University of Sao Paulo | Barja B.,University of Sao Paulo | Barja B.,Institute Meteorologia Of Cuba | Pauliquevis T.,Unifesp | And 5 more authors.
Atmospheric Measurement Techniques

A permanent UV Raman lidar station, designed to perform continuous measurements of aerosols and water vapor and aiming to study and monitor the atmosphere from weather to climatic time scales, became operational in the central Amazon in July 2011. The automated data acquisition and internet monitoring enabled extended hours of daily measurements when compared to a manually operated instrument. This paper gives a technical description of the system, presents its experimental characterization and the algorithms used for obtaining the aerosol optical properties and identifying the cloud layers. Data from one week of measurements during the dry season of 2011 were analyzed as a mean to assess the overall system capability and performance. Both Klett and Raman inversions were successfully applied. A comparison of the aerosol optical depth from the lidar and from a co-located Aerosol Robotic Network (AERONET) sun photometer showed a correlation coefficient of 0.86. By combining nighttime measurements of the aerosol lidar ratio (50-65 sr), back-trajectory calculations and fire spots observed from satellites, we showed that observed particles originated from biomass burning. Cirrus clouds were observed in 60% of our measurements. Most of the time they were distributed into three layers between 11.5 and 13.4 km a.g.l. The systematic and long-term measurements being made by this new scientific facility have the potential to significantly improve our understanding of the climatic implications of the anthropogenic changes in aerosol concentrations over the pristine Amazonia. © Author(s) 2014. Source

Alvarez Escudero L.,Institute Meteorologia Of Cuba | Sanchez Gacita M.,National Institute for Space Research | Bezanilla Morlot A.,Institute Meteorologia Of Cuba | Borrajero Montejo I.,Institute Meteorologia Of Cuba | Pire Rivas S.,Polytechnic University Jose Antonio Echeverria
Atmospheric Pollution Research

This paper evaluates the implementation of the Weather Research and Forecasting model, WRF, for its use as the meteorological pre-processor for diagnostic air quality modeling in Cuba. The implementation of the WRF involved two studies: the first one was aimed at defining which global meteorological data is more suited for Cuba; the second one consisted of an analysis of the results for long-term runs on two domains, with the specific objective of assessing the general performance of the model. The results of the model were compared with the observations of the National Weather Service surface stations. The comparisons showed good performance for temperature and acceptable performance for prediction of wind tendencies. On average, the wind speed is overestimated in the model and the wind direction deviations exceed 30 degrees for several of the meteorological stations. These deviations are related to nearby topography and the low-wind speed. Some additional studies must be conducted in order to clarify and reduce the wind deviations. The research concludes that the WRF output is able to provide realistic meteorological patterns for air quality models, which require high-resolution three-dimensional (3D) meteorological data. The WRF-fsl tool was developed to use WRF to feed the local models as AERMOD when upper air data is not available. This tool takes the WRF output and gets the upper air data, in the fsl radiosonde format. The WRF-fsl results were compared to other solution, which incorporates a surface data parameterization. The conclusion is that the efforts, to run WRF for long periods, are not justified with the improvement in the results for regulatory purposes. However, as the differences in convective mixing height could be significant, this solution would be very useful for other kind of studies. © Author(s) 2012. Source

Valdes D.R.,University of Pinar del Rio | Silverio A.Q.,University of Pinar del Rio | Jaime Y.G.,Institute Meteorologia Of Cuba | Santos O.C.,Institute Meteorologia Of Cuba | Diaz A.S.,Institute Meteorologia Of Cuba
Revista Brasileira de Meteorologia

The study was carried out in the city of Pinar del Rio in Cuba during the period 2006-2010, where the behavior of atmospheric stability and the mixing height was analyzed. For obtaining the category of atmospheric stability the classification according to the Monin -Obukhov length was used. The methodology for calculating the mixing height was based on the procedure in the meteorological preprocessor AERMET, with some modifications for lack of upper air soundings. Also the behavior of the atmospheric stability and the mixing height in the various types of synoptic situations (TSS) were characterized. Finally the hourly and monthly variations of atmospheric stability and height of the mixing layer, as well as the 7, 13, 16 and 17 hours monthly variations are shown. It was determined that the best conditions for dispersion and mixing of pollutants in the atmosphere occur in the summer months and in the daytime, 5PM as the most favorable schedule time. © 2015, Sociedade Brasileira de Meteorologia. All rights reserved. Source

Guerrero-Rascado J.L.,Brazilian Nuclear Energy Research Institute (IPEN) | Guerrero-Rascado J.L.,Instituto Interuniversitario Of Investigacion Del Sistema Tierra En Andalucia Iista Ceama | Guerrero-Rascado J.L.,University of Granada | Landulfo E.,Brazilian Nuclear Energy Research Institute (IPEN) | And 31 more authors.
Journal of Atmospheric and Solar-Terrestrial Physics

LALINET (Latin American Lidar Network), previously known as ALINE, is the first fully operative lidar network for aerosol research in South America, probing the atmosphere on regular basis since September 2013. The general purpose of this network is to attempt to fill the gap in the knowledge on aerosol vertical distribution over South America and its direct and indirect impact on weather and climate by the establishment of a vertically-resolved dataset of aerosol properties. Similarly to other lidar research networks, most of the LALINET instruments are not commercially produced and, consequently, configurations, capabilities and derived-products can be remarkably different among stations. It is a fact that such un-biased 4D dataset calls for a strict standardization from the instrumental and data processing point of view. This study has been envisaged to investigate the ongoing network configurations with the aim of highlighting the instrumental strengths and weaknesses of LALINET. © 2016 Elsevier Ltd. Source

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