Retrieval of the optical properties of tropospheric aerosols over Athens, Greece combining a 6-wavelength Raman-lidar and the CALIPSO VIS-NIR lidar system: Case-study analysis of a Saharan dust intrusion over the Eastern Mediterranean

The National Technical University of Athens (NTUA) 6-wavelength (355, 387, 407, 532, 607 and 1064 nm) Raman lidar system has been used to derive the aerosol optical properties (e.g. the lidar ratio, the aerosol backscatter and extinction profile) and the water vapour mixing ratios over Athens, Greece during the CALIPSO space lidar overpasses over our area at 355, 532 and 1064 nm. These data have been analyzed for the case of a Saharan dust intrusion over the Eastern Mediterranean, occurred on January 26, 2007, using concurrent aerosol optical depth (AOD) data at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS) and forecasted data from the Dust Regional Atmospheric Modeling (DREAM) model

Optical-microphysical Properties of Saharan Dust Aerosols and Composition Relationship Using a Multi-wavelength Raman Lidar, in Situ Sensors and Modelling: a Case Study Analysis

A strong Saharan dust event that occurred over the city of Athens, Greece (37.9° N, 23.6° E) between 27 March and 3 April 2009 was followed by a synergy of three instruments: a 6-wavelength Raman lidar, a CIMEL sun-sky radiometer and the MODIS sensor. The BSC-DREAM model was used to forecast the dust event and to simulate the vertical profiles of the aerosol concentration. Due to mixture of dust particles with low clouds during most of the reported period, the dust event could be followed by the lidar only during the cloud-free day of 2 April 2009. The lidar data obtained were used to retrieve the vertical profile of the optical (extinction and backscatter coefficients) properties of aerosols in the troposphere. The aerosol optical depth (AOD) values derived from the CIMEL ranged from 0.33-0.91 (355 nm) to 0.18-0.60 (532 nm), while the lidar ratio (LR) values retrieved from the Raman lidar ranged within 75-100 sr (355 nm) and 45-75 sr (532 nm). Inside a selected dust layer region, between 1.8 and 3.5 km height, mean LR values were 83 ± 7 and 54 ± 7 sr, at 355 and 532 nm, respectively, while the Ångström-backscatter-related (ABR 355/532) and Ångström-extinction-related (AER 355/532) were found larger than 1 (1.17 ± 0.08 and 1.11 ± 0.02, respectively), indicating mixing of dust with other particles. Additionally, a retrieval technique representing dust as a mixture of spheres and spheroids was used to derive the mean aerosol microphysical properties (mean and effective radius, number, surface and volume density, and mean refractive index) inside the selected atmospheric layers. Thus, the mean value of the retrieved refractive index was found to be 1.49( ± 0.10) + 0.007( ± 0.007)i, and that of the effective radiuses was 0.30 ± 0.18 μm. The final data set of the aerosol optical and microphysical properties along with the water vapor profiles obtained by Raman lidar were incorporated into the ISORROPIA II model to provide a possible aerosol composition consistent with the retrieved refractive index values. Thus, the inferred chemical properties showed 12-40% of dust content, sulfate composition of 16-60%, and organic carbon content of 15-64%, indicating a possible mixing of dust with haze and smoke. PM10 concentrations levels, PM10 composition results and SEM-EDX (Scanning Electron Microscope-Energy Dispersive X-ray) analysis results on sizes and mineralogy of particles from samples during the Saharan dust transport event were used to evaluate the retrieval

Six-month ground-based water vapour raman lidar measurements over Athens, Greece and system validation

Water vapour is one of the most important greenhouse gases, since it causes about two third of the natural greenhouse effect of the Earth's atmosphere. To improve the understanding of the role of the water vapour in the atmosphere, extensive water vapour profiles with high spatio-temporal resolution are therefore necessary. A ground-based Raman lidar system is used to perform water vapour measurements in Athens, Greece (37.9°N, 23.6°E, 200 m asi.). Water vapour mixing ratio measurements are retrieved from simultaneous inelastic H2O and N2 Raman backscatter lidar signals at 387 nm (from atmospheric N2) and 407 nm (from H2O). Systematic measurements are performed since September 2006. A new algorithm is used to retrieve water vapour vertical profiles in the lower troposphere (0.5-5 km range height asl.). The lidar observations are complemented with radiosonde measurements. Radiosonde data are obtained daily (at 00:00 UTC and 12:00 UTC) from the Hellenic Meteorological Service (HMS) of Greece which operates a meteorological station at the "Hellinikon" airport (37. 54° N, 23.44° E, 15m asl) in Athens, Greece. First results of the systematic intercomparison between water vapour profiles derived simultaneously by the Raman lidar and by radiosondes are presented and discussed

Indemnity Rights and Duties

Este trabajo intenta mostrar que las concepciones filosóficas del derecho de daños más influyentes, que entienden que es una práctica de justicia correctiva, adolecen de tres defectos básicos. En primer lugar, son incapaces de explicar perfectamente la correlatividad entre los derechos y deberes de las partes. En segundo lugar, dejan sin explicar la contribución del derecho de daños en la propia conformación de los derechos y deberes primarios, a diferencia de los derechos y deberes de compensación que son secundarios porque surgen cuando los primeros resultan vulnerados. Finalmente, tienen dificultades para reconstruir la responsabilidad objetiva como algo distinto de la culpa. Argumento, en cambio, que el derecho de daños es una práctica compleja que satisface funciones correctivas y distributivas. En su aspecto distributivo, el derecho de daños establece los términos equitativos de interacción entre particulares mediante el reconocimiento de derechos y deberes de indemnidad, es decir, derechos a no sufrir cierto tipo de daños y deberes de no causarlos. Estos derechos y deberes son parte de lo que Rawls denominó bienes primarios, útiles para cualquier plan de vida. Una vez expuestos los elementos centrales de esta teoría, muestro cómo ella puede superar los problemas mencionados más arriba.This paper tries to show that the most influential philosophical conceptions of tort law, that see tort law as a practice of corrective justice, have three shortcomings. First, they are unable to perfectly explain the correlativity of the parties’ rights and duties. Second, they leave without explanation the contribution of tort law in the very conformation of primary rights and duties, in contrast to compensatory rights and duties which are secondary, for they arise once the former are infringed. Finally, they have a hard time in reconstructing strict liability as something different form the fault principle. I argue, on the other hand, that tort law is a complex practice that satisfies corrective and distributive functions. In its distributive aspect, tort law settles the fair terms of interaction between private parties by recognizing a set of indemnity rights and duties, that is, rights not to suffer certain types of harms, and duties no to cause them. These rights and duties are part of what Rawls called primary goods, useful for whatever the persons’ plan of life is. Once the central elements of this theory are presented, I show how the problems mentioned above can be surmounted.Este trabajo fue realizado en el marco del proyecto DER2010-21331-C02-02, del Ministerio de Ciencia e Innovación (España)

Choroidal neovascularization management in pathological myopia

New approaches in the diagnosis and therapy of myopic Choroidal neovascularization (CNV). Long-tem effects of anti-VEGF therapy for subfoveal myopic CNV. Best treatment drug: Bevacizumab versus Ranibizumab. Effects of treatment regimen. Effects of myopic CNV location (Juxtafoveal versus Extrafoveal myopic CNV). Agreement between FA and spectral domain OCT in detecting the activity of myopic subfoveal CN

Relative humidity vertical profiling using lidar-based synergistic methods in the framework of the Hygra-CD campaign

Accurate continuous measurements of relative hu- midity (RH) vertical profiles in the lower troposphere have become a significant scientific challenge. In recent years a synergy of various ground-based remote sensing instru- ments have been successfully used for RH vertical profil- ing, which has resulted in the improvement of spatial reso- lution and, in some cases, of the accuracy of the measure- ment. Some studies have also suggested the use of high- resolution model simulations as input datasets into RH ver- tical profiling techniques. In this paper we apply two syn- ergetic methods for RH profiling, including the synergy of lidar with a microwave radiometer and high-resolution at- mospheric modeling. The two methods are employed for RH retrieval between 100 and 6000 m with increased spatial res- olution, based on datasets from the HygrA-CD (Hygroscopic Aerosols to Cloud Droplets) campaign conducted in Athens, Greece from May to June 2014. RH profiles from synergetic methods are then compared with those retrieved using single instruments or as simulated by high-resolution models. Our proposed technique for RH profiling provides improved sta- tistical agreement with reference to radiosoundings by 27 % when the lidar–radiometer (in comparison with radiometer measurements) approach is used and by 15 % when a lidar model is used (in comparison with WRF-model simulations). Mean uncertainty of RH due to temperature bias in RH pro- filing was ~ 4 . 34 % for the lidar–radiometer and ~ 1 . 22 % for the lidar–model methods. However, maximum uncer- tainty in RH retrievals due to temperature bias showed that lidar-model method is more reliable at heights greater than 2000 m. Overall, our results have demonstrated the capabil- ity of both combined methods for daytime measurements in heights between 100 and 6000 m when lidar–radiometer or lidar–WRF combined datasets are available.Peer ReviewedPostprint (author's final draft

Influence of E.E.C. unions on economic policy

The practice of workers' participation the decision-making process of management, as well as trade union participation in advisory bodies which Influence various aspects of government socio-economic policies, has long been established in Western Europe. With the development of tripartite bodies in the European Economic Community CE.E.C.) the influence of trade union organisations in the formulation of the Commission's social and economic policies has increased as a whole in the last two decades, despite the fact that the influence of trade unions in the Federal Republic of Germany and the United Kingdom has decreased in the last few years. This happened because of the deteriorating relations between the trade unions and the conservative governments of those two countries, and especially of the latte