Multiwavelength fluorescence lidar observations of smoke plumes

A five-channel fluorescence lidar was developed for the study of atmospheric aerosol. The fluorescence spectrum induced by 355 nm laser emission is analyzed in five spectral intervals using interference filters. Central wavelengths and the widths of these five interference filters are, respectively, as follows: 438 and 29, 472 and 32, 513 and 29, 560 and 40, and 614 and 54 nm. The relative calibration of these channels has been performed using a tungsten–halogen lamp with a color temperature of 2800 K. This new lidar system was operated during summer–autumn 2022, when strong forest fires occurred in the Moscow region and generated a series of smoke plumes analyzed in this study. Our results demonstrate that, for urban aerosol, the maximal fluorescence backscattering is observed in a 472 nm channel. For the smoke, the maximum is shifted toward longer wavelengths, and the fluorescence backscattering coefficients in 472, 513 and 560 nm channels have comparable values. Thus, from the analysis of the ratios of fluorescence backscattering in available channels, we show that it is possible to identify smoke layers. The particle classification based on single-channel fluorescence capacity (ratio of the fluorescence backscattering to the elastic one) has limitations at high relative humidity (RH). The fluorescence capacity indeed decreases when water uptake of particles enhances the elastic scattering. However, the spectral variation of fluorescence backscattering does not exhibit any dependence on RH and can be therefore applied to aerosol identification.</p

Study on the influence of different error sources on sky radiance measurements and inversion-derived aerosol products in the frame of AERONET

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.Financial support from the Spanish MICINN under projects with ref. CGL2009-09740, CGL2011-23413, CGL2010-09480-E and CGL2011-13085-E is gratefully acknowledged

PHOTONS/AERONET sunphotometer network overview. Description – Activities - Results

Fourteenth International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics celebrado del 24 al 30 de junio de 2007 en Buryatia, Russia

The AERONET-Europe calibration facility: access within the ACTRIS project

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.This work has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement N. 262254. Financial support from the Spanish Ministry of Science (MICINN) under projects with ref. CGL2009-09740, CGL2011-23413, CGL2010-09480-E and CGL2011-13085-E as well as from Junta de Castilla y León are gratefully acknowledged

Pointing error and field of view of AERONET CIMEL-318 sun photometers

Resumen de la comunicación oral presentada en: 1st Iberian Meeting on Aerosol Science and Technology – RICTA 2013, celebrado del 1 al 3 de julio de 2013 en Évora, Portugal

Comparison of aerosol optical properties above clouds between POLDER and AeroCom models over the South East Atlantic Ocean during the fire season

Aerosol properties above clouds have been retrieved over the South East Atlantic Ocean during the fire season 2006 using satellite observations from POLDER (Polarization and Directionality of Earth Reflectances). From June to October, POLDER has observed a mean Above-Cloud Aerosol Optical Thickness (ACAOT) of 0.28 and a mean Above-Clouds Single Scattering Albedo (ACSSA) of 0.87 at 550 nm. These results have been used to evaluate the simulation of aerosols above clouds in 5 AeroCom (Aerosol Comparisons between Observations and Models) models (GOCART, HadGEM3, ECHAM5-HAM2, OsloCTM2 and SPRINTARS). Most models do not reproduce the observed large aerosol load episodes. The comparison highlights the importance of the injection height and the vertical transport parameterizations to simulate the large ACAOT observed by POLDER. Furthermore, POLDER ACSSA is best reproduced by models with a high imaginary part of black carbon refractive index, in accordance with recent recommendations

Climatological aspects of the optical properties of fine/coarse mode aerosol mixtures

Aerosol mixtures composed of coarse mode desert dust combined with fine mode combustion generated aerosols (from fossil fuel and biomass burning sources) were investigated at three locations that are in and/or downwind of major global aerosol emission source regions. Multiyear monitoring data at Aerosol Robotic Network sites in Beijing (central eastern China), Kanpur (Indo-Gangetic Plain, northern India), and Ilorin (Nigeria, Sudanian zone of West Africa) were utilized to study the climatological characteristics of aerosol optical properties. Multiyear climatological averages of spectral single scattering albedo (SSA) versus fine mode fraction (FMF) of aerosol optical depth at 675 nm at all three sites exhibited relatively linear trends up to similar to 50% FMF. This suggests the possibility that external linear mixing of both fine and coarse mode components (weighted by FMF) dominates the SSA variation, where the SSA of each component remains relatively constant for this range of FMF only. However, it is likely that a combination of other factors is also involved in determining the dynamics of SSA as a function of FMF, such as fine mode particles adhering to coarse mode dust. The spectral variation of the climatological averaged aerosol absorption optical depth (AAOD) was nearly linear in logarithmic coordinates over the wavelength range of 440-870 nm for both the Kanpur and Ilorin sites. However, at two sites in China (Beijing and Xianghe), a distinct nonlinearity in spectral AAOD in logarithmic space was observed, suggesting the possibility of anomalously strong absorption in coarse mode aerosols increasing the 870 nm AAOD

Aerosol optical properties and direct radiative forcing based on measurements from the China Aerosol Remote Sensing Network (CARSNET) in eastern China

Aerosol pollution in eastern China is an unfortunate consequence of the region's rapid economic and industrial growth. Here, sun photometer measurements from seven sites in the Yangtze River Delta (YRD) from 2011 to 2015 were used to characterize the climatology of aerosol microphysical and optical properties, calculate direct aerosol radiative forcing (DARF) and classify the aerosols based on size and absorption. Bimodal size distributions were found throughout the year, but larger volumes and effective radii of fine-mode particles occurred in June and September due to hygroscopic growth and/or cloud processing. Increases in the fine-mode particles in June and September caused AOD440 nm > 1.00 at most sites, and annual mean AOD440 nm values of 0.71-0.76 were found at the urban sites and 0.68 at the rural site. Unlike northern China, the AOD440 nm was lower in July and August (∼ 0.40-0.60) than in January and February (0.71-0.89) due to particle dispersion associated with subtropical anticyclones in summer. Low volumes and large bandwidths of both fine-mode and coarse-mode aerosol size distributions occurred in July and August because of biomass burning. Single-scattering albedos at 440 nm (SSA440 nm) from 0.91 to 0.94 indicated particles with relatively strong to moderate absorption. Strongly absorbing particles from biomass burning with a significant SSA wavelength dependence were found in July and August at most sites, while coarse particles in March to May were mineral dust. Absorbing aerosols were distributed more or less homogeneously throughout the region with absorption aerosol optical depths at 440 nm ∼ 0.04-0.06, but inter-site differences in the absorption Angström exponent indicate a degree of spatial heterogeneity in particle composition. The annual mean DARF was −93 ± 44 to −79 ± 39 W m−2 at the Earth's surface and ∼ −40 W m−2 at the top of the atmosphere (for the solar zenith angle range of 50 to 80∘) under cloud-free conditions. The fine mode composed a major contribution of the absorbing particles in the classification scheme based on SSA, fine-mode fraction and extinction Angström exponent. This study contributes to our understanding of aerosols and regional climate/air quality, and the results will be useful for validating satellite retrievals and for improving climate models and remote sensing algorithms

Асинхронная репликация у онкологических больных

Epigenetics is a science studying mechanisms of heritable changes in gene function that occur without a change in the DNA sequence. One of the most important marks of epigenetic misbalance of cell genome is an replication asynchrony of genes with biallelic expression. Interphase fluorescence in situ hybridization (I-FISH) in phytohaemagglutinin-stimulated lymphocytes of peripheral blood is a proper method of estimation of aberrant DNA replication time e. g. DNA replication asynchrony. In this review we analyzed reports referring to asynchronous DNA replication of biallelically expressed genes in lymphocytes of peripheral blood of cancer patients. Analysis shows the DNA replication asynchrony is a nonspecific tumor marker observing both in tumor cells and lymphocytes of peripheral blood in oncohematological patients and patients with solid tumors. It’s stated the frequency of lymphocytes with asynchronous DNA replication of studied genes in cancer patients is increased significantly compares with healthy donors and is enhanced during malignance process. It gives the opportunity of potential using asynchronous replication as molecular genetic marker for cancer patients early revealing.Эпигенетика – наука об обратимых наследственных изменениях функционирования гена, которые происходят без изменений в нуклеотидной последовательности ДНК. Один из важнейших маркеров нарушений эпигенетической регуляции генома клетки – асинхронность репликации ДНК биаллельно экспрессирующихся генов. Удобным методом оценки нарушения синхронности репликации (асинхронной репликации) в культивированных лимфоцитах периферической крови человека, как правило, является интерфазная флуоресцентная in situ гибридизация (I-FISH). В обзоре проведен анализ работ, направленных на изучение асинхронной репликации биаллельно экспрессирующихся генов в лимфоцитах периферической крови онкологических больных. Этот анализ показал, что асинхронная репликация – неспецифический маркер злокачественных новообразований и наблюдается как у онкогематологических больных, так и у пациентов с солидными опухолями, причем не только в клетках опухоли, но и в лимфоцитах периферической крови. Проведенный анализ продемонстрировал, что встречаемость лимфоцитов с асинхронной репликацией изученных генов у онкологических больных достоверно повышена по сравнению со здоровыми лицами и увеличивается в процессе малигнизации (злокачественного перерождения) заболеваний. Это дает потенциальную возможность использовать асинхронную репликацию как молекулярно-генетический маркер для раннего выявления лиц с онкологическими заболеваниями

Preparation of polycaprolactone nanoparticles via supercritical carbon dioxide extraction of emulsions

Polycaprolactone (PCL) nanoparticles were produced via supercritical fluid extraction of emulsions (SFEE) using supercritical carbon dioxide (scCO2). The efficiency of the scCO2 extraction was investigated and compared to that of solvent extraction at atmospheric pressure. The effects of process parameters including polymer concentration (0.6–10% w/w in acetone), surfactant concentration (0.07 and 0.14% w/w) and polymer-to-surfactant weight ratio (1:1–16:1 w/w) on the particle size and surface morphology were also investigated. Spherical PCL nanoparticles with mean particle sizes between 190 and 350 nm were obtained depending on the polymer concentration, which was the most important factor where increase in the particle size was directly related to total polymer content in the formulation. Nanoparticles produced were analysed using dynamic light scattering and scanning electron microscopy. The results indicated that SFEE can be applied for the preparation of PCL nanoparticles without agglomeration and in a comparatively short duration of only 1 h