Boyan Tatarov
National Institute for Environmental Studies
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Featured researches published by Boyan Tatarov.
Optics Express | 2012
Nobuo Sugimoto; Zhongwei Huang; Tomoaki Nishizawa; Ichiro Matsui; Boyan Tatarov
A lidar for measuring fluorescence from atmospheric aerosols was constructed with a third harmonic Nd:YAG laser, a 1-m diameter telescope, and a 32-channel time-resolved photon-counting spectrometer system. Fluorescence spectrum and vertical distribution of fluorescent aerosols in the lower atmosphere were observed during the nighttime with excitation at 355 nm. Relatively strong broad fluorescence was observed from Asian dust and air-pollution aerosols transported from urban and industrial areas. Rough estimates of the fluorescence efficiency were given for these aerosols. The intensity of the total fluorescence over the spectral range from 420 to 510 nm was comparable to that of nitrogen vibrational Raman scattering. That indicates the possibility of making a compact Raman-Mie-fluorescence lidar for aerosol monitoring.
Optics Letters | 2005
Boyan Tatarov; Nobuo Sugimoto
A remote sensing method is presented that enables the determination of quartz concentration in mineral aerosols from simultaneously measured, high-spectral-resolution lidar and quartz Raman lidar signals.
International Journal of Remote Sensing | 2005
Nikolay Kolev; Boyan Tatarov; Vera Grigorieva; E Donev; P. Simeonov; V. Umlensky; Boiko K. Kaprielov; Ivan N. Kolev
A complex investigation of the planetary boundary layer (PBL) is presented. Observations were carried out on 11 August 1999 during the solar eclipse over Bulgaria using a Light Detection and Ranging Device (Lidar), ozone meters and ground meteorological stations. The Lidar was used to measure the height of the mixing layer before, during and after the solar eclipse in Sofia city; the ozone meters measured the surface O3 concentrations during the phenomenon, while the ground stations took meteorological parameters of the atmospheric ground layer. Weather conditions in all the regions (Sofia, Shabla, Ahtopol and Rozhen peak) were favourable for the observations. The data of the three types of measurements demonstrate with certainty that the solar eclipse affects the meteorological parameters of the atmosphere near the ground, the ozone concentration and the height of the mixing layer. It was found that a certain time delay exists in the solar eclipses impact on the meteorological parameters, the ozone concentration and the mixing layer height and that this delay was different for each of the different parameters.
Optics Express | 2011
Boyan Tatarov; Detlef Müller; Dong Ho Shin; Sung Kyun Shin; Ina Mattis; Patric Seifert; Young Min Noh; Y. J. Kim; Nobuo Sugimoto
We developed a novel measurement channel that utilizes Raman scattering from silicon dioxide (SiO2) quartz at an ultraviolet wavelength (361 nm). The excitation of the Raman signals is done at the primary wavelength of 355 nm emitted from a lidar instrument. In combination with Raman signals from scattering from nitrogen molecules, we may infer the mineral-quartz-related backscatter coefficient. This technique thus allows us to identify in a comparably direct way the mineral quartz content in mixed pollution plumes that consist, e.g., of a mix of desert dust and urban pollution. We tested the channel for the complex situation of East Asian pollution. We find good agreement of the inferred mineral-quartz-related backscatter coefficient to results obtained with another mineral quartz channel which was operated at 546 nm (primary emission wavelength at 532 nm), the functionality of which has already been shown for a lidar system in Tsukuba (Japan). The advantage of the novel channel is that it provides a better signal-to-noise ratio because of the shorter measurement wavelength.
Asia-pacific Journal of Atmospheric Sciences | 2013
Sung-Kyun Shin; Detlef Müller; Y. J. Kim; Boyan Tatarov; Dongho Shin; Patric Seifert; Young Min Noh
The linear particle depolarization ratios were retrieved from the observation with a multiwavelength Raman lidar at the Gwangju Institute of Science and Technology (GIST), Korea (35.11°N, 126.54°E). The measurements were carried out in spring (March to May) 2011. The transmission ratio measurements were performed to solve problems of the depolarization-dependent transmission at a receiver of the lidar and applied to correct the retrieved depolarization ratio of Asian dust at first time in Korea. The analyzed data from the GIST multiwavelength Raman lidar were classified into three categories according to the linear particle depolarization ratios, which are pure Asian dust on 21 March, the intermediate case which means Asian dust mixed with urban pollution on 13 May, and haze case on 10 April. The measured transmission ratios were applied to these cases respectively. We found that the transmission ratio is needed to be used to retrieve the accurate depolarization ratio of Asian dust and also would be useful to distinguish the mixed dust particles between intermediate case and haze. The particle depolarization ratios of pure Asian dust were approximately 0.25 at 532 nm and 0.14 at 532 nm for the intermediate case. The linear particle depolarization ratios of pure Asian dust observed with the GIST multiwavelength Raman lidar were compared to the linear particle depolarization ratios of Saharan dust observed in Morocco and Asian dust observed both in Japan and China.
International Journal of Remote Sensing | 2009
Boyan Tatarov; H. Nakane; Ch. B. Park; N. Sugimoto; I. Matsui
Differential absorption lidar (DIAL) at the National Institute for Environmental Studies (NIES) in Tsukuba (36°N, 140°E), Japan has been making routine observations for almost 20 years. Since 1988, more than 600 vertical profiles of stratospheric ozone and temperature have been obtained. We compared the lidar data with satellite data from the Stratospheric Aerosol and Gas Experiment (SAGE II) and assimilation data from the National Center for Environmental Prediction (NCEP). The lidar and SAGE II ozone profiles agreed within 5% in altitude range from 18 km to 40 km and within 10% up to 45 km. The lidar and NCEP temperatures agreed within 7 K in the 35- to 50-km range. Ozone levels were highest in spring at altitudes below 20 km. Above 30 km, the ozone maximum occurred during summer. The annual cycle of temperature is observed with a spring maximum for all altitudes in the 35- to 50-km range. Ozone variations caused by the quasi-biennial oscillation (QBO) and the 11-year solar cycle are discussed. The ozone trends after subtraction of the QBO and solar effects for the altitude range from 30 to 40 km are –6.0 ± 0.5%/decade for the period from 1988 to 1997 and statistically insignificant after 1998.
Lidar Remote Sensing for Environmental Monitoring XIII | 2012
Nobuo Sugimoto; Zhongwei Huang; Tomoaki Nishizawa; Ichiro Matsui; Boyan Tatarov
A lidar for measuring fluorescence from atmospheric aerosols was constructed with a third harmonic Nd:YAG laser, a 1- m diameter telescope, and a 32-channel time-resolved photon counting spectrometer system. Fluorescence of aerosols in the spectral range from 420 nm to 510 nm was studied with the excitation at 355 nm. The distribution of fluorescent aerosols was studied in the time-height indications of the broad fluorescence. Type of the aerosols was identified from simultaneous observation with a polarization lidar in the Asian dust and aerosol observation lidar network (AD-Net). It was found that Asian dust and air-pollution aerosols transported from urban or industrial areas emit fluorescence. Fluorescence efficiency was roughly estimated for these aerosols. The results suggest fluorescence measurements combined with the measurement of microphysical parameters of aerosols using a multiple-wavelength Raman lidar or high-spectral-resolution lidar will provide useful information for characterizing chemical properties of aerosols.
12th International School on Quantum Electronics Laser Physics and Applications | 2003
Boyan Tatarov; Nikolai I. Kolev; Boiko K. Kaprielov; Ivan N. Kolev
In the paper methods and experimental techniques for study of various types of clouds in the PBL (St, Sc, Cu, Stfr, fair weather clouds, etc.) accompanied by the obtained related information are presented and discussed. The abilities of different methods for determination of the cloud base height and its dynamics are also considered. The possibility for determination of the clouds phase composition through analysis of the lidar signal polarization characteristics is shown. The basic physical mechanisms grounding the lidar study of cloud formations and the limits of their applicability are discussed. The algorithms of data processing and desired information extraction are described as well. The studies presented in the paper were carried out using a backscatter aerosol lidar system with a polarization unit and module for the viewing angle variation. The results obtained employing the methods and techniques, subject of the paper, could be summarized as follows: (1) following of the base height of various types of clouds and its dynamics in different atmospheric situations and synoptic conditions, including atmospheric fronts passage; (2) determination of crystal (ice) phase within the volume of different types of clouds; (3) estimation of the density of cloud formations; (4) determination of some microphysical characteristics of the clouds, such as droplets mean size, water content, etc.
Atmospheric Chemistry and Physics | 2018
Sung-Kyun Shin; Matthias Tesche; Kwanchul Kim; Maria Kezoudi; Boyan Tatarov; Detlef Müller; Youngmin Noh
Knowledge of the particle lidar ratio ( Sλ) and the particle linear depolarisation ratio ( δλ) for different aerosol types allows for aerosol typing and aerosol-type separatio n in lidar measurements. Reference values generally origina te from dedicated lidar observations but might also be obtaine d 5 from the inversion of AERONET sun/sky radiometer measurements. This study investigates the consistency of spec tral Sλ andδλ provided in the recently released AERONET version 3 inversion product for observations of undiluted mineral dust in the vicinity of major deserts: Gobi, Sahara, Ara 10 bian, Great Basin and Great Victoria deserts. Pure dust conditions are identified by an Ångstöm exponent < 0.4 and a fine-mode fraction< 0.1. The values of spectral Sλ are found to vary for the different source regions but generally show an increase with de15 creasing wavelength. The feature correlates to AERONET retrieving an increase in the imaginary part of the refractive index with decreasing wavelength. The smallest values of Sλ = 35− 45sr are found for mineral dust from the Great Basin desert while the highest values of 50-70 sr have been 20 inferred from AERONET observations of Saharan dust. Values ofSλ at 675, 870, and 1020 nm seem to be in reasonable agreement with available lidar observations while those at 440 nm are up to 10 sr higher than the lidar reference. The spectrum ofδλ shows a maximum of 0.26-0.31 at 1020 nm 25 and decreasing values as wavelength decreases. AERONETderivedδλ at 870 and 1020 nm are in line with the lidar reference while values of 0.19-0.24 at 440 nm are smaller than the independent lidar observations by a difference of 0.03 t o 0.08. This general behaviour is consistent with earlier stu dies 30 based on AERONET version 2 products.
Lidar Remote Sensing for Environmental Monitoring XI | 2010
Boyan Tatarov; Nobuo Sugimoto; Ichiro Matsui; Dongho Shin; Detlef Müller
In inelastic Raman scattering the scattered signal consists of radiation that has undergone a frequency shift which is characteristic for the stationary energy states of an irradiated molecule. Nowadays, Raman and fluorescence spectroscopy is commonly used in chemistry. Information on the radiation that results from transition between the vibrational energy states of the excited molecules, respectively, is specific to the chemical bonds and symmetry of molecules. This radiation therefore provides unique information regarding the irradiated molecule according to which the molecular species can be identified. Raman spectroscopy represents a particularly powerful tool for laser remote sensing because it allows us to both identify and quantify the trace constituent relative to the major constituents of a mixture. In this paper we present a multi-channel spectrometric lidar system which allows us to measure Raman and fluorescence spectrums that give us information on chemical signatures characteristic for chemical components of aerosol particles and pollutions. In the following, we describe the methodology, the system and we show experimental results.