O. A. Bukin

Optical and Nonlinear Optical Properties of Sea Glass Sponge Spicules

Originating in nature, the combination of spongin protein with silicon dioxide extracted from seawater by silicatein protein presents a natural nanocomposite material of unique optical and mechanical properties. Mechanically, it combines the elasticity of protein with the flexibility and durability of silica. The light propagation inside spicules of glass sponges is of substantial interest for developing novel elements for photonics applications. The glass sponge spicules have remarkable light guiding properties. Our experimental research on passing laser pulses through spicules of Hyalonema sieboldi and Pheronema sp. reveals a concentration of guided light in the paraxial region. The multi-layer cladding of glass sponge spicules produced by nature has an obvious analogy with some contemporary artificial microstructured optical fibers. Our researches have shown that the core diameter and cladding layers thickness of the spicules of H. sieboldi and Pheronema sp. glass sponges are appropriate for causing photonic bandgaps in the infrared, visible, and ultraviolet wavelength regions. This enables singlemode waveguide and Bragg light propagation regimes in the spicules and provides exciting prospects of using them for the development of fundamentally new integrated optical elements based on peculiar waveguide properties of such structures, e.g., single-way waveguides (optical diodes) with increased mode field diameter and unique frequency and dispersion characteristics. Also, we have investigated the dynamics of propagation of intensive ultra-short pulses with durations T (0) < 40 fs through various patterns of spicules. Comparative analysis of the spectra of the output signals has shown that chromatic dispersion in spicules is considerably reduced, which can be explained by waveguide dispersion prevailing over material dispersion because of the multilayer structure of the cladding.

Optical properties of Peter the Great Bay waters compared with satellite ocean colour data

The shipboard measurements of optical and hydrological properties of seawater were used for development of regional bio-optical algorithms of waters of Peter the Great Bay. The shipboard measurements of chlorophyll-a and dissolved organic matter (DOM) concentrations were obtained by flow-through laser fluorometer (LF-3) (Institute for Automation and Control Processes, Vladivostok, Russia) and Sea-Bird Profiling CTD SBE-19plus (Conductivity, Temperature and Depth Sea-Bird Electronics, Sea-Bird Electronics, Inc., Washington, USA) equipped with WetStar fluorometers (WET Labs, Oregon, USA). The measurements were optically weighted according to light attenuation by depth. Ocean colour Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data were used for our comparative analysis. Chlorophyll-a concentrations from ocean colour data were retrieved by OC3M, Garver-Siegel-Maritorena (GSM) and Carder algorithms. Relationships of the shipboard and satellite sensor data were analysed comparatively in our work. The Carder model gives the most general results of estimation of chlorophyll-a concentrations for all observed water cases. OC3M and GSM algorithms show good performance in case I water but they have large errors in the Amur Bay waters because of a large impact of the Razdolnaya river and Vladivostok city anthropogenic activity. Two regional chlorophyll-a algorithms were offered and they improve significantly the accuracy of chlorophyll-a concentration estimation. The first one is based on empirical regression between chlorophyll-a concentration and remotely sensed reflectance ratio. The second one uses satellite-derived values of sun-induced chlorophyll-a fluorescence when chlorophyll-a concentrations are higher than 3 mg m−3. The last one gives the best results for all water cases and provides an approach for separation between DOM produced by phytoplankton and DOM not connected with phytoplankton activity. This allows a regional DOM algorithm to be made.

Results of an integrated aerosol experiment in the continentocean transition zone (primorye and the Sea of Japan). Part 2. Analysis of spatiotemporal variations of aerosol characteristics according to satellite data and lidar measurements

In the paper, we discuss the results of the study of the spatiotemporal aerosol optical depth (AOD) variations in the “continent-ocean” transition zone, performed in spring 2009 in Primorye and in the Sea of Japan with the use of satellite and ground-based AOD measurements. Also, the results of a joint analysis of lidar atmospheric sensing data, back trajectory analysis of air mass transport, and satellite monitoring of the state of the atmosphere of the studied region are given.

Optical properties of natural biominerals—the spicules of the glass sponges

In the article are given the results of the researches of the glass sea sponges Hyalonema sieboldi and Ferronema sp. spicules as new object of nano-photonics. The distribution of refractive index over the cross section of spicule is given. It is shown that the presence of organosilicon lamination is the reason for the appearance periodic space modulation of the spicule material dielectric constant. With the excitation of basal spicules by the pulses of the second harmonic Nd : YAG—laser was observed a significant increase in the intensity of fluorescence in the long-wave range, with the maximum at the wavelength 770 nm, It is shown that the periodicity of axial cylindrical layers from silicon dioxide of nanometer scale, which is observed in the basal spicules, leads to the formation of the photon bandgaps. This makes it possible to consider the spicules of glass sponges as natural one-dimensional photon crystals.

Results of an integrated aerosol experiment in the continent-ocean transition zone (Primorye and the Sea of Japan); Part 1: Variations of atmospheric aerosol optical depth and vertical profiles

We discuss the results of an integrated aerosol experiment, performed in spring 2009 simultaneously in two regions: near Ussuriysk and in the Sea of Japan onboard the Nadezhda training boat. For the measurements of aerosol optical depth (AOD) and moisture content of the atmosphere, we used multiwavelength sun photometers operating in the wavelength range 0.34–2.14 μm. The measurements of the vertical profiles of aerosol characteristics were made using two types of lidars: a lidar based on a three-frequency (1.064, 0.532, and 0.355 μm) Big Sky Laser CFR 200 in Primorye and a one-frequency laser based on the second harmonic of the Nd:YAG (0.532 μm) laser onboard the sailing vessel. It was shown that the springtime atmosphere in the Far East region has two times larger aerosol turbidity in comparison with other (maritime and continental) midlatitude regions. Average values of the atmospheric AOD in the region of 0.5 μm were 0.46 in Primorye and 0.35 in the Sea of Japan. The elevated atmospheric turbidity is caused by continental aerosol of different types (smoke, anthropogenic, and dust) blown off the neighboring regions. We present the characteristic vertical profiles of aerosol-molecular scattering for the cases of advection of air masses from arid regions of Southeastern Asia and the boreal zone of Siberia. A relation is demonstrated between the dust activity in the Taklamakan Desert and light scattering characteristics of aerosol layers in tropopause region.

Variations in aerosol microphysical parameters of the surface air layer in the “ocean-continent” transitional zone

This article provides the study results of variations in microphysical parameters of atmospheric aerosol in the surface layer of the “ocean-continent” transitional zone. The analyzed data were obtained during the period from August 1, 2010, to December 31, 2012, at the lidar station of the Institute of Automation and Control Processes, Far Eastern Branch, Russian Academy of Sciences (IACP FEB RAS), Vladivostok. Mass concentrations of fine aerosol and black carbon and particle size distribution functions typical for the region under study were obtained. In winter, with strong north winds and low relative humidity (50 ± 20)%, dry continental aerosol predominates, and values of the aerosol number density Na are increased, with maxima in the range from 100 and 120 cm−3. In summer, when south winds prevail and the relative humidity attains 98%, sea aerosol predominates and Na took values from (5 ± 5) cm−3 in June, 2011, to (44 ± 20) cm−3 in July, 2011. Periodicity of diurnal variations in the mass and number density of atmospheric aerosol and black carbon are pronounced the best in winter. The modal radius of fine aerosol particles is from 0.275 μm in summer to 0.375 μm in winter, and of coarse aerosol particles, from 1.05 to 2.5 μm, respectively. Seasonal and diurnal variations in the mass concentration of black carbon MBC are the most stable; its values vary from (0.5 ± 0.5) μg/m3 in the early summer to (3.0 ± 2.0) μg/m3 in January–February. It has been ascertained that diurnal variations in MBC in Siberia (Tomsk) and in the “ocean-continent” transitional zone (Vladivostok) are similar in shape, but the amplitude of variations is higher in the latter case and is maximal in winter.

Use of laser induced fluorescence method for phytoplankton communities describing

THe seawater flurescence spectra were measured by laser induced fluorescence (LIF) method. ND:YAG laser with frquency-doubled output at 532 nm was used to induce the fluorescence. The laser fluorometer measured the fluorescence spectral distribution in the band from 540 nm to 740 nm. Chlorophyll-a concentration and conventional concentration of dissolved organic matter fluorescence (FDOM) in wavelength range from 560nm to 740nm wer calulated from LIF spectra. The correlation coefficient between chlorophyll-a and FDOM concentrations was calculated in the floating window along ship track. High value coefficient means that FDOM produced by phhytoplankton living on the investigation sea area at the given time interval. Chlorophyll-a-FDOM relationships were described by linear regression. Intercept coefficient is a background FDOM (or FDOM do not produced by phytoplankton living on the investigation sea area in given time interval) and the slope coefficient is FDOM productivity by one μg/l of chlorophyll-a of phytoplankton. The clusters were determined from calculated slope, intercept and correlation coefficients. The clusters correspond to phytoplankton communities and calculating coefficients characterize condition and the evloution stage of these phytoplakton communities.

Laser spectroscopy methods in the development of laser sensor elements for underwater robotics

Laser technologies that are used for the development of sensor elements for Remotely Operated Vehicles (ROVs) are presented, as well as the latest developments in underwater robotics where laser spectroscopy methods are applied to environmental monitoring. A submersible laser spectrometer unit intended for studying Raman scattering and laser-induced fluorescence (LIF) spectra is presented. The spectrometer was developed as an element of an ROV sensor system for remote detection and measurements of organic matter concentrations in sea water and underwater objects. The results of environmental tests of the submersible LIF spectrometer in various marine areas, including the Arctic, are described.

Typical patterns of PBL structure and dynamics in transitional ocean-continent zone in summer and winter in Far East region

The paper is connected with planetary boundary layer (PBL) the lowermost part of the atmosphere its structure and dynamics investigations in the Far Eastern coastal zone in winter and summer. The data have been analyzed were obtained by means of aerosol polarization lidar. Mean values of PBL height, top of the convective layer and mean height of the nocturnal layer were presented. Well-developed nocturnal convection in the PBL was analyzed and explained. On the example of several summer days specific features of the PBL structure and dynamics are identified, presented and analyzed. Maximal values of breeze circulation heights are also presented.

Performance of satellite regional bio-optical algorithms depending on relationships between chlorophyll-a and dissolved organic matter concentrations

The validity of satellite regional algorithms depends on variability of optical properties of coastal waters and especially on relationships between concentrations of chlorophyll-a (chlA) and dissolved organic matter (DOM). The subject of the current researches is the role of characteristics of clusters in chlA - DOM scatter plot while developing of the regional biooptical algorithm. Regular undersatellite shipboard measurements of chlorophyll-a and DOM concentrations by means of contemporary laser fluorometer obtained in the various regions of Peter the Great Bay from 2007 to 2010 were used for the analysis.