Laboratory of Atmospheric Absorption Spectroscopy

headed by Prof. Yurii N Ponomarev

Investigations

laser and Fourier spectroscopy of selective and non-selective absorption of gaseous molecules, molecular complexes and atmospheric nanoparticles;
investigation of the influence of minor gaseous components of the atmosphere on the optical radiation attenuation;
development of physical bases for methods for designing instruments for diagnostics of gas emissions to the atmosphere from lito-, hydro-, and biospheres;
development of instrumentation for multiwave gas-analysis.

Fundamental results

Values of nanopore diameters in aerogels and their dependence on the specimen density are determined for the first time from the measured half-widths of CO spectral line absorptions. A strong dependence of the CO spectral line half-widths inside nanopores on rotational quantum numbers is found for the first time. These data will enable the accuracy augmentation of the spectroscopic nanoporometry method.

The dependence of CO spectral line half-widths on quantum rotational numbers in aerogel (1), in aerogel with pore sizes of 80 nm [J.-M. Hartmann, C. Boulet, J. Wander Auwera, H. El. Hamzaoui, B. Capoen, and M. Bouazaoui, “Line broadening of confined CO gas: From molecule-wall to molecule-molecule collisions with pressure,” J. Chem. Phis, 140, 064302 (2014)] (2); under standard conditions (3). For convenience of comparison, the value series (2) and (3) were multiplied by 3.5 and 47, respectively (m = J + 1 for R branch and m = -J for P branch of CO absorption band)
It is shown that the radiation continual absorption in pure water vapor of the near IR region is conditioned by water dimers. Based on the analysis of recent experimental and theoretical results, it is shown with high degree of reliability that the spectral structure of that absorption is formed as a result of inter-supplementing contribution of coupled and quasi-connected dimers. It is also shown that water vapor continual absorption in transparence windows of the atmosphere in the near IR range by an order of magnitude exceeds predictions of the most usable today models of the continuum, including the MT SCD one. In the studies, Fourier spectra were used, obtained at Rutherford Appleton Laboratory (MSF RAL, UK). The investigations were also conducted in collaboration and under financial support of Department of Meteorology University of Reading (UK) and Obukhov Institute of Atmospheric Physics, RAN.

Experimental continuum (Paynter et al., JGR-2009) is compared with contribution from bonded (Kjaergaard et al., J. Phys. Chem. 2008) and quasibonded dimers. The figure is taken from the work of Ptashnik et al., JQSRT (2011).
Complex studies have shown for the first time the increased concentrations of CO₂ and H₂O in saw cuts of coniferous trees with year-to-year distributions (chronologies) to the depth up to 300 years, which have a proper 4-year biological cycle, impacted by climatic parameters (precipitations, temperature, clouds). In order to widen the list of gases, Fourier spectra of gaseous specimens absorption from year rings of conifer cuts have been measured. The isotope ¹³CO₂ was found in specimens along with the basic isotope CO₂.

The Fourier absorption spectrum of gas specimen from the year ring cut of 300-year larch (the year ring refers to 1777 year)

Scientific-technical programs and contracts

Program 11.10. Actual problems of optics and laser physics, including the attainment of ultimate concentrations of power and energy in time, space, and spectral regions; assimilation of novel regions of the spectrum; ultrahigh resolution spectroscopy; pureness standards; precision optical measurements; problems of quantum and atom optics; interaction of radiation with a matter.
Project 11. 10. 3. 4. “Development of laser and optical methods of sensing the atmosphere”.
Project 11. 10. 3. 7. “Investigation of high resolution spectra of greenhouse gases and ozone cycle gases aiming at their monitoring with the help of ground- and space-based spectral instrumentation”. Project 11.10. 3. 8. “Investigation of non-selective absorption of IR radiation by atmospheric gaseous components”.

Program VIII. 80. Scientific foundations for working out methods, technologies, and means for study of the Earth surface and interiors; the atmosphere, including ionosphere and magnetosphere of the Earth, hydrosphere, and cryosphere; numerical modeling; geoinformatics: infrastructure of space data, and GIS-technologies.
Project VIII.80.1.3. “Development of physical bases for spectroscopic and radiometric methods for studying gas emissions of lito-, bio-, and techno-spheres for ecological monitoring and special control”.

Integration Project of SB RAS No. 79 of interdisciplinary fundamental investigations “Space rays effect on atmospheric water vapor condensation and cloud-formation processes”.

International contract “Aerosol-fluorescence lidar” (Rainbow -2) in cooperation with Chi Lin Center of Technology for international exchange, China, Nanchang.

Grant of Russian Federation President MK-7801. 2015.2 for state support of young Russian scientists – candidates of sciences, “Investigation of the effect of the rotational energy of molecules on the broadening of absorption lines, induced by collisions with nanopore walls”.

Project of RSF 16-17-10096 “Determination of continual absorption of IR radiation by water vapor in atmospheric transparency windows”.

Scientific – research developments

Processional mirror modulator of laser radiation intensity

The device is intended for supporting the laser radiation modulation frequency in problems, requiring a raised accuracy and long-time stability.
Fields of application: the wide-used spectrometers with modulation of radiation intensity; opto-acoustic spectrometers with differential resonance cell.

Basic module of the remote gas-analyzer with IR lasers

The device is intended for designing path gas-analyzers based on the middle IR laser: wave-guide lasers on CO2 isotopes with discrete retuning of the generation wavelength, quantum-cascade semiconducting lasers with fast frequency scanning, parametric IR generators.
Fields of application: building of scientific instrumentation for ecological and safety problems.

Mirror telescope with built in chamber controlling the accuracy of aiming

Compact and light mirror multi-component optical system, worked out on the basis of Mersen-type telescope, serving as the receiving objective in the system of laser remote sensing. The device is intended for application in mobile lidars.

Three-wave beam expander

Compact lens multi-component three-wave optical system is intended for installing as a collimator into systems of laser remote sensing. It allows one to sense simultaneously at different distances and wavelengths (fundamental, third, and forth harmonics of ND-YAG laser). The system can be applied in lidars and remote gas-analyzers.

The lidar "FARAN-M2"

The mobile multi-wave aerosol lidar operates at three laser radiation wavelengths: 1062, 355, and 266 nm with two channels for signal receiving: IR scattering and UV channel of the Raman scattering and fluorescence. The lidar is intended for detection and investigation the distribution in the atmosphere of natural and anthropogenic aerosol formations and gases.
Fields of application: study of distribution and transformation of aerosol gaseous formations of different origins, study of optical properties of the atmosphere and stratosphere, the control for atmospheric pollutions and finding sources of these pollutions

Lidar scanner free of housing

Mobile lidar "FARAN-M2"

Personnel

Boris G Ageev, senior staff scientist, Dr., E-mail: ageev@iao.ru
Aleksei V Chentsov, staff scientist, Dr., E-mail: cav@iao.ru
Tat'yana Yu Chesnokova, senior staff scientist, Dr., E-mail: ches@iao.ru
Venedikt A Kapitanov, senior staff scientist, Dr., E-mail: venedikt@iao.ru
Anton V Klimkin, staff scientist, phone: +7 3822 12-30, E-mail: anton@iao.ru
Tat'yana E Kuraeva, senior staff scientist, Dr., E-mail: kte@iao.ru
Aleksei N Kuryak, leader electronic eng., E-mail: kurjak@iao.ru
Ol'ga Yu Nikiforova, senior staff scientist, Dr., E-mail: nik@iao.ru
Konstantin Yu Osipov, leader programmer, Dr., phone: +7 3822 13-76, E-mail: osipov@iao.ru
Yurii N Ponomarev, main staff scientist, Prof., phone: +7 3822 492-020, 491-111 + 10-04, E-mail: yupon@iao.ru
Aleksandr E Protasevich, senior staff scientist, Dr., E-mail: a.e.protasevich@mail.ru
Valeriya A Sapozhnikova, adv.engineer, E-mail: sapo@iao.ru
Anna A. Simonova, staff scientist, PhD, E-mail: saa@iao.ru
Aleksandr A Solodov, senior staff scientist, Dr., E-mail: asolodov@iao.ru
Yuliya V Voronina, staff scientist, Dr., E-mail: yulia@iao.ru