Institute for Atmospheric Optics SB RAS

Akademicheskii Ave. 1, Tomsk, 634055, Russia
Phone: 7(382-2) 25-98-86; Fax: 7(382-2) 25-90-86
Internet: http://www.iao.ru

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Polarisation lidar for high-altitude remote sensing of the atmosphere - "Lidar"
Aircraft-Laboratory AN-30 "Optic - E"
Siberian Lidar Station (SLS)
A set of spectrometers
Large-size aerosol chambers
  Polarisation lidar for high-altitude remote sensing of the atmosphere - "Lidar"

Brief description:
Purpose: The lidar is intended for use in remote studies in atmospheric physics, atmospheric optics, meteorology, and climatology. The quantities that are directly measured with the lidar are the Stokes parameters of radiation scattered in the atmosphere due to physical effects that accompany the propagation of laser radiation through the atmosphere. The entire measurement procedure is arranged so that the Stokes parameters measured are then used to determine the back-scattering phase matrix of the medium sounded. To do this the Stokes parameters are being measured at four polarisation states of sounding radiation. The possibility of measuring the back-scattering phase matrix with this lidar makes it a unique lidar facility with no analogues in the world lidar community. The experiments on measuring the scattering phase matrices provide for most complete information on the scattering properties of the aerosol formations, regarding their microstructure. When observing the variations of the elements of the matrix one may relate them to the variations in the aerosol ensemble characteristics that can be caused by the action of physical fields in the atmosphere. For instance the presence of preferred orientation of non-spherical particles may occur due to the action of electric fields or atmospheric jet streams. The investigations that have been being carried out now are aimed at studying peculiar features of the effect of crystal clouds on the propagation and scattering of radiation in the atmosphere that in turn may provide data for refinement of the existing models of the radiation balance in the atmosphere. The lidar may also be used for studying the wave processes in the atmosphere as well as of the solar wind influence on the scattering properties of aerosol layers in the middle atmosphere. It is also possible to use the lidar for studying, on the global scale, the transfer of aerosols coming to the middle atmosphere as a result of natural or anthropogenic catastrophes. The lidar operates in a pulsed mode at the wavelength of 532nm. Mean power of sounding radiation is about 0.8W at the pulse repetition frequency of 25Hz. Lidar returns are recorded in the photon counting mode. The accuracy of return signal measurements is about 3%. The root-mean-square measurement error in the values of the normalised elements of the back-scattering phase matrix is about 0.04, with the range of the measured values being from -1 to 1. A more detailed description of the lidar may be found in the directories:

1) Third International Lidar Researchers Directory compiled by M.P.McCormick //Atm.Scie.Div., NASA Langley Res.Center. Hampton, Virginia, 23681-0001;
2) Unique research facilities in Russia // Megascience:the OECD Forum. Paris1995. Condition: The lidar is being operated in a routine mode. While studying the atmosphere the researchers from Tomsk State University and from IAO SB RAS also perform the student training function for the Radiophysics Faculty of the University. The lidar maintenance costs, including personnel wages, make up about 30,000 USD a year. The infrastructure of the IAO SB RAS and Tomsk State University is capable of providing full year research/training for 2 or 3 persons. The costs of lodging in this case could be from 30 to 100 USD a day.

  Aircraft-Laboratory AN-30 "Optic - E" Brief description:
Applications. The aircraft Laboratory AN - 30 "Optic - E" is equipped with the instrumentation for acquiring the data on the meteorological parameters, gas composition, and aerosol content of the atmosphere at the altitudes of flights, as well as for measuring characteristics of the underlying surface. Maximum altitude of flights is 8000 m, the speed of flight varies from 250 to 400 km per hour, maximum range of flights is about 2400 km, sufficient length of the landing strip is 1300 m.
Instrumentation:
- meteorological complex;
- aerosol complex (photoelectric counter,
diffusion battery, nephelometer supplied by thermo- and hydrooptics means, filtration accessories);
- gas analysing complex;
- lidar "Macrel-2";
- spectro-photo-radiometric complex;
- thermal imaging camera TV-03;
- board recording system;
- navigation complex. Measured parameters:
- air temperature and its fluctuations;
- humidity;
- pressure;
- wind velocity and its fluctuations;
- number and/or mass density of aerosol;
- aerosol particle size distribution in the size range from 0.005 to 10.0 micron;
- chemical composition of aerosol (ions: F, NH, NO, SO, CL, Na, K, Cd, As;
elements: Al, Co, Cr, Mo, Ni, Ti, Zn, B, Si, Ag, Ba, Br, Cu, Pb, Sn, V, Mn, Mg, Fe, Ga, W, Ca, Hg, Sb, In, Be);
- aerosol scattering coefficient (at the scattering angle of 45, at = 0.42, 0.52, and 0.61 micron) and the polarisation degree of scattered;
- light at these wavelength;
- content of aerosol volatile components at temperature 10-400 C;
- gases: ammonia, acetylene, acetone, petrol, benzene, xylene, ozone, nitric oxide, nitrogen peroxide, carbon monoxide, carbon dioxide, sulphur anhydride, hydrogen sulphide, toluene, chlorine;
- extinction coefficient of water (at depths down to 25 m);
- extinction of clouds (= 0.53 micron);
- vertical profile of the aerosol scattering coefficient (= 0.53 micron);
- intensity of up-welling radiation in the atmosphere - underlying surface system at the wavelengths = 0.44, 0.63, 0.67, 1.05, 1.20, 1.60, and 8 to 15.0 micron;
- temperature of the underlying surface in the range from -40 to 1600 C;
- board recording system is based on the use of CAMAC and IBM PC/AT with a streamer and provides for recording: the flight course; the air and actual speed of flight; drift angles;
- barometric altitude; bank and pitching angles; overload;
- presence of thunderstorms (radar indicator).

Other possible applications:
- investigation of trans-boundary transfer;
- studies of air pollution over urban areas with indication of the emission sources;
- measurements of water turbidity in the upper 25m layer of oceans;
- determination of chlorophyll and hydrosol content in water;
- detection of oil spills on the water surface;
- measurement of trees height and their spectral albedo.
Condition: - aircraft-laboratory AN-30 "Optic - E" is a continuously operated airbornelaboratory;
- flight cost 2000 $/hr;
- accommodation 50-90 $/night single room.

  Siberian Lidar Station (SLS) Siberian Lidar Station (SLS) of the Institute of Atmospheric Optics. SLS is situated in Tomsk (56.50 N, 85.00 E), in the forest suburban zone at a distance of 500 m from the eastern edge of Tomsk city. Tomsk is situated in Western Siberia - a large part of Eurasian continent covered by large forest areas far from seas, oceans and mountains.

Lidar with principial receiving mirror 2,2m in diameter

Brief description: A complex of lidar and spectrophotometric systems for optical remote sensing of the atmosphere at the SLS has been developed and put into regular operation by Laboratory of Remote Spectroscopy of the Atmosphere of IAO. The basic scientific researches directions of this laboratory are: development and refinement of theoretical background and methods as well as design and development of technical means for active and passive optical remote sensing of the atmosphere intended for integrated monitoring of the climatic and ecological atmospheric parameters including investigation into geophysical and physical- chemical mechanisms of transformation of the ozonosphere. Now the multichannel multifrequency lidar complex of the SLS comprises:
  1. Laser transmitters, namely, the excimer XeCl Raman-shifted laser (the wavelengths are 308 and 353 nm); the Nd:YAG laser (the wavelengths are 1064, 532 and 683 nm, which is first stokes order of the 532 nm in Raman cell with hydrogen); the copper-vapour lasers (511 and 578 nm) with laser frequency conversion in non-linear crystals (271 and 289 nm); the gold-vapour laser (628 nm)
  2. The receiving telescope with a large mirror 2.2 m in diameter, mounted in a specially equipped pit and the receiving optical systems with the mirrors 1.0, 0.5 and 0.3 m in diameter.
  3. The system for multichannel photoelectronic recording of lidar returns. This lidars allows us to measure simultaneously the aerosol, ozone and temperature in different altitude ranges of the troposphere and stratosphere by different sensing methods. In addition, to study mechanisms of variability of the stratospheric ozone, regular spectrophotometric measurements of the total content of ozone as well as of the total content and vertical distribution of NO2 are carried out at the SLS. In complex experiments the following parameters are measured:
    - vertical distribution of optical and microphysical aerosol characteristics (lidar, 0.5-30 km);
    - vertical distribution of ozone concentration (lidar, 1.0-35 km). The spatial resolution of ozone and aerosol measurements is 100-300 m, temporal resolutions is 15-30 min., the measurement error is no more then 10% at height 35 km;
    - total ozone content (brightness spectrophotometer M-124);
    - vertical distribution and total content of NO2 (twilight spectrophotometer, 0-50 km);
    - vertical distribution of temperature (lidar, 2-60 km);
    - the spatiotemporal variability of optical (the extinction coefficient, optical thickness), geometrical (lower and upper clouds boundaries) and phase state of cloudiness, including sensing of Cirrus clouds through low cloudiness, at night and in the daytime (lidar). Spatial resolution of the lidar is 100 m, temporal resolution is 3-4 s;
    - ultraviolet (A,B,C) radiation (spectrophotometer).

     Structure and block-diagram.
The data of integrated observations performed over a period of many years (aerosol, lidar - since 1986; ozone, lidar - since 1989; ozone and NO2, spectrophotometer - since 1993) allow us to develop empirical regional models of the atmospheric parameters and to elucidate the mechanisms that determine interconnections and dynamics of the measurable parameters, in particular, to estimate the contribution of photochemical and dynamic atmospheric factors to anomalous ozone layer variations.
Feasibility of simultaneous integrated measurements of the most important climatic and ecological atmospheric parameters is a salient feature of investigations carried out at the SLS. It is provided by application of various methods of laser sensing of the atmosphere combined with spectrophotometric measurements. In 1995 the Russian Ministry of Science issued the directive that the SLS was included in the List of Unique Research and Experimental Systems of National Significance (its registration number is 01-64).
Tomsk is the only point at the vast territory of Siberia where regular lidar and spectrophotometric observations of the atmospheric characteristics are carried out. Because of this the obtained measurement data are of particular interest for the specialists in regional and global ecology, meteorology, climatology and atmospheric physics. Comparative analysis of the data obtained at the SLS and Lidar Network can be used to study the processes of transboundary and global transfer in the stratosphere. We have numerous scientific-technical contacts with Russian and foreign scientific organisations in the framework of programs: "Siberia", 18th SSTP of Russia "Global environmental and climate change", "Laser technologies in climatic-ecological monitoring" with the Chinese Academy of sciences, ground - based correlative measurements under the NASA LITE program, projects of EUROTRAC program, the Program on atmospheric radiation measurement (ARM) is executed under the contract with the Pacific Northwest National Laboratory of USA.
     We welcome Russian and foreign specialists interested in collaboration.
Collaboration may have different forms (based on contract): pursuance of co-ordinated measurement companies; exchange by measurement procedures and results of investigations; apprenticeship of specialists by exchange; use of the SLS measuring complex, including a receiving mirror 2.2 m in diameter, for high- altitude sensing of the atmospheric parameters of interest to our future partners with the help of laser sources and receiving systems of the SLS and systems delivered by our partners.
Foreign and Russian scientist can be received to perform experiments at the Station, groups of 3-5 scientists can work.
They can be accommodated in the modern hotel "Rubin" and the comfortable guest cottage.
The hotel Rubin and the guest cottage are situated in a picturesque place of Akademgorodok, where the SLS is situated also. Akademgorodok is situated in the forest suburban zone of Tomsk city.
The cost of single room is about $50 in hotel "Rubin" and about $70 in the guest cottage.
Contact person. Corresponding Member of the RAS, Ph. Dr., Prof. Zuev Vladimir Vladimirovich.

  A set of spectrometers Up A spectrophotometric complex for measuring weak absorption spectra of molecular gases in UV-visible and IR spectral ranges. The complex is designed for accurate measuring of gases absorbency in controllable conditions and for study the characteristics of laser radiation at interaction with medium under variations of propagation conditions. The complex includes: unique 30- and 110 meter vacuum multi-pass gaseous cell (MPGC) supplied with Barskaya and Barskaya-Cherin optical systems; radiation sources - high - power crystalline neodymium-dopted glass lasers as well as YAG, alexandrite, and ruby ones with frequency multiplication and conversion band on non-linear crystals and SCR cells; metal-vapour, gaseous, and dye lasers; system of recording and processing the experimental data; systems of control of thermodinamical parameters of medium. Besides, the complex includes high-sensitive photoacoustic detector (PAD), the use of which significantly widens the capability of the complex both for investigation of the absorption spectra of molecular gases themselves and for widening their range (small value of the PAD cell allows one to study gaseous media of light cost). The complex specification Spectral range, nm 235-270, 350-800,1045-1075, 2090, 2650, 2936, 5300, 10600 Spectral resolution, cm-1 1.E-3-1.E-2.
Parameters of MPGG: length, m 30, 112 diameters, m 1, 0.7 pressure range, Torr 5.E-3, 1.E+3 temperature range, K 288-360 length of optical path, m 30-10000 error of transmission measurements, % 0.5-1.
Parameter of PAD call value, cm3 5-100 sensitively V/W cm-1 20-100 noise level, V/Hz-1/2 1.E-6-1.E-8.
Laser spectrometers for high accuracy measurements band on diode lasers spectral resolution, cm-1 1.E-3 spectral range, nm (depend on the used diode) 900-3000 spectrometer is supplied with high-accuracy recording system allowing one to obtain 1000 signal/noise ratio. Length of optical path, m 100. Intracavity (IC) laser spectrometer. IC is supplied with registration system based on photodiode line and polychromator with 0.018 cm-1 resolution The IC allows one to study molecules exited by electrical and magnetic fields in a charge and by resonance optical radiation in the laser spark. The IC - spectrometer with non-dispersion cavity allows measuring of absorption spectra within 9360-9480 cm-1 range and at general time 1 mc of provides the limit of the absorption registration
of 3.E-8 cm-1.
Potential partners from EU countries.

Condition - the cost of the installation use is 50-150$ per day; *
accommodation 20-30$/night single room.

  Large-size aerosol chambers for modelling and study of the processes of generation and transformation of aerosol pollution of air. Brief description. Purpose:
The large-size aerosol chambers present a unique possibility of carrying out the aerosol investigation in the great volume of air under controlled conditions. They allow to investigate the effect of some dynamic factors on aerosol and to repeat measurements if necessary. It is known that in the real atmosphere such possibilities are limited due to the high spatial-temporal variability of aerosol under simultaneous effect of synoptic, meteorological, and other factors.
Hermeticity and thermal isolation of the chambers remove the effect of such factors as advective and convective transfer and turbulence. Control of the gas composition and the illumination conditions makes it possible to remove the influence of chemical and photochemical processes. Blackness of the walls removes the optical interference. Large volume allows to avoid the wall effect. Material of the walls (stainless steel) makes it possible to operate with chemically active aerosol and gases. Specifications of "big" and "small" aerosol chambers.

Length, m

26

12.7

Pressure, atm

0.3

0.3

Diameter, m

10

5

Temperature, C, up to

+130

Volume, m3

1800

217

+ 60 Aerosol water

Maximum pressure, atm

1.7

Clouds, fogs, smokes, dust, rain, etc

The small chamber can be 2/3 full of water

1.7 Minimum


The possibility of generation of the determined aerosol and gas composition, formation of illumination conditions and meteorological parameters (pressure, temperature and humidity) allows to generate and study the atmospheres of Earth and other planets. Such investigations are destined to solving a lot of problems, including the followings:
  1. Study of the features of aerosol generation processes and development of dynamical optical-microphysical models of aerosol,
  2. Multiple scattering of optical radiation in dense aerosol media at the laser sounding of the atmosphere and in the optical channels of communication at long paths,
  3. Study of the features of optical image transfer in aerosol objects,
  4. Long-range action of laser navigation systems for steering ships and landing aircrafts under poor visibility conditions,
  5. Modelling and investigations of forest fires: particle-size distribution, soot content, etc. In addition, the small aerosol chamber is capable of carrying out the hydrooptical measurements in the water medium that simulates the sea and lake conditions. Some cycles of such investigations for different modelled aerosol media were carried out in aerosol chambers. The aerosol chambers can be used for applied purposes of testing the instrumentation, intercalibration of devices, estimating the range of operation of the optical systems, etc.
Potential partners from the EU countries. Functional possibilities of the aerosol chambers makes it possible to use them as an aerosol research centre for common usage with the aim of caring out the individual and complex scientific experiments with simultaneous participation of scientists from different countries for solving the problems of climatology and weather prediction, ecology, atmospheric physics and optics. There are wide possibilities of international co-operation of specialists from the EU countries for realisation of joint aerosol programs and investigations on the base of our centre.

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