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Atmospheric Brown Cloud


Lidar Investigations of Atmospheric Brown Cloud in the Central Asia

Tech Area / Field

  • ENV-APC/Air Pollution and Control/Environment
  • ENV-MIN/Monitoring and Instrumentation/Environment
  • PHY-OPL/Optics and Lasers/Physics

8 Project completed

Registration date

Completion date

Senior Project Manager
van der Meer A

Leading Institute
Kyrgyz-Russian Slavonic University, Kyrgyzstan, Bishkek

Supporting institutes

  • Institute of Dynamics of the Geosphere, Russia, Moscow


  • Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft / Institut für Technische Chemie Bereich Wasser- und Geotechnologie, Germany, Karlsruhe\nUniversité des Sciences et Technologies de Lille / Laboratoire d'Optique Atmospherique, France, Villeneuve d' Ascq

Project summary

Purposes and Scientific Program

The purpose of the project is the fundamental research and acquisition of objective data about optical and microphysical characteristics of the Atmospheric Brown Cloud (ABC) in the region of Central Asia. This research is performed to eliminate insufficient knowledge on the ABC and to formulate the decisions directed to softening of the ABC action on a society as a whole.

The following problems will be solved within the scientific program of the project:

  • development of algorithms and software for processing of the data of measurements and solution of the inverse backscattering problems for light propagation;
  • in-situ measurements of optical and microphysical characteristics of the ABC; collection, analysis and classification of nano- and microscale particles which form the ABC;
  • development of models of aerosol radiative forcing;
  • development of a model of radiative transfer and photochemical processes which describes the ABC forcing on the atmosphere;
  • evaluation of direct and indirect aerosol forcing of the ABC.

State of the Art and Importance of the Proposed Project

The Atmospheric Brown Clouds (Brown gas) consisting of a mixture of particles of anthropogenic sulfates, nitrates, organic origin, black carbon, dust, ashes, and also natural aerosols such as sea salt and mineral dust is an important problem of this century. The brown color is a result of absorption and scattering of solar radiation by the anthropogenic black carbon, ashes, the particles of salt dust, and nitrogen dioxide.

Estimates show that if the density of crystal carbon in the atmosphere is only several millionth of the density of carbon containing in the carbon dioxide and the efficiency of the sources of CO2 is small then the efficiency of the soot particles in the radiation processes is much higher than that of CO2. This is due to a wide absorption band of the soot particles which corresponds to the wavelengths from 0.3 to 3–4 m in contrast to a narrow absorption band of CO2. The short–wave absorption by aerosols is connected mostly with the existence of submicron (nanoscale) sub–fraction consisting of the soot particles. Thus the radiative and climatologic influence of aerosol is connected mainly with the soot component. We note that up to now an analysis of nanoscale particles containing in the ABC, which includes the distributions of particles in sizes, study of their properties, chemical and mineralogical compositions, has not been carried out.

At present the investigation of the ABC is a fundamental problem for prevention of degradation of the environment. The Aral catastrophe, the ABC and other examples of similar scale convince that the aerosol environmental security becomes an important component of strategics of the national policy and a basic aspect of the state priorities.

Competence of Participants

Scientific teams of the Kyrgyz–Russian Slavic University and the Institute of Geosphere Dynamics of the Russian Academy of Sciences will execute the project. The scientific personnel of the teams includes the experts in optical methods of research of atmospheric aerosol and statistics in geophysical processes, in theoretical and numerical methods of physics and chemistry of atmosphere, in processes of cloud formation at different altitudes, in optical and thermochemical properties of the atmospheric aerosols constituting clouds, in interactions of solar radiation with the substance of the clouds. Among the participants of the project there are 4 doctors and 9 candidates of sciences.

Workload, Structure, Approaches, and Methodology

Methodology of the project is oriented to the creation of a station which can provide lidar and radiometry monitoring of the ABC in the region of Central Asia and can be able to become a part of global network of environment monitoring. The latter is being formed by means of the development of regional networks.

The scientific program is stated in the form of distinct tasks which altogether provide the achievement of the project purposes:

  • Development of algorithms and software for the data processing and solution of inverse backscattering problem for light propagation;
  • In-situ measurements, collection, analysis, and classification of nano- and miocroscale particles constituting the ABC;
  • Increase in quantity of information carried by the monitoring data due to coordinated lidar and radiometric measurements and development of a model for calculation of aerosol radiative forcing;
  • Development of a model of radiative transfer and photochemical processes which describes the ABC forcing on the atmosphere and evaluation of direct and indirect aerosol forcing of the ABC.

Expected Results and Their Application

The project comes under fundamental investigation.

The basic result of the project is the formation of a lidar and radiometry station on the Central Asia territory which gives rise to systematic measurements of the ABC. The station will support directly the purposes of the ABC Program – South Asia UNEP/NOAA, extending the region of the ABC study to the region of Central Asia.

A developed model of aerosol radiative forcing on the basis of the data of lidar and radiometric measurements will be applied to calculations of direct and indirect aerosol regional effects.

Estimates of radiation fluxes and temperature changes related to radiant energy release, the increase in hothouse gas densities, the ozone density decrease, and changes in temperature and humidity near the Earth surface will be performed on the basis of the developed model of radiative transfer and photochemical processes which describes the ABC forcing on the atmosphere.

9.6. International Collaboration and Role of Foreign Collaborators

Permanent collaboration on development of methodology of lidar monitoring, data base formation, representation of the information, and performance of coordinated observations directed to the study of the ABC in the region, will be performed with the existing lidar networks CIS-LiNet, AD-Net, and the monitoring network ABC established by UNEP/NOAA in the South–Asian subregion., as well as with the radiometry network AERONET/PHOTONS. The scientists included in the project will collaborate closely with leading scientists of the radiometric network AERONET/PHOTONS (France) and famous experts in atmospheric chemistry and nano- and microscale particles of the Forschungszentrum (Research Center) Karlsruhe GmbH (Germany), namely with the collaborators of the project, Dr. Philippe Goloub and Dr. Peter G. Weidler, providing therethrough possibilities for the achievement of the professional prestige and promotion.

The forms of interaction with the foreign collaborators are also preparation of joint publications reflecting the results of joint investigations. Exchange of scientific information concerning the results of the analysis of nano- and microscale particles and determination of their properties is supposed. The experts will be invited to the participating institutions for familiarization with equipment and methodology as well as for the participation in the experiments.

The results of joint research will be presented at seminars and conferences. The Summary and Annual Reports will be sent to the foreign collaborators for their comments.

9.7. Meeting ISTC Goals and Objectives

The most of the proposed researchers of participating institutions belonged earlier to weapon scientific personnel working in various military branches.

The participation in the project allows this group of researchers to use scientific ideas, technical projects, and experience, acquired when performing the military research works, for civilian technology development which is directed to formation of the environmental control system and the effective use of natural resources. The work of the scientific staff together with the lidar networks CIS-LiNet, AD-Net, and the monitoring net ABC UNEP/NOAA will serve a way of integration of the staff in the international scientific community.

The expected results will be useful to the international community. They correspond to the interests of different countries in the area of the environment protection.


The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.


ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.

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