​​​​​​​​​​​​​​​​​​Atmospheric Brown Cloud (ABC)



Atmospheric brown clouds (ABCs) are widespread layers of brownish haze of air pollutants, such as aerosol particles (black carbon (BC) and non BC), and precursor gases (e.g. CH4, CO, NMVOCs, NOx), which produce aerosols and ozone. ABCs and their interaction with build-up of greenhouse gases significantly affect the regional climate, hydrological cycle, glacial melting, agriculture production, ecosystem and human health. [read more...]

Atmospheric Brown Cloud (ABC) programme is addressing the issue of ABCs through measurements, impact assessment, demonstration of mitigation solutions, and creating awareness to underpin the issue at the policy forums. More than 200 scientists are working on ABCs, generating a wealth of science-based knowledge on sources, evidences of significant impacts, and demonstration of mitigation solutions.

ABC programme promote science-policy interface by engaging and providing a common platform to scientists, academia, researchers, students, government and non-government organizations, and international agencies. The objectives of science-policy interface are to create awareness and transfer the science-based knowledge to policy makers so that they can incorporate the knowledge in the policy making process.

ABC helped to develop consensus and effectiveness of available emission reduction technologies. Many governments have responded positively and developed national programmes or supporting national efforts to reduce the emissions of ABCs. ABC programme has also helped to place the ABCs issue in the international agenda.

Atmospheric Brown Cloud (ABC) Programme is an effort to mitigate near-term climate change and improve air quality for the better living of the human being.

​The South Asian Pollution Experiment (SAPOEX-2016), an international measurement campaign led by Prof. Örjan Gustafsson (an ABC Scientist), will be held in January-February 2016 at Maldives Climate Observatory-Hanimaadhoo (MCOH) and some selected measurement sites in India and Bangladesh. The scientific objectives of SAPOEX-2016 are characterization of aerosol properties for South Asian region; investigation of processing of different aerosol components during long-range transport; and monitoring of background conditions which influences long-range transport and processing of the aerosols. The research output of SAPOEX-2016 will improve our understanding on regional scale emissions and their impacts on regional climate system and human health. This is an international measurement campaign involving scientists from Stockholm University, Sweden; Finnish Meteorology Institute, Finland; Indian Institute of Science, Bangalore, India; Indian Institute of Technology, Kanpur, India; Dhaka University, Bangladesh; Maldives Meteorology Service, Maldives; and Maldives National University, Maldives.


ABC Meeting 2015.jpgThe Atmospheric Brown Cloud (ABC) Programme Science Team Meeting was organized on November 25, 2015 at UNCC, Bangkok, Thailand.

The meeting commenced with a welcome remarks from Mr. Osamu Mizuno, Director of the Regional Resource Center for Asia and the Pacific (RCC.AP), who expressed appreciation to the ABC scientists for making ABC programme a tremendous success in terms of networking of scientists and observatories, assessing the impacts, and demonstrating mitigation solutions while raising awareness at various national and international fora.

Mr. Kaveh Zahedi, Regional Director of UNEP Regional Resource Center for Asia and the Pacific (UNEP ROAP) and Prof. Nakajima, Chairperson of ABC-Asia Science Team delivered the opening remarks. Mr. Zahedi had stressed on the need to define new objectives for the ABC programme while Prof. Nakajima highlighted that ABC programme is a unique integration of the science of climate change and air pollution to assess the impacts on environment and society. He added that ABC has achieved significant success in terms of building a network of scientists, generating a wealth of scientific knowledge on air pollution and establishing linkages between air pollution and climate change. The data measured at the observatories located at strategic locations in Asia-Pacific region is very useful for modeling and regional assessment.

The meeting was conducted in an open and closed-door sessions. The open session discussed the following items: (i) updates of the ongoing measurements of ABC components at the respective observatories; (ii) the status of data analysis at the Data Analysis Centers located in University of Tokyo, Japan and Seoul National University, Korea; (iii) the website and database management at RRC.AP; (iv) SustKat-ABC project; and (v) the atmospheric measurements in Nepal and Bhutan. During the closed-door meeting, the future plans and the way forward for the ABC programme was discussed.

The meeting was attended by ABC Scientists and representatives from RRC.AP, UNEP ROAP and some observers from other organizations. The meeting was coordinated by RRC.AP as the ABC Secretariat in collaboration with UNEP ROAP.



​The Chancellor of Maldives National University (MNU) Dr. Mohamed Latheef, along with a delegation of his colleagues Dr. Fawaz Shareef (Vice Chancellor), Muaviyath Mohamed and other MNU officials, has visited Maldives Climate Observatory-Hanimaadhoo (MCOH) on 17 August 2015. MCOH is a super observatory of the ABC programme with state-of-the art instruments and facilities for the measurements of air pollution and climate parameters. The delegation was hosted by Dr. Krishnakant Budhvant, Resident Scientist at the MCOH. Dr. Budhavant has shown them the ongoing measurements and explained how these measurements are immensely contributing in generating scientific knowledge on atmospheric sciences and climate change that has applications in various fields, such as, environment, agriculture, health, etc. The Chancellor agreed that, since MCO-H is well equipped with advanced scientific instruments and facilities, it is the best place for high quality research, organizing training/workshop for school and university students, and policy makers. The visit the Chancellor of the MUN, with a delegation, is a value added to the importance of MCOH at the academic and political level.
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 Project Surya

Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia, published in 2008 press release) (summary) is the first integrated assessment report on ABCs with focus on Asia. It disussed impacts of ABCs on regional climate, water resources, precipitation, agriculture production, glacier melting, and health. It reveals that ABC is a global phenomenon, spread heterogeneously over several parts of the world [read more].
The Asian Brown Cloud: Climate and Other Impacts, published in 2002 (press release) is the first comprehensive report of the South Asian haze and its impact on climate. It is largely based on the INDOEX studies. It provide a summary of the large brownish haze layers and its impacts on the radiative heating of the atmosphere and the surface for South Asia and the adjacent Indian Ocean [read more]
ABC Emission Inventory Manual (ABC-EIM), published in 2013 discussed the methodology for compilation of emissions of major pollutants from various sectors. ABC-EIM is accompanied with an Excel-based workbook, which can be used for compilation and estimation of emissions of the ABCs precursors [read more]

​Application is invited from suitable candidates for the position of Consultant for Project ABC. Detail announcement...


​An International Symposium for ABC (Atmospheric Brown Cloud) and SLCP (Short-Lived Climate Pollutant) will be held at the University of Tokyo, Japan during July 21-23, 2014. The symposium will cover the scientific findings of ABCs observations, modeling simulations, and health impact of SLCPs. The seminar will provide an opportunity for strategic  discussions to promote cohesion among various air pollution related projects in Asia and the Pacific such as ABC, CCAC, RECCA, and S-12.

First Announcement (last date for abstract and registration: 25 April 2014)

Last date for abstract and registration extended till 2 May 2014  

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