​​​​​​​​​​​​​​​​​​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.

Prof. V. Ramanathan (Chair ABC International Science Team) has won the third Tang Prize Award for sustainable development. Prof. Ramanathan has been studying the effects of greenhouse gases on global warming for the last 50 years. The Tang Prize has recognized him for his contributions to the atmospheric sciences. It is the professor's first major honor from Asia. For detail click here


MCOH.pngA recent edition of the PEMPHIS was dedicated to Hanimaadhoo Island. The PEMPHIS is an Environmental News Letter of the Ministry of Environment and Energy, Government of Maldives. The edition included a detail article on Maldives Climate Observatory - Hanimaadhoo (MCOH) with an interview of    Dr. Krishnakant Budhavant, Resident Scientist of MCOH. In the interview, Dr. Budhavant has discussed regional air pollution and climate change issues and how the measurements conducted at the MCOH are important to address these issues. The scientific contributions of the MCOH Science Team is guiding the policy making process at the national, regional, and global levels.    


The South Asian Pollution Experiment 2018 (SAPOEX-18) is now gearing up toward a new large high-intensity campaign to study the Climate Pollutant Outflow from South Asia in period Nov 2017- Mar 2018.  The MCOH will serve as the hub for the campaign with additional participating observatories, such as, Delhi (NPL) and Pune (IITM) from India; Univ. Of Dhaka and Bangladesh Climate Observatory Bhola (BCOB) from Bangladesh; and MCO-Gan from Maldives. The objectives of the campaign are to study Mass Absorption Cross Section (MAC) of ambient BC aerosols, optical properties of Brown Carbon (BrC), and differentiation of primary from secondary organic aerosols (POA and SOA) in the South Asian outflow. The observational data will be useful to estimate accurate emissions of BC from various sources from south Asian region along with optical properties of brown carbon (light observing OC), and coating enhancement and atmospheric residence time of BC aerosols.​

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 Project Surya


The Emission Inventory Manual (ABC_EIM) provide a framework for ABCs emission inventory suitable for to use in different countries especially in Asia. This manual also presents methods for temporal and spatial distribution of emissions. It accompanied with Excel-based software for estimation of emissions

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]

​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  

 ABC Picture Gallery

 ABC in Media