Atmospheric Brown Cloud
The Indian Ocean Experiment (INDOEX) carried out in February 1999 in the islands of the Maldives revealed a 3 km-thick toxic umbrella, or ‘Brown Cloud’, stretching over Afghanistan, Pakistan, Bangladesh, Bhutan, India, the Maldives, Nepal, and Sri Lanka, which are among the most densely populated places in the world. The finding came from observations gathered by more than 200 scientists supplemented by satellite readings and computer modeling.
The haze, 80 percent man-made, is composed of a grimy cocktail of toxic ash, black carbon, sulphate, nitrates, acids, and aerosols - tiny solid or liquid particles suspended in the atmosphere. The haze can extend far beyond the Indian subcontinent.
Realising the intensity of the problem, an initiated by UNEP and coordinated by ICIMOD, Nobel Laureate Paul Crutzen and Prof. V. Ramanathan (Ram) visited Kathmandu in March 2001 to discuss the situation and followed up by conducting a pilot study. The year-long study proved to be very informative, however a long-term study was needed to elucidate the exact reasons for the cloud. A permanent observatory known as the Nepal Climate Observatory (NCO) was setup at ICIMOD Headquarters and the ICIMOD Demonstration and Training Centre site at Godavari and equipped with radiation, aerosol, and rainwater chemistry measurement instruments, and meteorological instruments.
Duration
Current Phase: 2004 - 2009
Pilot Phase: 2002 - 2003
Geographical coverage
In Nepal the observatory sites are established at two different locations:
Godavari, Lalitpur (27.59°N, 85.38°E, 1590 m above mean sea level)
ICIMOD Headquarters, Khumaltar (27.38°N, 85.19°E, 1315 m above mean sea level)
Core financial partners/development partners/sponsors
UNEP RRC.AP
University of California, San Diego, USA
Scripps Institute of Oceanography (UCSD, SIO), USA
Stockholm University, Department of Meteorology, Sweden
University of Wisconsin, Madison, USA
Implementing partners
Supported by research work at the universities
Contact information
Bidya B. Pradhan
Environment Officer
IKM-MERNRIS
bbanmali@icimod.org
