An assessment of the impact of black carbon on air quality and climate in the Kathmandu Valley and surroundings - a model study

• Applicant: Professorin Dr. Andrea Mues
• Subject Area: Atmospheric Science
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262641669

Air quality has become a major environmental and health concern in Nepal and particularly in the urban areas of the Kathmandu Valley. Large parts of South Asia including this region are among the most heavily polluted and at the same time among the least studied regions in the world in terms of air quality. Despite the need for effective mitigation measures to improve air quality, there have only been a few past studies. This hampers the design of mitigation measures and the assessment of their anticipated effectiveness.The following three overarching scientific topics will be addressed in the proposed project: Air pollution (with a focus on black carbon (BC)) in the Kathmandu Valley and its implication for the surrounding regions (e.g. Himalayas) and vice versa; assessment of air quality measures; relevance of air pollutants from the Kathmandu Valley on climate. The main aim of this project is to design and conduct studies using the atmospheric chemistry model WRF/Chem (Weather Research and Forecasting model with chemistry and aerosols) to get better insights into the processes and mechanisms relevant to air quality and climate in the Kathmandu Valley and its surroundings. This includes an analysis of the meteorological conditions and dynamical processes in the valley and their effect on the mixing of pollutants in the atmosphere and on the long-range transport into and out of the valley. In addition to meteorology, local and regional emissions are expected to play a key role for the observed air pollution. An important part of the project is therefore to identify the main sources of air pollutants in the valley and to quantify their contributions to particulate matter (PM) and black carbon concentrations. The effectiveness of possible air pollution control measures will be assessed by performing a number of sensitivity studies for different emission reduction scenarios. The study will also investigate the impact of the short lived climate-forcing pollutants (SLCPs) BC and other aerosol compounds on the local and regional climate of the Kathmandu Valley and its surroundings. This includes the impact on the meteorology such as convection and boundary layer height as well as on the deposition of BC on snow and ice in the Himalayas.The project is planned to run for three years. In addition to the modeling work, important modules of the project are data analysis and the cooperation and dialog with international and local scientists, policy makers and experts from different research fields. This cooperation will help to look at air pollution in the greater Himalayas from many different perspectives which is essential for the development of plausible and for the region socially and politically feasible air pollution mitigation scenarios.

• DFG Programme: Research Grants
• International Connection: Nepal
• Participating Person: Dr. Vanisa Surapipith