Department of Environmental Sciences

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Seminar Abstracts
Environmental Sciences Seminar Abstract            

  Air Pollution and Climate Change in the Himalaya: Interactions, Unknows, and Research Directions
Arnico Panday
Princeton University

The Ganges Basin in South Asia is home to over half a billion people, who make it a hotspot of air pollution emissions. During the past decade it has increasingly been blanketed by thick aerosol haze for many months each year. The impacts of this haze upon the photochemistry of urban air pollution have been modeled. But what happens when the haze meets the Himalaya mountains? The scant available evidence suggests that it is transported to high altitudes, from where it can be exported towards the Pacific Ocean and beyond. It also appears to contribute to the observed rapid increases in temperature at high altitudes on the Tibetan Plateau, and to the retreat of mountain glaciers. Its impacts upon the hydrological cycle will have far reaching consequences for the billion people living downstream of the Himalaya.

Using numerical modeling (the WRF, and WRF/Chem modeling system), I have been exploring the transport pathways through the Himalaya of aerosols and other pollutants from the Ganges Basin, as well as their chemical transformations. Because of the complex topography and the spatial heterogeneity of mountain meteorology, very high resolution modeling is required in order to properly capture the transport processes. One of the biggest obstacles to modeling the Himalaya region is the scarcity of observational data. Without sufficient data to validate model runs, the results are, at best, just hypotheses. There is a need to design a network of long term monitoring stations, as well as a series of field campaigns aimed at understanding atmospheric processes. Field measurements in 2004-2005 in the Kathmandu Valley, Nepal, provided understanding of the processes controlling air pollution in one Himalayan valley, and a starting point for designing appropriate mitigation policies. More recently I have identified suitable sites in the Himalaya for monitoring regional atmospheric chemistry and climate, and have started to build collaborations to make the field measurements possible.

Last updated: 03/02/2009