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Photo by Khadak Mahata.


My doctoral research and postdoctoral training were about understanding the chemistry and physics of the atmosphere, with a particular focus on the interaction between human activities and changes to the composition of the atmosphere that result in air pollution and climate change. Over the past decade, even as I moved away from university settings, I have been fortunate to be able to continue to participate in the design and execution of research projects, monitoring systems and analyses that have provided new scientific insights about the changing atmosphere over mountain areas.

Relevant Experiences

Assessing and advancing the current state of the science:

Designing, hosting, and coordinating research projects

  • Co-Principal Investigator for the US National Science Foundation funded research project, Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Together with Bob Yokelson (University of Montana), Eri Saikawa (Emory University), Betsy Stone (University of Iowa), Peter DeCarlo (Drexel University / Johns Hopkins), Bill Keene (U. of Virginia), their students, and colleagues at ICIMOD, we quantified emissions from a large number of pollution sources commonly found in South Asia, from diesel pumps to motorcycles, garbage fires, cooking fires and a variety of brick kilns. We also measured real-time aerosol composition at multiple locations as well as from vehicles and cable cars. Data from the project not only supported half a dozen doctoral dissertations, but also provides modelers with much more accurate means to estimate emissions of pollution sources in South Asia.
Photos by Arnico Panday.
  • Together with Brent Holben and Si-Chee Tsay at NASA and colleagues at ICIMOD, I co-designed a satellite-surface-modeling study of pollutant transport from the Indo-Gangetic Plains through the mid-hills to Langtang in the high Himalaya. Several papers from the study are forthcoming.
  • Recognizing the regional scale and transboundary nature of the persistent winter fog over the Indo-Gangetic Plains that had been increasing over the past two decades, I initiated a 5-country interdisciplinary regional study. Hosted by ICIMOD the study included participating researchers and field sites in Pakistan, India, Nepal, Bhutan and Bangladesh. While we underestimated the challenge of collecting and shipping fog water samples to a central laboratory, we successfully carried out several smaller studies as well as detailed documentation of the fog’s impacts on people’s livelihoods across four countries.
Satellite image from NASA.
  • Working closely with Maheswar Rupakheti at IASS Potsdam, I co-designed and hosted the Sustainable Atmosphere for the Kathmandu Valley (SusKat) field research campaign, bringing to Kathmandu researchers and instruments from Germany, India, China and South Korea to comprehensively understand the science of air pollution in the Kathmandu Valley and its surroundings, while providing numerous research opportunities for doctoral students.
  • I led the design process and mobilized resources to start the air pollution monitoring networks for the governments of Bhutan and Nepal.
Photo by Subasana Shrestha.
  • Serving as Co-Investigator with the NASA AERONET aerosol robotic network, I helped create a dataset of aerosol optical depth (“haze thickness”) over Pokhara, Nepal, that has been used in a number of student theses.
Photo by Arnico Panday.
  • While at the University of Virginia, I served as a Principal Investigator for the NASA SEAC4RS research project in South and Southeast Asia. I helped plan flight routes for research aircraft, and coordinated field measurements and ozonesonde launches from Nepal that resulted in my student’s doctoral degree.
  • As a Research Assistant Professor at the University of Virginia, I initiated and supervised field measurements at several remote locations in Nepal to understand ozone, carbon monoxide and aerosol variations and transport. I also carried out proof-of-concept studies of atmospheric measurements from various mobile platforms in both Virginia and Nepal.
Photos by field assistants (L), Donnie Turlington (R).
  • As a postdoctoral researcher at Princeton University in 2007-2009, I was concerned by the recent discovery of haze layers extending from the Indo-Gangetic Plains deep into the Himalayas. To study possible pathways for air pollutants traveling from the plains to the high mountains I set up and ran high-resolution WRF model simulations of Himalayan meteorology on the super computers of the Geophysical Fluid Dynamics Laboratory.
  • As a doctoral student at the Massachusetts Institute of Technology (MIT) I was interested in cutting edge research that would be directly relevant to policymaking: I designed and ran an atmospheric measurement campaign in the Kathmandu Valley in 2004-2005, setting up up a rooftop station where I collected a year of high frequency measurements of CO, ozone, PM10 and weather variables. I also set up portable instruments and collected air samples in a variety of places around the Kathmandu Valley. Earlier I designed and hosted a shorter field measurement campaign with participants from MIT, ETH and Chalmers University using remote sensing instruments. I also designed and wrote code for a single column atmospheric model to examine the impact upon photochemical ozone formation of varying layers of clouds and aerosols, and later ran numerical models (MM5 and CAMx) to simulate airflow and pollution transport in central Nepal.
  • As a Master’s student at the University of Wisconsin-Madison, I was worried whether acid rain would impact Himalayan ecosystems: I collected rainwater samples along an east-west transect between Jiri and Pokhara, carried out laboratory analyses for anions and cations and ran the RAINS-ASIA model. Assessing the acid buffering capacity I concluded that the risks of acid rain damage were low in the central Himalayan region.

Relevant Journal Papers

Photos by field assistants.

Relevant Seminars / Lectures / Talks

  • Aryabhatta Research Institute of Observational Sciences, Inaugural Keynote at the International Conference on Aerosol Air Quality, Climate Change and Impact on Water Resources and Livelihoods in the Greater Himalaya [presented remotely], Nainital, India, 14 September 2020. “Aerosols and air quality across the Greater Himalayas: Emerging regional understanding and priorities for the decade ahead” [Available on Youtube:]

  • Paul Scherrer Institut, Invited Seminar, Villigen, Switzerland, 13 June 2019, “Air pollution research and mitigation in the Hindukush Himalaya”

    Third International Workshop on Atmospheric Composition and the Asian Monsoon (ACAM), workshop presentation, Guangzhou, China, 7 June, 2017. “New observatories, new data, and new insights on air pollution in the Himalaya”

  • Atmospheric Brown Cloud Science Team Meeting Presentation, Bangkok, Thailand, 25 November 2015. “Atmospheric Measurements in Nepal and Bhutan”

  • Massachusetts Institute of Technology, Seminar. Cambridge, MA, USA, 27 July 2015. “Atmospheric Research in the Himalaya: The Role of ICIMOD’s Atmosphere Initiative”

  • International Global Atmospheric Chemistry Project Asia Working Group Meeting presentation. Bangkok, Thailand, 2 March 2015. “Atmospheric Chemistry Research in Nepal”

  • AdaptHKH Conference, Panel Presentation. Kathmandu, Nepal, 10 November 2014. “Black Carbon and other atmospheric pollutants: Key scientific knowledge gap”

  • Asia Oceania Geosciences Society (AOGS) Annual Meeting, Invited Presentation, Sapporo, Japan, 29 July 2014.  “Observations and Modeling of Haze over the Himalaya” 

  • ETH Institute for Atmosphere and Climate, Extraordinary Seminar, Zurich, Switzerland, 28 March, 2014. “Building up atmospheric research in the Himalaya”

  • American Geophysical Union Annual Meeting. Oral Presentation. San Francisco, CA, USA. 9 December 2013. “Improving SLCF Science in the Himalayan Region: ICIMOD’s Atmosphere Initiative”

  • NASA Jet Propulsion Laboratory, Invited Seminar, Pasadena, CA, USA, 30 July 2013, “Atmospheric Research in the Nepal Himalaya”

  • International Workshop on Atmospheric Composition and the Asian Summer Monsoon (ACAM), Oral Presentation, Kathmandu, Nepal, 11 June 2013. “Pollution transport to the Tibetan Plateau by up-valley winds”

  • University of Virginia, Department of Environmental Sciences, Atmospheric Science Seminar. Charlottesville, VA, USA, 28 October 2011. “Atmospheric measurement adventures in the Himalaya, on the Himalaya, over the Himalaya”

  • Atmospheric Brown Cloud Science Team Meeting, Presentation, Kathmandu, Nepal, 24 March 2011. “New observatories and aircraft soundings in the Annapurna Himalaya”

  • NASA Goddard Space Flight Center, Seminar, Greenbelt, MD, USA, 28 September 2010. “Atmospheric Science Field Measurements in the Nepal Himalaya”

  • Massachusetts Institute of Technology, Department of Earth, Atmospheric and Planetary Sciences Special Seminar, Cambridge, MA, USA, 12 May 2010, “Canaries or Chimneys? The Role of the Himalaya in Regional and Global Atmospheric Chemistry and Climate Change”

  • University of Virginia, Department of Environmental Sciences, Seminar, Charlottesville, VA, USA 7 May 2009. “Air Pollution in the Himalaya: Observations, Implications, and Unknowns.”

  • European Geosciences Union General Assembly Session 3.5, Vienna, Austria, 23 April 2008, “Do the Himalaya Export Pollutants from the Ganges Basin?” (EGU2009-11081)

  • National Taiwan University, Department of Atmospheric Sciences¸ Invited Seminar, Taipei, Taiwan, 6 April 2009. “Local and Regional Air Pollution in the Himalaya”

  • Rutgers University, Department of Environmental Sciences, Environmental Science Seminar. New Brunswick, NJ, USA, 11 March 2009. “Air Pollution and Climate Change in the Himalaya: Interactions, Unknowns, and Future Directions”

  • International Centre for Integrated Mountain Development, Seminar, Kathmandu, Nepal, 11 July 2008, “Air Pollution, Haze, and Climate Change in the Himalaya Region”

  • European Geosciences Union General Assembly Session 3.5, Vienna, Austria, 15 April 2008, “Vertical Transport of Air Pollution in the Himalaya.” (EGU2008-A-00783)

  • University of Houston Department of Geosciences, Invited Presentation, Houston, TX, USA, 27 February 2008. “Local and Regional Air Pollution in the Himalaya.”

  • American Geophysical Union Fall 2007 Meeting, San Francisco, CA, USA, 14 December 2007, “Basin by Night and Plateau By Day: Air Pollution Accumulation and Ventilation in the Kathmandu Valley, Nepal.” (AGU A51G-04)

  • École Polytechnique Fédérale de Lausanne, LMCA Seminar, Lausanne, Switzerland, 5 July 2007. “The Diurnal Cycle of Air Pollution in the Kathmandu Valley, Nepal”

  • Max Planck Institute for Chemistry, Atmospheric Chemistry Seminar, Mainz, Germany, 2 July 2007. “A Field and Modeling Study of Air Pollution in the Kathmandu Valley, Nepal”

  • Geophysical Fluid Dynamics Laboratory, Seminar, Princeton, NJ, USA, 28 June 2007. “Air Pollution in the Himalaya: In the Kathmandu Valley and From the Ganges Plains”

  • University of Houston, Institute for Multidimensional Air Quality Studies, Seminar, Houston, TX, USA, 22 June 2007. “A Field and Modeling Study of Air Pollution in the Kathmandu Valley, Nepal”

  • University of Wisconsin, Center for Sustainability and the Global Environment, Seminar, Madison, WI, USA, June 18, 2007. “The Diurnal Cycle of Air Pollution in the Kathmandu Valley, Nepal”

  • Pennsylvania State University, Department of Meteorology, Special Seminar, State College, PA, USA, May 3, 2007. “The Diurnal Cycle of Air Pollution in the Kathmandu Valley, Nepal.”

  • Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Seminar, Atlanta, GA, USA, April 6, 2007. “Measurements and Modeling of Air Pollution in the Kathmandu Valley, Nepal”

  • ETH Institute for Atmospheric and Climate Science Aussergewöhnliches Seminar, Zürich, Switzerland, December 22, 2006. “Observations and Modeling of Air Pollution in the Kathmandu Valley, Nepal”

  • Asian Institute of Technology, School for Energy, Resources and Development, Seminar, Bangkok, Thailand, August 29, 2006. “The Diurnal Cycle of Air Pollution in the Kathmandu Valley, Nepal”

  • MIT Dept. of Earth, Atmospheric and Planetary Sciences, Doctoral Defense Lecture, Cambridge, MA, USA, April 26, 2006. “The Diurnal Cycle of Air Pollution in the Kathmandu Valley, Nepal”

  • ETH Institute for Atmospheric and Climate Science. Schär Group meeting presentation, Zürich, Switzerland, February 27, 2002. “Air Pollution in the Kathmandu Valley, Nepal: Hypothesized Effects of Topography.”

  • MIT Department of Earth Atmospheric and Planetary Sciences, Oral Presentation, Cambridge, MA, USA, May 17, 2001: “Radiative Transfer Effects of Clouds and Aerosols on Urban Photochemistry: A modeling study of the Kathmandu Valley, Nepal”

Relevant courses attended

  • The Atmosphere
    Harvard College
  • Introduction to Quantitative Methods
    Harvard College
  • Multivariable Calculus
    Harvard College
  • Applied Mathematics / Differential Equations
    Harvard College
  • Linear Algebra and Differential Equations
    Harvard College
  • Applied Mathematical Analysis
    U. of Wisconsin
  • Foundations of Chemistry
    Harvard College, taught by Nobel Laureate Dudley Hershbach
  • Principles of Organic Chemistry
    Harvard College
  • Atmospheric Chemistry
    Harvard College
  • Physical Chemistry
    U. of Wisconsin
  • Atmospheric Chemistry
    MIT, taught by Nobel Laureate Mario Molina
  • Physics – Mechanics
    Harvard College
  • Geophysical Fluid Dynamics
    U. of Wisconsin
  • Fluid Dynamics of Atmosphere and Ocean
    MIT & Woodshole Institute of Oceanography
  • Atmospheric Physics
  • Wave Motions: Ocean and Atmosphere
    MIT & Woodshole Institute of Oceanography
  • General Circulation of the Earth’s Atmosphere
  • Large-scale Flow Dynamics Laboratory
  • Quasi-balanced Circulations
  • Tropical Meteorology
  • Special Problems: Meteorology
  • MM5 Model Tutorial
    1 week course, National Center for Atmospheric Research, USA
  • CMAQ Model Tutorial
    1 week course, US EPA / UNC Chapel Hill