Related Experiment Video
Updated: Jun 14, 2026

Production and Measurement of Organic Particulate Matter in the Harvard Environmental Chamber
Published on: November 18, 2018
Asian monsoon transport of pollution to the stratosphere
William J Randel1, Mijeong Park, Louisa Emmons
1National Center for Atmospheric Research, Boulder, CO, USA. randel@ucar.edu
Abstract:
Transport of air from the troposphere to the stratosphere occurs primarily in the tropics, associated with the ascending branch of the Brewer-Dobson circulation. Here, we identify the transport of air masses from the surface, through the Asian monsoon, and deep into the stratosphere, using satellite observations of hydrogen cyanide (HCN), a tropospheric pollutant produced in biomass burning. A key factor in this identification is that HCN has a strong sink from contact with the ocean; much of the air in the tropical upper troposphere is relatively depleted in HCN, and hence, broad tropical upwelling cannot be the main source for the stratosphere. The monsoon circulation provides an effective pathway for pollution from Asia, India, and Indonesia to enter the global stratosphere.
Related Concept Videos
The Sulfur Cycle
Microbes and Climate Change
Global Climate Change
What is Climate?
Linear Approximations
The Carbon Cycle

