Map of south and southeast Asia showing the near-surface origins of ‘fast’ airmass trajectories connecting the surface and the upper troposphere/lower stratosphere
Near-surface origins of ‘fast’ airmass trajectories (transit times less than 10 days) connecting the surface and the upper troposphere/lower stratosphere (approximately 12 to 17 kilometers) during the Asian Monsoon Anticyclone 2017 campaign. The data points are color-coded according to the CH2CL2 mixing ratios measured at upper levels by the aircraft. Credit: Adcock et al. [2021], Figure 4
Source: Journal of Geophysical Research: Atmospheres

The Asian summer monsoon transports emissions from South and East Asia into the upper troposphere and lower stratosphere, but details on chemical composition are poorly known. High-altitude aircraft measurements from two recent field campaigns are providing new information on ozone-depleting substances (ODS) in this region, with observations extending into the lower stratosphere. The new data presented by Adcock et al. [2021] show enhancement of ODS above expected values, especially for several short-lived chlorine-containing species. Studies of the airmass origins identify regions of rapid vertical transport with source regions in South Asia. These new observations show that the Asian monsoon may be transporting larger than expected amounts of ODS into the upper troposphere and lower stratosphere, possibly leading to impact on stratospheric ozone.

Citation: Adcock, K. E., Fraser, P. J., Hall, B. D., Langenfelds, R. L., Lee, G., Montzka, S. A., et al. [2021]. Aircraft‐based observations of ozone‐depleting substances in the upper troposphere and lower stratosphere in and above the Asian summer monsoon. Journal of Geophysical Research: Atmospheres, 126, e2020JD033137.

—William J. Randel, Editor, JGR: Atmospheres

Text © 2021. The authors. CC BY-NC-ND 3.0
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