A Multimodel Investigation of Asian Summer Monsoon UTLS Transport Over the Western Pacific

Laura L. Pan (1) , Douglas Kinnison (1) , Qing Liang (2) , Mian Chin (2) , Michelle L. Santee (3) , Johannes Flemming (4) , Warren P. Smith (1) , Shawn B. Honomichl (1) , James F. Bresch (1) , Leslie R. Lait (5) , Yunqian Zhu (1) , Simone Tilmes (1) , Peter Colarco (2) , Juying Warner (6) , Adrien Vuvan (7) , Cathy Clerbaux (7) , Elliot Atlas (8) , Paul Newman (2) , Troy Thornberry (9) , William Randel (1) , Owen Toon (10)

1 NCAR - National Center for Atmospheric Research [Boulder]
2 GSFC - NASA Goddard Space Flight Center
3 JPL - Jet Propulsion Laboratory
4 ECMWF - European Centre for Medium-Range Weather Forecasts
5 SSAI - Science Systems and Applications, Inc. [Lanham]
6 University of Maryland [College Park]
7 TROPO - LATMOS
8 University of Miami
9 CSL - NOAA Chemical Sciences Laboratory
10 University of Colorado [Boulder]

The Asian summer monsoon (ASM) as a chemical transport system is investigated using a suite of models in preparation for an airborne field campaign over the Western Pacific. Results show that the dynamical process of anticyclone eddy shedding in the upper troposphere rapidly transports convectively uplifted Asian boundary layer air masses to the upper troposphere and lower stratosphere (UTLS) over the Western Pacific. The models show that the transported air masses contain significantly enhanced aerosol loading and a complex chemical mixture of trace gases that are relevant to ozone chemistry. The chemical forecast models consistently predict the occurrence of the shedding events, but the predicted concentrations of transported trace gases and aerosols often differ between models. The airborne measurements to be obtained in the field campaign are expected to help reduce the model uncertainties. Furthermore, the large-scale seasonal chemical structure of the monsoon system is obtained from modeled carbon monoxide, a tracer of the convective transport of pollutants, which provides a new perspective of the ASM circulation, complementing the dynamical characterization of the monsoon.

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

Laura L. Pan, Douglas Kinnison, Qing Liang, Mian Chin, Michelle L. Santee, et al.. A Multimodel Investigation of Asian Summer Monsoon UTLS Transport Over the Western Pacific. Journal of Geophysical Research: Atmospheres, 2022, 127 (24), pp.e2022JD037511. ⟨10.1029/2022JD037511⟩. ⟨insu-03897762⟩