Back to Search Start Over

Measurement report: Long-range transport patterns into the tropical northwest Pacific during the CAMP2Ex aircraft campaign: chemical composition, size distributions, and the impact of convection

Authors :
M. R. A. Hilario
E. Crosbie
M. Shook
J. S. Reid
M. O. L. Cambaliza
J. B. B. Simpas
L. Ziemba
J. P. DiGangi
G. S. Diskin
P. Nguyen
F. J. Turk
E. Winstead
C. E. Robinson
J. Wang
J. Zhang
Y. Wang
S. Yoon
J. Flynn
S. L. Alvarez
A. Behrangi
A. Sorooshian
Source :
Atmospheric Chemistry and Physics, Vol 21, Pp 3777-3802 (2021)
Publication Year :
2021
Publisher :
Copernicus Publications, 2021.

Abstract

The tropical Northwest Pacific (TNWP) is a receptor for pollution sources throughout Asia and is highly susceptible to climate change, making it imperative to understand long-range transport in this complex aerosol-meteorological environment. Measurements from the NASA Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex; 24 August to 5 October 2019) and back trajectories from the National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) were used to examine transport into the TNWP from the Maritime Continent (MC), peninsular Southeast Asia (PSEA), East Asia (EA), and the West Pacific (WP). A mid-campaign monsoon shift on 20 September 2019 led to distinct transport patterns between the southwest monsoon (SWM; before 20 September) and monsoon transition (MT; after 20 September). During the SWM, long-range transport was a function of southwesterly winds and cyclones over the South China Sea. Low- (high-) altitude air generally came from MC (PSEA), implying distinct aerosol processing related to convection and perhaps wind shear. The MT saw transport from EA and WP, driven by Pacific northeasterly winds, continental anticyclones, and cyclones over the East China Sea. Composition of transported air differed by emission source and accumulated precipitation along trajectories (APT). MC air was characterized by biomass burning tracers while major components of EA air pointed to Asian outflow and secondary formation. Convective scavenging of PSEA air was evidenced by considerable vertical differences between aerosol species but not trace gases, as well as notably higher APT and smaller particles than other regions. Finally, we observed a possible wet scavenging mechanism acting on MC air aloft that was not strictly linked to precipitation. These results are important for understanding the transport and processing of air masses with further implications for modeling aerosol lifecycles and guiding international policymaking to public health and climate, particularly during the SWM and MT.

Subjects

Subjects :
Physics
QC1-999
Chemistry
QD1-999

Details

Language :
English
ISSN :
16807316 and 16807324
Volume :
21
Database :
Directory of Open Access Journals
Journal :
Atmospheric Chemistry and Physics
Publication Type :
Academic Journal
Accession number :
edsdoj.f4fecb2e94724d649cdc2d09783ce006
Document Type :
article
Full Text :
https://doi.org/10.5194/acp-21-3777-2021