 |
| Titel |
Uplifting of carbon monoxide from biomass burning and anthropogenic sources to the free troposphere in East Asia |
| VerfasserIn |
K. Ding, J. Liu, A. Ding, Q. Liu, T. L. Zhao, J. Shi, Y. Han, H. Wang, F. Jiang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 5 ; Nr. 15, no. 5 (2015-03-12), S.2843-2866 |
| Datensatznummer |
250119518
|
| Publikation (Nr.) |
 copernicus.org/acp-15-2843-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| East Asia has experienced rapid development with increasing carbon monoxide (CO) emission in
the past decades. Therefore, uplifting CO from the boundary layer to the free
troposphere in East Asia can have great implications on regional air quality
around the world. It can also influence global climate due to the longer
lifetime of CO at higher altitudes. In this study, three cases of high CO
episodes in the East China Sea and the Sea of Japan from 2003 to 2005 are
examined with spaceborne Measurements of Pollution in the Troposphere
(MOPITT) data, in combination with aircraft measurements from the Measurement
of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program. High
CO abundances of 300–550 ppbv are observed in MOZAIC data in the free
troposphere during these episodes. These are among the highest CO abundances
documented at these altitudes. On average, such episodes with CO over
400 ppbv (in the 2003 and 2004 cases) and between 200 and 300 ppbv (in the
2005 case) may occur 2–5 and 10–20% in time, respectively, in the
respective altitudes over the region. Correspondingly, elevated CO is shown
in MOPITT daytime data in the middle to upper troposphere in the 2003 case, in the lower to middle troposphere in the 2004 case, and in the upper
troposphere in the 2005 case. Through analyses of the simulations from a
chemical transport model GEOS-Chem and a trajectory dispersion model
FLEXPART, we found different CO signatures in the elevated CO and distinct
transport pathways and mechanisms for these cases. In the 2003 case,
emissions from large forest fires near Lake Baikal dominated the elevated CO,
which had been rapidly transported upward by a frontal system from the fire
plumes. In the 2004 case, anthropogenic CO from the North China Plain
experienced frontal lifting and mostly reached ~ 700 hPa near the East
China Sea, while CO from biomass burning over Indochina experienced
orographic lifting, lee-side-trough-induced convection, and frontal lifting
through two separate transport pathways, leading to two distinct CO
enhancements around 700 and 300 hPa. In the 2005 case, the observed CO of
~ 300 ppbv around 300 hPa originated from anthropogenic sources over
the Sichuan Basin and the North China Plain and from forest fires over
Indochina. The high CO was transported to such altitudes through strong
frontal lifting, interacting with convection and orographic lifting. These
cases show that topography affects vertical transport of CO in East Asia via
different ways, including orographic uplifting over the Hengduan Mountains,
assisting frontal lifting in the North China Plain, and facilitating
convection in the Sichuan Basin. In particular, topography-induced lee-side
troughs over Indochina led to strong convection that assisted CO uplifting to
the upper troposphere. This study shows that the new daytime MOPITT
near-infrared (NIR) and thermal-infrared (TIR) data (version 5 or above) have
enhanced vertical sensitivity in the free troposphere and may help
qualitative diagnosis of vertical transport processes in East Asia. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|