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| Titel |
Investigation of NOx emissions and NOx-related chemistry in East Asia using CMAQ-predicted and GOME-derived NO2 columns |
| VerfasserIn |
K. M. Han, C. H. Song, H. J. Ahn, R. S. Park, J. H. Woo, C. K. Lee, A. Richter, J. P. Burrows, J. Y. Kim, J. H. Hong |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 3 ; Nr. 9, no. 3 (2009-02-11), S.1017-1036 |
| Datensatznummer |
250006827
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| Publikation (Nr.) |
 copernicus.org/acp-9-1017-2009.pdf |
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| Zusammenfassung |
| In this study, NO2 columns from the US EPA Models-3/CMAQ model
simulations carried out using the 2001 ACE-ASIA (Asia Pacific Regional
Aerosol Characterization Experiment) emission inventory over East Asia were
compared with the GOME-derived NO2 columns. There were large
discrepancies between the CMAQ-predicted and GOME-derived NO2 columns
in the fall and winter seasons. In particular, while the CMAQ-predicted
NO2 columns produced larger values than the GOME-derived NO2
columns over South Korea for all four seasons, the CMAQ-predicted NO2
columns produced smaller values than the GOME-derived NO2 columns over
North China for all seasons with the exception of summer (summer anomaly).
It is believed that there might be some error in the NOx emission
estimates as well as uncertainty in the NOx chemical loss rates over
North China and South Korea. Regarding the latter, this study further
focused on the biogenic VOC (BVOC) emissions that were strongly coupled with
NOx chemistry during summer in East Asia. This study also investigated
whether the CMAQ-modeled NO2/NOx ratios with the possibly
overestimated isoprene emissions were higher than those with
reduced isoprene emissions. Although changes in both the NOx chemical
loss rates and NO2/NOx ratios from CMAQ-modeling with the
different isoprene emissions affected the CMAQ-modeled NO2 levels, the
effects were found to be limited, mainly due to the low absolute levels of
NO2 in summer. Seasonal variations of the NOx emission fluxes over
East Asia were further investigated by a set of sensitivity runs of the CMAQ
model. Although the results still exhibited the summer anomaly possibly due
to the uncertainties in both NOx-related chemistry in the CMAQ
model and the GOME measurements, it is believed that consideration of both
the seasonal variations in NOx emissions and the correct BVOC emissions
in East Asia are critical. Overall, it is estimated that the NOx
emissions are underestimated by ~57.3% in North China and
overestimated by ~46.1% in South Korea over an entire year. In
order to confirm the uncertainty in NOx emissions, the NOx
emissions over South Korea and China were further investigated using the
ACE-ASIA, REAS (Regional Emission inventory in ASia), and CAPSS (Clean Air
Policy Support System) emission inventories. The comparison between the
CMAQ-calculated and GOME-derived NO2 columns indicated that both the
ACE-ASIA and REAS inventories have some uncertainty in NOx emissions
over North China and South Korea, which can also lead to some errors in
modeling the formation of ozone and secondary aerosols in South Korea and
North China. |
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