Constraints on Asian ozone using Aura TES, OMI and Terra MOPITT
Rapid industrialization in Asia in the last two decades has resulted in a significant increase in Asian ozone (O<sub>3</sub>) precursor emissions with likely a corresponding increase in the export of O<sub>3</sub> and its precursors. However, the relationship between this inc...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-01-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | http://www.atmos-chem-phys.net/15/99/2015/acp-15-99-2015.pdf |
Summary: | Rapid industrialization in Asia in the last two decades has resulted in a
significant increase in Asian ozone (O<sub>3</sub>) precursor emissions with
likely a corresponding increase in the export of O<sub>3</sub> and its
precursors. However, the relationship between this increasing O<sub>3</sub>, the
chemical environment, O<sub>3</sub> production efficiency, and the partitioning
between anthropogenic and natural precursors is unclear. In this work, we
use satellite measurements of O<sub>3</sub>, CO and NO<sub>2</sub> from TES
(Tropospheric Emission Spectrometer), MOPITT (Measurement of Pollution In
The Troposphere) and OMI (Ozone Monitoring Instrument) to quantify O<sub>3</sub> precursor
emissions for 2006 and their impact on free tropospheric O<sub>3</sub> over
northeastern Asia, where pollution is typically exported globally due to
strong westerlies. Using the GEOS-Chem (Goddard Earth Observing System Chemistry) global chemical transport model, we
test the modeled seasonal and interannual variation of O<sub>3</sub> based on
prior and updated O<sub>3</sub> precursor emissions where the updated emissions
of CO and NO<sub>x</sub> are based on satellite measurements of CO and NO<sub>2</sub>.
We show that the observed TES O<sub>3</sub> variability and amount are consistent
with the model for these updated emissions. However, there is little
difference in the modeled ozone between the updated and prior emissions. For
example, for the 2006 June time period, the prior and posterior NO<sub>x</sub>
emissions were 14% different over China but the modeled ozone in the
free troposphere was only 2.5% different. Using the adjoint of GEOS-Chem
we partition the relative contributions of natural and anthropogenic sources
to free troposphere O<sub>3</sub> in this region. We find that the influence of
lightning NO<sub>x</sub> in the summer is comparable to the contribution from
surface emissions but smaller for other seasons. China is the primary
contributor of anthropogenic CO, emissions and their export during the
summer. While the posterior CO emissions improved the comparison between
model and TES by 32%, on average, this change also had only a small
effect on the free tropospheric ozone. Our results show that the influence
of India and southeastern Asia emissions on O<sub>3</sub> pollution export to the
northwestern Pacific is sizeable, comparable with Chinese emissions in winter,
about 50% of Chinese emissions in spring and fall, and approximately
20% of the emissions in the summer. |
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ISSN: | 1680-7316 1680-7324 |