An analysis on abnormally low ozone in the upper troposphere over subtropical East Asia in spring 2004

Chan, Chia-Tai; Li, Y.S.; Tang, Jianhui; Wu, Man Chi; Chan, Ling-Yau; Chang, Chih-Chung; Liu, S.C.

doi:10.1016/j.atmosenv.2007.01.004

Cited by 12 publications

(11 citation statements)

References 17 publications

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“…We use two sets of in situ O 3 vertical profiles over Beijing obtained during April-May 2005: one from the Transport of Air Pollutants and Tropospheric Ozone over China (TAPTO-China) (Chan et al, 2007;Zhang et al, 2012) ozonesonde campaign and the other from the MOZAIC program . The concurrent availability of these two data sets allows cross validation of such measurements.…”

Section: Ozonesonde and Aircraft Measurementsmentioning

confidence: 99%

Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis

et al. 2015

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Abstract. Ozone (O 3 ) concentrations in the lower troposphere (LT) over Beijing have significantly increased over the past 2 decades as a result of rapid industrialization in China, with important implications for regional air quality and the photochemistry of the background troposphere. We characterize the vertical distribution of lower-tropospheric (0-6 km) O 3 over Beijing using observations from 16 ozonesonde soundings during a field campaign in April-May 2005 and MOZAIC (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft) over 13 days in the same period. We focus on the origin of LT O 3 enhancements observed over Beijing, particularly in May. We use a global 3-D chemistry and transport model (GEOS-Chem CTM; GEOS -Goddard Earth Observing System) driven by assimilated meteorological fields to examine the transport pathways for O 3 pollution and to quantify the sources contributing to O 3 and its enhancements in the springtime LT over Beijing. Output from the Global Modeling Initiative (GMI) CTM is also used. High O 3 concentrations (up to 94.7 ppbv) were frequently observed at the altitude of ∼ 1.5-2 km. The CTMs captured the timing of the occurrences but significantly underestimated their magnitude. GEOS-Chem simulations and a case study showed that O 3 produced in the Asian troposphere (especially from Asian anthropogenic pollution) made major contributions to the observed O 3 enhancements. Contributions from anthropogenic pollution in the European and North American troposphere were reduced during these events, in contrast with days without O 3 enhancements when contributions from Europe and North America were substantial. The O 3 enhancements typically occurred under southerly wind and warmer conditions. It is suggested that an earlier onset of the Asian summer monsoon would cause more O 3 enhancement events in the LT over the North China Plain in late spring and early summer.Published by Copernicus Publications on behalf of the European Geosciences Union.

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Section: Ozonesonde and Aircraft Measurementsmentioning

confidence: 99%

Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis

et al. 2015

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“…On April 14, abnormally low O 3 mixing ratios were simultaneously observed in the UT ($15 km) over Sanya, Hong Kong and Taipei. Chan et al [2007] reported that this low O 3 episode resulted from deep convective pumping of low O 3 maritime air masses near the center of typhoon Sudal. The low-O 3 abundances described above were largely responsible for the low average O 3 in the FT (Figure 6).…”

Section: Mid-and Upper-tropospheric Ozone From Ozonesonde Observationsmentioning

confidence: 99%

Distribution, variability and sources of tropospheric ozone over south China in spring: Intensive ozonesonde measurements at five locations and modeling analysis

Zhang¹,

Liu²,

Considine³

et al. 2012

J. Geophys. Res.

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[1] We examine the characteristics of the spatial distribution and variability of tropospheric ozone (O 3 ) by analysis of 93 ozonesonde profiles obtained at five stations over south N) during a field campaign in April-May 2004. We use a global 3-D chemical transport model (GEOS-Chem) to interpret these characteristics and to quantify the sources of tropospheric O 3 over south China during this period. The observed tropospheric O 3 mixing ratios showed strong spatiotemporal variability due to a complex interplay of various dynamical and chemical processes. A prominent feature in the upper and middle troposphere (UT/MT) was the frequent occurrence of high O 3 mixing ratios shown as tongues extending down from the lower stratosphere or as isolated layers at all stations. The model largely captured the observed pattern of day-to-day variability in tropospheric O 3 mixing ratios at all stations, but often underestimated those tongues or isolated layers of O 3 enhancements observed in the UT/MT, especially at low-latitude stations. We found that tropospheric O 3 along the southeast China coast was mainly produced within Asia. Lightning NO x emissions (over South Asia and equatorial Africa) and/or stratospheric influences were responsible for major events of high O 3 observed in the UT/MT at all stations. Underestimated contributions of these sources likely led to the model's underestimate in the low-latitude UT/MT O 3 . This study emphasizes the need for improved understanding of lightning NO x emissions and stratospheric influences over the Eurasian and African continents and for better representation of these processes in current global models.

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“…Finardi et al (2011) recently illustrated the role of regional transport in photochemical pollution (specifically, nitrogen dioxide and ozone). However, studies are available in the literature, which also support long-range transport of ozone from highly polluted areas in surrounding areas (CEC Report, 1997; So and Wang, 2003, Wei et al, 2007, Chan et al, 2007. In the past decade, dispersion models were used as a tool for assessing air quality and formulating regulatory measures.…”

Section: Introductionmentioning

confidence: 99%

Analysis of High Ozone Pollution Episode Using WRF/Chem Model Over Megacity Delhi, India

Kumar¹,

Goyal²

2018

Modelling, Simulation and Identification / 858: Intelligent Systems and Control

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Concentration of pollutants namely Ozone (O 3) and its precursors Carbon monoxide (CO) and Nitrogen oxide (NO X) over urban agglomeration Delhi, remain high during favourable meteorological conditions. A regional chemical transport model (CTM) Weather Research and Forecasting (WRF/Chem) model coupled with chemistry has been used to simulate concentration of O 3 and its precursors over Delhi during June 2012 and June 2013 respectively. In 2013, unusually high levels of O 3 and NO 2 were observed during late evening hours. This study investigates the causes and the temporal dynamics of ozone pollution. The simulations show a trend of underestimating maximum and overestimation for minimum ozone concentrations. Hourly O 3 exhibits an overall correlation of 0.51 with the observed values. Daily O 3 maxima are overestimated by about 26% in 2012. In 2013, a correlation of 0.47 was found between hourly observed and simulated values of O 3 with an underestimation of 42% in peak values. Hourly nitrogen dioxide (NO 2) is underestimated within a range of 18% to 28% and 31% to 67% with an overall correlation of 0.60 and 0.31 during 2012 and 2013 respectively. Back trajectory simulations performed using Hybrid single particle Lagrangian Integrated Trajectory (HYSPLIT) model further support the claim that the long-range transport of dust, gaseous and anthropogenic pollutants from the surrounding region affect the concentration level of pollutants in the innermost domain.

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An analysis on abnormally low ozone in the upper troposphere over subtropical East Asia in spring 2004

Cited by 12 publications

References 17 publications

Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis

Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis

Distribution, variability and sources of tropospheric ozone over south China in spring: Intensive ozonesonde measurements at five locations and modeling analysis

Analysis of High Ozone Pollution Episode Using WRF/Chem Model Over Megacity Delhi, India

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