Regional modeling of tropospheric NO&lt;sub&gt;2&lt;/sub&gt; vertical column density over East Asia during the period 2000–2010: comparison with multisatellite observations

Abstract. Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to, and thus can be used to estimate, surface NOx emissions. In this study, the NO2 VCD simulated by a regional chemical transport model with emissions data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated through comparison with multisatellite observations during the period 2000–2010. Rapid growth in NO2 VCD (~11% year−1) driven by the expansion of anthropogenic NOx emissions was identified above the central eastern China (CEC) region, except for the period during the economic downturn. In contrast, slightly decreasing trends (~2% year−1) were identified above Japan accompanied by a decline in anthropogenic emissions. To systematically compare the modeled NO2 VCD, we estimated sampling bias and the effect of applying the averaging kernel information, with particular focus on the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) data. Using the updated REAS, the modeled NO2 VCD reasonably reproduced annual trends observed by multisatellites, suggesting that the rate of increase of NOx emissions estimated by the updated REAS inventory would be robust. Province-scale revision of emissions above CEC is needed to further refine emission inventories. Based on the close linear relationship between modeled and observed NO2 VCD and anthropogenic NOx emissions, NOx emissions in 2009 and 2010, which were not covered by the updated REAS inventory, were estimated. NOx emissions from anthropogenic sources in China in 2009 and 2010 were determined to be 26.4 and 28.5 Tg year−1, respectively, indicating that NOx emissions increased more than twofold between 2000 and 2010. This increase reflected the strong growth of anthropogenic emissions in China following the rapid recovery from the economic downturn from late 2008 until mid-2009. Our method consists of simple estimations from satellite observations and provides results that are consistent with the most recent inventory of emissions data for China.

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Trend analysis of tropospheric NO<sub>2</sub> column density over East Asia during 2000–2010: multi-satellite observations and model simulations with the updated REAS emission inventory

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-11247-2013 ◽

2013 ◽

Vol 13 (4) ◽

pp. 11247-11268 ◽

Cited By ~ 2

Author(s):

S. Itahashi ◽

I. Uno ◽

H. Irie ◽

J. Kurokawa ◽

T. Ohara

Keyword(s):

Column Density ◽

Emission Inventory ◽

Transport Model ◽

Eastern China ◽

Satellite Observations ◽

Anthropogenic Sources ◽

Economic Downturn ◽

Nox Emissions ◽

Chemical Transport Model ◽

Vertical Column

Abstract. Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to surface NOx emissions and can thus be used to estimate the latter. In this study, the NO2 VCDs simulated by a regional chemical transport model with data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated by comparison with multi-satellite observations (GOME, SCIAMACHY, GOME-2, and OMI) between 2000 and 2010. Rapid growth in NO2 VCD driven by expansion of anthropogenic NOx emissions was revealed above the central eastern China region, except during the economic downturn. In contrast, slightly decreasing trends were captured above Japan. The modeled NO2 VCDs using the updated REAS emissions reasonably reproduced the annual trends observed by multi-satellites, suggesting that the NOx emissions growth rate estimated by the updated inventory is robust. On the basis of the close linear relationship of modeled NO2 VCD, observed NO2 VCD, and anthropogenic NOx emissions, the NOx emissions in 2009 and 2010 were estimated. It was estimated that the NOx emissions from anthropogenic sources in China beyond doubled between 2000 and 2010, reflecting the strong growth of anthropogenic emissions in China with the rapid recovery from the economic downturn during late 2008 and mid-2009.

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Application of SCIAMACHY and MOPITT CO total column measurements to evaluate model results over biomass burning regions and Eastern China

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-6083-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 6083-6114 ◽

Cited By ~ 28

Author(s):

C. Liu ◽

S. Beirle ◽

T. Butler ◽

J. Liu ◽

P. Hoor ◽

...

Keyword(s):

Biomass Burning ◽

Atmospheric Chemistry ◽

Eastern China ◽

Central Africa ◽

Satellite Observations ◽

Anthropogenic Sources ◽

Data Sets ◽

Vertical Column ◽

Data Set ◽

Vertical Column Density

Abstract. We developed a new CO vertical column density product from near IR observations of the SCIAMACHY instrument onboard ENVISAT. For the correction of a temporally and spatially variable offset of the CO vertical column densities we apply a normalisation procedure based on coincident MOPITT (version 4) observations over the oceans. The resulting normalised SCIAMACHY CO data is well suited for the investigation of the CO distribution over continents, where important emission sources are located. We use only SCIAMACHY observations for effective cloud fractions below 20 %. Since the remaining effects of clouds can still be large (up to 100 %), we applied a cloud correction scheme which explicitly considers the cloud fraction, cloud top height and surface albedo of individual observations. The normalisation procedure using MOPITT data and the cloud correction substantially improve the agreement with independent data sets. We compared our new SCIAMACHY CO data set, and also observations from the MOPITT instrument, to the results from three global atmospheric chemistry models (MATCH, EMAC at low and high resolution, and GEOS-Chem); the focus of this comparison is on regions with strong CO emissions (from biomass burning or anthropogenic sources). The comparison indicates that over most of these regions the seasonal cycle is generally captured well but the simulated CO vertical column densities are systematically smaller than those from the satellite observations, in particular with respect to SCIAMACHY observations. Because SCIAMACHY is more sensitive to the lowest part of the atmosphere compared to MOPITT, this indicates that especially close to the surface the model simulations systematically underestimate the true atmospheric CO concentrations, probably caused by an underestimation of CO emissions by current emission inventories. For some biomass burning regions, however, such as Central Africa in July–August, model results are also found to be higher than the satellite observations.

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Application of SCIAMACHY and MOPITT CO total column measurements to evaluate model results over biomass burning regions and Eastern China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-1265-2011 ◽

2011 ◽

Vol 11 (1) ◽

pp. 1265-1331 ◽

Cited By ~ 3

Author(s):

C. Liu ◽

S. Beirle ◽

T. Butler ◽

J. Liu ◽

P. Hoor ◽

...

Keyword(s):

Biomass Burning ◽

Atmospheric Chemistry ◽

Eastern China ◽

Central Africa ◽

High Sensitivity ◽

Satellite Observations ◽

Anthropogenic Sources ◽

Vertical Column ◽

Data Set ◽

Vertical Column Density

Abstract. We developed a new CO vertical column density product from near IR observations of the SCIAMACHY instrument onboard ENVISAT. For the correction of a temporally and spatially variable offset of the CO vertical column densities we apply a normalisation procedure based on coincident MOPITT (version 4) observations over the oceans. The resulting normalised SCIAMACHY CO data are well suited for the investigation of the CO distribution over continents, where important emission sources are located. We use only SCIAMACHY observations for effective cloud fractions below 20%. Since the remaining effects of clouds can still be large (up to 100%), we applied a cloud correction scheme which explicitly considers the cloud fraction, cloud top height and surface albedo of individual observations. We compared our new SCIAMACHY CO data set, and also observations from the MOPITT instrument, to the results from three global atmospheric chemistry models (MATCH, EMAC at low and high resolution, and GEOS-Chem); the focus of this comparison is on regions with strong CO emissions (from biomass burning or anthropogenic sources). The comparison indicates that over most of these regions the seasonal cycle is generally captured well but the simulated CO vertical column densities are systematically smaller than those from the satellite observations, in particular with respect to SCIAMACHY observations. Because of the high sensitivity of the SCIAMACHY observations to the lowest part of the atmosphere, this indicates that especially close to the surface the model simulations systematically underestimate the true atmospheric CO concentrations, probably caused by an underestimation of CO emissions by current emission inventories. For some biomass burning regions, however, such as Central Africa in July–August, model results are also found to be higher than the satellite observations.

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Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-8171-2011 ◽

2011 ◽

Vol 11 (15) ◽

pp. 8171-8188 ◽

Cited By ~ 87

Author(s):

J.-T. Lin ◽

M. B. McElroy

Keyword(s):

Economic Growth ◽

Nitrogen Oxides ◽

Industrial Development ◽

Thermal Power ◽

Satellite Observations ◽

Anthropogenic Emissions ◽

Economic Downturn ◽

Vertical Column ◽

Industrial Activity ◽

Tropospheric No2

Abstract. Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27–33 % in 12-month mean VCD of NO2 prior to the downturn, consistent with an increase of 49 % in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005–2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20 % from January 2008 to January 2009, close to the reduction of 18 % in TPG that occurred over the same interval. A combination of three independent approaches indicates that the economic downturn was responsible for a reduction in emissions by 9–11 % in January 2009 with an additional decrease of 10 % attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year; errors in the estimate are most likely less than 3.4 %.

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Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-193-2011 ◽

2011 ◽

Vol 11 (1) ◽

pp. 193-223 ◽

Cited By ~ 3

Author(s):

J.-T. Lin ◽

M. B. McElroy

Keyword(s):

Economic Growth ◽

Nitrogen Oxides ◽

Industrial Development ◽

Thermal Power ◽

Satellite Observations ◽

Anthropogenic Emissions ◽

Economic Downturn ◽

Vertical Column ◽

Industrial Activity ◽

Tropospheric No2

Abstract. Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27–33% in annual mean VCD of NO2 prior to the downturn, consistent with an increase of 49% in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005–2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20% from January 2008 to January 2009, close to the reduction of 18% in TPG that occurred over the same interval. A combination of three relatively independent approaches indicates that the economic downturn was responsible for a~reduction in emissions by 9–11% in January 2009 with an additional decrease of 10% attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year.

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Adjoint inverse modeling of NOx emissions over eastern China using satellite observations of NO2 vertical column densities

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.12.030 ◽

2009 ◽

Vol 43 (11) ◽

pp. 1878-1887 ◽

Cited By ~ 65

Author(s):

Jun-ichi Kurokawa ◽

Keiya Yumimoto ◽

Itushi Uno ◽

Toshimasa Ohara

Keyword(s):

Inverse Modeling ◽

Eastern China ◽

Satellite Observations ◽

Nox Emissions ◽

Vertical Column

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Impacts of Chemical and Synoptic Processes on Summer Tropospheric Ozone Trend in North China

Advances in Meteorology ◽

10.1155/2019/3148432 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Lihua Zhou ◽

Jing Zhang ◽

Xiaohui Zheng ◽

Wenhao Xue ◽

Siguang Zhu

Keyword(s):

Column Density ◽

North China ◽

Chemical Processes ◽

Satellite Observations ◽

Dynamic Processes ◽

Second Phase ◽

Process Variables ◽

Vertical Column ◽

Increasing Trend ◽

Vertical Column Density

Compared with other regions in China, air pollution on the North China Plain (NCP) is serious. Fine particle pollution has been studied in-depth, but there is less research on long-term troposphere ozone (O3) variation. This study focuses on the summer interannual tropospheric O3 variation on the NCP and its influential factors. Our analysis relies on satellite observations (O3, nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and formaldehyde (HCHO), determined as vertical column density of the troposphere) and dynamical processes (El Niño-Southern Oscillation (ENSO), potential vorticity (PV), the quasibiennial oscillation (QBO), and East Asian summer monsoon index (EASMI)). Our results show the vertical column density of tropospheric O3 has a transition from the increasing trend to decreasing trend during the summer of 2005–2016. The summer series of tropospheric O3 show two distinct phases: the first phase (2005–2011), with an average growth rate of 0.55 ± 0.20 DU/yr, and a second phase (2012–2016), with an average reduction rate of 0.16 ± 0.23 DU/yr. The tropospheric NO2 column in the NCP also has a transition from the increasing trend to decreasing trend during the summer of 2005–2016. Tropospheric NO2 and CO column concentrations obtained from satellite observations indicate that emission reductions might be the main cause of the tropospheric O3 decrease. Particularly, the reduction of nitrogen oxides (NOx) is more significant, and NO2 decreased by (0.45 ± 0.11) × 1015 molec·cm−2 per year in summer since 2012. However, tropospheric column HCHO shows an increase of 0.05 × 1015 molec·cm−2 per year during the whole period of 2005 to 2016. An O3-NOx-VOC sensitivity experiment in the NCP showed that the O3 is still in a NOx-saturated state in some heavily polluted cities, although the NOx emissions are decreasing overall. In addition to the chemical reactions, atmospheric dynamic processes also have an effect on tropospheric O3. Finally, we built a model to analyze the contributions of chemical processes and dynamic processes to the tropospheric O3 column in the NCP. For the chemical process variables, 69.73% of the observed trend of tropospheric O3 could be explained by the NO2 tropospheric column. Therefore, the reduction of tropospheric O3 since 2012 is associated with the reduction of NOx. For the dynamical process variables, ENSO, PV, and EASMI can explain 60.64% of the observed trend of tropospheric O3. This result indicates that the atmospheric circulation of the western Pacific Ocean in summer has a significant impact on the interannual trends of tropospheric O3 in the NCP. It is also found that chemical processes had a more important impact on interannual tropospheric O3 than dynamic processes, although the dynamic processes cannot be neglected.

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