scholarly journals Evaluation of Air Quality Model Performance for Simulating Long-Range Transport and Local Pollution of PM2.5in Japan

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Hikari Shimadera ◽  
Tatsuya Kojima ◽  
Akira Kondo
Keyword(s):  
Air Quality ◽  
Long Range ◽  
Model Performance ◽  
Anthropogenic Sources ◽  
Long Range Transport ◽  
Air Quality Model ◽  
Quality Model ◽  
Local Pollution ◽  
Range Transport ◽  
The Difference

The Community Multiscale Air Quality Model (CMAQ) v5.0.2 was applied to PM2.5simulation in Japan, which is strongly affected by long-range transport (LRT) from anthropogenic sources in the Asian Continent, for one year from April 2010 to March 2011. The model performance for LRT and local pollution (LP) of PM2.5was evaluated to identify the model processes that need to be improved. CMAQ well simulated temporal and spatial variation patterns of PM2.5but underestimated the concentration level by 15% on average. The contribution of LRT was estimated from the difference between the baseline simulation case and a zero-emission case for anthropogenic emissions in the continent. The estimated LRT contribution to PM2.5was 50% on average and generally higher in the western areas of Japan (closer to the continent). Days that were dominantly affected by LRT or LP were determined based on the contribution of LRT to sulfate, which was fairly well simulated and strongly affected by LRT among major PM2.5components. The underestimation of PM2.5was larger in LP days (by 26% on average) than LRT days (by 10% on average). Therefore, it is essential to improve local emissions, formation, and loss processes of precursors and PM2.5in Japan.

scholarly journals Impacts of transported background ozone on California air quality during the ARCTAS-CARB period – a multi-scale modeling study

2010 ◽  
Vol 10 (14) ◽  
pp. 6947-6968 ◽  
Author(s):  
M. Huang ◽  
G. R. Carmichael ◽  
B. Adhikary ◽  
S. N. Spak ◽  
S. Kulkarni ◽  
...  
Keyword(s):  
Air Quality ◽  
Long Range ◽  
Atmospheric Chemistry ◽  
Three Dimensional ◽  
Model Performance ◽  
Long Range Transport ◽  
Northern California ◽  
Multi Scale ◽  
Background Ozone ◽  
Range Transport

Abstract. Multi-scale tracer and full-chemistry simulations with the STEM atmospheric chemistry model are used to analyze the effects of transported background ozone (O3) from the eastern Pacific on California air quality during the ARCTAS-CARB experiment conducted in June, 2008. Previous work has focused on the importance of long-range transport of O3 to North America air quality in springtime. However during this summer experiment the long-range transport of O3 is also shown to be important. Simulated and observed O3 transport patterns from the coast to inland northern California are shown to vary based on meteorological conditions and the O3 profiles over the oceans, which are strongly episodically affected by Asian inflows. Analysis of the correlations of O3 at various altitudes above the coastal site at Trinidad Head and at a downwind surface site in northern California, show that under long-range transport events, high O3 air-masses (O3>60 ppb) at altitudes between about 2 and 4 km can be transported inland and can significantly influence surface O3 20–30 h later. These results show the importance of characterizing the vertical structure of the lateral boundary conditions (LBC) needed in air quality simulations. The importance of the LBC on O3 prediction during this period is further studied through a series of sensitivity studies using different forms of LBC. It is shown that the use of the LBC downscaled from RAQMS global model that assimilated MLS and OMI data improves the model performance. We also show that the predictions can be further improved through the use of LBC based on NASA DC-8 airborne observations during the ARCTAS-CARB experiment. These results indicate the need to develop observational strategies to provide information on the three-dimensional nature of pollutant distributions, in order to improve our capability to predict pollution levels and to better quantify the influence of these Asian inflows on the US west coast air quality.

scholarly journals Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model (C-TRAIL Model v1.0) derived from the Community Multiscale Air Quality Model (CMAQ Model v5.2)

2020 ◽  
Vol 13 (8) ◽  
pp. 3489-3505 ◽  
Author(s):  
Arman Pouyaei ◽  
Yunsoo Choi ◽  
Jia Jung ◽  
Bavand Sadeghi ◽  
Chul Han Song
Keyword(s):  
Air Quality ◽  
Lagrangian Model ◽  
Long Range Transport ◽  
Air Quality Model ◽  
Quality Model ◽  
Air Masses ◽  
Range Transport ◽  
Potential Sources ◽  
Model C ◽  
Co Concentrations

Abstract. This paper introduces a novel Lagrangian model (Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model, C-TRAIL version 1.0) output from a Eulerian air quality model for validating the source–receptor direct link by following polluted air masses. To investigate the concentrations and trajectories of air masses simultaneously, we implement the trajectory-grid (TG) Lagrangian advection scheme in the CMAQ (Community Multiscale Air Quality) Eulerian model version 5.2. The TG algorithm follows the concentrations of representative air “packets” of species along trajectories determined by the wind field. The diagnostic output from C-TRAIL accurately identifies the origins of pollutants. For validation, we analyze the results of C-TRAIL during the KORUS-AQ campaign over South Korea. Initially, we implement C-TRAIL in a simulation of CO concentrations with an emphasis on the long- and short-range transport effects. The output from C-TRAIL reveals that local trajectories were responsible for CO concentrations over Seoul during the stagnant period (17–22 May 2016) and during the extreme pollution period (25–28 May 2016), highly polluted air masses from China were distinguished as sources of CO transported to the Seoul Metropolitan Area (SMA). We conclude that during the study period, long-range transport played a crucial role in high CO concentrations over the receptor area. Furthermore, for May 2016, we find that the potential sources of CO over the SMA were the result of either local transport or long-range transport from the Shandong Peninsula and, in some cases, from regions north of the SMA. By identifying the trajectories of CO concentrations, one can use the results from C-TRAIL to directly link strong potential sources of pollutants to a receptor in specific regions during various time frames.

scholarly journals Ensemble Predictions of Air Pollutants in China in 2013 for Health Effects Studies Using WRF/CMAQ Modeling System with Four Emission Inventories

2017 ◽  
Author(s):  
Jianlin Hu ◽  
Xun Li ◽  
Lin Huang ◽  
Qi Ying ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Health Effects ◽  
Air Pollutants ◽  
Emission Inventory ◽  
Model Performance ◽  
Observation Data ◽  
Emission Inventories ◽  
Air Quality Model ◽  
Quality Model ◽  
Future Health

Abstract. Accurate exposure estimates are required for health effects analyses of severe air pollution in China. Chemical transport models (CTMs) are widely used tools to provide detailed information of spatial distribution, chemical composition, particle size fractions, and source origins of pollutants. The accuracy of CTMs' predictions in China is largely affected by the uncertainties of public available emission inventories. The Community Multi-scale Air Quality model (CMAQ) with meteorological inputs from the Weather Research and Forecasting model (WRF) were used in this study to simulate air quality in China in 2013. Four sets of simulations were conducted with four different anthropogenic emission inventories, including the Multi-resolution Emission Inventory for China (MEIC), the Emission Inventory for China by School of Environment at Tsinghua University (SOE), the Emissions Database for Global Atmospheric Research (EDGAR), and the Regional Emission inventory in Asia version 2 (REAS2). Model performance was evaluated against available observation data from 422 sites in 60 cities across China. Model predictions of O3 and PM2.5 with the four inventories generally meet the criteria of model performance, but difference exists in different pollutants and different regions among the inventories. Ensemble predictions were calculated by linearly combining the results from different inventories under the constraint that sum of the squared errors between the ensemble results and the observations from all the cities was minimized. The ensemble annual concentrations show improved agreement with observations in most cities. The mean fractional bias (MFB) and mean fractional errors (MFE) of the ensemble predicted annual PM2.5 at the 60 cities are −0.11 and 0.24, respectively, which are better than the MFB (−0.25–−0.16) and MFE (0.26–0.31) of individual simulations. The ensemble annual 1-hour peak O3 (O3-1 h) concentrations are also improved, with mean normalized bias (MNB) of 0.03 and mean normalized errors (MNE) of 0.14, compared to MNB of 0.06–0.19 and MNE of 0.16–0.22 of the individual predictions. The ensemble predictions agree better with observations with daily, monthly, and annual averaging times in all regions of China for both PM2.5 and O3-1 h. The study demonstrates that ensemble predictions by combining predictions from individual emission inventories can improve the accuracy of predicted temporal and spatial distributions of air pollutants. This study is the first ensemble model study in China using multiple emission inventories and the results are publicly available for future health effects studies.

Impact of field biomass burning on local pollution and long-range transport of PM2.5 in Northeast Asia

2019 ◽  
Vol 244 ◽  
pp. 414-422 ◽  
Author(s):  
Katsushige Uranishi ◽  
Fumikazu Ikemori ◽  
Hikari Shimadera ◽  
Akira Kondo ◽  
Seiji Sugata
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
Northeast Asia ◽  
Long Range Transport ◽  
Local Pollution ◽  
Range Transport

scholarly journals Long-range Transport of Aerosols from Biomass Burning over Southeastern South America and their Implications on Air Quality

2018 ◽  
Vol 18 (7) ◽  
pp. 1734-1745 ◽  
Author(s):  
Leila Droprinchinski Martins ◽  
Ricardo Hallak ◽  
Rafaela Cruz Alves ◽  
Daniela S. de Almeida ◽  
Rafaela Squizzato ◽  
...  
Keyword(s):  
Air Quality ◽  
South America ◽  
Long Range ◽  
Biomass Burning ◽  
Long Range Transport ◽  
Range Transport

scholarly journals Inconsistent decadal variations between surface and free tropospheric nitrogen oxides over United States

2017 ◽  
Author(s):  
Zhe Jiang ◽  
Helen Worden ◽  
John R. Worden ◽  
Daven K. Henze ◽  
Dylan B. A. Jones ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Climate Variability ◽  
Long Range ◽  
North American ◽  
Long Range Transport ◽  
Substantial Impact ◽  
Decadal Scale ◽  
Range Transport

Abstract. Decreases in surface emissions of nitrogen oxides (NOx = NO + NO2) in North America have led to substantial improvements in air-quality over the last several decades. Here we show that satellite observations of tropospheric nitrogen dioxide (NO2) columns over the contiguous United States (US) do not decrease after about 2009, while surface NO2 concentrations continue to decline through to the present. This divergence, if it continues, could have a substantial impact on surface air quality due to mixing of free-tropospheric air into the boundary layer. Our results show only limited contributions from local effects such as fossil fuel emissions, lightning, or instrument artifacts, but we do find a possible relationship of NO2 changes to decadal climate variability. Our analysis demonstrates that the intensity of transpacific transport is stronger in El Niño years and weaker in La Niña years, and consequently, that decadal-scale climate variability impacts the contribution of Asian emissions on North American atmospheric composition. Because of the short lifetime, it is usually believed that the direct contribution of long-range transport to tropospheric NOx distribution is limited. If our hypothesis about transported Asian emissions is correct, then this observed divergence between satellite and surface NOx could indicate mechanisms that allow for either NOx or its reservoir species to have a larger than expected effect on North American tropospheric composition. These results therefore suggest more aircraft and satellite studies to determine the possible missing processes in our understanding of the long-range transport of tropospheric NOx.

Resampling and extreme value statistics in air quality model performance evaluation

1985 ◽  
Vol 19 (9) ◽  
pp. 1503-1518 ◽  
Author(s):  
S.T. Rao ◽  
G. Sistla ◽  
V. Pagnotti ◽  
W.B. Petersen ◽  
J.S. Irwin ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Air Quality ◽  
Model Performance ◽  
Extreme Value ◽  
Extreme Value Statistics ◽  
Air Quality Model ◽  
Quality Model ◽  
Model Performance Evaluation

scholarly journals Sources of organic carbon in fine particulate matter in northern European urban air

2008 ◽  
Vol 8 (20) ◽  
pp. 6281-6295 ◽  
Author(s):  
S. Saarikoski ◽  
H. Timonen ◽  
K. Saarnio ◽  
M. Aurela ◽  
L. Järvi ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Diurnal Variation ◽  
Long Range ◽  
Major Ions ◽  
Water Soluble ◽  
Anthropogenic Sources ◽  
Biomass Combustion ◽  
Long Range Transport ◽  
Northern European ◽  
Range Transport

Abstract. A major fraction of fine particle matter consists of organic carbon (OC) but its origin is still inadequately known. In this study the sources of OC were investigated in the northern European urban environment in Helsinki, Finland. Measurements were carried out over one year and they included both filter (PM1) and online methods. From the filter samples OC, elemental carbon (EC), water-soluble OC (WSOC), levoglucosan and major ions were analyzed. Filter data together with the concentrations of inorganic gases were analyzed by Positive matrix factorization (PMF) in order to find the sources of OC (and WSOC) on an annual as well as on a seasonal basis. In order to study the diurnal variation of sources, OC and EC were measured by a semicontinuous OC/EC analyzer and major ions were determined by a Particle-into-Liquid Sampler coupled to ion chromatographs. According to PMF, OC concentrations were impacted by four sources: biomass combustion, traffic, long-range transport and secondary production. On an annual basis the OC concentration was dominated by secondary organic aerosol (SOA). Its contribution to OC was as high as 64% in summer, which besides anthropogenic sources may also result from the large biogenic volatile organic carbon (VOC) emissions in the boreal region. In winter biomass combustion constituted the largest fraction in OC due to domestic wood combustion for heating purposes. Traffic contributed to OC from 15 to 27%. Regarding the diurnal variation, the contribution from traffic was higher from 08:00 to 18:00 on weekdays than on weekends. The contribution from long-range transport to OC was 24% on average. All four sources also influenced the WSOC concentrations, however, the contribution of SOA was significantly larger for WSOC than OC.

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