Impact of Shanghai urban land surface forcing on downstream city ozone chemistry

Zhu, Bin; Kang, Hanqing; Zhu, Tong; JiFeng, Su; Hou, Xiyong; Gao, Jian

doi:10.1002/2014jd022859

Cited by 57 publications

(51 citation statements)

References 41 publications

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“…Although the answers are probably negative, the systematic analyses of AH over South China in this paper can enhance the understanding of the magnitude of AH emission from megacities and its impact on regional meteorology and atmospheric chemistry. Compared with the effects from urban land use (Wang et al, 2007;Feng et al, 2012;Chen et al, 2014b;Li et al, 2014;Liao et al, 2015;Zhu et al, 2015), the impacts of AH are relatively small. Especially in some cities with less air pollution and AH emissions, such as Haikou, the effects of AH on air quality may be ignored.…”

Section: Discussionmentioning

confidence: 99%

“…surfaces to artificial ones (Civerolo et al, 2007;Lo et al, 2007;Wang et al, 2007;Jiang et al, 2008;Lu et al, 2010;Wu et al, 2011;Chen et al, 2014b;Liao et al, 2015;Zhu et al, 2015;Li et al, 2016) and the release of anthropogenic heat from human activities in cities (Ryu et al, 2013;Yu et al, 2014;Xie et al, 2016). Anthropogenic heat (AH) can increase turbulent fluxes in sensible and latent heat (Oke, 1988), implying that it can modulate local and regional meteorological processes (Ichinose et al, 1999;Block et al, 2004;Fan and Sailor, 2005;Ferguson and Woodbury, 2007;Zhu et al, 2010;Feng et al, 2012Feng et al, , 2014Menberg et al, 2013;Ryu et al, 2013;Wu and Yang, 2013;Bohnenstengel et al, 2014;Chen et al, 2014a;Meng et al, 2011;Yu et al, 2014;Xie et al, 2016) and thereby exert an important influence on the formation and the distribution of ozone (Ryu et al, 2013;Yu et al, 2014;Xie et al, 2016) as well as aerosols (Yu et al, 2014;Xie et al, 2016).…”

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confidence: 99%

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Changes in regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

et al. 2016

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Abstract. Anthropogenic heat (AH) emissions from human activities can change the urban circulation and thereby affect the air pollution in and around cities. Based on statistic data, the spatial distribution of AH flux in South China is estimated. With the aid of the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem), in which the AH parameterization is developed to incorporate the gridded AH emissions with temporal variation, simulations for January and July in 2014 are performed over South China. By analyzing the differences between the simulations with and without adding AH, the impact of AH on regional meteorology and air quality is quantified. The results show that the regional annual mean AH fluxes over South China are only 0.87 W m −2 , but the values for the urban areas of the Pearl River Delta (PRD) region can be close to 60 W m −2 . These AH emissions can significantly change the urban heat island and urban-breeze circulations in big cities. In the PRD city cluster, 2 m air temperature rises by 1.1 • in January and over 0.5 • in July, the planetary boundary layer height (PBLH) increases by 120 m in January and 90 m in July, 10 m wind speed is intensified to over 0.35 m s −1 in January and 0.3 m s −1 in July, and accumulative precipitation is enhanced by 20-40 % in July. These changes in meteorological conditions can significantly impact the spatial and vertical distributions of air pollutants. Due to the increases in PBLH, surface wind speed and upward vertical movement, the concentrations of primary air pollutants decrease near the surface and increase in the upper levels. But the vertical changes in O 3 concentrations show the different patterns in different seasons. The surface O 3 concentrations in big cities increase with maximum values of over 2.5 ppb in January, while O 3 is reduced at the lower layers and increases at the upper layers above some megacities in July. This phenomenon can be attributed to the fact that chemical effects can play a significant role in O 3 changes over South China in winter, while the vertical movement can be the dominant effect in some big cities in summer. Adding the gridded AH emissions can better describe the heterogeneous impacts of AH on regional meteorology and air quality, suggesting that more studies on AH should be carried out in climate and air quality assessments.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Changes in regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

et al. 2016

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“…Developed at the National Center for Atmospheric Research (NCAR), WRF is a new generation of mesoscale weather forecast model and assimilation system. Numerous applications have proven that it shows a good performance in all kinds of weather forecasts and has broad application prospects in China (Jiang et al, 2008(Jiang et al, , 2012Liu et al, 2013;Xie et al, 2014Xie et al, , 2016aLiao et al, , 2015Li et al, 2016;Zhu et al, 2015). WRF provides offline meteorological fields as the input for the chemical transport model CMAQ.…”

Section: Model Description and Configurationsmentioning

confidence: 99%

“…Many studies on the O 3 pollution, including satellite data analyses, field experiments and model simulations, have been carried out over China in order to investigate the temporal and spatial characteristics of surface photochemical pollution (Lu and Wang, 2006; H. X. Tu et al, 2007;Zhang et al, 2007Zhang et al, , 2008Geng et al, 2008;Tang et al, 2008Tang et al, , 2009Chen et al, 2009;Han et al, 2011;Ding et al, 2013;Xie et al, 2016b), nonlinear photochemistry of O 3 and its precursors (Lam et al, 2005;Ran et al, 2009;Liu et al, 2010;Li et al, 2011;Xie et al, 2014), interactions between O 3 and aerosols (Lou et al, 2014;Shi et al, 2015), the effects of urbanization on O 3 formation Liao et al, 2015;Li et al, 2016;Xie et al, 2016a;Zhu et al, 2015) and other essential impact factors (Jiang et al, 2012;Li et al, 2012;Wei et al, 2012;Liu et al, 2013;Gao et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

et al. 2016

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Abstract. Severe high ozone (O 3 ) episodes usually have close relations to synoptic systems. A regional continuous O 3 pollution episode was detected over the Yangtze River Delta (YRD) region in China during 7-12 August 2013, in which the O 3 concentrations in more than half of the cities exceeded the national air quality standard. The maximum hourly concentration of O 3 reached 167.1 ppb. By means of the observational analysis and the numerical simulation, the characteristics and the essential impact factors of the typical regional O 3 pollution are comprehensively investigated. The observational analysis shows that the atmospheric subsidence dominated by the western Pacific subtropical high plays a crucial role in the formation of high-level O 3 . The favorable weather conditions, such as extremely high temperature, low relative humidity and weak wind speed, caused by the abnormally strong subtropical high are responsible for the trapping and the chemical production of O 3 in the boundary layer. In addition, when the YRD cities are at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause worse air quality. However, when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O 3 pollution. The integrated process rate (IPR) analysis incorporated in the Community Multi-scale Air Quality (CMAQ) model is applied to further illustrate the combined influence of subtropical high and typhoon system in this O 3 episode. The results show that the vertical diffusion (VDIF) and the gas-phase chemistry (CHEM) are two major contributors to O 3 formation. During the episode, the contributions of VDIF and CHEM to O 3 maintain the high values over the YRD region. On 10-12 August, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb h −1 in Shanghai and 19.76 ppb h −1 in Hangzhou. In contrast, the cities far away from the sea can hardly be affected by the periphery circulation of typhoon system. When the typhoon system significantly weakens the subtropical high, the contribution values of all individual processes decrease to a low level in all YRD cities. These results provide an insight for the O 3 pollution synthetically impacted by the western Pacific subtropical high and the tropical cyclone system.

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“…According to [11], this phenomenon, together with the increase in temperature, results in an increase in surface ozone concentrations in urban areas with a maximum of 2.5 ppb in winter and 4 ppb in summer. The authors of [12] show that on average, daytime ozone concentrations decrease by about 2 ppbv in the lower boundary layer, while they increase by about 40 ppbv in the upper levels in a city downwind of Shanghai.…”

Section: Introductionmentioning

confidence: 99%

Impact of Highly Reflective Materials on Meteorology, PM10 and Ozone in Urban Areas: A Modeling Study with WRF-CHIMERE at High Resolution over Milan (Italy)

Falasca

Curci

2018

Urban Science

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Abstract:The Urban Heat Island (UHI) is a well-known phenomenon concerning an increasing percentage of the world's population due to the growth rates of metropolitan areas. Given the health and economic implications of UHIs, several mitigation techniques are being evaluated and tested. In this study, we consider the use of highly reflective materials for urban surfaces, and we carried out numerical experiments using the Weather Research and Forecasting model coupled with the CHIMERE model in order to investigate the effects of these materials on the meteorology and air quality in the urban area of Milan (Italy). Results show that an increase in albedo from 0.2 to 0.7 for urban roofs, walls and streets leads to a decrease in UHI intensity by up to 2-3 • C and of the planetary boundary layer (PBL) height of about 500 m. However, the difference of PM10 and ozone between urban and surrounding areas increases by a factor of about 2, attributable to the reduction of PBL height and wind speed and to the increased reflected solar radiation that may enhance photochemical production during the daytime. Therefore, if anthropogenic emissions are held at the same levels, the potential benefit to the UHI in terms of thermal discomfort may have negative repercussions on air quality.

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Impact of Shanghai urban land surface forcing on downstream city ozone chemistry

Cited by 57 publications

References 41 publications

Changes in regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

Changes in regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

Impact of Highly Reflective Materials on Meteorology, PM10 and Ozone in Urban Areas: A Modeling Study with WRF-CHIMERE at High Resolution over Milan (Italy)

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