Numerical study on seasonal variations of gaseous pollutants and particulate matters in Hong Kong and Pearl River Delta Region

[1] This study presents Community Multiscale Air Quality (CMAQ) model results for Hong Kong (HK) and the Pearl River Delta region in January, April, July, and October 2004, representing winter, spring, summer, and autumn seasons. Two sets of observations/measurement data are referred to in order to evaluate model performance. The first set consists of hourly observations of criteria pollutants at HK Environmental Protection Department (HKEPD) ambient stations throughout HK, while the second set contains speciated PM measurements, sampled at 6-day intervals, at six of the HKEPD ambient stations. Model-observation agreement is good in PM species sulfate, organic carbon (OC), and elemental carbon (EC). The good performance for OC and EC, when compared to similar evaluation for North America and Europe, demonstrates the importance of correct speciation in an emission sector. Underprediction of NOx and NH3 suggests a desperate need of emission estimation improvement in these species. PM levels are higher in autumn and winter, lower in spring, and lowest in summer, coinciding with northeasterly winds due to continental outflow in autumn and winter, and with southwesterly monsoon in summer. The model is also able to reproduce the seasonal and spatial patterns for PM and O3. In terms of PM composition, the model agrees with the measured fractions of sulfate, OC, and EC. Additionally, CMAQ was rerun with emission sources partially removed, with results suggesting that pollution sources beyond the Pearl River Delta also contribute to the PM and sulfate levels in HK, particularly during the winter season.

[1]  Francis S. Binkowski,et al.  AEROSOLS IN MODELS-3 CMAQ , 1999 .

[2]  J. Seinfeld,et al.  Atmospheric Chemistry and Physics: From Air Pollution to Climate Change , 1997 .

[3]  D. Fahey,et al.  Ozone production in the rural troposphere and the implications for regional and global ozone distributions , 1987 .

[4]  J. Chow,et al.  Characterization of chemical species in PM2.5 and PM10 aerosols in Hong kong , 2003 .

[5]  Judith C. Chow,et al.  Characteristics of carbonaceous aerosol in Pearl River Delta Region, China during 2001 winter period , 2003 .

[6]  Xiangde Xu,et al.  The influence of tropical cyclone Melor on PM10 concentrations during an aerosol episode over the Pearl River Delta region of China: Numerical modeling versus observational analysis , 2007 .

[7]  Regional and global distributions and lifetimes of sulfate aerosols from Mexico City and southeast China , 1999 .

[8]  G. Grell,et al.  A description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5) , 1994 .

[9]  C. Chan,et al.  Air pollution in mega cities in China , 2008 .

[10]  Julius Chang,et al.  A non-local closure model for vertical mixing in the convective boundary layer , 1992 .

[11]  M. Zheng,et al.  The long-range transport of aerosols from northern China to Hong Kong – a multi-technique study , 1999 .

[12]  Hai Guo,et al.  Long-term variation of PM2.5 levels and composition at rural, urban, and roadside sites in Hong Kong : increasing impact of regional air pollution , 2007 .

[13]  Jiming Hao,et al.  Improving Urban Air Quality in China: Beijing Case Study , 2005, Journal of the Air & Waste Management Association.

[14]  R. Turco,et al.  SMVGEAR: A sparse-matrix, vectorized gear code for atmospheric models , 1994 .

[15]  Composition and sources of carbonaceous aerosols at three contrasting sites in Hong Kong , 2006 .

[16]  J. Hao,et al.  Chemical characteristics of airborne particulate matter near major roads and at background locations in Macao, China. , 2003, The Science of the total environment.

[17]  P. Midgley,et al.  Global emissions of hydrogen chloride and chloromethane from coal combustion, incineration and industrial activities: Reactive Chlorine Emissions Inventory , 1999 .

[18]  A. Miguel,et al.  Pedestrian Exposure to Ultrafine Particles in Hong kong under Heavy Traffic Conditions , 2008 .

[19]  Jianping Huang,et al.  Integrated processes analysis and systematic meteorological classification of ozone episodes in Hong Kong , 2006 .

[20]  J. Fung,et al.  Identification and spatiotemporal variations of dominant PM10 sources over Hong Kong , 2006 .

[21]  C. Chan,et al.  Source apportionment of PM2.5 in urban area of Hong Kong. , 2006, Journal of hazardous materials.

[22]  Judith C Chow,et al.  Comparison of PM2.5 carbon measurement methods in Hong Kong, China. , 2005, Environmental pollution.

[23]  Sanford Sillman,et al.  The sensitivity of ozone to nitrogen oxides and hydrocarbons in regional ozone episodes , 1990 .

[24]  Judith C Chow,et al.  PM2.5 chemical composition in Hong Kong: urban and regional variations. , 2005, The Science of the total environment.

[25]  Gail S. Tonnesen,et al.  Development of a tagged species source apportionment algorithm to characterize three‐dimensional transport and transformation of precursors and secondary pollutants , 2009 .

[26]  F. Binkowski,et al.  The Regional Particulate Matter Model 1. Model description and preliminary results , 1995 .

[27]  Alexis K.H. Lau,et al.  Seasonal characteristics and regional transport of PM2.5 in Hong Kong , 2005 .

[28]  K. Wai,et al.  Relationship between ionic composition in PM10 and the synoptic-scale and mesoscale weather conditions in a south China coastal city: A 4-year study , 2005 .

[29]  Junji Cao,et al.  Spatial and seasonal distributions of atmospheric carbonaceous aerosols in pearl river delta region, china , 2003 .

[30]  Mark Z. Jacobson,et al.  An integrated air pollution modeling system for urban and regional scales: 2. Simulations for SCAQS 1987 , 1997 .

[31]  C. W. Gear,et al.  The automatic integration of ordinary differential equations , 1971, Commun. ACM.

[32]  E. Mlawer,et al.  Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave , 1997 .

[33]  Kebin He,et al.  Modeling Regional/Urban Ozone and Particulate Matter in Beijing, China , 2009, Journal of the Air & Waste Management Association.

[34]  C. W. Gear,et al.  Numerical initial value problem~ in ordinary differential eqttations , 1971 .

[35]  Nghiem Trung Dung,et al.  Particulate air pollution in six Asian cities: Spatial and temporal distributions, and associated sources , 2006 .

[36]  Godwin A. Ayoko,et al.  Receptor modeling of source apportionment of Hong Kong aerosols and the implication of urban and regional contribution , 2009 .

[37]  Tao Wang,et al.  Influence of regional pollution outflow on the concentrations of fine particulate matter and visibility in the coastal area of southern China , 2005 .

[38]  F. Binkowski,et al.  Models-3 community multiscale air quality (cmaq) model aerosol component , 2003 .

[39]  K. Ho,et al.  Carbonaceous characteristics of atmospheric particulate matter in Hong Kong. , 2002, The Science of the total environment.

[40]  R. Gunst,et al.  Response of ozone to changes in hydrocarbon and nitrogen oxide concentrations in outdoor smog chambers filled with Los Angeles air , 1990 .

[41]  Kaarle Kupiainen,et al.  Modeling carbonaceous aerosol over Europe: Analysis of the CARBOSOL and EMEP EC/OC campaigns , 2007 .

[42]  H. Pan,et al.  Nonlocal Boundary Layer Vertical Diffusion in a Medium-Range Forecast Model , 1996 .

[43]  J. Fung,et al.  Urban Modification in a Mesoscale Model and the Effects on the Local Circulation in the Pearl River Delta Region , 2007 .

[44]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[45]  S. Liu,et al.  On the nonlinearity of the tropospheric ozone production , 1988 .

[46]  Robert A. Gorse,et al.  IMPACT OF METHANOL VEHICLES ON OZONE AIR QUALITY , 1989 .

[47]  S. C. Liu,et al.  Models and observations of the impact of natural hydrocarbons on rural ozone , 1987, Nature.

[48]  Jing-chun Duan,et al.  Sources and characteristics of carbonaceous aerosol in two largest cities in Pearl River Delta Region, China , 2007 .

[49]  Z. Yuan,et al.  Water-soluble organic carbon and oxalate in aerosols at a coastal urban site in China: Size distribution characteristics, sources, and formation mechanisms , 2006 .

[50]  Heather Simon,et al.  Emissions inventory of PM2.5 trace elements across the United States. , 2009, Environmental science & technology.

[51]  Tijian Wang,et al.  Impact of biogenic VOC emissions on a tropical cyclone-related ozone episode in the Pearl River Delta region, China , 2007 .

[52]  Ralf Koppmann,et al.  Methyl Halide Emissions from Savanna Fires in Southern Africa , 1996 .

[53]  J. Fung,et al.  Investigation of enhanced cross‐city transport and trapping of air pollutants by coastal and urban land‐sea breeze circulations , 2006 .

[54]  D. Streets,et al.  MICS-Asia II. Modeling gaseous pollutants and evaluating an advanced modeling system over East Asia , 2008 .

[55]  Shaocai Yu,et al.  A performance evaluation of the 2004 release of Models-3 CMAQ , 2006 .

[56]  Michael Q. Wang,et al.  An inventory of gaseous and primary aerosol emissions in Asia in the year 2000 , 2003 .

[57]  Alexis K.H. Lau,et al.  Analysis of aerosol vertical distribution and variability in Hong Kong , 2008 .

[58]  Binyu Wang,et al.  Air quality during the 2008 Beijing Olympic Games , 2007 .

[59]  J. M. Watt.  Numerical Initial Value Problems in Ordinary Differential Equations , 1972 .

[60]  K. Wyat Appel,et al.  Evaluation of the community multiscale air quality (CMAQ) model version 4.5: Sensitivities impacting model performance; Part II—particulate matter , 2008 .

[61]  David G Streets,et al.  Modeling study of air pollution due to the manufacture of export goods in China's Pearl River Delta. , 2006, Environmental science & technology.

[62]  K. Selby.  A Modeling Study of Atmospheric Transport and Photochemistry in the Mixed Layer during Anticyclonic Episodes in Europe. Part II. Calculations of Photo-Oxidant Levels along Air Trajectories , 1987 .

[63]  Stephen E. Schwartz,et al.  Sulfate over the North Atlantic and adjacent continental regions: Evaluation for October and November 1986 using a three-dimensonal model driven by observation-derived meteorology , 1994 .

[64]  J. Fung,et al.  Abundance and seasonal characteristics of elemental and organic carbon in Hong Kong PM10 , 2004 .

[65]  Chapter 7 NUMERICAL TRANSPORT ALGORITHMS FOR THE COMMUNITY MULTISCALE AIR QUALITY ( CMAQ ) CHEMICAL TRANSPORT MODEL IN GENERALIZED COORDINATES , 1999 .

[66]  P. Jansens,et al.  Biomass combustion in fluidized bed boilers: Potential problems and remedies , 2009 .

[67]  Uri M. Ascher,et al.  Computer methods for ordinary differential equations and differential-algebraic equations , 1998 .