Significant contribution of organics to aerosol liquid water content in winter in Beijing, China

Abstract. The aerosol liquid water content (ALWC), an important component of atmospheric particles, has a significant effect on atmospheric optical properties, visibility and multiphase chemical reactions. In this study, ALWC is determined from aerosol hygroscopic growth factor and particle number size distribution (PNSD) measurements and also simulated by the ISORROPIA II thermodynamic model with measured aerosol chemical composition data at an urban site in Beijing from 8 November to 15 December 2017. Rich measurements made during the experiment concerning virtually all aerosol properties allow us not only to derive the ALWC but also to study the contributions by various species for which little has been done in this region. The simulated ALWC including the contribution of organics and the calculated ALWC are highly correlated (coefficient of determination R2 = 0.92). The ALWC contributed by organics (ALWCOrg) accounts for 30 % ± 22 % of the total ALWC during the sampling period. These results suggest a significant contribution of organics to ALWC, which is rather different from previous studies that showed negligible contributions by organics. Our results also show that ALWC correlates well with the mass concentrations of sulfate, nitrate, and secondary organic aerosols (SOA) (R2 = 0.66, 0.56, and 0.60, respectively). We further noted that accumulation mode particles play a key role in determining ALWC, dominating among all the aerosol modes. ALWC is an exponential function of ambient relative humidity (RH) whose strong diurnal variation influence the diurnal variation of ALWC. However, there is a three-hour lag between the extremes of ALWC and RH values, due to the diurnal variations in PNSD and aerosol chemical composition. Finally, a case study reveals that ALWCOrg plays an important role in the formation of secondary aerosols through multiphase reactions at the initial stage of a heavy haze episode.

[1]  J. Veefkind,et al.  Humidity dependence of the light scattering by mixtures of ammonium nitrate, ammonium sulfate and soot , 1996 .

[2]  R. Robinson,et al.  Interactions in Aqueous Nonelectrolyte Solutions. I. Solute-Solvent Equilibria , 1966 .

[3]  P. Paatero,et al.  Evaluation of an automatic algorithm for fitting the particle number size distributions , 2005 .

[4]  Kebin He,et al.  Heterogeneous chemistry: a mechanism missing in current models to explain secondary inorganic aerosol formation during the January 2013 haze episode in North China , 2014 .

[5]  B. Turpin,et al.  Secondary organic aerosol formation in cloud droplets and aqueous particles (aqSOA): a review of laboratory, field and model studies , 2011 .

[6]  M. Salter,et al.  Revising the hygroscopicity of inorganic sea salt particles , 2017, Nature Communications.

[7]  Erik Swietlicki,et al.  A closure study of sub-micrometer aerosol particle hygroscopic behaviour , 1999 .

[8]  A. Frey,et al.  Chemical characterization of submicron Aerosol particles in Santiago de Chile , 2013 .

[9]  P. Paatero,et al.  Positive matrix factorization: A non-negative factor model with optimal utilization of error estimates of data values† , 1994 .

[10]  J. Thornton,et al.  N2O5 hydrolysis on sub-micron organic aerosols: the effect of relative humidity, particle phase, and particle size , 2003 .

[11]  Barbara J. Turpin,et al.  Secondary organic aerosol formation in cloud and fog droplets: a literature evaluation of plausibility , 2000 .

[12]  K. T. Whitby.  THE PHYSICAL CHARACTERISTICS OF SULFUR AEROSOLS , 1978 .

[13]  J. Mao,et al.  Aerosol pollution and air mass history in Beijing, China , 2008 .

[14]  Qi Zhang,et al.  Liquid water: Ubiquitous contributor to aerosol mass , 2016 .

[15]  R. Volkamer,et al.  Potential of Aerosol Liquid Water to Facilitate Organic Aerosol Formation: Assessing Knowledge Gaps about Precursors and Partitioning. , 2017, Environmental science & technology.

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

[17]  D. Worsnop,et al.  Effects of Aqueous-Phase and Photochemical Processing on Secondary Organic Aerosol Formation and Evolution in Beijing, China. , 2017, Environmental science & technology.

[18]  Yan Yin,et al.  Aerosol and monsoon climate interactions over Asia , 2016 .

[19]  A. Nenes,et al.  ISORROPIA II: a computationally efficient thermodynamic equilibrium model for K + –Ca 2+ –Mg 2+ –NH 4 + –Na + –SO 4 2− –NO 3 − –Cl − –H 2 O aerosols , 2007 .

[20]  J. Li,et al.  Rapid formation and evolution of an extreme haze episode in Northern China during winter 2015 , 2016, Scientific Reports.

[21]  J. Seinfeld,et al.  General circulation model assessment of direct radiative forcing by the sulfate-nitrate-ammonium-water inorganic aerosol system , 2001 .

[22]  Significant contribution of organics to aerosol liquid water content in winter in Beijing, China , 2020 .

[23]  Fang Zhang,et al.  Persistent sulfate formation from London Fog to Chinese haze , 2016, Proceedings of the National Academy of Sciences.

[24]  John H. Seinfeld,et al.  Global impacts of gas‐phase chemistry‐aerosol interactions on direct radiative forcing by anthropogenic aerosols and ozone , 2005 .

[25]  Nan Ma,et al.  A parameterization of low visibilities for hazy days in the North China Plain , 2012 .

[26]  Zhanqing Li,et al.  Estimating 1-km-resolution PM2.5 concentrations across China using the space-time random forest approach , 2019, Remote Sensing of Environment.

[27]  M. Mochida,et al.  Assessment of the aerosol water content in urban atmospheric particles by the hygroscopic growth measurements in Sapporo, Japan , 2009 .

[28]  Sonia M. Kreidenweis,et al.  A single parameter representation of hygroscopic growth and cloud condensation nucleus activity – Part 3: Including surfactant partitioning , 2012 .

[29]  A. Wexler,et al.  Atmospheric aerosol models for systems including the ions H+, NH4+, Na+, SO42−, NO3−, Cl−, Br−, and H2O , 2002 .

[30]  Rodney J. Weber,et al.  Enhanced secondary organic aerosol formation due to water uptake by fine particles , 2008 .

[31]  D. Blake,et al.  Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact , 2010 .

[32]  Chunsheng Zhao,et al.  Deliquescent phenomena of ambient aerosols on the North China Plain , 2016 .

[33]  Yele Sun,et al.  Aerosol composition, sources and processes during wintertime in Beijing, China , 2013 .

[34]  A. Nenes,et al.  Hygroscopicity and composition of Alaskan Arctic CCN during April 2008 , 2011 .

[35]  A. Piazzalunga,et al.  High secondary aerosol contribution to particulate pollution during haze events in China , 2014, Nature.

[36]  Alfred Wiedensohler,et al.  Atmospheric particle number size distribution in central Europe: Statistical relations to air masses and meteorology , 2001 .

[37]  C. Sioutas,et al.  Exceeding of Henry's law by hydrogen peroxide associated with urban aerosols. , 2006, Environmental science & technology.

[38]  Zhanqing Li,et al.  Enhanced hydrophobicity and volatility of submicron aerosols under severe emission control conditions in Beijing , 2017, Atmospheric Chemistry and Physics.

[39]  Charles E. Kolb,et al.  Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer , 2003 .

[40]  Armin Sorooshian,et al.  Evidence for organosulfates in secondary organic aerosol. , 2007, Environmental science & technology.

[41]  B. Wehner,et al.  Aerosol number size distribution and new particle formation at a rural/coastal site in Pearl River Delta (PRD) of China , 2008 .

[42]  Hugh Coe,et al.  A curved multi-component aerosol hygroscopicity model framework: Part 1 Inorganic compounds , 2005 .

[43]  J. Thornton,et al.  Quantifying trace gas uptake to tropospheric aerosol: recent advances and remaining challenges. , 2012, Chemical Society reviews.

[44]  Hongyu Guo,et al.  On the link between hygroscopicity, volatility, and oxidation state of ambient and water-soluble aerosols in the southeastern United States , 2014 .

[45]  T. Zhu,et al.  High N2O5 Concentrations Observed in Urban Beijing: Implications of a Large Nitrate Formation Pathway , 2017 .

[46]  Kebin He,et al.  Reactive nitrogen chemistry in aerosol water as a source of sulfate during haze events in China , 2016, Science Advances.

[47]  Fei Li,et al.  An analysis of aerosol liquid water content and related impact factors in Pearl River Delta. , 2017, The Science of the total environment.

[48]  J. Thornton,et al.  Toward a general parameterization of N 2 O 5 reactivity on aqueous particles: the competing effects of particle liquid water, nitrate and chloride , 2009 .

[49]  J. Seinfeld,et al.  Atmospheric Gas-Aerosol Equilibrium I. Thermodynamic Model , 1993 .

[50]  Bian He,et al.  Advances in studying interactions between aerosols and monsoon in China , 2015, Science China Earth Sciences.

[51]  Yuanhang Zhang,et al.  Aerosol Liquid Water Driven by Anthropogenic Inorganic Salts: Implying Its Key Role in Haze Formation over the North China Plain , 2018 .

[52]  C. Stanier,et al.  A Method for the In Situ Measurement of Fine Aerosol Water Content of Ambient Aerosols: The Dry-Ambient Aerosol Size Spectrometer (DAASS) Special Issue of Aerosol Science and Technology on Findings from the Fine Particulate Matter Supersites Program , 2004 .

[53]  A. Wahner,et al.  Heterogeneous reaction of N2O5 on sodium nitrate aerosol , 1998 .

[54]  Meigen Zhang,et al.  Emission controls versus meteorological conditions in determining aerosol concentrations in Beijing during the 2008 Olympic Games , 2011 .

[55]  Zhanqing Li,et al.  Impact of aerosols on convective clouds and precipitation , 2012, Reviews of Geophysics.

[56]  Yuxuan Wang,et al.  Enhanced sulfate formation during China's severe winter haze episode in January 2013 missing from current models , 2014 .

[57]  M. Facchini,et al.  Aerosol liquid water driven by anthropogenic nitrate: implications for lifetimes of water-soluble organic gases and potential for secondary organic aerosol formation. , 2014, Environmental science & technology.

[58]  B. Turpin,et al.  Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water , 2013 .

[59]  C. Chen,et al.  “APEC Blue”: Secondary Aerosol Reductions from Emission Controls in Beijing , 2016, Scientific Reports.

[60]  M. Petters,et al.  A single parameter representation of hygroscopic growth and cloud condensation nucleus activity , 2006 .

[61]  S. Pandis,et al.  Prediction of multicomponent inorganic atmospheric aerosol behavior , 1999 .

[62]  Jian Wang,et al.  CCN Activity of Organic Aerosols Observed Downwind of Urban Emissions during CARES , 2013 .

[63]  J. Chen,et al.  A study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain , 2014 .

[64]  J. R. Hite,et al.  monoterpenes in the southeastern United States , 2014 .

[65]  Pasi Aalto,et al.  Atmospheric Chemistry and Physics Discussions , 2001 .

[66]  S. Sjogrena,et al.  Hygroscopic growth and water uptake kinetics of two-phase aerosol particles consisting of ammonium sulfate, adipic and humic acid mixtures , 2007 .

[67]  A. Nenes,et al.  ISORROPIA: A New Thermodynamic Equilibrium Model for Multiphase Multicomponent Inorganic Aerosols , 1998 .

[68]  A. Wiedensohler,et al.  An approximation of the bipolar charge distribution for particles in the submicron size range , 1988 .

[69]  Chunsheng Zhao,et al.  A novel method for calculating ambient aerosol liquid water content based on measurements of a humidified nephelometer system , 2017 .

[70]  S. Pandis,et al.  Water content of aged aerosol , 2010 .

[71]  Ying Wang,et al.  Chemical characteristics of PM2.5 and PM10 in haze-fog episodes in Beijing. , 2006, Environmental science & technology.

[72]  Jonathan Crosier,et al.  © Author(s) 2007. This work is licensed under a Creative Commons License. Atmospheric Chemistry and Physics A revised linear ozone photochemistry parameterization for use in transport and general circulation models: multi-annual simulations , 2006 .