Influence of the Surf Zone on the Marine Aerosol Concentration in a Coastal Area

Sea-salt aerosol concentrations in the coastal zone are assessed with the numerical aerosol-transport model MACMod that applies separate aerosol source functions for open ocean and the surf zone near the sea–land transition. Numerical simulations of the aerosol concentration as a function of offshore distance from the surf zone compare favourably with experimental data obtained during a surf-zone aerosol experiment in Duck, North Carolina in autumn 2007. Based on numerical simulations, the effect of variations in aerosol production (source strength) and transport conditions (wind speed, air–sea temperature difference), we show that the surf-zone aerosols are replaced by aerosols generated over the open ocean as the airmass advects out to sea. The contribution from the surf-generated aerosol is significant during high wind speeds and high wave events, and is significant up to 30 km away from the production zone. At low wind speeds, the oceanic component dominates, except within 1–5 km of the surf zone. Similar results are obtained for onshore flow, where no further sea-salt aerosol production occurs as the airmass advects out over land. The oceanic aerosols that are well-mixed throughout the boundary layer are then more efficiently transported inland than are the surf-generated aerosols, which are confined to the first few tens of metres above the surface, and are therefore also more susceptible to the type of surface (trees or grass) that determines the deposition velocity.     

基于航测的珠三角气溶胶垂直分布及活化特性

2017年9月14—27日在珠江三角洲地区开展了6个架次飞机观测试验。利用飞行获取的气溶胶、云凝结核、云滴及常规气象探头观测资料,结合天气形势、气象条件及气团后向轨迹分析,研究了珠江三角洲地区深圳气溶胶数浓度及其谱的垂直分布特征,配合不同过饱和度条件下云凝结核浓度观测,分析了气溶胶活化特性。结果表明:在不同天气条件下,深圳低层气溶胶数浓度变化范围为500~9000 cm-3;边界层内气溶胶分布相对均匀,谱型随高度变化与气象条件相关。将6个架次气溶胶观测资料根据数浓度及谱型分为3种类型:类型Ⅰ为海洋型气溶胶,数浓度小,粒子尺度大,谱型呈双峰分布;类型Ⅲ为大陆型气溶胶,数浓度高,粒子尺度小,谱宽较宽且呈三峰分布;类型Ⅱ为海洋大陆影响型气溶胶,即受海洋和大陆共同影响,数浓度低于类型Ⅲ高于类型Ⅰ,谱型为双峰分布。拟合了包含海洋型及大陆型气溶胶的3个架次近地面云凝结核活化谱,计算了气溶胶在不同过饱和度条件下的活化效率。     

Airborne Observations of Cloud Condensation Nuclei Spectra and Aerosols over East Inner Mongolia

A set of vertical profiles of aerosol number concentrations, size distributions and cloud condensation nuclei(CCN)spectra was observed using a passive cloud and aerosol spectrometer(PCASP) and cloud condensation nuclei counter, over the Tongliao area, East Inner Mongolia, China. The results showed that the average aerosol number concentration in this region was much lower than that in heavily polluted areas. Monthly average aerosol number concentrations within the boundary layer reached a maximum in May and a minimum in September, and the variations in CCN number concentrations at different supersaturations showed the same trend. The parameters c and k of the empirical function N = c S~kwere 539 and1.477 under clean conditions, and their counterparts under polluted conditions were 1615 and 1.42. Measurements from the airborne probe mounted on a Yun-12(Y12) aircraft, together with Hybrid Single-Particle Lagrangian Integrated Trajectory model backward trajectories indicated that the air mass from the south of Tongliao contained a high concentration of aerosol particles(1000–2500 cm~(-3)) in the middle and lower parts of the troposphere. Moreover, detailed intercomparison of data obtained on two days in 2010 indicated that the activation efficiency in terms of the ratio of NCCNto N_a(aerosols measured from PCASP) was 0.74(0.4 supersaturations) when the air mass mainly came from south of Tongliao, and this value increased to 0.83 on the relatively cleaner day. Thus, long-range transport of anthropogenic pollutants from heavily polluted mega cities,such as Beijing and Tianjin, may result in slightly decreasing activation efficiencies.     

华北中部夏季气溶胶垂直分布及其与云凝结核和云滴转化关系的飞机观测研究

气溶胶的时空分布及其核化成云的转化过程是云降水物理研究的重点,也是气候变化中气溶胶间接效应关注的热点问题。利用2013～2014年期间在华北中部山西地区开展的9架次夏季晴天和积云天气情况下的气溶胶、云凝结核（CCN）及云滴数浓度观测资料,分析研究了气溶胶的垂直分布、谱分布、来源特征及其与云凝结核、云滴数浓度的转化关系。研究结果表明,大气边界层逆温层结对气溶胶、CCN垂直分布有重要影响,不同天气条件下气溶胶谱型在低层差异较大而高层基本一致;垂直方向上CCN数浓度与气溶胶数浓度有较好的相关性,过饱和度0.3%条件下CCN比率（云凝结核/凝结核）与气溶胶有效直径呈线性关系;积云云下气溶胶与云滴的线性拟合方程为y=1.3x?616.3,拟合相关系数为0.96,气溶胶转化为云滴的比率可达到47%。在过饱和度0.3%条件下,云下CCN与云滴的线性拟合方程为y=1.6x?473.8,拟合相关系数也为0.96,CCN转化为云滴的比率可达到69%。     

Assessment of Individual Direct Radiative Effects of Major Aerosol Species in East Asia

To assess individual direct radiative effects of diverse aerosol species on a regional scale,the air quality modeling system RAMS-CMAQ(Regional Atmospheric Modeling System and Community Multiscale Air Quality) coupled with an aerosol optical properties/radiative transfer module was used to simulate the temporal and spatial distributions of their optical and radiative properties over East Asia throughout 2005.Annual and seasonal averaged aerosol direct radiative forcing(ADRF) of all important aerosols and individual components,such as sulfate,nitrate,ammonium,black carbon(BC),organic carbon(OC),and dust at top-of-atmosphere(TOA) in clear sky are analyzed.Analysis of the model results shows that the annual average ADRF of all important aerosols was in the range of 0 to-18 W m?2,with the maximum values mainly distributed over the Sichuan Basin.The direct radiative effects of sulfate,nitrate,and ammonium make up most of the total ADRF in East Asia,being concentrated mainly over North and Southeast China.The model domain is also divided into seven regions based on different administrative regions or countries to investigate detailed information about regional ADRF variations over East Asia.The model results show that the ADRFs of sulfate,ammonium,BC,and OC were stronger in summer and weaker in winter over most regions of East Asia,except over Southeast Asia.The seasonal variation in the ADRF of nitrate exhibited the opposite trend.A strong ADRF of dust mainly appeared in spring over Northwest China and Mongolia.     

Anthropogenic Aerosol Pollution over the Eastern Slope of the Tibetan Plateau

In this study, a combination of satellite observations and reanalysis datasets is used to analyze the spatiotemporal distribution, classification and source of pollutants over the eastern slope of the Tibetan Plateau(ESTP). The aerosol optical depth(AOD) over the ESTP is extremely large and even larger than some important industrialized regions and deserts. The main aerosol component over the ESTP is sulfate, followed by carbonaceous and dust aerosols. Local emissions related to human activity directly contribute to the accumulation of sulfate and carbonaceous aerosols over the Sichuan Basin. In addition, in spring, abundant carbonaceous aerosols emitted from forest, grassland and savanna fires in Southeast Asia can be transported by the prevailing southwesterly wind to southern China and the ESTP. The dust AOD over the ESTP peaks in spring because of the transport from the Taklimakan and Gobi deserts. Additionally, the high aerosol loading over the ESTP is also directly related to the meteorological background. Due to the special topography, the terrain-driven circulation can trap aerosols in the Sichuan Basin and these aerosols can climb along the ESTP due to the perennial updraft. The aerosol loading is lowest in summer because of effective wet deposition induced by the strong precipitation and better dispersion conditions due to the larger vertical temperature gradients and ascending air movement enhanced by the plateau heat pump effect. In contrast,the aerosol loading is greatest in winter. Abundant anthropogenic aerosols over the ESTP may generate some climatic and environmental risks and consequently greatly influence the downstream regions.     

华北地区一次气溶胶与浅积云微物理特性的飞机观测研究

2014年8月15日,山西省人工降雨防雹办公室在山西忻州开展了气溶胶和浅积云的飞机观测,本文利用机载云物理资料,详细分析了华北地区气溶胶、云凝结核(CCN)和浅积云微物理特性及其相互影响.主要结论有:(1)此次过程的边界层高度约为3600 m,不同层结情况下,0.1～3μm尺度范围内的气溶胶粒子浓度Na、有效直径Da和...     

华北及其周边地区秋季气溶胶光学性质的星载和地基遥感观测

利用2004～2009年秋季臭氧监测仪的3级观测资料,分析了华北及周边地区的气溶胶光学性质。结果表明:大部分区域气溶胶光学厚度(Aerosol Optical Depth,AOD)和气溶胶紫外吸收指数(Ultra Violet Aerosol Index,UVAI)平均值分别高于0.8和0.75;高气溶胶事件发生频次统计表明,AOD高值(>0.4)频发于北京及其周边地区,UVAI高值(>1.0)频发于河北中部及南部地区;华北及其周边地区绝大多数城市平均AOD和UVAI分别高于0.7和0.60,而张家口、承德和阳泉3个城市的平均AOD和UVAI值分别低于0.6和0.65。作者进一步研究了2006年10月30日的一次霾事件中气溶胶的光学性质以及其时空分布特征。结果表明,霾由华北地区输送至渤海海域,并向东北方向输送;香河地基EZlidar激光雷达的垂直观测结果进一步表明,工业和城市型气溶胶主要集中在1500m以下,其中高浓度部分集中于650m以下,平均峰值位于285m,平均消光系数达2.15km-1;CALIOP卫星观测资料结合后向轨迹分析表明,大气低层气溶胶类型以工业和城市型气溶胶为主,而高层则由于上游大气输送沙尘粒子的混入使气溶胶类型转变为污染—沙尘型。霾事件期间,香河站CE-318太阳光度计观测的AOD平均值(标准差)从背景值0.08(0.04)升高至1.17(0.14);ngstrm指数平均值(标准差)从背景值0.90(0.10)升至1.12(0.09);核模态、积聚模态和粗模态的气溶胶粒子数柱总量均增加,其中细粒子所占比例明显升高。     

Aerosol Properties and Their Impacts on Surface CCN at the ARM Southern Great Plains Site during the 2011 Midlatitude Continental Convective Clouds Experiment

Aerosol particles are of particular importance because of their impacts on cloud development and precipitation processes over land and ocean. Aerosol properties as well as meteorological observations from the Department of Energy Atmospheric Radiation Measurement(ARM) platform situated in the Southern Great Plains(SGP) are utilized in this study to illustrate the dependence of continental cloud condensation nuclei(CCN) number concentration(NCCN) on aerosol type and transport pathways. ARM-SGP observations from the 2011 Midlatitude Continental Convective Clouds Experiment field campaign are presented in this study and compared with our previous work during the 2009–10 Clouds, Aerosol, and Precipitation in the Marine Boundary Layer field campaign over the current ARM Eastern North Atlantic site. Northerly winds over the SGP reflect clean, continental conditions with aerosol scattering coefficient(σ_(sp)) values less than 20 Mm~(-1) and NCCNvalues less than 100 cm~(-3). However, southerly winds over the SGP are responsible for the observed moderate to high correlation(R)among aerosol loading(σ_(sp) 60 Mm~(-1)) and NCCN, carbonaceous chemical species(biomass burning smoke), and precipitable water vapor. This suggests a common transport mechanism for smoke aerosols and moisture via the Gulf of Mexico,indicating a strong dependence on air mass type. NASA MERRA~(-2) reanalysis aerosol and chemical data are moderately to highly correlated with surface ARM-SGP data, suggesting that this facility can represent surface aerosol conditions in the SGP, especially during strong aerosol loading events that transport via the Gulf of Mexico. Future long-term investigations will help to understand the seasonal influences of air masses on aerosol, CCN, and cloud properties over land in comparison to over ocean.     

A Modeling Study of Seasonal Variation of Atmospheric Aerosols over East Asia

In this study, a regional air quality model system (RAQMS) was applied to investigate the spatial distributions and seasonal variations of atmospheric aerosols in 2006 over East Asia. Model validations demonstrated that RAQMS was able to reproduce the evolution processes of aerosol components reasonably well. Ground-level PM₁₀ (particles with aerodynamic diameter ≤10 μm) concentrations were highest in spring and lowest in summer and were characterized by three maximum centers: the Taklimakan Desert (～1000 μg m^-3), the Gobi Desert (～400 μg m^-3), and the Huabei Plain (～300 μm^-3) of China. Vertically, high PM₁₀ concentrations ranging from 100 μg m^-3 to 250 μg m^-3 occurred from the surface to an altitude of 6000 m at 30^o--45^oN in spring. In winter, the vertical gradient was so large that most aerosols were restricted in the boundary layer. Both sulfate and ammonium reached their highest concentrations in autumn, while nitrate reached its maximum level in winter. Black carbon and organic carbon aerosol concentrations reached maximums in winter. Soil dust were strongest in spring, whereas sea salt exerted the strongest influence on the coastal regions of eastern China in summer. The estimated burden of anthropogenic aerosols was largest in winter (1621 Gg) and smallest in summer (1040 Gg). The sulfate burden accounted for ～42% of the total anthropogenic aerosol burden. The dust burden was about twice the anthropogenic aerosol burden, implying the potentially important impacts of the natural aerosols on air quality and climate over East Asia.     

基于飞机和MODIS观测的华北地区气溶胶标高分析

为研究华北地区的气溶胶分布情况,利用2012—2014年飞机观测资料和MODIS卫星资料,对石家庄等地的气溶胶标高进行了分析。结果表明:(1)与飞机观测资料对比后认为可以利用MODIS光学厚度和常规能见度资料计算气溶胶标高;(2)华北地区春夏季气溶胶标高一般大于秋冬季;6个主要城市中,位于平原地区的城市气溶胶标高较低,西北山区城市标高较高;(3)在不进行飞行探测,仅使用地面资料和卫星资料,通过计算得到气溶胶垂直分布是可行的,尤其是在对流层中层的结果比底层更可信;(4)分别使用观测资料与拟合数据计算光学厚度,分析其误差后,确认在计算光学厚度的过程中可以使用气溶胶数密度指数递减假设。     

华北中部夏季气溶胶和云分布特征

气溶胶与云的垂直分布特征是气溶胶间接气候效应关注的重点。基于2018年7—8月华北中部6架次飞机观测数据,研究气溶胶和云滴的垂直和水平分布特征。结果表明:华北中部780~5687 m高度内气溶胶数浓度( N_a )平均值为821.36 cm-3,最大量级可达到104 cm-3,云中气溶胶数浓度(N_acc)占总颗粒浓度的80%以上,表明细颗粒占大多数,气溶胶粒子算术平均直径( D_m )平均值为0.12~0.52 μm;大气层结对气溶胶垂直分布影响较大,逆温阻挡气溶胶垂直输送,高空(高度2000 m以上) D_m 的垂直分布受到相对湿度影响较大; N_a 和 D_m 在垂直方向波动较大,水平方向波动较小;低层云中云滴数浓度(N_c)较大、液态水含量(L)较小,而中层和高层云中N_c较小、L较大,N_c和云滴有效半径(R_e)的概率密度函数均为双峰型分布,L的概率密度函数为单峰型分布;气溶胶数浓度谱基本呈现多峰型分布,而云滴数浓度谱多呈现单峰型分布。     

西北地区气溶胶光学特性及辐射影响

利用SACOL（兰州大学半干旱气候与环境观测站）2006~2012年AERONET（全球气溶胶自动监测网）level 2.0和太阳短波辐射计资料,分析了中国西北地区气溶胶的光学特性与辐射影响。利用辐射传输模式SBDART（平面平行大气辐射传输模式）检验TOA（大气层顶）处辐射强迫为正的原因。BOA（地表）、TOA、Atmosphere（大气）的辐射强迫年均值分别是-59.43 W m-2、-17.03 W m-2、42.40 W m-2,AOD（光学厚度,550 nm）年均值0.37,α（波段的波长指数,440~675 nm）年均值0.91,变化趋势与AOD位相相反,当AOD为0.3~2.2时,α很小（0.0~0.2）,表明粒子尺度很大。SSA（单次散射反照率,675 nm）年均值0.93,g（不对称因子,675 nm）年均值0.68,复折射指数（675 nm）实部年均值1.48,虚部0.007。复折射指数实部的年变化趋势与AOD一致,虚部与AOD反位相,所以西北地区多为粗模态散射性气溶胶。气溶胶对大气的加热率最大值出现在0~2 km,随高度递减。冬、夏半年在地表加热率分别是2.6 K d-1和0.6 K d-1;季节变化中,冬季、秋季、春季和夏季,在地表的加热率依次是2.5 K d-1、1.4 K d-1、1.2 K d-1和0.2 K d-1,主要因为秋季气溶胶的吸收性大于春季。地表反照率和SSA对TOA正辐射强迫贡献率分别是22.5%和77.5%。     

环球海洋大气气溶胶化学研究 III：金属形态和入海通量

中国第三次南极考察和环球科学考察，历经北太平洋、南太平洋、南极半岛海域、南大西洋、北印度洋、以及沿途近岸海域，共收集58个气溶胶样品，采用石墨炉原子吸收法分析其中的水可溶态和酸可溶态的Mn、Fe、Pb、Cu、Cd。气溶胶中金属表现明显陆源向大洋输送的浓度梯度，近岸海域上空金属含量大于大洋上空含量，北太平洋上空含量高于南太平洋和南极半岛海域。气溶胶中金属的水可溶程度，在近岸海域上空依次为Cd＞Mn＞Cu＞Fe＞Pb，百分比分量分别为39%，36%， 23%，14%和5.3%；在大洋上空依次为Cd＞Mn＞Fe＞Cu＞pb，百分比分量分别为62%，44%，11%，3.1%和2.5%。本文还计算和比较各观测海区上空金属从大气输入海水的通量。     

北京PM1中的化学组成及其控制对策思考

通过分析北京城区2007年夏季和秋季、2008年冬季和春季4个季节PM₁中硫酸盐、硝酸盐、铵盐、有机物和黑碳等气溶胶化学组成,结合对我国及全球主要区域PM₁₀中上述气溶胶组分及矿物气溶胶组成的评估,发现因受干旱区产生的沙尘和城市逸散性粉尘的共同影响,整个亚洲大陆,尤其是我国的矿物气溶胶浓度与欧美国家城市区域气溶胶总和的平均值相当或更高。我国在重视控制PM_2.5等细粒子污染的同时,不应忽视对PM_2.5~PM₁₀之间粗粒子的控制力度;北京城区春、夏、秋、冬的PM₁平均质量浓度分别约为94,74,66 μg·m-3和91 μg·m-3,全年平均约为81 μg·m-3,其中有机物气溶胶约占41%,硫酸盐占16%,硝酸盐占13%,铵盐占8%,黑碳和氯化物分别占11%和3%,细矿物气溶胶约贡献7%。对于PM_2.5污染的控制,关键是消减PM₁中主要气溶胶粒子的排放与转化,其中对有机物的控制更为重要,尽管对于北京而言进一步污染控制的难度已经很大。从科学上来说,即使我国的控制措施能百分之百实现,也很难稳定地达到欧美国家的空气质量水平,因为我国本底矿物气溶胶的浓度较高。应进一步评估各项控制措施的适用性,并制定考虑我国人群健康状况的PM_2.5空气质量标准。     

近10年东亚沙尘气溶胶时空分布与起尘通量的数值研究

利用一个耦合了沙尘模型的区域气候模式RegCM3和NCEP再分析资料,对近10年(2000-2009年)东亚地区沙尘气溶胶(直径≤20μm)时空分布特征和起尘通量进行了数值模拟。结果表明,(1)耦合模式能较好地模拟东亚地区沙尘气溶胶的时空分布特点。东亚地区沙尘气溶胶光学厚度、柱含量高值区主要位于塔克拉玛干沙漠和巴丹吉林沙漠。沙尘气溶胶柱含量的季节变化特征明显,春季最大,冬季次之,秋季最小。东亚地区110°E以东,沙尘主要以700hPa高度为中心向东传输。(2)东亚地区起沙源区主要位于塔克拉玛干沙漠、巴丹吉林沙漠、藏北沙漠化地区及蒙古国西南部,起沙强度存在明显的季节变化。2000-2009年东亚地区年平均起沙通量为1015.34mg.m-2.d-1,其中62.4%和2.3%分别通过干、湿过程重新沉降在东亚地区,其余35.3%被净释放进入大气或进行远距离传输。     

近22 a人为气溶胶对东亚地区夏季风环流影响的数值模拟研究

运用区域气候模式RegCM3耦合入一个化学过程,对东亚地区三类人为排放气溶胶（硫酸盐、黑碳和有机碳）的时空分布特征及其对夏季风环流的影响进行了数值模拟研究。模拟结果显示,气溶胶的引入会引起东亚地区夏季850 hPa风场发生改变,我国江淮以东洋面上空出现了一个气旋式距平环流中心,中心以西的偏北风气流将削弱东亚地区夏季西南季风。通过讨论春季中国地区气溶胶浓度与夏季东亚地区850 hPa经向风的时滞关系,以及夏季中国地区气溶胶浓度与同期东亚地区850 hPa经向风的关系,可以发现,春、夏季中国地区气溶胶浓度均与夏季东亚地区850 hPa经向风有很好的负相关关系,当春季中国北方和夏季中国南方地区气溶胶浓度增加时,中国东部地区夏季偏南季风减弱。这可能与气溶胶改变了大气层顶和地表的辐射强迫,进而引起了海陆气压差异和位势高度场的变化有关。     

Identification of Aerosol Types and Their Optical Properties in the North China Plain Based on Long-Term AERONET Data

Characterization of aerosols is required to reduce uncertainties in satellite retrievals of global aerosols and for modeling the effects of these aerosols on climate.Aerosols in the North China Plain(NCP) are complex,which provides a good opportunity to study key aerosol optical properties for various aerosol types.A cluster analysis of key optical properties obtained from Aerosol Robotic Network(AERONET) data in Beijing and Xianghe during 2001-11 was performed to identify dominant aerosol types and their associated optical properties.Five dominant aerosol types were identified.The results show that the urban/industrial aerosol of moderate absorption was dominant in the region and that this type varied little with season.Urban/industrial aerosol of weak absorption was the next most common type and mainly occurs in summer,followed by that strong aerosols occurring mainly in winter.All were predominantly fine mode particles.Mineral dust(MD) and polluted dust(PD) occurred mainly in spring,followed by winter,and their absorption decreased with wavelength.In addition,aerosol dynamics and optical parameters such as refractive index and asymmetry factor were examined.Results show that the size of coarse mode particles decreased with AOD indicating the domination of external mixing between aerosols.     

Observations of Cloud Condensation Nuclei in North China

Using a DMT （Droplet Measurement Technologies） continuous flow streamwise thermal gradient cloud condensation nuclei （CCN） counter mounted on a Cheyenne IIIA aircraft, about 20 flights for aircraft mea- surements of CCN over North China were conducted in the autumn of 2005 and spring of 2006. According to the design for aircraft observation, the method of spiral ascent or descent in the troposphere was used for the vertical measurement of CCN, and some certain levels were chosen for horizontal measurement. The vertical distributions of CCN concentrations show that most CCN particles are concentrated in the low level of troposphere and CCN concentration decreased with height increasing. It suggests that the main source of CCN is from the surface. This result is consistent with former studies during 1983-1985 in China with a static thermal gradient CCN counter. The comparison of vertical observations between polluted rural area near Shijiazhuang and non-polluted rural area near Zhangjiakou shows that there is about five times difference in CCN concentration. But over two polluted cities, Shijiazhuang and Handan, there is no notable difference in CCN concentration. The horizontal flight measurements for penetrating the cumulus clouds experiment show the apparent decrease of CCN in clouds. It confirms that cloud has a definite consumptive effect on CCN particles because some CCN particles can form cloud droplets. The surface measurements of CCN in Shijiazhuang City were made during June-August 2005. The statistical CCN data show the great difference in concentration at the same supersaturation （S） in Shijiazhuang summertime. The minimum CCN concentrations were 584, 808, and 2431 cm-3, and the maximum concentrations were 9495, 16332, and 21812 cm-3 at S=0.1%, 0.3%, and 0.5%, respectively. CCN has a diurnal variation cycle. From 0600 BT, the concentration began to increase and reached the maximum at about noon. Then it generally decreased throughout the afternoon. The reason maybe is related to the onset o     

Ship measurements of submicron aerosol size distributions over the Yellow Sea and the East China Sea

During the spring of 2005, the total particle concentrations and the submicron aerosol size distributions were measured on board the research vessel over the south sea of Korea and the Korean sector of the Yellow Sea. Similar measurements were made over the East China Sea in autumn 2005. The aerosol properties varied dynamically according to the meteorological conditions, the proximity to the land masses and the air mass back trajectories. The average total particle concentration was the lowest over the East China Sea, 4335 ± 2736 cm^− 3, but the instantaneous minimum, 837 cm^− 3, for the entire ship measurement was recorded during the Yellow Sea cruise. There was also a long (more than 6 h) stretch of low total particle concentrations that fell as low as 1025 cm^− 3 during the East China Sea cruise when the ship was the farthest from the shores and the air mass back trajectories resided long hours over the sea. These observations lead to the suggestion of ~ 1000 cm^− 3 as the background total particle concentration over the marine boundary layer in the studied region of the Yellow Sea and the East China Sea, implying significant anthropogenic influence even for the background value. In the mean time, average aerosol size distributions were unimodal and the mode diameter ranged between 52 and 86 nm, excluding the fog periods, which suggests that the aerosols measured in this study experienced relatively less aging processes within the marine boundary layer.