The chemical characteristics of aerosols in the Kuroshio area——Ⅰ. Sources and fluxes

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Non-sea-salt sulfate in the marine boundary layer and its possible impact on chloride depletion

1Introduction Sulfurisoneofthemostimportantelements whosebiogeochemicalcyclesarepivotaltotheatmo- sphericenvironmentandtotheclimaticchanges.The predominant,stablechemicalspeciesofsulfurinthe atmosphereissulfuricacidorsulfatewhichunderor- dinaryconditionsexistsmainlyinsmallaerosolparti- cles(Chinetal.,1996;Kerminenetal.,2000;Restadet al.,1998).Sulfuricacidorsulfate-dominatedaerosols areubiquitousintheloweratmosphere.Inthemarine boundarylayer(MBL),non-sea-saltsulfuricacidorsulfate(nss-SO42-)…     

Preliminary study on concentrations and size distribution of marine aerosols over the East China Sea

In summer and winter, 1987,and in spring and autumn, 1988, the concentrations and size distribution of marine aerosols were measured over the East China Sea and the South Japan Sea. This paper deals with the study on the seasonal variation of the marine aerosols with the meteorological parameters, the differences and the relations between the marine and continental aerosols. The results show that the marine aerosol concentrations and size distribution over the East China Sea have distinct seasonal change characteristics, which may be attributed to the East Asian atmospheric circulation. The size distribution is discussed by using a three-parameter size distribution model.     

海洋大气气溶胶的采集和中子活化分析的应用

本工作应用带有风向风速自动控制的M241大容量空气颗粒采样器,采集了海洋大气中的气溶胶,采用中子活化分析方法,分析了样品中的重金属元素。结果表明,该采样系统具有较准确的流量测定,较均匀的样品捕集,适应于海洋大气气溶胶样品分析,中子活化分析可同时测定海洋大气中Na、Al、V 等不同来源指示元素。     

The Increase of Biogenic Sulfate Aerosol and Particle Number in Marine Atmosphere over the Northwestern North Pacific

During a cruise aboard the R/V Hakuho-maru in the northwestern North Pacific in the summer of 1998 the particle number concentrations and the major ionic components of size fractionated aerosols were measured to investigate the aerosol produced by marine biological activity. Continuous low concentrations of nitrate (<1.8 nmol m⁻³), similar to the marine air background level, were found over the northwestern North Pacific (40–45°N) and the Sea of Okhotsk (44–45°N). Over the Sea of Okhotsk, a high concentration of chlorophyll-a (5.4 mg m⁻³) in seawater was observed, and atmospheric concentrations of non sea-salt (nss-) sulfate (44 nmol m⁻³), methane sulfonic acid (MSA) (1.8 nmol m⁻³) and particle number in the size range of 0.1 < D < 0.5 μm (199 cm⁻³) were found to be 9, 7, and 2 times, respectively, higher than those in the background marine air. The increase in particle number concentrations mainly in the size range of 0.2 < D < 0.3 μm was likely caused by the increase of biogenic sulfate over the high productive region of the Sea of Okhotsk. In humid air conditions (R.H. > 96%), the increased biogenic sulfate that condensed the large amount of water vapor would not have sufficient solute mass to activate as cloud condensation nuclei (CNN) and would remain as aerosol particles in the marine air with frequent sea-fogs over the high productive region. Biogenic sulfate originating from dimethyl sulfide (DMS) would gradually grow into the CCN size and continuously supply a great number of CCN to the marine air in the northwestern North Pacific. This revised version was published online in July 2006 with corrections to the Cover Date.     

Organic components in size-separated aerosols from the western North Pacific

Marine aerosols in the western North Pacific were collected using a cascade impactor. Size-separated aerosols were analyzed for organic carbon, alkanes and polycyclic aromatic hydrocarbons (PAH). The results showed that the rate of decrease of the atmospheric concentrations of these organic components with increase in distance from Japan as well as from the coast of the Eurasian Continent was in the order PAHalkanes>organic carbon. The bulk of all these organic components occurred in the smallest size fraction of particles (<1m). Analysis of the alkanes and PAH indicated that the hydrocarbons in aerosols in Japanese coastal marine areas are primarily derived from terrestrial anthropogenic sources which also contribute to a lesser extent to aerosols in marine areas about 1,000 km off the coast of Japan. In remote marine areas the hydrocarbons on small particles (<1m) have principally a natural terrestrial origin while those on larger particles are marine in origin.     

厦门海域大气气溶胶观测站风与气溶胶关系

本文的工作是中美海气合作实验厦门观测站的一项内容，应用该站1990年的风速和气溶胶浓度的观测数据，初步分析了观测站风速变化特征及风速、风向与气溶胶传输的关系，结果表明气溶胶中物质浓度变化受到风向风速的重要影响，而呈现出季节性的陆向和海向的传输方向变化特征。     

Dimethyl sulfide in the atmospheric surface layer of the Equatorial Pacific Ocean

This paper reports a case study of atmospheric stability effect on dimethyl sulfide(DMS) concentration in the air. Investigation includes model simulation and field measurements over the Pacific Ocean. DMS concentration in surface sea water and in the air were measured during a research cruise from Hawaii to Tahiti. The diurnal variation of air temperature over the sea surface differed from the diurnal cycle of sea surface temperature because of the high heat capacity of sea water. The diurnal cycle of average DMS concentration in the air was studied in relation to the atmospheric stability parameter and surface heat flux. All these parameters had minima at noon and maxima in the early morning. The correlation coefficient of the air DMS concentration with wind speed (at 15 m high) was 0. 64. The observed concentrations of DMS in the equatorial marine surface layer and their diurnal variability agree well with model simulations. The simulated results indicate that the amplitude of the cycle and the mean     

Chemical Composition of North Atlantic Aerosols

The paper presents new information on the chemical composition of the insoluble aerosol fraction in the atmospheric surface boundary layer of different climatic zones of the North Atlantic (temperate humid, arid and semiarid, equatorial humid). The material for this study was collected during 12 expeditions. Nylon meshes were used to catch aerosols along the course of vessels. Aerosols above the North Atlantic consist of lithogenic, biogenic, and anthropogenic particles transported from different regions, which governs the differences in their concentrations and mineral and chemical compositions. Significant (by more than an order of magnitude) enrichment of aerosols in Cu, Cd, Zn, Pb, Sb, and Se is related to anthropogenic atmospheric pollution.     

Source regions of ammonium nitrate,ammonium sulfate,and natural silicates in the surface aerosols of Moscow oblast

Maps of potential source regions of ammonium nitrate, ammonium sulfate, and natural silicates in the surface aerosols in 2002–2005, 2010, and 2012–2015 are obtained based on measurements of the optical depth of 1–2 μm surface aerosol samples and the analysis results of backward trajectories of air parcels at the Zvenigorod scientific station (ZSS) of the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The most likely potential source regions of ammonium nitrate are in western and central Europe; those of ammonium sulfate are in southern Ukraine, southern Russia, and northwest Kazakhstan; and those of natural silicates are in the Caspian and Aral regions. The maps of potential source regions are consistent with EMEP fields of surface concentrations of nitrates and sulfates and natural aerosol concentration in PM2.5.     

A study of the chemical composition and transport of marine aerosols over the ocean near China

In this paper the authors cite the aerosol samples collected with a KA-200 Anderson cascade Impactor and a KB-120 sampler during the first cruise of the Kuroshio investigation operated by the People's Republic of China and Japan cooperative program, from July 23 to August 21, 1987. The concentration size distributions and composition of marine aerosols over the Kuroshio area are analyzed. Neutron activation analysis is used to determine the elemental composition of the aerosols. The authors also discuss some characteristics of marine aerosols relating to long-range transport of crustal and anthropogenic elements from the continent to the remote ocean. Analytical results indicate that elements Al, Fe, Sc and Sb over this area are obviously influenced by the continent of Asia, and the size distributions are changed after long-range transport. The concentration of large particles increase. The concentrations of the elements C1 and Na are closely related to ocean conditions; the source of the elements Cl an     

The distributions of particulate atmospheric trace metals and mineral aerosols over the Indian Ocean

Data are presented for the concentrations of Al, Fe, Mn, Ni, Co, Cr, V, Cu, Zn, Pb and Cd in aerosols collected over two contrasting regions of the Indian Ocean. These are: (1) the northern Arabian Sea (AS), from which samples were collected in the northeast monsoon, during which the region receives an input of crustal material from the surrounding arid land masses; and (2) the Tropical Southern Indian Ocean (TSIO), a remote region from which samples were collected from air masses for which there were no large-scale up-wind continental aerosol sources. The TSIO samples can be divided into two populations: Population I aerosols, collected from air masses which have probably impinged on Madagascar, and Population II aerosols, which have been confined to open-ocean regions to the south of the area.The data indicate that there are strong latitudinal variations in the chemical signatures of aerosols over the Indian Ocean. The input of crustal material to the Arabian Sea gives rise to an average Al concentration of about 1000 ng m⁻³ of air in the northeast monsoon regime. As a result, the concentrations of all trace metals are relatively high, and the values of crustal enrichment factors are less than 10 for most metals, in the AS aerosols. In contrast, TSIO Population II ‘open-ocean southern air’ sampled during the southwest monsoon season, has an average Al concentration of only about 10 ng m⁻³ of air. Trace metal concentrations in the TSIO ‘open-ocean southern air’ during the southwest monsoon season are representative of ‘clean’ remote marine air and are generally similar to those reported over the central North Pacific.Mineral dust concentrations over the Indian Ocean decrease in a north to south direction, from about 15–20 μg m⁻³ of air in the extreme north to about 0.01–0.25 μg m⁻³ of air in the far south. The deposition of mineral dust over the northern Arabian Sea can account for approximately 75% of the non-carbonate material incorporated into the underlying sediments.In the Arabian Sea the dissolved atmospheric inputs of all the trace metals, with the exception of Cu and Co, exceed those from fluvial run-off by factors which range from 9.6 for Pb to 1.6 for Cr.     

Characterization of the proteinaceous matter in marine aerosols

Marine aerosols play a dominant role in the transfer of oceanic material to the atmosphere. Most marine aerosol originates when air bubbles burst at the sea surface ejecting material from the sea surface microlayer and bubble surface layers into the air. Concentrations of chemical compounds in these surface layers often differ from their concentrations in bulk water. We examined the enrichment of aerosols with proteinaceous matter and attempted to characterize the physical nature and sources of this matter. We measured concentrations of dissolved free (DFAA), dissolved combined (DCAA), and particulate (PAA) amino acids, transparent stainable particles (TSP), and bacteria and virus-like particles as carriers of protein, in natural and simulated aerosols. We also evaluated D/L ratios certain amino acids in all amino acid fractions.DFAA and DCAA enriched the aerosols we sampled by 1.2–20 times compared to bulk seawater; PAA enrichment was usually higher (up to 50-fold). Aerosols contained particles typical of seawater, e.g., microorganisms, organic debris, inorganic particles with adsorbed organic matter, but also a large number of semitransparent gel-like particles, which all contained amino acids. Some of these particles were probably scavenged from bulk water, but new particles produced as bubbles burst at the surface comprised at least 10% of total proteinaceous matter in the aerosol. D/L ratios of certain amino acid suggested that the particles were most likely made from dissolved polymers secreted by phytoplankton that were concentrated on bubble surfaces and in the microlayer. Examination with Alcian Blue (a dye that targets carbohydrates) and Coomassie Blue (a dye that targets proteins) showed that most TSP in the aerosols contained both proteins and polysaccharides. Microorganisms enriched the aerosols by up to two orders of magnitude, but contributed less than 4% to the total protein pool.     

Spatio-temporal distribution of floating objects in the German Bight (North Sea)

Floating objects facilitate the dispersal of marine and terrestrial species but also represent a major environmental hazard in the case of anthropogenic plastic litter. They can be found throughout the world's oceans but information on their abundance and the spatio-temporal dynamics is scarce for many regions of the world. This information, however, is essential to evaluate the ecological role of floating objects. Herein, we report the results from a ship-based visual survey on the abundance and composition of flotsam in the German Bight (North Sea) during the years 2006 to 2008. The aim of this study was to identify potential sources of floating objects and to relate spatio-temporal density variations to environmental conditions. Three major flotsam categories were identified: buoyant seaweed (mainly fucoid brown algae), natural wood and anthropogenic debris. Densities of these floating objects in the German Bight were similar to those reported from other coastal regions of the world. Temporal variations in flotsam densities are probably the result of seasonal growth cycles of seaweeds and fluctuating river runoff (wood). Higher abundances were often found in areas where coastal fronts and eddies develop during calm weather conditions. Accordingly, flotsam densities were often higher in the inner German Bight than in areas farther offshore. Import of floating objects and retention times in the German Bight are influenced by wind force and direction. Our results indicate that a substantial amount of floating objects is of coastal origin or introduced into the German Bight from western source areas such as the British Channel. Rapid transport of floating objects through the German Bight is driven by strong westerly winds and likely facilitates dispersal of associated organisms and gene flow among distant populations.     

Partitioning of trace metals released from polluted marine aerosols in coastal seawater

Mobilization and transfer of atmospherically transported metals to major suspended particulate matter components in seawater have been studied in a multichamber leaching experiment. Data on the meteorological air mass history, enrichment factors and sequential extraction analysis indicate that the highly polluted marine aerosol samples collected on Helgoland are of anthropogenic origin. A significant fraction of the total cadmium (81%), zinc (58%), copper (41%), and lead (40%) was released in seawater within 1 h. When exposed to the aerosol and artificial suspended particulate matter components for another 100 h, a portion of the released metals ranging from 10 to 60% was readsorbed. Zinc and lead were scavenged by iron/manganese oxides or readsorbed by the aerosol particulates. Of the total scavenged copper portion 67% was bound to phytoplankton cell walls which evidences an ecological impact of the polluted marine aerosols even in the coastal environment.     

Organic compounds in the aerosols and surface waters of the East Atlantic

The data on the content and composition of lipids and aliphatic hydrocarbons (HC) in aerosols and surface waters obtained during the spring-summer periods of 2001 and 2003 along the vessel route from the North Sea to the Antarctic and backwards are presented. It was shown that the distribution of organic compounds is caused by the influence of the zonal supply of eolian matter from land, anthropogenic, and marine autochtonous sources. The concentrations of organic compounds in the aerosols varied from 0.22 to 13.04 ng/m³ for the lipids and from 0.04 to 7.03 ng/m³ for the aliphatic HC; in the surface waters, it from 9 to 84 and from 1 to 53 μg/l, respectively. There is a correlation between the fluxes of the lithogenic fraction of the aerosols, HC, and lipids. The growth of the aquatic area productivity increases the levels of the HC in the surface waters but to a lower degree than the HC supply with oil contamination.     

典型自然源气溶胶沉降引起的海洋初级生产响应

大气沉降是陆源物质向海洋输入营养盐的重要方式,沙尘、野火和火山喷发均能够产生气溶胶,这些典型的自然源气溶胶在风场的作用下,能够进行远距离的输运,期间由于沉降作用进入海洋,为上层海洋提供限制性营养盐促进海洋浮游植物生长,提升海洋的初级生产力,促进碳循环过程。以海表叶绿素浓度作为海洋初级生产力的重要指标,通过海表叶绿素浓度的响应,探究沙尘、野火和火山这三种典型自然源气溶胶的传输路径及其沉降对海洋初级生产的影响。结果显示,海洋初级生产对气溶胶沉降的响应不仅与气溶胶排放类型有关,也与温度、动力过程、光合有效辐射等海域初级生产影响因素有关,体现了海洋初级生产对自然源气溶胶的敏感性,自然源气溶胶沉降所驱动的海洋初级生产在全球碳循环中具有重要的潜在影响。     

雾霾天对青岛P M2.5中铁、磷浓度及溶解度的影响

大气气溶胶中铁(Fe)和磷(P)溶解度决定了其沉降入海后对海洋初级生产及固碳能力的影响.本文分析了2017—2018年冬季在青岛采集的PM2.5样品中总态、溶解态Fe(Total Fe,TFe;Soluble Fe,SFe)和总态、溶解态P(Total P,TP;Soluble P,SP)浓度,讨论了雾、雾霾、霾和晴天...     

Identifying anthropogenic sources of nitrogen oxide emissions from calculations of Lagrangian trajectories and the observational data from a tall tower in Siberia during the spring-summer period of 2007

The task of identifying climatically significant regional anthropogenic emissions and estimating their contribution to the variability of nitrogen oxides observed at a monitoring station is considered on the basis of NO and NO₂ surface concentrations measured at the Zotino background observation station (60°26′ N, 89°24′ E, Krasnoyarsk Territory). The approach used is based on an estimation of the conditional probability of polluted air arriving from individual regions by using the results of calculating backward Lagrangian trajectories in the lower troposphere. It is established that the contribution of air masses supplied from industrial regions in the south of the Krasnoyarsk Territory to episodes of high concentrations of nitrogen oxides (>0.7 ppb) is larger than the contribution from cities and towns located in the south of Western Siberia. The results indicate that anthropogenic sources of pollution substantially affect the balance of minor gases in the lower troposphere on a regional scale and that this factor must be taken into account when observational data from the Zotino background station are analyzed and interpreted.     

海洋中单环芳烃(BTEX)的来源、分布与迁移及其生态环境效应

挥发性有机物排放是目前大气环境污染的一个焦点问题,以苯、甲苯、乙苯和邻/间/对二甲苯(BTEX)为主要代表的单环芳烃是其中一类重要的化合物。受人类生产活动的影响,BTEX在大气、土壤、地表及地下径流、海洋中普遍存在,其环境效应与生态毒害受到广泛关注。本文从大气-海水-沉积物-生物体入手,综述了海洋环境中BTEX的分布、来源及其迁移过程等研究进展。研究显示海洋环境中BTEX浓度变化范围较大,在分布上呈现出近海高、远洋低的趋势。海洋中BTEX的主要来源是人为来源,即海洋是陆源BTEX重要的汇,而海-气交换和生物降解则被认为是BTEX的主要去除途径。此外,本文阐释了海洋中BTEX的生态与大气环境效应。BTEX具有生物毒性,威胁海洋生物的生存与繁衍,破坏海洋生态系统平衡;而进入大气的BTEX能够影响大气的氧化能力,对于臭氧和二次有机气溶胶的形成具有重要贡献。尽管海洋BTEX研究取得了一定的认识,但目前海洋环境不同介质中BTEX来源解析、迁移转化过程及生物毒性机理亟需深入系统研究,为深入认识BTEX的生物地球化学过程与环境效应奠定基础。