Biomonitoring of Atmospheric Heavy Metal Deposition by Mosses in the Vicinity of Industrial Sites

At four industrial regions, heavy metal concentrations and calculated depositions were investigated by sampling and analysing mosses. In each region, a special spatial pattern of heavy metal concentrations was detected, reflecting the industrial processes. Metals most likely originating from the industrial sites showed an exponential decrease of concentrations and depositions with increasing distance from the pollution source. The exponential deposition pattern was in some cases modified by a series of natural factors, like the main direction of winds or orographic conditions. The distance at which deposition dropped to background values was up to 20 km. Beside the fact that the moss-metho is a useful tool for deposition measurement in the vicinity of stationary sources, some improvements for using this method are discussed, highlighting factors such as a proper calculation of deposition from concentrations, or the better knowledge of correlations between heavy metal concentrations in mosses and effects on human health.     

Biomonitoring of Element Deposition Using Mosses in the 2000 French Survey: Identifying Sources and Spatial Trends

In the year 2000, the elemental composition of mosses collected from 528 French sites has been studied as part of the 2000 European Moss Survey. Five moss species were collected: Scleropodium purum (56%), Pleurozium schreberi (18%), Hypnum cupressiforme (18%), Thuidium tamariscinum (4.5%.) and Hylocomium splendens (3.5%). Mosses were kept whole for analysis, including green and brownish parts. Summary statistics on element concentrations (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, V and Zn), and comparisons made with data from the other 27 participating European countries are shown here. The sources of these elements are identified using calculations of enrichment factors (EF) and principal component analysis (PCA). Finally, the spatial distribution in France of 10 elements is also shown, using maps underscoring areas showing highest concentration levels for each metal.     

Atmospheric Deposition of Trace Elements in Romania Studied by the Moss Biomonitoring Technique

The first systematic study in Romania of atmospheric pollution from heavy metals and other toxic elements based on moss analysis was undertaken as a Romanian–Russian–Norwegian collaboration, primarily in order to assess the general state of heavy metal pollution in Romania. An additional goal was to contribute to the European heavy metals in mosses survey, conducted under the auspices UNECE ICP Vegetation which reports to the Working Group of Effects of the Long-range Transboundary Air Pollution Convention. Samples of the moss species Hypnum cupressiforme, Hylocomium splendens and Brachytechium salebrosum and B. rutabulum were collected during the period 1995–2001. A total of 40 elements were determined using NAA and AAS. The total concentrations of arsenic, cadmium, copper, nickel, vanadium and zinc are presented in the form of contour maps. Generally, the observed concentrations in Romania are markedly higher than those observed in most other countries of Europe using the moss technique.     

Sorption Characteristics of Inorganic, Methyl and Elemental Mercury on Lichens and Mosses: Implication in Biogeochemical Cycling of Mercury

The sorption studies of Hg²⁺, CH₃Hg⁺ and elemental mercury (Hg⁰) were carried out on lichen (Parmelia sulcata) and moss (Funaria hygrometrica) samples under laboratory conditions. Desorption studies with HCl indicate that inorganic mercury (Hg⁺²) and methyl mercury could be completely desorbed with 1 M HCl and 0.5 M HCl, respectively. Samples loaded with elemental mercury, however, needed 4–5 M HCl concentration for complete desorption of the adsorbed elemental mercury. When similar desorption studies were carried out with field samples collected around a thermometer factory with elevated levels of mercury (8 mg/kg), it was found that only about 10–15% of total mercury was desorbed with 1M HCl, while 4–5 M acid was required for complete desorption. We have tried to correlate this information to understand the transformations of mercury species that may occur either in the atmosphere or on the biomonitors. The results indicated that the elemental mercury, the principal form of mercury contamination around the thermometer factory, is converted into a strongly held form by some chemical binding agents on the surface of lichen/moss, or elemental mercury could diffuse into the cells of the lichen/moss, which then needs the stronger acid to release it. Sorption capacity studies suggest that the lichens and mosses can also be used as sorbent material for the decontamination of inorganic and methyl mercury from aqueous solutions.     

Problems Related to Lichen Transplants to Monitor Trace Element Deposition in Repeated Surveys: A Case Study from Central Italy

The results of a transplant experiment with the fruticose lichen Evernia prunastri aimed at monitoring the trends of trace elements deposition in a repeated biomonitoring study are reported. Data comparability between the two surveys and interpretation of the results were addressed in this study. The ratio between the concentration of each element after the exposure and in control samples prior to exposure (exposed-to-control ratio, EC ratio), as well as an appropriate interpretative scale, were adopted as a means of determining the temporal trends of element accumulation by lichen transplants. The results showed that the method adopted is indeed a reliable tool, pinpointing a Zn smelting plant and an oil refinery as principal pollution sources in the area, which indicate that elements associated with the former were similarly accumulated in both 2002 and 2003, while elements associated with the latter tended to decrease in 2003.     

Current Atmospheric Deposition Loads and Their Trends in the Czech Republic Determined by Mapping the Distribution of Moss Element Contents

Biomonitoring of atmospheric deposition loads of 13, 14 and 35 elements and their compounds through moss analysis was carried out in the Czech Republic (CZ) in 1991, 1995 and 2000, respectively. The last biomonitoring campaign revealed very high contents of typical soil elements and lanthanides in southern Moravia. The variations in current element contents in moss, which can be explained by the action of six factors, were correlated with altitude, with total biennial precipitation, and with the bedrock types in the sampling plots. The element contents in moss samples repeatedly collected from the identical plots showed a steady decrease in atmospheric deposition loads in the CZ in the last decade of the 20th century. The main reasons for this phenomenon are listed. The results of cluster analyses and PCAs have found no substantial changes in the qualitative element composition of atmospheric deposition in CZ in recent years. Isoline maps are presented, which document changes in the distribution of Cd, Pb and S contents in moss in 1995 and 2000. An estimate of absolute deposition loads (g m^–2 year^–1) for given areas of the CZ can be made, using the list of bulk deposition indices.     

Vertical Distribution Patterns of Trace Elements in an Urban Environment as Reflected by their Accumulation in Lichen Transplants

The results of an investigation about the vertical distribution patterns of selected trace elements in an urban environment, as reflected by their accumulation in lichen transplants, are reported. Thalli of the lichen Pseudevernia furfuracea were transplanted in 2 sites in the urban area of Thessaloniki (N Greece), subjected to very different traffic loads: 1) Tsimiski, downtown of Thessaloniki, at one of the busiest streets of the city, a street canyon 2) Toumba, far from the city centre, at the edge of the city, at an open street. In each site, thalli were suspended along a vertical transect at 3, 6, 9 and 12 m, and retrieved after one year. The results showed that while at Toumba the elemental composition of lichen samples was essentially influenced by natural occurrence, mainly airborne soil dust, at Tsimiski also anthropogenic input of pollutants determined by vehicle traffic was involved for some elements such as Cd, Cu, Ni, Pb and Zn. The vertical distribution patterns of heavy metals accumulated in lichens showed that in general elevation has no statistically significant influence on the concentration of most metals, but this was not true for Pb, whose concentrations increased with increasing elevation from ground. Residents may thus be more exposed to high concentrations of Pb than pedestrians.     

Spatial and Temporal Variations of Trace Element Contents in Xanthoria Parietina Thalli Collected in a Highly Industrialized Area in Northern France as an Element for a Future Epidemiological Study

This work was made in Dunkirk, which is located on the French coast, in the north, near Belgium and Great Britain. The study concerned the industrial and urban surroundings of Dunkirk and Dunkirk itself. Objectives of our study is (1) to monitor spatial patterns and temporal trends (1995–2003) of trace element (As, Cd, Hg, Ni, Pb, V, Zn) deposition and (2) to make a first evaluation of exposed population to highest metals concentrations. This work is the first step of future epidemiological investigation. In 1995, the high lead concentrations were due to industrial emissions and to traffic. Zinc and arsenic concentrations were also high and widespread in the entire studied zone, but higher near industrial area. Mercury concentrations were limited in the western part and clearly revealed the impact of waste incinerator. We did not find any significant difference between trace element contents in lichens between 1995 and 2003 except for mercury, which decreased. In 2003, the contamination by lead was more focused in the biggest metallurgical plant, which is now the predominant source for this element. The traffic impact decreased, but there was still lead remaining. For the other elements the highest concentrations were observed near the industrial zone. Highest contaminations concern 25–33% of the population, who live near industrial zone in districts where annual average incomes are the lowest. Those results confirm the needs for a further epidemiological study, which could take place in priority where population is the most exposed.     

我国极端高温事件的年代际变化及其与大气环流的联系

利用1957～2004年全国181个气象台站观测逐日最高气温,分析了我国年平均极端高温事件(Ex-treme Hot Events,EHE)日数、强度、最早发生日期(EHE Onset Date,EHE-OD)和最迟发生日期(EHETermination Date,EHE-TD)的气候态及年代际变化的时空特征.气候态分...     

The Impact of Arctic Ozone Depletion on Northern Middle Latitudes: Interannual Variability and Dynamical Control

We have investigated the effect of the export of Arctic ozone loss, or`dilution', on mid-latitude ozone depletion during the 1990s, and its relation tointerannual meteorological variability. A stratospheric chemical-transport modelincorporated a simple gas-phase ozone scheme with the addition of a parameterisation ofpolar depletion which depended only on temperature and duration of sunlight. Themodel was forced with the U.K. Meteorological Office analyses from 1991 to 1999 covering eight Northern Hemisphere winters. The modelled Arctic ozone column losses wereabout half the magnitude of those in the Antarctic and showed a considerablevariation from year to year. The northern middle latitudes (40°–60° N)were mainly affected through dilution and experienced a variable 5–20%depletion. Year-round there is a depletion of about 1% in northern middle latitudes due toactivation at the pole but there is no evidence that this depletion increases with timeduring this integration. A series of inert tracer experiments for the winters from 1996 to 1999 showed that the dilution occurs primarily at the 560 K and 465 K isentropic levels where up to 30% of the airoriginating northward of 67° N on 1 March is found at 47° N later in spring. Thestrength and persistence of the Arctic vortex were crucial in determining the severity and the timing of the ozone dilution every year by influencing, respectively, the magnitude of the high-latitude depletion and the effectiveness of mixing to lower latitudes. This spring dilution was correlated with the winter/spring planetary wave activity indicating the important role of dynamical processes in regulating the polar-driven mid-latitude ozone depletion.     

Altimetric Data Assimilation by EnOI and 3DVAR in a Tropical Pacific Model: Impact on the Simulation of Variability

When altimetric data is assimilated,3DVAR and Ensemble Optimal Interpolation(EnOI) have different ways of projecting the surface information downward.In 3DVAR,it is achieved by minimizing a cost function relating the temperature,salinity,and sea level.In EnOI,however,the surface information is propagated to other variables via a stationary ensemble.In this study,the differences between the two methods were compared and their impacts on the simulated variability were evaluated in a tropical Pacific model.Sea level anomalies(SLA) from the TOPEX/Poseidon were assimilated using both methods on data from 1997 to 2001 in a coarse resolution model.Results show that the standard deviation of sea level was improved by both methods,but the EnOI was more effective in the central/eastern Pacific.Meanwhile,the SLA evolution was better reproduced with EnOI than with 3DVAR.Correlations of temperature with the reanalysis data increased with EnOI by 0.1-0.2 above 200 m.In the eastern Pacific below 200 m,the correlations also increased by 0.2.However,the correlations decreased with 3DVAR in many areas.Correlations with the independent TAO profiles were also compared at two locations.While the correlations increased by up to 0.2 at some depths with EnOI,3DVAR generally reduced the correlations by 0.1-0.3.Though both methods were able to reduce the model-data difference in climatological sense,3DVAR appears to have degraded the simulated variability,especially during El Nin o-Southern Oscillation events.For salinity,similar results were found from the correlations.This tendency should be considered in future SLA assimilations,though the comparisons may vary among different model implementations.     

东亚冬季风异常的空间结构及与海陆热力差异的联系

对NCEP／NCAR再分析资料采用经验正交函数和奇异谱分析方法研究东亚冬季风异常的空间结构和时间变率，在进行相关分析的基础上用奇异值分解方法研究东亚冬季风异常与海陆热力差异的联系。分析结果表明：在东亚季风区内冬季风异常有明显的地理差异，根据经向风的气修平均图及均方差图上极值中心的位置、形态，确定三个区域。WM1、WM2、WM3区为东亚冬季风的三个子系统，分别位于南海、东海、日本海上。三个子系统强度的年际、年代际变率都不同。近40aWM3区冬季风呈减弱趋势，而WM1、WM2区冬季风没有明显的减弱趋势，不同地区海陆热力差异明显不同子系统的强度，WM1、WM2区冬季风与热带西太平洋海温相关紧密，WM3区冬季风与高纬度海陆热力差异相关密切。     

Summertime Seawater Concentrations of Dimethylsulfide in the Western Indian Ocean: Reconciliation of Fluxes and Spatial Variability with Long-Term Atmospheric Observations

Dimethylsulfide (DMS) measurements in the seawater of the subtropical and the temperate western Indian Ocean were conducted for the first time from 3 December to 20 December 1997. In total, 443 surface seawater DMS determinations were performed between 24°–49° S and 50° E–77° E with a frequency of 1 sample every 10 km. An important spatial variability was observed in seawater DMS concentrations with values ranging from 0.9 to 35.8 nM. DMS maxima coincided in most cases with thermal fronts and were in reasonable agreement with mean pigment figures obtained from satellite observations. The deduced DMS fluxes are consistent with long-term observations of atmospheric DMS and rainwater concentrations of nss- SO4= and MSA measured at Amsterdam island (37° S, 77° E); then account for the differences observed in atmospheric DMS concentrations between Amsterdam island and Cape Grim, Indian Ocean monitoring stations.     

中国冬季气温变化的空间模态及其与大尺度环流异常的联系

分析了近55 a来中国冬季气温变化特征及其与大尺度环流异常的关系,结果显示：1) 中国冬季气温变化有两个主要空间模态,第一模态表现为20世纪80年代中期以后全国一致变暖;第二模态表现为80年代以后东北、西北地区冬季气温升高,而西南、华南地区气温降低。2) 西伯利亚高压变化与中国冬季气温变化的第一模态关系密切,当西伯利亚高压偏强时,我国大部分地区气温偏低,反之亦然。3) 北极涛动（AO）与冬季气温变化的第二模态关系密切,它与中国冬季气温相关最显著的区域主要在东北和西北地区,当AO为正位相时,上述区域气温往往偏高。     

郑州市大气气溶胶数浓度和质量浓度时空变化研究

利用激光粒子计数器和颗粒物自动测定仪测量的郑州市大气气溶胶粒子的数浓度和质量浓度,分析了局地气溶胶的干沉降和湿沉降以及郑州市大气气溶胶数浓度和质量浓度的时空变化,结果表明:郑州市局地区域大气气溶胶中粒径≥2μm的粒子,沉降速度随粒径的增大而增大,而粒径≤0.3μm的粒子,沉降速度变化不大;湿沉降率大于干沉降率。气溶胶浓度有明显的日变化特征,17:00-19:00为最高峰,6:00-9:00为次高峰,这是早晨及下午上下班汽车运行高峰期向大气排放的尾气和汽车扬尘所致。在垂直分布上,45-80 m处的粒子数多于1.5 m处的粒子数;在水平分布上,交通建筑区内的浓度高于其他功能区的浓度。     

Summer Monsoon Impacts on Chlorophyll-a Concentration in the Middle of the South China Sea: Climatological Mean and Annual Variability

Climatological mean and annual variations of Chlorophyll-a(Chl-a) distribution,sea surface wind(SSW),and sea surface temperature(SST) from 1998 to 2008 were analyzed in the middle of the South China Sea(SCS),focusing on the typical region off the east coast of Vietnam(8.5-14°N,109.5-114°E).Based on remote sensing data and SCS summer monsoon index(SCSSMI) data,high Chl-a concentrations in the middle of the SCS in the southwest summer monsoon season(June-September) may be related to strong Ekman pumping and strong wind stress.The maximum of the monthly averaged climatological Chl-a in the summer appeared in August.According to the annual variation,there was a significant negative correlation(r =-0.42) between the SCSSMI and SST,a strongly positive correlation(r=0.61) between the SCSSMI and Chl-a,and a strongly negative correlation(r =-0.74) between the SST and Chl-a in the typical region off the east coast of Vietnam during 1998-2008.Due to the El Ni?o event specifically,the phenomena of a low Chl-a concentration,high SST and weak SCSSMI were extremely predominant in the summer of 1998.These relationships imply that the SCSSMI associated with the SST could be used to predict the annual variability of summer Chl-a in the SCS.     

Trend and Interannual Variability of Chinese Air Pollution since 2000 in Association with Socioeconomic Development: A brief Overview

air pollution, trend and variability, socioeconomic development, satellite measurements, bottom-up emission inventories, top-down constraints     

四川不同等级雾的时空分布及其生消时间

利用四川省153个气象观测站点的逐时能见度和相对湿度资料,根据水平能见度将雾分为大雾、浓雾、强浓雾和特强浓雾四个等级,分析了四川不同等级雾的时空分布、持续时间及生消时间,结果表明：四川地区,雾在冬季最多,夏季最少,特强浓雾在4~9月比较罕见;各等级雾均在后半夜到早上（03~09时）最为频发,午后到晚上最少,强浓雾和特强浓雾几乎不会在午后到晚上（13~20时）发生;四川盆地是雾的多发区,川西高原和攀西地区雾较少,四川大部地区没有强浓雾和特强浓雾发生;四川大雾和浓雾持续时间短,一般为1~3h;强浓雾和特强浓雾一旦形成,便不容易在短时间内消散;成雾时间主要在夜间到日出前,消雾时间主要在日出后。     

西藏泥石流、滑坡时空分布特征及其与降水条件的分析

通过对1970~2006年西藏泥石流、滑坡的时空分布特征与降水条件分析,得出西藏地区泥石流、滑坡主要发生在藏东地区、喜马拉雅山南侧及沿雅鲁藏布江一线,每年6~8月是泥石流、滑坡多发时段,降水是诱发泥石流、滑坡的主要气象条件,发生泥石流、滑坡可能性与不同雨型、不同等级降水和与前期降水情况密切相关。该研究分析结论,为西藏泥石流、滑坡预警预报提供了参考依据。     

西藏泥石流、滑坡时空分布特征及其与降水条件的分析

通过对1970～2006年西藏泥石流、滑坡的时空分布特征与降水条件分析,得出西藏地区泥石流、滑坡主要发生在藏东地区、喜马拉雅山南侧及沿雅鲁藏布江一线,每年6～8月是泥石流、滑坡多发时段,降水是诱发泥石流、滑坡的主要气象条件,发生泥石流、滑坡可能性与不同雨型、不同等级降水和与前期降水情况密切相关。该研究分析结论,为西藏泥石流、滑坡预警预报提供了参考依据。