The Relation Between Sandstorms and Strong Winds in Xinjiang,China

With observational data spanning 1961–1999 from 90 meteorological stations in Xinjiang, China, the spatial and temporal characteristics of sandstorms and strong winds, and the contribution of strong winds to the occurrence of sandstormsare analyzed. Moreover, the dominant wind direction and minimumwind speeds during sandstorm periods are discussed. The research shows that although possessing similar climatic trends, sandstorms and strong winds in Xinjiang have opposite geographical distributions, i.e. places with more sandstorms show fewer strong winds. The contribution of strongwinds to sandstorms in northern Xinjiang is larger than that insouthern Xinjiang. The dominant wind directions clearly indicatethe paths of the weather systems that introduced the sandstorms.The minimum wind speeds in the sandstorms were over 10 ms^-1in northern and eastern Xinjiang and in the Turpan and Yanqi Basins of southern Xinjiang. In Tarim Basin of southern Xinjiang,however, the minimum wind speed was about 6–8 ms^-1, and even 6 ms^-1 at its southern edge.     

On Sand and Duststorms and Associated Significant Dustfall Observed in Chongju-Chongwon,Korea during 1997–2000

Monitoring of the occurrence of sandstorms and dustfallphenomena from 1997 to 2000 was carried out. We refer tosandstorms, duststorms and blowing sand as the phenomenaoccurring in the source region, while significant dustfall is thephenomenon that occur in the sink area. It was noted that while the sandstorms in deserts and loess in NW-N China and Mongolia occurred any time during the year while severe sandstorms occurred frequently from March to May after the springthaw. The wind erosion in the source region usually occurred withwind speeds greater than 8 ms^-1. However, severe sandstorm phenomenon occurred with wind greater than 15 ms^-1 for at least 3 hr or more. In the source regions, sandstorms occurred over60–120 days per year. In Mongolia, the observation of thenumber of sandstorm days decreased due to the increase in rainy days.When a dust cloud from a desert reached the sink region,significant dustfall in the Korean Peninsula occurred due tothe lack of strong winds. We defined the episode ofsignificant dustfall (SD) with the following values: TSP250, PM₁₀ 190 g m^-3 and visibility 6.5 km or less. In Korea, 8–12 episodes of SD occurred per yearwith 12 to 22 SD days. The maximum concentrations of TSP recorded were 989–1396 g m^-3 with PM₁₀ values of 861–996 g m^-3 and with the lowestvisibility of 1.4–1.6 km.     

Climatology,Trend Analysis and Prediction of Sandstorms and their Associated Dustfall in China

Based on statistical data about Sand and Dust Storms (SDS) and their associated dustfall, features of temporal and spatialdistribution were studied first in this article. SDS and associateddustfalls occurred most often in northern China, especiallynorthwestern China. However, in the last two years, they have atendency to occur on the central and western parts of the Inner Mongolia Autonomous Region. As a result, Beijing is now among the impact areas, and the Chinese government is paying greaterattention to the matter. The changing trends of SDS and associated dustfalls were subsequently analyzed. Occurrences were seen to be decreasing with the feature of fluctuation duringthe period of 1954–2001, but they have slightly increased since 2000. Also, climate factors related to SDS and associated dustfalls were discussed. Finally, it was recommended that methods to predict SDS in China be further studied in the future.     

Observations of Dust-Storms in China, Mongolia and Associated Dust Falls in Korea in Spring 2003

A joint monitoring of dust-storms that occurred in East Asia from March until May 2003 has been carried. Our discussions include dust-storm observations in the source areas of China and Mongolia, and measurements with satellites and ground monitors in central Korea. Differences were found in the definition and measurement of dust-storms. Over the source area of Mongolia there were 6 dusty days in March, 18 days in April, and 10 dusty days in May. In Inner Mongolia of northern China there were 4 dust-storms with 14 dusty days observed over the three months. In central Korea, a sink area, there were 4 cases of weak dust-storm and 17 dusty days in the spring of 2003. The highest PM10 value was 607 μgm⁻³ and PM 2.3 was 149 μgm⁻³, respectively. These observations identify the growing need for further universal observation practices and dust-storm reporting in future. Observations indicated that snow covered the central part of the Gobi Desert, near the boundary of China and Mongolia, from December until mid-March. This is in contrast to other years when the Gobi was relatively wet, producing unfavourable conditions for the formation of intense dust-storms. In addition, the very strong winds associated with intense cyclones and anticyclones were not apparent and the systems shifted northward during the spring. As a result, the frequency and intensity of observed dust-storms in 2003 in this region were very low. This confirms that there is variability in the frequency of dust-storm formation due to the current process of desertification and climate change.     

内蒙古环境承载力与工业三废间关系的实证研究

在国内外学者对环境承载力与工业三废关系研究的基础上,探究了内蒙古环境承载力与工业三废间的关系.数据统计分析说明环境承载力与工业三废间存在长期稳定关系,但二者间不存在短期或长期的因果关系.实证分析说明近年来内蒙古环境承载力水平较低,但保持着稳步上升的趋势,缓解了工业三废带来的负外部效应.     

Study of Asian Dust Phenomena in 2001–2003 Using A Network of Continuously Operated Polarization Lidars

We have conducted dust observations at a number of locations including Beijing, Hefei, Suwon, Fukue, Nagasaki, Tsukuba, and Sapporo using automated two-wavelength polarization lidars o study Asian dust phenomena, including generation, transport, and change during transport. We developed a method using the depolarization ratio for estimating the contributions of Asian dust and spherical air-pollution aerosols in observed aerosol mixtures. We analyzed the dust profiles statistically to derive climatological characteristics and year-on-year variations. We also studied dust source and transport path for each dust event using the regional chemical transport model CFORS. The statistical analysis clearly demonstrated the year-on-year variation of dust phenomena and the characteristics depending on the locations of the observational sites. Most major dust events in 2001 and 2002 originated in Inner Mongolia and/or Mongolia at the southern edge of a low-pressure area located in Siberia and were transported by strong westerlies. In 2003, the typical meteorological pattern for heavy dust cases accompanying a strong low in Siberia was not seen, except for one case in April. Furthermore, the lidar observation in Beijing suggests that less dust was generated in the source regions in Inner Mongolia and/or Mongolia, probably due to higher precipitation in 2003.     

Environmental Conditions of Dust Events in Northern China during 2000–2001

To investigate the large-scale environmental conditions of duststorms occurring in Northern China, a synoptic situation of tendust events in Northern China during 2000–2001 was composed andits dynamic features were identified. The composite synoptic situation showed that the occurrence of the ten dust events was associated with the eastward movement of a strong cold high fromMongolia, and the development of a cyclone in Northeast China, which caused the pressure gradient to intensify considerably in Northern China. The upper level circulation revealed that a 500 hPa trough developed rapidly above Northern China, and diagnosis showed that composite ascending motion was pronouncedabove the Siberian district. The change of vertical motion in themiddle and low troposphere above Mongolia was also related to theoccurrence of the ten dust events. When the descendingcurrent, 12 hr before the occurrence, was completely replacedby the ascending current, the instable atmospheric stratificationof the lower troposphere enabled dry dust to be transported from the surface to high altitudes toward Northern China.     

Simulating the Impact of Cover Degradation on RCRA Landfill Performance

The ability of near‐surface disposal facility cover designs to meet percolation performance criteria is influenced by degradation occurring over long periods of time. This study was conducted to determine the effect of degradation on percolation based on probabilistic distributions derived from historical climate data. Water‐balance predictions were evaluated using the HELP model, employing several variations of degradation in a traditional Resource Conservation and Recovery Act disposal facility cover design over a 100‐year simulation period. Analysis results were evaluated relative to two different selected thresholds for annual percolation (1 mm and 3 mm). Approximately 20 percent of the results did not exceed both the 1‐mm and 3‐mm thresholds, while 10 percent of the realizations exceeded the 1‐mm threshold but not the 3‐mm threshold, with remaining cases exceeding the 3‐mm threshold. These results demonstrate the importance of considering degradation in designing near‐surface disposal facilities, especially given the very long performance periods desired by different regulators. © 2013 Wiley Periodicals, Inc.     

The Effects of Three Thermo Electric Power Plants on Yerkesik-Denizova Forests in Mugla Province (Turkey)

Mugla is a city that is located in the southwest part of Turkey. Three thermo-electric power plants called Yatagan (3 × 210 MW) and Yenikoy (2 × 210 MW)and Kemerkoy (Gokova, 3 × 210 MW) havebeen constructed in this region and also have begun operation in 1982 – 1983 – 1984 (three units), in 1988 and in 1995, respectively. The Pinus brutia forests in Yerkesik–Denizova region have been under the common effects of Yenikoy and Yatagan thermo-electric power plants. Therefore, these Pinus brutia forests have startedto dry in groups since 1988. In addition, Kemerkoy thermo-electric power plant, began operation in 1995.Polluting gases arrived in Denizova-Yerkesik throughKoca Stream Valley Forests.Increasing quantities of polluting gases and especially SO₂ have dried the trees in large amounts in this 1650 ha forestland area. YataganThermo-electric power plant has caused drying of Pinus brutia in Bencik Mountain, which was on the south in 1984–1985. The same phenomenon was seen in Denizova-Yerkesik Forest in 1999–2000. It was observed that sulphur content was varying between 4218–6676 ppm at the Pinus brutia needle samples taken in this region on 16 December 2000. Sulphur contents were correlated with the age of needle (1–2 yr old), density of yellow stains on the needles and amount of drying needles. Particularly in 1996–2000 period, the destruction of chlorophyll in needles due to the impacts of SO₂ was also correlated with narrowing of the annual rings from one year to another. The narrowing ratio of yearly rings reached 60–504% for 94–95 yr old, and 375–661% for 58–63 yr old Pinus brutia trees during the 1986–1990, 1991–1995 and 1996–2000 periods.All these results clearly showed that the decrease in the chlorophyll content in needles under the effect of air pollution caused important reduction in the raw timber production and its inputs to the economy. In other words, drying due to increased ecological sensitivity or direct hazard of pollutants emitted by the power plants and cutting of trees have been notably increased in the region. This has created serious economic losses.     

Storage stability of injection-molded starch-zein plastics under dry and humid conditions

Corn starch and zein mixtures (4 : 1 dry weight) were extruded and injection-molded in the presence of plasticizers (glycerol and water). Tensile strength and percentage elongation of the molded plastics were measured before and after 1 week of storage under a dry or humid condition (11 or 93% RH). With 10–12% glycerol and 6–8% water, injection-molded plastics had relatively good tensile properties (20- to 25-MPa tensile strength and 3.5–4.7% elongation). But while exposed to dry conditions (11% RH), the molded plastics lost weight (0.5–1.5% in 7 days) and became very brittle, with significant decreases in tensile strength and elongation. Partial replacement (5–10%) of starch with a maltodextrin (average DE 5) reduced the glass transition and melting temperatures of the starch-zein mixture as well as the dry storage stability. Using potato starch instead of corn starch significantly improved the dry storage stability of the injection-molded starch-zein plastics (18- vs 11-MPa tensile strength). Anionic corn starches with a maleate or succinate group (DS<0.01) produced injection-molded plastics with improved tensile properties and storage stability. Plastics prepared from the starch maleate and zein mixture retained the strength during 1 week of dry storage without a significant change (26-MPa tensile strength and 3.7% elongation after 1 week of storage).Paper presented at the Bio/Environmentally Degradable Polymer Society—Second National Meeting, August 19–21, 1993, Chicago, Illinois.Journal paper No. J-15561 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2863.     

A Chronology of Nitrogen Deposition in the UK Between 1900 and 2000

Measurements of the concentrations of nitrogen compounds in air and precipitation in the UK have been made since the mid-19th century, but no networks operating to common protocols and having traceable analytical procedures were established until the 1950s. From 1986 onwards, a high-quality network of sampling stations for precipitation chemistry was established across the UK. In the following decade, monitoring networks provided measurement of NO₂, NH₃, HNO₃ and a satisfactory understanding of the dry deposition process for these gases allowed dry deposition to be quantified. Maps of N deposition for oxidized and reduced compounds at a spatial scale of 5 km × 5 km are available from 1986 to 2000. Between 1950 and 1985, the more limited measurements, beginning with those of the European Air Chemistry Network (EACN) provide a reasonable basis to estimate wet deposition of NO ₃ ^– –N and NH ₄ ⁺ –N. For the first half of the century, estimates of deposition were scaled with emissions assuming a constant relationship between emission and deposition for each of the components of the wet and dry deposition budget at the country scale. Emissions of oxidized N, which dominated total nitrogen emissions throughout the century, increased from 312 kt N annually in 1900 to a peak of 787 kt for the decade 1980–1990 and then declined to 460 kt in 2000. Emissions of reduced N, largely from coal combustion were about 168 kt N in 1900, increasing to a peak of 263 kt N in 2000 and by now dominated by agricultural sources. Reduced N dominated the deposition budget at the country scale, increasing from 163 kt N in 1900 to 211 kt N in 2000, while deposition of oxidized N was 66 kt N in 1900 and 191 kt N in 2000. Over the century, 68 Mt (Tg) of fixed N was emitted within the UK, 78% as NO _x , while 29 Mt of nitrogen was deposited (43% of emissions), equivalent to 1.2 t N ha^–1, on average, with 60% in the reduced form. Deposition to semi-natural ecosystems is approximately 15 Tg N, equivalent to between 1 and 5 t N ha^–1, over the century and appears to be accumulating in soil. The N deposition over the century is similar in magnitude to the total soil N inventory in surface horizons.     

The practice and challenges of solid waste management in Singapore

This paper presents an overview of the current solid waste management situation in Singapore and provides a brief discussion of the future challenges. Singapore is a small island city-state with a large population, warm climate and high humidity. Over the past two to three decades, rapid industrialization and economic development have caused a tremendous increase in solid waste generation. The yearly disposed solid waste increased from 0.74 million tonnes in 1972 to 2.80 million tonnes in 2000. Solid waste management in Singapore has traditionally been undertaken by the Ministry of Environment (ENV), with the participation of some private sectors in recent years. The hierarchy of solid waste management in Singapore is waste minimization (reduce, reuse and recycle or so-called 3 Rs), followed by incineration and landfill. As land is extremely scarce and only one newly constructed offshore landfill site is available, solid waste incineration has been identified as the most preferred disposal method. Waste minimization, the utilization of incineration ashes, industrial waste management are regarded to be the major challenges in the future.     

Estimation of Cumulative Frequency Distribution for Carbon Monoxide Concentration from Wind-Speed Data, in Buenos Aires (Argentina)

In this article we apply and test a methodology to estimate cumulative frequency distribution for air pollutant concentration from wind-speed data. We use the inverse relationship after Simpson et al. (Atmospheric Environment, 19, 75–82, 1985) between the opposing percentile values in the statistical distributions for air pollutant concentrations and wind-speed data. This relationship is valid, irrespective of the statistical distributions of both variables, if an inverse relationship between them is also applicable. The available data are five years of 8-h average carbon monoxide concentration and 8-h mean wind-speed, observed in Buenos Aires (Argentina). The performance of the obtained empirical expressions in estimating cumulative frequency distributions for 8-h CO is statistically evaluated. The results show that it is possible to obtain an acceptable cumulative frequency distribution for 8-h CO concentration at the site if the cumulative frequency distribution for wind-speed is known. Q–Q plots show a good agreement between estimated and observed values. From our data, the mean relative error of the estimations was found to be as much as 8.0%.     

Utilization of red mud as catalyst in conversion of waste oil and waste plastics to fuel

The aim of this study was to investigate the possibilities of using a by-product (red mud) from alumina production as a catalyst for recovery of waste. The conversion of waste mineral oil (WMO) and waste mineral oil/municipal waste plastic (WMO/MWP) blends over red mud (RM), a commercial hydrocracking catalyst (silica–alumina), and a commercial hydrotreating catalyst (Ni–Mo/alumina) to fuel has been studied. The effect of the catalyst and the temperature on the product distribution (gas, liquid, and wax) and the properties of liquid products were investigated. In the case of hydrotreatment of WMO, the liquids obtained over RM at both 400° and 425°C had larger amounts of low-boiling hydrocarbons than that of thermal or catalytic treatment with hydrotreating catalyst. Gas chromatography and nuclear magnetic resonance analysis of the liquid products showed that RM had hydrogenation and cracking activity in hydrotreatment of WMO. In coprocessing of WMO with municipal waste plastics, temperature had an important effect as well as the amount of MWP in the blend and the catalyst type. The hydrocracking at 400°C produced no liquid product. In hydrocracking at 425°C, the product distribution varied with catalyst type and MWP amount. The commercial hydrocracking catalyst had more cracking ability in the conversion of WMO/MWP to liquid and gas fuel than RM. In the case of hydrocracking over RM, the largest amount of liquid having satisfactory quality was obtained only from the blend containing 20% MWP.     

Characteristics of air pollution in Beijing during sand-dust storm periods

In the Beijing area, March and April have the highest frequency of sand-dust weather. Floating dust, blowing sand, and dust storms, primarily from Mongolia, account for 71%, 20%, and 9% of sand-dust weather, respectively. Ambient air monitoring and analysis of recent meteorological data from Beijing sand-dust storm periods revealed that PM₁₀ mass concentrations during dust storm events remained at 1500 μg m⁻³, which is five to ten times higher than during non-dust storm periods, for fourteen hours on both April 6 and 25, 2000. During the same period, the concentrations in urban areas were comparable to those in suburban areas, while the concentrations of gaseous pollutants, such as SO₂, NO _x , NO₂, and O₃, remained at low levels, owing to strong winds. Furthermore, during sand-dust storm periods, aerosols were created that consisted not only of many coarse particles, but also of a large quantity of fine particles. The PM_2.5 concentration was approximately 230 μg m⁻³, accounting for 28% of the total PM₁₀ mass concentration. Crustal elements accounted for 60–70% of the chemical composition of PM_2.5, and sulfate and nitrate for much less, unlike the chemical composition of PM_2.5 on pollution days, which was primarily composed of sulfates, nitrates, and organic material. Although the very large particle specific surface area provided by dust storms would normally be conducive to heterogeneous reactions, the conversion rate from SO₂ to SO₄ ²⁻ was very low, because the relative humidity, less than 30%, was not high enough.     

Temporal variability of soil gas composition in landfill covers

In order to assess the temporal variability of the conditions for the microbial oxidation of methane in landfill cover soils and their driving variables, gas composition at non-emissive and strongly emissive locations (hotspots) was monitored on a seasonal, daily and hourly time scale on an old, unlined landfill in northern Germany. Our study showed that the impact of the various environmental factors varied with the mode of gas transport and with the time scale considered. At non-emissive sites, governed by diffusive gas transport, soil gas composition was subject to a pronounced seasonal variation. A high extent of aeration, low methane concentrations and a high ratio of CO₂ to CH₄ were found across the entire depth of the soil cover during the warm and dry period, whereas in the cool and moist period aeration was less and landfill gas migrated further upward. Statistically, variation in soil gas composition was best explained by the variation in soil temperature. At locations dominated by advective gas transport and showing considerable emissions of methane, this pattern was far less pronounced with only little increase in the extent of aeration during drier periods. Here, the change of barometric pressure was found to impact soil gas composition. On a daily scale under constant conditions of temperature, gas transport at both types of locations was strongly impacted by the change in soil moisture. On an hourly scale, under constant conditions of temperature and moisture, gas migration was impacted most by the change in barometric pressure. It was shown that at diffusion-dominated sites complete methane oxidation was achieved even under adverse wintry conditions, whereas at hotspots, even under favorable dry and warm conditions, aerobic biological activity can be limited to the upper crust of the soil.     

Trends in the Water Chemistry of High Altitude Lakes in Europe

Here we present the chemical trends of seven high altitude lakes, analysed within the AL:PE and MOLAR Projects of the EU (1999) and selected on the basis of the availability of complete and reliable data for the period 1984–1999. The lakes are representative of the Scandinavian Alps, the Cairngorm Mountains in Scotland, the Alps and the Pyrenees. Significant trends were identified for some indicators of acidification, for instance pH and alkalinity, but not all lakes reacted similarly to decreasing depositions of sulphate and base cations. Differences in lake response are discussed in relation to recent variations of atmospheric deposition chemistry and associated changes in climatic conditions. Beside individual variations of the studied lakes, depending, among other things, on altitude and morphology, catchment characteristics and climate trends play a major role for the reaction of high altitude lakes on changes in atmospheric depositions.     

Influence of flue-gas desulfurization systems on coal combustion by-product quality at kentucky power stations burning high-sulfur coal

Two Kentucky power plants burning similar blends of high-sulfur western Kentucky and southern Indiana coal provide a unique opportunity to examine the variations in coal combustion by-products due to differences in the method of wet flue-gas desulfurization (FGD). One plant employed carbide lime-based scrubbing for two units and a dual-alkali process for the third unit. The second plant employed a Mississippian limestone from Kentucky for all four units. This study provides an example of optical and SEM petrographic techniques, supplemented by chemical analyses, applied to the study of, at least from the geologic perspective, non-traditional materials. The coal sources comprise a blend of high volatile C and B bituminous, high vitrinite (85–90%, mmf), high-sulfur (> 3%, dry) coals. The fly ash is dominated by glassy phases (70–80%) with about 5–10% spinel (predominately magnetite), 3–10% quartz, and 4–10% isotropic coke comprising the remaining portion of the ash. SEM observations indicate that the glassy particles exhibit a bimodal size distribution with sub-micron glass spheres and a population of larger (several 10s of microns) spheres. The bottom ash has higher proportions of spinels and mullite, with negligible carbon forms, compared to the fly ash from the same units. Fly ashes were observed to be lower in Fe and higher in Al, Si, and S compared to the bottom ashes. Carbide lime, a by-product of acetylene manufacture, soda ash, and limestone were the reagents used in the flue-gas desulfurization processes. The primary FGD by-product is a calcium sulfite slurry which is vacuum filtered and mixed with fly ash and, usually, lime, to form a stable product for disposal. The FGD by-products have some potential, as yet unrealized, for utilization.     

Uncertainties in Predictions of Surface Water Acidity using the MAGIC Model

In this study, we have used the MAGIC model together with data from the Birkenes catchment in Norway, at which 27 years of data (1974–2000) are available. We calibrated the MAGIC model to the five year observed average chemistry around 1990, and then used the data from the five year period around 1980 to refine the calibration. From 1990, forecasts were run for the different sets of inputs and parameters, and the sets of inputs and parameters were further refined using observations for the period 1996–2000. Through an automatic calibration routine, the model was calibrated a large number of times with different sets of input data to account for the uncertainties in the observed data using a Monte Carlo set-up. The results show that the uncertainty in the model predictions decreases as more observed data from different points in time are used in the model calibration. The results also show that when usingthe time series data in calibration, the distribution of the forecastchanged. The distribution of the predicted Acid Neutralisation Capacity (ANC) in the future is lower for the more refined model calibration. The 10 and 90 percentiles of predicted ANC in 2010 are –3 to 21 μeq L^-1 when only a five-year average is used for calibration, but are –7 to 9 μeq L^-1 when data from the three different time periods are used.     

Modelling Seasonal Dynamics from Temporal Variation in Agricultural Practices in the UK Ammonia Emission Inventory

Most ammonia (NH₃) emission inventories have been calculated on an annual basis and do not take into account the seasonal variability of emissions that occur as a consequence of climate and agricultural practices that change throughout the year. When used as input to atmospheric transport models to simulate concentration fields, these models therefore fail to capture seasonal variations in ammonia concentration and dry and wet deposition. In this study, seasonal NH₃ emissions from agriculture were modelled on a monthly basis for the year 2000, by incorporating temporal aspects of farming practice. These monthly emissions were then spatially distributed using the AENEID model (Atmospheric Emissions for National Environmental Impacts Determination). The monthly model took the temporal variation in the magnitude of the ammonia emissions, as well as the fine scale (1-km) spatial variation of those temporal changes into account to provide improved outputs at 5-km resolution. The resulting NH₃ emission maps showed a strong seasonal emission pattern, with the highest emissions during springtime (March and April) and the lowest emissions during summer (May to July). This emission pattern was mainly influenced by whether cattle were outside grazing or housed and by the application of manures and fertilizers to the land. When the modelled emissions were compared with measured NH₃ concentrations, the comparison suggested that the modelled emission trend corresponds fairly well with the seasonal trend in the measurements. The remaining discrepancies point to the need to develop functional parametrisations of the interactions with climatic seasonal variation.