Observations of Visibility and Chemical Compositions Related to Fog,Mist and Haze in South Korea

Since 1970, the yearly consumption of fossil fuel in south Korea has steadily increased to 165 MT from 14 MT. It has been found that the number of days of low visibility (≤10 km) was significantly increased by the occurrence of fog, mist and haze. For example, the low visibility days in Seoul during 1989 were over 207 days in comparison with 21 days at a rural site. This similar trend has been observed in other large cities. In Chongwon of central Korea, daily measurements of visibility at 09 LST have been made since 1991. It is observed that the increase in the frequency of low visibility days was related to the increase in anthropogenic air pollution and water vapor in the study area. The occurrence of fog-mist-haze was much related to the influence of local, regional and synoptic meteorology. With the increase in both water supply and emission of air pollution, in Korea we commonly observe the typical historical type of London mist and haze. In this study, chemical analyses of fog, mist, haze and frost was carried out. According to analyses of data obtained in 1995, the pH values for 65.9% of all fog and mist samples collected were less than 5.6. The lowest pH value of fog was 4.0. On the other hand, pH values observed for dew and frost in early spring were generally neutral to alkaline in nature, although there was an abundant existence of sulphates and nitrates. This suggests that characteristics of yellow sand and soil dust occurring in spring appear to determine the pH values in hydrometeors occurring on the Korean peninsula. A satellite observation of sea fog is also discussed. It has been observed that the advection fog occurred with air pollutants over the Yellow Sea which were moving out of China.     

Interaction between simulated rain and barren rock surface

During the latter decades extensive fish kills have been observed in the mountainous areas of southernmost Norway. These kills have been attributed to the increased acidity of the river-water. The increased acidity is generally assumed to be caused by acid precipitation. However, the relationship between precipitation and runoff quality is very complex. The present paper is concerned with the relationship between chemical composition of simulated rain and that of runoff from bare granitic rock, partly covered by lichens. When supplying simulated rain with a pH value of approximately 5 the very first runoff had pH values between 4.1 and 4.3. However, the pH in the runoff increased rapidly and leveled out at values between 4.6 and 4.7. When supplying simulated rain with pH approximately 3.5, the pH in the first runoff varied between 3.8 and 3.6. The pH then gradually decreased to the same values as those in the simulated rain. Runoff from ‘rain’ with pH 4.3, obtained the same pH value as that of the ‘rain’. The pH of the runoff was dependent not only on the rain acidity, but also on its content of neutral salts.     

2006—2007年南昌市城郊地带的酸雨特征

为了解南昌地区酸雨现状,通过对南昌农区、郊区、市区布设观测点,根据有关监测数据资料,对2006—2007年酸雨pH值、酸雨频率、酸雨成分、空气污染状况进行了统计分析。结果表明,3个测点观测的南昌地区酸雨年均pH值处强酸性标准,3测点酸雨发生概率为88%～97%,9—4月酸雨较重、5—8月减弱,酸雨pH值与空气污染物浓度有极显著相关关系。酸雨呈硫酸性酸雨,主要阴离子为SO4^2-、NO3^-、Cl^-,阳离子为NH4＋、Ca^2＋、K^＋,且SO4^2-/NO3^-比值较小。农田保护区因处于城市及工业污染源下风向,降水总离子及SO24-浓度较高,酸雨强度不亚于城市。在新设工业园及迁出企业布局上,应考虑设于较小风频方位,以减轻南昌农田保护区及城市污染,建议选择城市西北、东南侧安排新设排放源。     

Long range transport of air pollutants in Europe and acid precipitation in Norway

Observations show that pollutants from large emission sources may cause significant air concentrations 500 to 1000 mi away. Very acid precipitation occurs in such periods. The scavenging is often intensified by the topography. Case studies will be presented with special emphasis on acid precipitation in Scandinavia. Large scale dispersion models have been developed recently in order to estimate the long range transport of air pollutants. The models take into account chemical transformations as well as deposition of pollutants. The calculations will be compared with observations from airplanes and surface stations. A simple model has been integrated over a long period of time in order to derive the best value for the decay rate of SO₂. This best value is based on a day-by-day comparison with surface observations.     

Development of Automatic Continuous Measurement System of Chemical Constituents in the Precipitation

Nowadays, acid rain is generally noticed as a global environmental problem. While acid rain has very much to do with the air pollutants, the relation between air pollution and chemical constituents in precipitation is not understood clearly yet. It is important to measure a variation of ion concentration in precipitation in short term for understanding the formation mechanism of acid rain. Therefore, an automatic continuous measurement system of chemical constituents in precipitation was developed and put into practical use in this study. The developed system was able to collect automatically every 1mm of precipitation and analyze major ions within 20 minutes.     

Material Damage Caused by Acidic Air Pollution in East Asia

Atmospheric and laboratory corrosion tests were carried out to assess the intensity of air pollution in East Asia. Qualitative and quantitative atmospheric corrosion was estimated from the damage caused to bronze, copper, steel, marble, cedar, cypress and urushi (Japanese lacquer) plates, exposed to outdoor and indoor airs in some cities of East Asia. Brochantite and cuprite were formed on copper at sites where the sulfur dioxide concentrations were high, and basic cupric nitrate and cuprite at sites where nitrogen dioxide concentrations were high. Gypsum was formed on marble pieces exposed to indoor air at all sites but was not found on pieces exposed to outdoor air. Numerous fine spots (0.2–0.3 mm in diameter) were observed on surfaces of urushi plates exposed at foggy cities such as Chongqing, China and Taejon, Korea. The effects of atmospheric and meteorological factors on the damage to copper and marble plates in several cities in East Asia were estimated using regression analysis. The results indicate that sulfur dioxide is the most destructive of materials especially in China and South Korea. In Japan copper plates may be damaged under natural conditions and by sea salt. Copper may also be damaged by surface deposition of sulfur and chlorine. Marble may be substantially degraded by gaseous sulfur dioxide but sulfate ions in rain had no effect. The analysis of air pollution from the point of view of material damage was very useful in evaluating and visualizing the intensity of air pollution in East Asia.     

辽宁地区春季降水多、少月大气环流的差异分析

应用合成分析、距平分析和差值分析等方法,对美国NCEP／NCAR的再分析资料和辽宁地区逐日降水资料进行分析,对比春季降水多、少月份的大气环流、影响系统、风场和温湿场特征。结果表明：降水多月,乌山脊和东亚大槽减弱,位相比历年平均偏西,中高纬大气环流纬向度增大,导致冷空气移动快,活动频繁;辽宁位于地面气压场负距平带内,地面辐合上升加强;40°N附近80°E-125°E区域的冷干平流、中低纬地区中国大陆东部20°N-38°N区域的暖湿平流均增强,辽宁位于冷干平流和暖湿平流交汇的区域。降水少月,乌山脊和东亚大槽增强,位相比历年平均偏东,中高纬大气环流经向度增大,系统稳定少动,辽宁位于脊前,对应地面反气旋控制,多晴天少雨天气;辽宁在地面气压场正距平带内,地面辐散加强;40°N附近80°E-125°E区域的冷干平流、中低纬地区中国大陆东部20°N-38°N区域的暖湿平流均减弱,冷干平流和暖湿平流交汇活动减少,导致少雨。     

皇甫川流域水利水保工程减沙效益分析

皇甫川流域,50年代降雨量、径流量和产沙量偏丰,80年代偏枯,70年代暴雨次数多、雨量大、雨强高。采用“水保法”计算,水利水保工程平均每年减沙444.7万t,占多年于均产沙量的7.9%;采用“降雨-产沙公式法”计算,平均每年减沙276～332万t,约占多年平均产沙量的5％。水利水保工程起到了减沙作用。为进一步减少入黄泥沙,今后仍需继续加强流域综合治理工作。     

森林植被截留对大气污染物湿沉降的影响

试验研究了裸地、马尾松林、香樟林的大气降水、穿透雨和树干径流以及地表径流的污染物离子浓度。结果表明:大气降水的污染物质离子浓度大小依次为SO42->NO3->Cl->F-;马尾松、香樟林群落的穿透雨、树干径流的污染物质含量显著高于大气降水,说明它们对降水中污染离子的富集作用很强,马尾松林的穿透雨和树干径流的污染物离子的总量高于香樟林。各林型大气污染物降水的SO42-离子含量都较高,两种林型的地表径流污染物质含量显著高于大气降水,但污染物浓度比树干径流有显著降低,说明土壤表面和枯枝落叶对降水中污染物的吸附能力很强。     

1970—2019年济南市极端降水事件时空变化特征

为了研究济南市极端降水事件时空变化特征,采用线性趋势、Mann-Kendall突变分析、小波分析等方法,基于济南市1970—2019年49个雨量站50 a的逐日降水资料,选用12个极端降水指数进行研究。结果表明:年降水量(PRCRTOT)呈显著增加趋势(p<0.05),增加速率为31.04 mm/10 a; 连续干旱日数(CDD)呈大幅下降趋势(p<0.05),下降速率为16.51 d/10 a,雨日日数(RD)、极端降水日数(R95)、极端降水总量(R95P)呈明显上升趋势(p<0.05),年降水强度呈下降趋势(p<0.05),其余指数呈不显著增加趋势; 研究区雨日日数、极端降水日数、极端降水总量、连续干旱日数及年降水量发生明显突变,其他指数突变不明显; 在周期变化上,多数指数存在22～27 a,17～17 a,7～10 a,4～5 a的主振荡周期; 从空间分布看,极端降水指数的空间差异明显,大雨日数、1日最大降雨量、5日最大降雨量及年降水量高值区基本集中在原济南市中心城区、东南部山区和莱芜附近,低值区集中在北部郊区。总体而言,济南市极端降水事件频发,应重视城市排水,减少内涝风险。     

Effects of Acid Deposition on Urushi Lacquer in East Asia

Urushi (Japanese lacquer) plates were exposed to indoor air in 7 cities in East Asia from summer 1995 through winter 1997. The plates, collected every 3 months, were optically observed by using a gloss meter, a digital microscope and a microscopic infrared spectrophotometer for evaluation of a seasonal impact by acidic air pollutants. The gloss losses were high on the urushi surface in autumn, when fog frequently appeared. Numerous fine spots were observed in 0.2–0.3 mm in diameter on the surfaces of the plates exposed at Chongqing, China, Taejon, Korea and Nara, Japan, where dense fog occurred. The spots were dark and opaque at Chongqing, where heavy air pollution was observed. A dark and opaque core was observed in each semitransparent spot at Taejon and Nara, while no spots were observed at Kyoto and Ishikawa, where fog often appeared but air pollution was at a low level. Carbonyl group, identified by microscopic infrared spectrometry, was found in the spots on the urushi surfaces. The carbonyl group may be formed by oxidation of a side-chain in urushiol (a major component of urushi sap, alkyl phenol). Urushi lacquer may be damaged by high concentration of sulfate anion, included in acid fog.     

坡面泥石流形成之降水条件探讨——以重庆北碚地区为例

从坡面泥石流的形成条件入手,结合重庆北碚地区地质地貌和气象条件,分析了北碚地区从1962~2003年发生的坡面泥石流的数据及降雨资料,认为在该区域,降水是该区域发生坡面泥石流的决定性因素,并且通过对具体坡面泥石流事例的分析,认为坡面泥石流的发生与前期降雨量和1h雨强关系密切,前期降雨对泥石流形成的贡献比较大,1h雨强主要起到激发作用。最后本文利用发生坡面泥石流前三天累计降雨量和当日前期降雨量,得出了该区域降水诱发坡面泥石流的临界雨量方程:y=106-0.757x(y为当日前期雨量,x为前三天累计雨量)。     

Meteorological characteristics of large acidic deposition events at Kejimkujik,Nova Scotia

The characteristics of acidic deposition at Kejimkujik National Park, a rural site in south-central Nova Scotia, were determined for the period from May 1979 to December 1983. The acidifying pollutants investigated were H⁺, sulphate ion and nitrate ion. Thirty per cent of the total annual amount of acidifying pollutants deposited by precipitation at Kejimkujik was deposited by only about 8% of the precipitation events during the year. These occasions of large deposition are referred to as episodes and occurred, on average, about five times per year, usually between March and November. The precipitation events that produced episodes were almost always rain events. The major meteorological feature producing deposition episodes at Kejimkujik is the sequence of a large high pressure area from mid-continent moving south of Nova Scotia, producing a prolonged southwesterly to westerly flow over the site, and then a weak frontal system, usually from south of the Great Lakes region, bringing moderate amounts of precipitation to the site. Since deposition episodes were almost always preceded by the above sequence of events, the ability to predict episodes was investigated. The results indicate that many “false alarms” could be anticipated because this sequence also occurs for non-episodes.     

贵州省猫跳河流域土壤侵蚀动态变化分析

通过实际观测,获得蒋家沟流域近2a的径流资料,总结出2008—2009年间径流的年内特征。通过收集蒋家沟流域土壤、土地利用和气象数据,用SWAT模型模拟了蒋家沟流域的基流月径流模拟和日径流变化。基流月模拟中旱季的模拟效果比较好,汛期由于泥石流暴发时无法观测流量,导致实测资料不完整,模拟结果比较差。日径流模拟分为旱季和汛期模拟,模拟结果的Nash效率系数和相关系数都在0.7以上,表明SWAT模型可以应用于泥石流流域蒋家沟地区的降雨—产流机制研究。     

Atmospheric Dispersion of Current-Use Pesticides: A Review of the Evidence from Monitoring Studies

Recently, evidence has accumulated that the extensive use of modern pesticides results in their presence in the atmosphere at many places throughout the world. In Europe over 80 current-use pesticides have been detected in rain and 30 in air. Similar observations have been made in North America. The compounds most often looked for and detected are the organochlorine insecticide lindane and triazine herbicides, especially atrazine. However, acetanilide and phenoxyacid herbicides, as well as organophosphorus insecticides have also frequently been found in rain and air. Concentrations in air normally range from a few pg/m³ to many ng/m³. Concentrations in rain generally range from a few ng/L to several µg/L. In fog even higher concentrations are observed. Deposition varies between a few mg/ha/y and more than 1 g/ha/y per compound. However, these estimates are usually based on the collection and analysis of (bulk) precipitation and do not include dry particle deposition and gas exchange. Nevertheless, model calculations, analysis of plant tissue, and first attempts to measure dry deposition in a more representative way, all indicate that total atmospheric deposition probably does not normally exceed a few g/ha/y. So far, little attention has been paid to the presence of transformation products of modern pesticides in the atmosphere, with the exception of those of triazine herbicides, which have been looked for and found frequently. Generally, current-use pesticides are only detected at elevated concentrations in air and rain during the application season. The less volatile and more persistent ones, such as lindane, but to some extent also triazines, are present in the atmosphere in low concentrations throughout the year. In agricultural areas, the presence of modern pesticides in the atmosphere can be explained by the crops grown and pesticides used on them. They are also found in the air and rain in areas where they are not used, sometimes even in remote places, just like their organochlorine predecessors. Concentrations and levels are generally much lower there. These data suggest that current-use pesticides can be transported through the atmosphere over distances of tens to hundreds, and sometimes even more than a thousand kilometres. The relative importance of these atmospheric inputs varies greatly. For mountainous areas and remote lakes and seas, the atmosphere may constitute the sole route of contamination by pesticides. In coastal waters, on the other hand, riverine inputs may prevail. To date, little is known about the ecological significance of these aerial inputs.     

Wet Deposition of Pollutants and Precipitation Patterns Classified by Cluster Analysis of 850 hPa Geopotential Height in South Korea

Synoptic meteorological conditions for precipitating systems over South Korea are characterized into several similar types using a clustering technique based on the K-mean principles with the daily mean 850 hPa grid pointed geopotential height in the spatial resolution of 5° × 5° data obtained from NCEP in the domain of 25° ～ 50°N and 110° ～ 140°E for five years from 1994 to 1998. The consecutive three-day gridded NCEP data with the precipitation event on the last day over South Korea are used for the cluster analysis. With the use of the precipitation chemistry monitored data at 8 sites in South Korea, wet depositions of SO₄ ^2?, NO₃ ^? and NH₄ ⁺ belonging to each cluster are examined to identify the deposition levels for each cluster. The result indicates that the present methodology is found to identify the deposition levels clearly and be used more practically in the field of acid rain study without heavy computational requirement.     

1961-2013年东北地区夏季降水变化趋势分析

选取东北地区84个气象站1961—2013年逐日降水资料,利用Mann-Kendall统计检验方法、线性回归、气候倾向率和变异系数方法分析了近50年东北地区夏季降水日数、降水量和降水强度的时空变化特征,讨论了夏季不同等级降水日数和降水强度变化趋势和变异场特征。结果表明:近53年,东北地区夏季降水日数呈显著的下降趋势,其变化总体呈现出60年代 > 70年代≈80年代 > 90年代 > 21世纪前13年（2001—2013年）的特征,而降水量和降水强度的升降变化并不显著。东北地区夏季小雨雨日总体呈下降趋势,其中,东北地区东南部降幅最大,平均为-2.5～-1 d/10 a;中雨雨日倾向率也以下降为主;大雨、暴雨雨日倾向率的下降区域位于黑龙江中部、吉林西北部和辽东半岛,而在辽宁中部、黑龙江西部和内蒙东北部为大雨和暴雨雨日上升区。东北地区夏季小雨雨强倾向率在东北地区东南部以上升为主,升幅为0～0.1 mm/10 a,而西北部主要以下降为主,降幅为-0.1～0 mm/10 a;东北地区夏季大雨和暴雨日数波动较大,尤以暴雨日数的波动最为显著,相比于大雨和暴雨,小雨、中雨雨日和雨强的变化都要更稳定。     

A comparison of bulk and wet-only precipitation collectors at rural sites in the United Kingdom

Co-Located wet-only and bulk precipitation collectors have been used to measure precipitation amount and ionic composition at nine rural sites in the United Kingdom. The wet-only collector collects less rain, particularly at more exposed, windier sites. This is believed to arise primarily from aerodynamic blockage rather than from late opening of the collector at the onset of rain. In general, agreement between the two types of collector for ionic composition is good. However, at two sites which experience low rainfall and elevated concentrations of primary and secondary pollutants in easterly airflow, the bulk collector yields larger concentrations of non-marine sulphate. Measurements of particulate sulphate suggest that dry deposition of particles is sufficient to explain the observed differences. In contrast, larger ammonium concentrations are measured with the wet-only collector. The observations are consistent with loss of ammonium from the bulk collector, particularly at sites of low annual mean acidity. These differences are greater in summer than in winter suggesting a biological loss mechanism.     

Effects of simulated acid rain on uptake,accumulation, and retention of fluoride in forage crops

Forage crops accumulate F from exposures to the air pollutant HF and the rate and amount taken up can be affected by a number of external factors, one of which is precipitation. To assess how precipitation, including acidic precipitation, alters F uptake and retention in forage, alfalfa (Medicago sativa L. var. Saranac) and tall fescue (Festuca arundinacea Schreb. var. Kentucky 31) were subjected to extended exposures to HF and were treated periodically with various solutions (pH 5.6, 4.0, and 3.0) supplied as simulated rain or, for comparisons, as soil amendments. None of the treatments affected growth, but precipitation treatments significantly reduced the F content of both species relative to plants that received the same volumes of the same solutions added to the soil. Analyses of washed and unwashed foliage indicated that this loss of F was primarily due to the removal of F from foliar surfaces. There was no effect of pH of rain on the F content of tall fescue, but for alfalfa an increase in acidity from pH 4.0 to 3.0 resulted in a further decrease in the F content of foliage, suggesting that in addition to removing superficial F, the more acidic simulated rain resulted in the leaching of F from within foliage was well.     

四川省典型区域滑坡泥石流与降水的关系

[目的]对四川典型区域滑坡泥石流与降水的关系进行研究,为进一步分析四川地区气候变化与地质灾害分布规律之间的关系提供基础。[方法]四川滑坡、泥石流灾害多由降水引发,在收集整理近15a滑坡泥石流灾害事件后,确定出四川滑坡、泥石流的典型区域,进而分析典型区域滑坡、泥石流与降水气候特征的关系。[结果]四川省滑坡典型区域在川东地区,泥石流典型区域在阿坝州地区。近年典型区域滑坡、泥石流近年频次明显增加,典型区域滑坡属于较长日数降水诱发型,与15d有效降水密切相关,前期降水中,强降水所占比例较大;典型区域泥石流属于较短日数降水诱发型,与3d有效降水密切相关,前期降水中,中小型降水所占比例较大。[结论]研究区15d有效降水量和3d有效降水与降水气候特征间的关系密切,可分别作为典型区域滑坡、泥石流预报因子。