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1.
《Atmospheric Research》2009,91(2-4):264-271
This study was carried out to understand the contribution of PM10 from China emission to Seoul Metropolitan Area (SMA) during high concentration period in January, 2007. The hourly PM10 concentration in Seoul Metropolitan Area had reached up to over 150 μg/m3 on 17th and 23rd of January in 2007. The aerosol transports from China along the Northwestern wind becomes the background concentrations in Korea and the assessment of the amount of contribution from China is very important in managing the air quality improvement plan in SMA.The U.S. EPA's Models-3/CMAQ (Community Multiscale Air Quality) was used to simulate PM10 concentration. The CMAQ performance was evaluated by comparing with the measurements in SMA for the episode period. The predictions were relatively in a good agreement with the measurements.The results show that the PM10 transport from China to Korea is significant and its contribution reaches up to 80% in the episode period. In order to assess more extensively the aerosol transport in East Asia region, the study to run the model in full year with speciated PM component measurements in super site is underway.  相似文献   

2.
Sandstorms in the desert and loess regions of north China and Mongolia, as well as the associated dustfall episodes on the Korean Peninsula, were monitored in 2005. The ground mass concentrations of PM10 and PM2.5 were analyzed during dustfall episodes at Cheongwon, in central south Korea, based on synoptic features at surface, 850 hPa and 500 hPa levels. A total of seven dustfall episodes lasting eleven days were observed and the mass concentration ratios of PM2.5 and PM10 during dustfall episodes were classified into a severe dustfall episode (SDE) and a moderate dustfall episode (MDE) depending upon two synoptic features. The main synoptic feature was for SDEs, which occurred frequently under a surface anticyclone and cyclone located in the west and east of the Korean Peninsula with large amplitude trough at 500 hPa over the northern Korean Peninsula. The sandstorms at the source headed directly to Korea via a strong N-NW wind without passing through any large cities or industrial areas of east China. The PM10 mass concentration sharply increased during the SDEs; however, the fine aerosol fraction of PM2.5 levels was relatively low with 13.6% of the mass concentration. In a synoptic feature for MDEs, a slow moving cyclone headed to Korea via the industrial areas of northeastern China under a small amplitude trough at a 500 hPa level. A weak anticyclone was also located over China. MDEs showed low mass concentrations of coarse PM10 particles and large fraction of fine PM2.5 particles at 46.3%.  相似文献   

3.
We present a comprehensive discussion on what cause high ozone episodes at a suburban photochemical observation site of the Seoul Metropolitan Area (population ～23 million). The observational site, Taehwa Research Forest (TRF), is situated ～30 km from the center of Seoul. In June 2011, we observed two very distinctive ozone periods-high ozone (peak up to 120 ppbv) and low ozone (peak up to 60 ppbv) in the mid and early month, respectively. The trace gas measurement dataset, especially CO and NO X clearly indicate that less anthropogenic influences during the high ozone period. Volatile organic compound (VOC) measurement results show that at the observational site, biogenic VOCs (mostly isoprene) contribute most of chemical reactivity towards OH, although toluene from anthropogenic activities was observed in higher concentrations. Back-trajectory analysis indicates that air-masses from the forest part of Korea Peninsula were dominant influences during the high ozone episode event. On the other hand, Aged air masses from China were the dominant influence during the low ozone episode event. Model calculations conducted using the University of Washington Chemical Mechanism (UWCM) box model, also consistently show that BVOC, especially isoprene photochemistry, can be the significantly contribution to local ozone formation in the given photochemical environments of TRF. These research results strongly suggest that ozone control strategy in the Eastern Asian megacities, mostly situated in surrounding forest areas should be based on the comprehensive scientific understanding in BVOC photochemistry and interplays between anthropogenic and biogenic interactions.  相似文献   

4.
文章针对大同市2006—2009年、榆社县2006—2008年PM10质量浓度数据,使用趋势分析、后向轨迹模拟不同高度的PM10的传输路径,可以看出:PM10浓度的日变化特征为"两高三低";PM10浓度日际变化不明显,只在典型日PM10浓度值明显增大;PM10浓度月变化特征为1、5、12月浓度高,春季5月份由于为沙尘期浓度高。PM10浓度季节变化规律与采暖期和非采暖期变化相符合,即采暖期的冬春季浓度高、非采暖期的夏秋季浓度低;从2006—2009年间,两站PM10质量浓度基本呈逐年下降趋势。不同气象要素与PM10浓度的相关性,按相关系数绝对值从大到小排列依次为:露点温度、气温、降水量、相对湿度。其中露点温度和PM10浓度呈显著负相关性,气温与PM10浓度呈较弱负相关性。  相似文献   

5.
Large-scale air pollution transport (LSAPT) in the Yellow Sea region and their inflow onto the Korean Peninsula were observed through satellite images and ground measurements. LSAPT includes regional continental air-masses saturated with pollutants originating from China and subsequently landing on or passing through the Korean Peninsula. It is also possible to identify the distribution and transport patterns of LSAPT over the Yellow Sea. The ground concentrations for PM10, PM2.5 and CO measured at Cheongwon, located in the centre of south Korea, were compared with NOAA satellite images. Notably, the episodes observed of the LSAPT show a PM2.5 to PM10 ratio of 74% of the daily maximum concentrations. However, cases of duststorms were clearly distinguished by much higher PM10 concentrations and a ratio of 30% of PM2.5 to PM10 for daily maximum concentrations. For the episode on January 27, 2006, the inflow of a regionally polluted continental air-mass into the central and southwestern regions of the Korean Peninsula was observed sequentially at various ground observatories as well as by satellite. The north airflow dissipated the clouds over Mt. Halla on Jeju Island and further downwind, reducing air pollution and creating a von Kármán vortex.  相似文献   

6.
2016年1月我国中东部一次大气污染物传输过程分析   总被引：1，自引：1，他引：0  
王继康  花丛  桂海林  张恒德 《气象》2017,43(7):804-812
利用常规气象数据和空气质量模式CAMx对2016年1月15—19日一次冷空气影响下郑州、武汉、南京的大气污染物传输过程进行了分析。观测发现,本次过程中武汉和南京在地面锋线到达后出现明显的PM2.5浓度的快速增长。通过分析发现,两地在1000~950 hPa高度层上偏北风的侵入带来上风向的大气污染物,同时在垂直方向上锋区内的稳定性层结抑制了大气污染物的扩散,两种作用共同导致污染物快速增长。在冷空气主体影响下,尤其是950~900 hPa高度层上弱风区消失后,污染物得到清除。大气污染物的传输作用主要发生在1000~950 hPa高度上。模式PM2.5来源示踪模拟结果表明,武汉(17日夜间至18日)和南京(17日夜间)在本次污染物快速增长过程中区域污染物输入的贡献在51%和58%左右。由于模式对PM2.5传输过程的低估,区域输送贡献率仍存在不确定性。但是,与1月15—19日平均相比, PM2.5的本地贡献明显减少,上风区域贡献明显增加。  相似文献   

7.
This study analyzes and compares aerosol properties and meteorological conditions during two air pollution episodes in 19–22 (E1) and 25–26 (E2) December 2016 in Northeast China. The visibility, particulate matter (PM) mass concentration, and surface meteorological observations were examined, together with the planetary boundary layer (PBL) properties and vertical profiles of aerosol extinction coefficient and volume depolarization ratio that were measured by a ground-based lidar in Shenyang of Liaoning Province, China during December 2016–January 2017. Results suggest that the low PBL height led to poor pollution dilution in E1, while the high PBL accompanied by low visibility in E2 might have been due to cross-regional and vertical air transmission. The PM mass concentration decreased as the PBL height increased in E1 while these two variables were positively correlated in E2. The enhanced winds in E2 diffused the pollutants and contributed largely to the aerosol transport. Strong temperature inversion in E1 resulted in increased PM2.5 and PM10 concentrations, and the winds in E2 favoured the southwesterly transport of aerosols from the North China Plain into the region surrounding Shenyang. The large extinction coefficient was partially attributed to the local pollution under the low PBL with high ground-surface PM mass concentrations in E1, whereas the cross-regional transport of aerosols within a high PBL and the low PM mass concentration near the ground in E2 were associated with severe aerosol extinction at high altitudes. These results may facilitate better understanding of the vertical distribution of aerosol properties during winter pollution events in Northeast China.  相似文献   

8.
Long-term variations and trends of atmospheric aerosols in the East Asian region were analyzed by using aerosol optical depth (AOD or τ), and ångström exponent (AE or α) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2010. The increased emission of anthropogenic fine aerosols in east China resulted in the high AOD in this region during summer. The steady increasing emission of anthropogenic fine aerosols caused an increasing trend of AOD in east China, and the large-scale transport of sandstorms and smoke plume caused by forest fires affected intense inter-annual variations of AOD in the East Asian region. While in the central part of South Korea, located in the lee side of the East Asian continent, AE tended to rise to a level higher than in east China, the ground-based mass concentrations continued to decline. A noticeable decrease of PM10 mass concentration in spring and winter in central Korea is most likely attributable to decreases in sandstorms in the source region of East Asia. However, the ratio of PM2.5 mass concentration to PM10 increases overall with a high level in summer. Aerosol types were classified into dust, smoke plume, and sulphate by using satellite data over Cheongwon in central Korea. The columnar AOD, with different aerosol types, was compared with the ground-based mass concentrations at Cheongwon, and the relatively high level of the correlations presented between PM2.5 and AOD produced in sulphate. Growth and increases of fine hygroscopic aerosols generated as gas-to-particle conversion particularly in summer contribute to increases of columnar AOD in the East Asian region.  相似文献   

9.
秦皇岛地处河北省东北部,是环渤海重要的港口城市,在近几年京津冀地区减排效果较好的情况下,于2019年1月出现了多次持续细颗粒物（PM2.5）污染过程。因此本文利用耦合了数值源解析模块ISAM（Integrated Source Apportionment Method）的区域空气质量模式RAMS-CMAQ（Regional Atmospheric Modeling System–Community Multiscale Air Quality）,对2019年1月秦皇岛地区PM2.5进行模拟,并将PM2.5质量浓度高于（低于）75 μg m－3的时段划分为污染（清洁）时段,分别探讨了两个时段本地排放源对秦皇岛市PM2.5质量浓度的贡献情况,并且进一步探讨了秦皇岛各区县及外地排放源对秦皇岛市4个国控环境监测站点（第一关站、北戴河站、市监测站、建设大厦站）PM2.5质量浓度的区域传输特征。结果表明,秦皇岛地区PM2.5质量浓度整体呈“南高北低”式分布。清洁时段,PM2.5质量浓度受本地贡献较大,青龙县、卢龙县大部分地区贡献为40%～50%,海港区、抚宁区、北戴河区、第一关区及昌黎县大部分地区贡献在60%以上;4个国控环境监测站点受跨界输送贡献占34.7%～41.6%。污染时段,秦皇岛市本地贡献相对于清洁时段整体下降10%左右,当地大气污染受到跨界区域传输影响增加;而在4个国控站中,北戴河站、第一关站受到跨界输送贡献分别下降1.0%和2.3%;市监测站、建设大厦站受到跨界输送贡献分别上升2.9%和2.0%。  相似文献   

10.
PM2.5 is a big issue as it is considerably more harmful than other sizes of particulate matter. World Health Organization (WHO) recommends 25 μg m?3 as the daily average concentration, and 10 μg m?3 per day as an annual average. To keep up with global trends, it is first necessary to understand the current status and characteristics of PM2.5 concentrations in Korea. Using the PM2.5 data measured by Seoul Metropolitan City from November 2005 to March 2012, the author analyzed its statistical characteristics and correlations with other air pollutants. For the time period from 2005 to 2012, the annual average concentration of PM2.5 was 27 μg m?3, three times the WHO standard. Also, the daily average PM2.5 concentration of 215 days per year also exceeded the WHO standard. However, the number days exceeding the Korean daily average standard of 50 μg m?3 to be enacted in 2014 was only three. PM2.5 concentration had a high correlation (r = 0.84) with PM10, and also showed high correlations with gaseous pollutants, such as SO2, NO2, and CO, but not O3. This study suggests that the Korean government should strengthen their standard to match the criteria used by WHO.  相似文献   

11.
We analyzed aerosol optical and chemical properties over Northeast Asia for two pollution episodes caused by contrasting weather conditions, stagnant anticyclone (November, 2011) and fastmoving continental outflow associated with migratory cyclone/anticyclone (February, 2003). Pollution levels were significantly high and even comparable with heavily polluted urban cities in China and Korea even though these levels were from the episodic measurements since Gosan is an internationally well-known remote background site. Space-borne MODIS measurements clearly show that the pollution plume with high aerosol optical depth (AOD) overlaid and very slowly moved over Northeast Asia during the stagnation episode. On the other hand, a strong synoptic wind transported the plume from eastern China to its downwind regions during the continental outflow episode. The two pollution episodes showed discriminative aerosol chemical compositions associated with different source characteristics. Concentrations of nss (non-sea-salt)-sulfates and ammonium in the continental outflow episode were almost two times higher than those in the stagnation episode due to the influence of anthropogenic emissions from China. A higher fraction of nitrate, accompanied with an increase of carbonaceous species in the stagnation episode, was attributable to vehicular emissions originated from Korea.  相似文献   

12.
Source attribution of urban smog episodes caused by coal combustion   总被引：1，自引：0，他引：1  
Stable weather conditions together with extensive use of coal combustion often lead to severe smog episodes in certain urban environments, especially in Eastern Europe. In order to identify the specific sources that cause the smog episodes in such environments, and to better understand the mixing state and atmospheric processing of aerosols, both single particle and bulk chemical characterization analysis of aerosols were performed in Krakow, Poland, during winter 2005.Real-time measurements of the bulk PM10 aerosol during a severe smog episode (PM10 mass > 400 µg m− 3) showed a stable concentration of black carbon in the aerosol, and an increase in the sulphate and chlorine mass contributions towards the end of the episode. Chemical characterization of single particles further helped to identify residential coal burning as the main source that caused this severe smog episode, consisting of single particles with major signals for carbon with simultaneous absence of sulphate, chlorine and calcium. Particles from industrial coal combustion gained importance towards the end of that episode, after residential coal combustion was switched off, indicated by an increase of the percentage of sulphate and chlorine containing particles. Traffic was not a significant source during the severe smog episode. During a lighter smog episode, residential and industrial coal combustion was still predominant, with an increased contribution of traffic and processed/aged aerosols. On a clean day, particle classes containing nitrate were the most abundant. In addition, the aerosol was more internally mixed showing that there were more sources contributing to the total aerosol population.  相似文献   

13.
选用2007年1月8—30日期间8个无云天的激光雷达资料进行分析。基于Fernald方法反演得到气溶胶消光系数廓线,结合无线电探空资料分析了边界层内气溶胶时空分布,并将反演的激光雷达最低观测高度处(180 m)的气溶胶消光系数与地面PM10、能见度资料进行对比分析。结果表明：冬季大连市区气溶胶主要分布在2 km以下区域,早晨和夜间在0.5 km以下区域经常存在一个气溶胶层;气溶胶消光系数廓线与探空资料较吻合;反演激光雷达最低观测高度处(180 m)的气溶胶消光系数与地面的PM10浓度呈正相关,与能见度呈负相关,相关性较好。  相似文献   

14.
Some connections between aerosols, atmospheric transport, and relative humidity are investigated based on measurements at Basic Environmental Observatory (BEO) station, peak Musala (2,925 masl) for the period January 2009–January 2010. Data are chosen at 0:00 and 12:00 GMT every day. Main methods employed in this research are statistical—nonparametric tests of Mann–Whitney and Spearman. The main conclusion is that greater aerosol load at peak Musala is connected with transport of air masses from north to east horizon quarters. Bigger particles with longer lifetimes come from there. Air coming from the south horizon quarter is aerosol clearer. Relative humidity shows opposite distribution—higher values for transport from south horizon quarter. Correlation between this parameter and aerosols is negative with significant but small value. Distribution of blue, green, and red scattering and backscattering coefficients is similar to distribution of total aerosol concentration. Correlations between scattering and backscattering coefficients and total aerosol concentration are significant and positive. Courses of total aerosol concentration; diameter of particles with maximum concentration; and blue, green, and red scattering and backscattering coefficients have summer maximum and winter minimum. Diurnal course of total aerosol concentration in the two main seasons, winter (January) and summer (July), has day maximum and night minimum. Aerosols at peak Musala are predominantly of transparent or translucent type. The calculation of Ångström exponent α is more precise by using scattering coefficients. The nephelometers data could successfully characterize the haziness of the atmosphere above peak Musala.  相似文献   

15.
“一带一路”建设让古代丝绸之路的起点——西安成为世界焦点，西安的空气质量也是政府和公众关注的焦点。以2017年5月我国北方的一次强沙尘过程为例，首次利用中国科学院大气物理研究所气溶胶和大气化学模式系统IAP-AACM（Aerosol and Atmospheric Chemistry Model of the Institute of Atmospheric Physics）模拟关中地区细颗粒物（PM2.5）的时空分布，并结合地面逐小时PM2.5观测数据对沙尘气溶胶和PM2.5模拟的关系进行深入探究。结果表明:加入沙尘组分对模拟关中地区PM2.5时空变化特征作用显著，相关性可提升0.4～0.6，并且可以很好地再现强沙尘时段PM2.5浓度骤增的过程；在强沙尘时段和一般时段，沙尘组分对PM2.5的贡献分别为60%～80%和10%～30%；0.11°×0.11°高分辨率模拟有助于提升模式捕捉污染物时空变化的能力。  相似文献   

16.
The results are presented of measurements of aerosol content at different heights in the Arctic troposphere in the area of Naryan-Mar city and the Yamal Peninsula on June 24, 2014 using in situ and remote instruments installed on the Yak-42D "Roshydromet" research aircraft. The maximum aerosol content was detected in the layer up to 3000 m, and the aerosol concentration in the troposphere over the Yamal Peninsula is higher than that in the area of Naryan-Mar by 100 times. The in situ aircraft instrument measured the number concentration of black carbon particles in the tropospheric aerosol. To identify the sources of aerosol in the Arctic troposphere during airborne measurements the air mass trajectory analysis was performed. Simulations were conducted using the TRACAO trajectory model and FLEXPART particle dispersion model. The possible contribution of long-range and local transport of industrial pollutants to the Arctic troposphere was analyzed. The air mass transport was simulated using the trajectory model. Model computations of aerosol concentration in the troposphere using the satellite data on the gas flaring incite that the high content of black carbon in the lower troposphere over the Yamal Peninsula was caused by its transfer from the oil-producing areas located on the adjoining territory of Russia. The contribution of long-range transport of pollutants from industrial enterprises in Western Europe to the Arctic area under study was insignificant in the period under consideration.  相似文献   

17.
Three comprehensive acid deposition models were used to simulate the sulfur concentrations over northeast Asia over the period covering entire year of 2002, and discussed the aggregated uncertainties and discrepancies of the three models. The participating models are from the countries participating in the project of Longrange Transboundary Air Pollutants in Northeast Asia (LTP): China, Japan and Korea. The Eulerian Model-3/CMAQ (by China), Regional Air Quality Model (RAQM, by Japan), and Comprehensive Acid Deposition Model (CADM, by Korea) were employed by each country with common emissions data established by the administrative agencies of China, Japan and Korea. The episodic simulation results between 1 to 15, March 2002 are also presented, during which aircraft measurements were carried out over the Yellow sea. The episodic results show both a wide short-term variability in simulations against measurements, and maximum concentration differences of 3～5 times among the three models, requiring that further attention before confidence among the three models can be claimed for short-term simulations. However, the year-long cumulative simulations showed almost the same general features, with lower aggregated uncertainties between the three models, produced by the long term integration over northeast Asia.  相似文献   

18.
Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility.Characterization of the chemical composition of PM 2.5 and in situ measurements of the optical properties of aerosols were conducted in July 2008 at an urban site in Guangzhou,Southern China.The mean PM 2.5 concentration for the entire period was 53.7±23.2 μg m 3.The mean PM 2.5 concentration (82.7±25.4 μg m 3) on hazy days was roughly two times higher than that on clear days (38.8±8.7 μg m 3).The total water-soluble ion species and the total average carbon accounted for 47.9%±4.3% and 35.2%±4.5%,respectively,of the major components of PM 2.5.The increase of secondary and carbonaceous aerosols,in particular ammonium sulfate,played an important role in the formation of haze pollution.The mean absorption and scattering coefficients and the single scattering albedo over the whole period were 53±20 M m 1,226±111 M m 1,and 0.80±0.04,respectively.PM 2.5 had a high linear correlation with the aerosol extinction coefficient,elemental carbon (EC) was correlated with aerosol absorption,and organic carbon (OC) and SO 4 2 were tightly linked to aerosol scattering.  相似文献   

19.
Surface measurements of aerosol physical properties were made at Anantapur(14.62°N,77.65 °E,331 m a.s.l),a semiarid rural site in India,during August 2008-July 2009.Measurements included the segregated sizes of aerosolsas as well as total mass concentration and size distributions of aerosols measured at low relative humidity(RH<75%) using a Quartz Crystal Microbalance(QCM) in the 25-0.05 μm aerodynamic diameter range.The hourly average total surface aerosol mass concentration in a day varied from 15 to 70 μg m-3,with a mean value of 34.02±9.05μgm-3 for the entire study period.A clear diurnal pattern appeared in coarse,accumulation and nucleation-mode particle concentrations,with two local maxima occurring in early morning and late evening hours.The concentration of coarse-mode particles was high during the summer season,with a maximum concentration of 11.81±0.98μgm-3 in the month of April,whereas accumulationmode concentration was observed to be high in the winter period contributed >68% to the total aerosol mass concentration.Accumulation aerosol mass fraction,A f(=Ma/Mt) was highest during winter(mean value of Af～0.80) and lowest(Af～0.64) during the monsoon season.The regression analysis shows that both R eff and R m are dependent on coarse-mode aerosols.The relationship between the simultaneous measurements of daily mean aerosol optical depth at 500 nm(AOD500) and PM 2.5 mass concentration([PM2.5]) shows that surface-level aerosol mass concentration increases with the increase in columnar aerosol optical depth over the observation period.  相似文献   

20.
北京2004年一次强沙尘暴过程的辐射特征研究   总被引：6，自引：1，他引：5  
利用2004年3月27～29 日北京沙尘暴期间观测的辐射、气象以及气溶胶质量浓度的资料,分析了该过程的地面辐射、气象要素以及气溶胶与辐射相互作用的变化特征.结果表明,沙尘暴期间紫外辐射的衰减与可见光辐射强度衰减规律不一致.紫外衰减主要受到细粒子浓度影响,同时紫外辐射占总辐射的比重与气溶胶中细粒子含量成负相关;而可见光辐射强度衰减与总辐射衰减同步.辐射变化和气溶胶质量浓度观测结果均表明,此次沙尘暴过程分为3个阶段,即,细粒子累积期、外地沙尘输入期和清除期.在沙尘暴期间地面一直维持一个低压、干冷的状态;当过程结束后,气压急剧增高,并在一段时间内处于高压控制之下.  相似文献   

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