Direct radiative forcing due to aerosols in East Asia during a Hwangsa (Asian dust) event observed on 19–23 March 2002 in Korea

Park, Soon-Ung,Chang, Lim-Seok,Lee, Eun-Hee Elsevier 2005 Atmospheric environment Vol.39 No.14

<P><B>Abstract</B></P><P>The Asian dust aerosol model (ADAM) and the aerosol dynamic model with the output of the fifth generation of mesoscale model (MM5) in a grid of 30×30km<SUP>2</SUP> have been employed to simulate the temporal and spatial distribution of the Asian dust aerosol and the anthropogenic aerosol concentrations in East Asia for the period of 19–23 March 2002 when a severe Asian dust (Hwangsa) event was observed in Korea. The simulated aerosols are implemented to estimate radiative forcing at the surface and the top of atmosphere (TOA) with the use of the National Center for Atmospheric Research (NCAR) column radiation model (CRM) of community climate model 3 (CCM3). The results indicate that the ADAM model simulates quite well the spectral-mass concentration distribution with the <SUP>R2</SUP> value of 0.7 whereas the aerosol dynamic model underestimates the observed anthropogenic aerosol by a factor of 4 over Korea. The estimated mean total aerosol mass in the analysis domain for the period of 19–20 March 2002 is found to be about 880mgm<SUP>−2</SUP>, of which 98% and 2% are, respectively contributed by the Asian dust aerosol and the anthropogenic aerosol. However, the direct radiative forcing contributed by the anthropogenic aerosol are about 40% of the mean radiative forcing at the surface (−11Wm<SUP>−2</SUP>) and 45% of the mean radiative forcing at TOA (−6Wm<SUP>−2</SUP>), implying the importance of the anthropogenic aerosol on the direct radiative forcings at both the surface and TOA. The difference between the radiative forcing at TOA and the surface that indicates the atmospheric absorption is found to be 5Wm<SUP>−2</SUP>, of which 3 and 2Wm<SUP>−2</SUP> are, respectively contributed by the Asian dust aerosol and the anthropogenic aerosol, suggesting the importance of the Asian dust aerosol on the regional radiative energy balance especially in the high occurrence frequency season of spring.</P>

한반도 에어로졸 라이다 네트워크(KALION)의 에어로졸 유형 구분 및 질량 농도 산출 알고리즘

여희동 ( Hui Dong Yeo ),김상우 ( Sang Woo Kim ),이철규 ( Chul Kyu Lee ),김덕현 ( Duk Hyeon Kim ),김병곤 ( Byung Gon Kim ),김세원 ( Se Won Kim ),남형구 ( Hyoung Gu Nam ),노영민 ( Young Min Noh ),박수진 ( Soo Jin Park ),박찬봉 ( Cha 대한원격탐사학회 2016 大韓遠隔探査學會誌 Vol.32 No.2

한반도 에어로졸 라이다 관측 네트워크(Korea Aerosol Lidar Observation Network; KALION)의 라이다 관측자료 처리 및 실시간 표출을 위한 표준 알고리즘을 개발하였다. KALION 표준 알고리즘은 라이다 관측으로부터 얻어진 후방산란강도와 편광소멸도 자료를 이용하여 (1) 에어로졸과 구름 구분, (2) 에어로졸 유형 구분, (3) 에어로졸 소산계수 그리고 (4) 에어로졸 질량농도를 산출하는 단계로 구성이 되어 있다. 에어로졸의 유형은 후방산란강도와 편광소멸도 자료에 근거하여, (대륙 기원) 청정기단 에어로졸(clean continental aerosol), 황사(dust aerosol) 그리고 오염 입자(polluted continental/urban pollution aerosol)로 구별된다. 에어로졸 소산계수에 필요한 라이다 상수는 약 9년간의 라이다와 스카이 라디오미터 자료로부터 도출된 63.31 sr을, 에어로졸 질량소산효율은 약 9년간의 라이다와 기상청 Particulate Matter(PM10) 질량농도 자료를 이용하여 도출된 3.36 m2 g-1 (황사는 1.39 m2 g-1)을 적용한다. 2015년 3월28일부터 30일까지 라이다 관측 사례(서울 관악)에서 KALION 표준 알고리즘을 통해 산출된 에어로졸 유형 구분, 특히 황사 판별 결과는 기상청의 황사 보고와 잘 일치하였으며, 2006년 6월부터 약 9년 동안의 라이다 관측자료로부터 산출된 에어로졸 질량농도 역시 지상 PM10 농도와 약 3 μg m-3 내에서 잘 일치하였다. 향후 에어로졸의 유형에 따른 서로 다른 라이다 상수 및 에어로졸 질량소산효율 적용 알고리즘, 빙정 구름(ice cloud)과 물방울 구름(water droplet cloud) 구분 알고리즘, 그리고 운저 고도와 혼합고 판별 알고리즘을 개발할 계획에 있다. Descriptions are provided of the automated aerosol-type classification and mass concentration calculation algorithm for real-time data processing and aerosol products in Korea Aerosol Lidar Observation Network (KALION, http://www.kalion.kr). The KALION algorithm provides aerosolcloud classification and three aerosol types (clean continental, dust, and polluted continental/urban pollution aerosols). It also generates vertically resolved distributions of aerosol extinction coefficient and mass concentration. An extinction-to-backscatter ratio (lidar ratio) of 63.31 sr and aerosol mass extinction efficiency of 3.36 m2 g-1 (1.39 m2 g-1 for dust), determined from co-located sky radiometer and PM10mass concentration measurements in Seoul from June 2006 to December 2015, are deployed in the algorithm. To assess the robustness of the algorithm, we investigate the pollution and dust events in Seoul on 28-30 March, 2015. The aerosol-type identification, especially for dust particles, is agreed with the official Asian dust report by Korean Meteorological Administration. The lidar-derived mass concentrations also well match with PM10 mass concentrations. Mean bias difference between PM10 and lidar-derived mass concentrations estimated from June 2006 to December 2015 in Seoul is about 3 μg m-3. Lidar ratio and aerosol mass extinction efficiency for each aerosol types will be developed and implemented into the KALION algorithm. More products, such as ice and water-droplet cloud discrimination, cloud base height, and boundary layer height will be produced by the KALION algorithm.

성남시 환경대기중의 Aerosol 성분의 정기 관측

유영식 서울保健大學 1996 論文集 Vol.16 No.1

1994 년 3월부터 1995년 2월까지 1년간 성남지역 환경대기 중의 Aerosol을 monitoring 하였다. 총부유분진 및 PM-10 농도 , Aerosol로 부터 추출한 유기물 농도 및 발생원 지표 금속류의 농도를 조사하였으며, 그 결과는 다음과 같다. 1. 월평균 Aerosol 농도는 총부유분진(TSP) 의 경우 110.2∼264.3㎍/㎥ 의 범위이었고 연평 균치는 198.9㎍/㎥로 환경기준치 150㎍/㎥를 초과하였다. 경월변동은 동고하저의 전형적인분포를 나타내었고, 황사현상으로 인하여 봄철의 농도가 높게 나타났다. PM-10은 31.3∼124.6㎍/㎥의 범위로 연평균치는 57.1㎍/㎥로 TSP의 28.7%를 차지하였다. 입경별 분포는 2m를 분기점으로 하는 전형적인 bimodal type의 분포 패턴을 나타내었다. 2 ㎛보다 큰 coarse 입자는 대부분 자연적인 발생원에 의존하여 4∼9월에, 2㎛보다 작은 fine 입자는 대부분 인위적인 발생원에 의존하여 10∼3월에 높게 나타나는 특징이 관찰되었다 . 2. 포집 부유분진의 단위 중량에 대한 추출 유기물 농도는 10.6∼34.5%이었고 연평균치는 24.2%로, 무기물대 유기물 함량비는 약 3:1이었다. 계절별 분포는 TSP와 동일한 동고하저 분포를 나타냈으나, 황사현상으로 인하여 가장높은 TSP 농도를 나타낸 4월의 경우 추출 유기물 농도는 연평균치 보다 낮은 14.6%로, 중국 대륙으로부터 비래하는 황사는 무기물 함량이 유기물에 비하여 약 6배에 이르는 것으로 시사되었다. 3. 자연발생원인 토양애서 유래되는 Si 및 Al은 각기 2.3∼8.5 및 0.8∼2.8㎍/㎥로 Si가 Al 에 비하여 약3배 높았다. 황사현상이 나타나는 봄철의 농도가 타계절에 비하여 2배 높게 나타났고 타계 절은 큰 변동이 없었다 . 해염입자 유래인 Na은 큰 계절 변동없이 0.3∼0.7㎍/㎥의 범위로, 해안도 시에 비하여 내륙에 위치하는 성남에서의 농도는 낮게 나타났다 . 인위 발생원인 석유사용 지표금속 V 및 Ni은 각기 11∼32 및 3∼11㎍/㎥로, 연료 사용량을 반영하는 동고하저의 특징을 나타내었다. 이동발생 원으로부터 유래되는 Pb는 0.22-0.59㎍/㎥이었고, 자동차타이어 또는 소각장 유래로 추정되는 Zn은 0.6∼2.2㎍/㎥이었다. 4. 성남시의 부유 Aerosol 농도는 환경기준치를 초과하고, 동고하저, bimodal 분포 등 일반적인 도시형 특성이 나타났으나, 비교적 2㎛보다 큰 입경의 입자들이 상대적으로 높게 나타난 점, 유기물보다 무기물의 함량이 높게 나타난 점, 토사유래인 Si와 Al이 높은 함량을 나타낸 점으로 미루어볼 때, 이는 성남지역에서 시행되고 있는 각종 건설공사에서 유래되는 것으로 사료되었다. The aim of this study was to characterize atmospheric aerosol suspended in Sungnam City. Atmospheric suspended aerosol were collected by high-volume and Andersen air sampler from Mar. 1994 to Feb. 1995. Organic components were extracted by ultrasonication with benzene-ethanol(4:1). Seven metals used as indicators of emitting sources were analyzed by atomic absorption method for Na, Zn, Pb and Ni, aluminon method for Al, and ammonium molybdate method for Si. Monthly average concentrations of total suspended particulates(TSP) had a range of 110.2~264.3㎍/㎥ and annual average value was 198.9㎍/㎥, exceeded 150㎍/㎥ which is allowed long-term environmental standard value. Low and high values were shown during summer and winter, respectively. Due to the yellow sand phenomena, the highest value was shown in April. Annual average concentration of PM-10 was 57.1㎍/㎥, 28.7% of TSP. As to aerosol-size distribution, the typical bimodal-type distribution with a division point of 2μm size was observed. During the period of Apr. ~Sep. the major particle size was bigger than 2 μm due to the natural emissions and that was smaller than 2 μm due to the anthropogenic emissions during period of Oct.~Feb. Extracted organic components consisted of 24.2% by weight. The lowest concentration of organic extracts was shown in Apr. which had highest TSP concentration due to yellow sand phenomena. Concentrations of Si and AI occurred from soil and sand naturally had a range of 2.3~8.5 and 0.8~2.8㎍/㎥, respectively. That of Na emitted from sea spray was 0.3-0.7㎍/㎥ without seasonal variation and those of V and Ni, emitted from petroleum use were 11~32 and 3~11ng/㎥ with the property of winter-high. Concentration of Pb, emitted from automobiles was 0. 22-0.59㎍/㎥ and that of Zn was 0.6-2.2㎍/㎥

Aerosol Observation with Raman LIDAR in Beijing, China

Chen-Bo Xie,Jun Zhou,Nobuo Sugimoto,Zi-Fa Wang 한국광학회 2010 Current Optics and Photonics Vol.14 No.3

Aerosol observation with Raman LIDAR in NIES (National Institute for Environmental Studies, Japan) LIDAR network was conducted from 17 April to 12 June 2008 over Beijing, China. The aerosol optical properties derived from Raman LIDAR were compared with the retrieved data from sun photometer and sky radiometer observations in the Aerosol Robotic Network (AERONET). The comparison provided the complete knowledge of aerosol optical and physical properties in Beijing, especially in pollution and Asian dust events. The averaged aerosol optical depth (AOD) at 675 nm was 0.81 and the Angstrom exponent between 440 nm and 675 nm was 0.99 during experiment. The LIDAR derived AOD at 532 nm in the planetary boundary layer (PBL) was 0.48, which implied that half of the total AOD was contributed by the aerosol in PBL. The corresponding averaged LIDAR ratio and total depolarization ratio (TDR) were 48.5sr and 8.1%. The negative correlation between LIDAR ratio and TDR indicated the LIDAR ratio decreased with aerosol size because of the high TDR associated with nonspherical and large aerosols. The typical volume size distribution of the aerosol clearly demonstrated that the coarse mode radius located near 3 μm in dust case, a bi-mode with fine particle centered at 0.2 μm and coarse particle at 2 μm was the characteristic size distribution in the pollution and clean cases. The different size distributions of aerosol resulted in its different optical properties. The retrieved LIDAR ratio and TDR were 41.1sr and 19.5% for a dust event, 53.8sr and 6.6% for a pollution event as well as 57.3sr and 7.2% for a clean event. In conjunction with the observed surface wind field near the LIDAR site, most of the pollution aerosols were produced locally or transported from the southeast of Beijing, whereas the dust aerosols associated with the clean air mass were transported by the northwesterly or southwesterly winds.

A novel optical aerosol detector utilizing an optic fiber with conductive polymer coating

Qin, Hongyi,Kulkarni, Atul,Zhang, Hang,Jiang, Dong,Kim, Taesung Elsevier 2012 Journal of aerosol science Vol.45 No.-

<P><B>Abstract</B></P><P>The detection of atmospheric aerosol particles is becoming an important issue in many fields such as environmental science, occupational medicine, semiconductor industry and material science. In the present paper, we utilized the conductive polymer, polypyrrole (PPy), as a sensitive membrane for detecting aerosol particles optically. A polymer optical fiber reflectance probe is constructed by depositing the PPy nanofilm at the end face of the fiber. The sensor principle relies on the change in the refractive index of the PPy nanofilm upon its interaction with aerosol nanoparticles and on the electrostatic induction between aerosol particles and the PPy nanofilm, which leads to a change in the reflected intensity. For preliminary evaluation of optical aerosol detector, three types of aerosol particles, NaCl, black carbon (BC) and polystyrene latex (PSL), are selected. The fabricated fiber optic reflectance probe using the PPy nanofilm shows distinct variations in the reflected light intensity depending on the type of aerosol particle and its properties. The proposed sensing approach may promote the use of conductive polymers in optical techniques for the detection of atmospheric aerosols.</P> <P><B>Highlights</B></P><P>► A novel optical fiber sensor based on the polypyrrole nanofilm for aerosol detection. ► The electrostatic induction between aerosol particles and polypyrrole nanofilm is utilized as the detection mechanism. ► This novel optical detection approach shows a good sensitivity for the aerosol detection.</P>

구름과 에어로솔의 혼재시 에어로솔의 광학특성이 상향 단파 복사에 미치는 영향

이권호 ( Kwon-ho Lee ) 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.3

에어로솔의 광학특성과 연직고도는 태양 복사의 반사와 흡수과정을 통하여 지구복사수지에 영향을 미치게 된다. 본 연구에서는 복사전달모델과 위성관측자료를 이용하여 동북아시아 지역에서 구름의 존재 시에어로솔 층에 의한 복사특성을 분석하였다. 복사전달 모의 결과는 구름이 하부에 존재하는 경우에 에어로솔 층의 고도가 높아짐에 따라 대기 온난화 효과가 증가하였다. 이러한 관계는 에어로솔의 광 흡수성이 커질수록, 지표 반사도가 증가할수록 비례하는 경향을 나타내었다. 그리고 연구대상지역 (20-50 °N, 110-140 °E)에서 주요 에어로솔 이벤트 사례에 대하여, UV Absorbing Aerosol Index (AAI) derived from Total Ozone Mapping Spectrometer (TOMS), cloud parameters derived from the Moderate Resolution Imaging Spectro-radiometer (MODIS), with Upward Shortwave Flux (USF) Clouds and the Earth`s Radiant Energy System (CERES) 위성관측자료를 이용하여 광 흡수성 에어로솔에 의한 영향을 정량적으로 분석하였다. 각 사례에 대한 평균적인 복사효과는 약 6 - 26 %에 해당하는 상향 단파 복사량의 감쇄효과가 나타났다. 이러한 결과는 에어로솔에 의한 직접효과와 간접효과를 정량화 하기 위한 중요성을 설명해 준다. Aerosol optical properties as well as vertical location of layer can alter the radiative balance of the Earth by reflecting and absorbing solar radiation. In this study, radiative transfer model (RTM) and satellite-based analysis have been used to quantify the top-of-atmosphere (TOA) radiative effect of aerosol layers in the cloudy atmosphere of the northeast Asia. RTM simulation results show that the atmospheric warming effect of aerosols increases with their height in the presence of underlying cloud layer. This relationship is higher for stronger absorbing aerosols and higher surface albedo condition. Over study region (20-50 °N, 110-140 °E) and aerosol event cases, it is possible to qualitatively identify absorbing aerosol effects in the presence of clouds by combining the UV Absorbing Aerosol Index (AAI) derived from Total Ozone Mapping Spectrometer (TOMS), cloud parameters derived from the Moderate Resolution Imaging Spectro-radiometer (MODIS), with TOA Upward Shortwave Flux (USF) from the Clouds and the Earth`s Radiant Energy System (CERES). As the regional-mean radiative effect of aerosols, 6 - 26 % lower the USF between aerosols and cloud cover is taken into account. These results demonstrate the importance of estimation for the accurate quantification of aerosol`s direct and indirect effect.

지상관측장비를 이용하여 관측한 봄철 황사의 연직분포와 광학적 특성 분석

이병일(Byung-Il Lee),윤순창(Soon-Chang Yoon),김윤재(Yoonjae Kim) 한국기상학회 2008 대기 Vol.18 No.4

The vertical profiles and optical properties of Asian dust are investigated using ground-based measurements from 1998 to 2002. Vertical profiles of aerosol extinction coefficient are evaluated using MPL (Micro Pulse Lidar) data. Optical parameters such as aerosol optical thickness (τ), Angstrom exponent (α), single scattering albedo (ω), refractive index, and volume size distribution are analyzed with sun/sky radiometer data for the same period. We can separate aerosol vertical profiles into three categories. First category named as 'Asian dust case', which aerosol extinction coefficient is larger than O. I 5 ㎞<SUP>-1</SUP> and dust layer exists from surface up to 3-4 ㎞. Second category named as 'Elevated aerosol case', which aerosol layer exists between 2 and 6 ㎞ with 1-2.5 ㎞ thickness, and extinction coefficient is smaller than 0.15 ㎞<SUP>-1</SUP>. Third category named as 'Clear sky case', which aerosol extinction coefficient appears smaller than 0.05 ㎞<SUP>-1</SUP> and shows that diurnal variation of background aerosol in urban area. While optical parameters for first category indicate that τ and a are 0.63±0.14, 0.48±0.19, respectively. Also, aerosol volume concentration is increased for range of 1 and 4 ㎛, in coarse mode. Optical parameters for second category can be separated into two different types. Optical properties of first type are very close to Asian dust cases. Also, dust reports of source region and backward trajectory analyses assure that these type is much related with Asian dust event. However, optical properties of the other type are similar to those of urban aerosol. For clear sky case, τ is relatively smaller and a is larger compare with other cases. Each case shows distinct characteristics in aerosol optical parameters.

Aerosol optical properties over an urban industrial area, Raipur, Chhattisgarh, India

Ajay Vikram Ahirwar,Pallavi Pradeep Khobragade 대한공간정보학회 2023 Spatial Information Research Vol.31 No.3

Optical properties of aerosols including Aerosol optical depth (AOD), Angstrom exponent (AE) and Single scattering albedo (SSA)) were derived and analyzed for classifying the aerosols and identification of possible sources with percentage contribution over an urban-industrial city Raipur, India, during the year 2019 to 2021. The mean annual values of AOD and AE during 2019–2021 were 0.53 ± 0.2 and 1.20 ± 0.33 respectively, with the highest AOD (AE) values in summer:(0.67 ± 0.21 (0.98 ± 0.13)), spring: (0.52 ± 0.17 (0.93 ± 0.23)), autumn: (0.59 ± 0.21 (1.36 ± 0.26)) and winter: (0.44 ± 0.15 (1.49 ± 0.15)) respectively. The results revealed the dominance of finer aerosols with higher (lower) AE value during the winter (summer) season. Whereas, lower (higher) SSA values during the winter (summer) indicated the presence of absorbing types of aerosols. Based on the aerosol optical characteristics (AOD versus AE), three distinct aerosol types were discovered throughout the study period, namely mixed aerosols (60%), biomass-urban (37%), and dust aerosols (3%). To discriminate between urban and biomass burning aerosols, optical characteristics (AE versus SSA) were examined and found three main sources: mixed aerosols (71%) urban-industrial (21%) and biomass burning aerosols (8%). These findings will be useful for identifying potential sources as well as serve as an input for estimating the radiative forcing caused by regional aerosols.

Atmospheric Aerosol Detection And Its Removal for Satellite Data

Dong Ha Lee,Kwon Ho Lee,Young Joan Kim 大韓遠隔探査學會 2006 大韓遠隔探査學會誌 Vol.22 No.5

Satellite imagery may contain large regions covered with atmospheric aerosol. A high-resolution satellite imagery affected by non-homogenous aerosol cover should be processed for land cover study and perform the radiometric calibration that will allow its future application for Korea Multi-Purpose Satellite (KOMPSAT) data. In this study, aerosol signal was separated from high resolution satellite data based on the reflectance separation method. Since aerosol removal has a good sensitivity over bright surface such as man-made targets, aerosol optical thickness (AOT) retrieval algorithm could be used. AOT retrieval using Look-up table (LUT) approach for utilizing the transformed image to radiometrically compensate visible band imagery is processed and tested in the correction of satellite scenery. Moderate Resolution Imaging Spectroradiometer (MODIS), EO-1/HYPERION data have been used for aerosol correction and AOT retrieval with different spatial resolution. Results show that an application of the aerosol detection for HYPERION data yields successive aerosol separation from imagery and AOT maps are consistent with MODIS AOT map.

Chemical Composition Based Aerosol Optical Properties According to Size Distribution and Mixture Types during Smog and Asian Dust Events in Seoul, Korea

정창훈,이지이,엄준식,이승수,김용표 한국기상학회 2018 Asia-Pacific Journal of Atmospheric Sciences Vol.54 No.1

This study investigated the optical properties of aerosols involved in different meteorological events, including smog and Asian dust days. Carbonaceous components and inorganic species were measured in Seoul, Korea between 25 and 31 March 2012. Based on the measurements, the optical properties of aerosols were calculated by considering composition, size distribution, and mixing state of aerosols. To represent polydisperse size distributions of aerosols, a lognormal size distribution with a wide range of geometric mean diameters and geometric standard deviations was used. For the optical property calculations, the Mie theory was used to compute single-scattering properties of aerosol particles with varying size and composition. Analysis of the sampled data showed that the watersoluble components of organic matter increased on smog days, whereas crustal elements increased on dust days. The water content significantly influenced the optical properties of aerosols during the smog days as a result of high relative humidity and an increase in the water-soluble component. The absorption coefficients depended on the aerosol mixture type and the aerosol size distributions. Therefore, to improve our knowledge on radiative impacts of aerosols, especially the regional impacts of aerosols in East Asia, accurate measurements of aerosols, such as size distribution, composition, and mixture type, under different meteorological conditions are required.