동아시아 지역 봄철에 주로 발생하는 황사의 물리적 특성을 알아보기 위하여 부산지역에서 발생한 2009년 황사 기간의 종관 일기도와 자동기상관측장비(AWS)를 이용한 기상해석, PM10 샘플러와 레이저입자계수기(LPC)를 이용한 대기입자상 물질농도 분석, 위성영상과 역궤적분석 모델을 이용한 발생원을 조사하였다. 2009년 2월 20일의 경우 (사례 1), PM10 농도가 급격히 증가할 때 0.3-1.0μm의 작은 입자의 에어로솔 체적 농도 분포가 감소한 반면 1.0-10.0μm의 큰 입자의 농도는 증가하였다. 그 후 PM10 농도가 감소할 때 지상의 풍향은 북풍에서 남서풍으로 변하였으며, 전체 에어로솔 농도는 감소하였다. PM10과 1.0-10.0μm의 큰 입자 농도의 상관계수는 0.9 이상으로 높은 양의 상관관계를 나타내었다. 이는 내몽골 지역에서 발달된 황사가 중국 고비 사막을 통과하여 한반도로 유입된 것으로 추측할 수 있었다. 2009년 4월 25일의 경우 (사례 2), PM10 농도가 급격히 증가할 때 0.3-0.5μm의 작은 입자의 에어로솔 체적 농도 분포가 감소한 반면 0.5-10.0μm의 큰 입자의 농도는 증가하였다. 그 후 PM10 농도가 감소할 때 0.3-0.5μm의 작은 입자의 농도는 증가한 반면 0.5-10.0μm의 큰 입자의 농도는 감소하였다. 이 때 지상의 풍향은 북동풍에서 남서풍으로 변한 후 다시 북동풍으로 변하였다. PM10과 1.0-10.0μm의 큰 입자의 농도의 상관계수는 약 0.9에 가까운 높은 양의 상관관계를 나타내었다. 입자의 역궤적 수송 모델 분석 결과, 만주지역과 중국 동쪽 해안으로부터 한반도로 유입된 것으로 추측할 수 있었다.

The aerosol chemical components in PM2.5 in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) (26 μg/m3 and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC (21.7 Mm-1) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

Asian dust (or yellow sand) occurring mainly in spring in East Asia is affected by the distribution of weather systems. This study was performed to investigate the characteristics of suspended particulate for Asian dust at Busan, Korea in 20 March 2010, which was one of the extreme case for the last 10 years. There was used the data of weather chart, satellite, automatic weather system (AWS), PM10, laser particle counter (LPC), and backward trajectories model. In synoptically, the high pressure was located in the northwestern part and low pressure was located in the northeastern part of Korea. The strong westerly winds from surface to upper layer makes it possible to move air masses rapidly. Air masses passing through Gobi Desert in Mongolia and Inner Mongolia plateau covered the entire Korean peninsula. As the results of aerosol analysis, PM10 concentration at Gudeok mountain in Busan was recorded 2,344 ㎍/m3 in 2300 LST 20 March 2010 and their concentration was markedly increased at coarse mode particle. In surface condition, westerly wind about 3 ∼ 5 m/s was dominant and small particles of 0.3 ∼ 0.5 ㎛ were distributed on the whole. In heavy metal components analysis, the elements from the land was predominated.

The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan in Jeju Island, which is known as background area in Korea, from March 2010 to February 2011. The obtained results of asian dust events and non-asian dust period have been compared. The results show that the entire averaged aerosol number concentration from APS measurement during asian dust events and non-asian dust period are about 341 particles/㎝3 and 240 particles/㎝3, respectively. During asian dust events, the number concentration in small size ranges(≤0.4 ㎛) are similar to non-asian dust period, however, those in large size ranges(≥0.7 ㎛) are very higher than non-asian dust period. The contributions of the size resolved number concentration(23 channel in 0.25∼10.0 ㎛) to total number concentration in that range are dramatically decreased with increased particle size. The contributions of smaller size ranges(≤0.4 ㎛) during asian dust events are very low compared with non-asian dust period, on the other hand, those of larger size ranges(≥0.4 ㎛) are higher than non-asian dust period. total aerosol number concentration are depended on the number concentration in range of smaller than 0.58 ㎛ during non-asian dust period and asian dust events. On the other hand, PM10 mass concentration has mainly affected with the number concentration in range of smaller than 1.0 ㎛ during non-asian dust period, however, during asian dust events, the mass concentration has mainly affected with the number concentration in range of 0.65∼3.0 ㎛.

The versatile aerosol concentration enrichment system (VACES) have proven useful for providing elevated levels of atmospheric aerosol to human and animal exposures. In this study, we describe a VACES and tests conducted to both optimize the enhancement factor (EF) and characterize how it depends on experiment conditions. Particle number concentrations were measured from upstream and downstream of the system by scanning mobility particle sizer (SMPS) with a long differential mobility analyzer (DMA) in combination with a condensation particle counter (CPC). SMPS was used for to determine VACES particle EF. Particle EF tends to increase for higher the saturator temperature (TSat) and lower the condenser temperature (TCon). TCon higher than 0 °C and TSat lower than 50 °C was the best to obtain the most increase in particle concentration. Correlation analysis of EF with factor variables of TSat and TCon resulted in correlation 0.662 and 0.416, respectively. With all five predictor variables included in a multiple regression model, the EF had a liner correlation with R2 = 0.643.

The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan site, which is known as background area in Korea, from January to September 2011. The temporal variation and the size distribution of aerosol number concentration have been investigated. The entire averaged aerosol number concentration in the size range 0.25∼32.0 ㎛ is about 252 particles/㎝3. The number concentration in small size ranges(≤ 0.5 ㎛) are very higher than those in large size ranges, such as, the number concentration in range of larger than 6.5 ㎛ are almost zero particles/㎝3. The contributions of the number concentration to PM10 and/or PM2.5 are about 34%, 20.1% and 20.4% in the size range 0.25∼0.28 ㎛, 0.28∼0.30 ㎛ and 0.30∼0.35 ㎛, respectively, however, the contributions are below 1% in range of larger than 0.58 ㎛. The monthly variations in the number concentration in smaller size range(<1.0 ㎛) are evidently different from the variations in range of larger than 1.0 ㎛, but the variations are appeared similar patterns in smaller size range(<1.0 ㎛), also the variations in range of larger than 1.0 ㎛ are similar too. The diurnal variations in the number concentration for smaller particle(<1.0 ㎛) are not much, but the variations for larger particle are very evident. Size-fractioned aerosol number concentrations are dramatically decreased with increased particle size. The monthly differences in the size-fractioned number concentrations for smaller size range(<0.7 ㎛) are not observed, however, the remarkable monthly differences are observed for larger size than 0.7 ㎛.

The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan site in Jeju, Korea, from March 2010 to March 2011. And then the atmospheric aerosol number concentration, the temporal variation and the size distribution of aerosol number concentration have been investigated. The aerosol number concentration varies significantly from 748 particles/㎝3 to zero particles/㎝3. The average number concentration in small size ranges are very higher than those in large size ranges. The number concentrations in the size range 0.25∼0.28 ㎛, 0.40∼0.45 ㎛ and 2.0∼2.5 ㎛ are about 84 particles/㎝3, 2 particles/㎝3 and 0.4 particles/㎝3, respectively. The number concentrations in range of larger than 7.5 ㎛ are below 0.001 particles/㎝3. The seasonal variations in the number concentration for smaller particle(<1.0 ㎛) are not much, but the variations for larger particle are very evident. And strong amplitudes of diurnal variations of entire averaged aerosol number concentration are not observed. Size-fractioned aerosol number concentrations are dramatically decreased with increased particle size. The size-fractioned aerosol number concentrations in size range 0.8∼4.0 ㎛ during nighttime are evidently higher than during daytime, but similar levels are appeared in other size range. The seasonal differences in the size-fractioned number concentrations for smaller size range(<0.7 ㎛) are not observed, however, the remarkable seasonal differences are observed for larger size than 0.7 ㎛.

To examine the fluctuations of aerosol number concentration with different size in the boundary layer of marine area during summer season, aerosol particles were assayed in the Ieodo Ocean Research Station, which is located 419 km southwest of Marado, the southernmost island of Korea, from 24 June to 4 July, 2008. The Laser Particle Counter (LPC) was used to measure the size of aerosol particles and NCEP/NCAR reanalysis data and sounding data were used to analyze the synoptic condition. The distribution of aerosol number concentration had a large variation from bigger particles more than 3 μm in diameter to smaller particles more than 1 μm in diameter with wind direction during precipitation. The aerosol number concentration decreased with increasing temperature. An increase (decrease) of small size of aerosol (0.3∼0.5 μm in diameter) number concentration was induced by convergence (divergence) of the wind fields. The aerosol number concentration of bigger size more than 3 μm in diameter after precipitation was removed as much as 89∼94% compared with aerosol number concentration before precipitation. It is considered that the larger aerosol particles would be more efficient for scavenging at marine boundary layer. In addition, the aerosol number concentration with divergence and convergence could be related with the occurrence and mechanism of aerosol in marine boundary layer.

To understand the development mechanism of the aerosols in the surface boundary layer, the variation in the aerosol number concentration due to the divergence and convergence of the wind fields was investigated. The aerosol number concentration was measured in the size ranges of 0.3∼10.0 ㎛ using a laser particle counter(LPC) from 0000 LST on 03 Feb. to 0600 LST on 07 Feb. 2004 at Mokpo in Korea during snowfall. The Velocity Azimuth Display(VAD) technique was used to retrieve the radar wind fields such as the horizontal wind field, divergence, and deformations including the vertical air velocity from a single Doppler radar. As a result, the distribution of the aerosol number concentration is apparently different for particles larger than 1 ㎛ during snowfall, and it has a tendency to increase at the beginning of the snowfall. The increase and decrease in the aerosol concentration due to the convergence and divergence of the wind fields corresponded to the particles with diameters greater than 1 ㎛. It is found that the fluctuations in the aerosol number concentration are well correlated with the development and dissipation of snowfall radar echoes due to the convergence and divergence of horizontal wind fields near the surface boundary layer in the inland during the snowfall.

This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3～1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss SO42-, nss S, NO3-, K and C showed the double peak pattern, high in April～May and August～September and showed the lowest concentration in Winter. The other constituents concentration except for Cl-, Na, Mg was high in local trajectory than marine trajectory. A ratio nss SO42- to SO42- was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss SO42- and nss S decreased but the the springtime concentration increased.