• Korean Journal of Remote Sensing
• /
• v.34 no.3
• /
• pp.507-517
• /
• 2018

Aerosol optical depth (AOD) data retrieved by the Communication, Ocean and Meteorological Satellite (COMS) during 2011-2014 were compared with AOD measurements from 134 Aerosol Robotic Network (AERONET) sites over the East Asia. Overall, COMS and AERONET AODs were weakly correlated (R = 0.297). The agreement between COMS and AERONET AODs was improved when data from near Korean peninsula sites were selected (R = 0.475). Regression analysis results for each AERONET site are vary from R=0.026 at AOE_Baotou to 0.905 at DRAGON_Anmyeon. It was also shown that the bias in COMS AOD was not systematic with respect to effective radius, precipitable water, surface reflectance, and sun zenith angle. Together, these results suggest that COMS AOD measurements may be suitable for near Korea. Finally, the current results will help to improve the retrieval algorithm and vary when using alternative COMS AOD version in the future.

• Atmosphere
• /
• v.34 no.3
• /
• pp.233-255
• /
• 2024

This study analyzed the distribution of Aerosol Robotic Network (AERONET) Version 3 Level 2.0 data, spanning over two decades, across South Korea and its six administrative regions (Seoul metropolitan area, Chungcheong, Jeolla, Gangwon, Gyeongsang, and Jeju). The research assessed long-term trends in aerosol optical depth (AOD) and mass concentration of particulate matter (i.e., PM₁₀ and PM_2.5), using data from the AERONET direct sun product and AirKorea, respectively. Additionally, eight aerosol types were identified using the scattering Ångström exponent and absorption Ångström exponent from the AERONET inversion product. The study further explored their domestic and regional distributions. Findings indicated that AERONET data were predominantly concentrated in the western regions of South Korea, including the Seoul metropolitan area, Chungcheong, and Jeolla, with a higher frequency of data in spring, thus demonstrating spatial and temporal heterogeneity. The annual average AOD exhibited a declining trend of -0.006 yr^-1. Similarly, PM₁₀ and PM_2.5 mass concentrations decreased by -1.324 ㎍ m^-3 yr^-1 and -1.335 ㎍ m^-3 yr^-1, respectively. These trends in AOD and PM₁₀ (PM_2.5) demonstrated positive correlations, with correlation coefficients of 0.674 (0.753) and statistically significant low p-values of 0.00058 (0.03), respectively. The analysis also revealed that aerosols in South Korea predominantly consisted of black carbon (BC) or BC-mixed types (84.09%), with a notable presence of smaller, less absorbent aerosol types (13.11%).

• Journal of Korean Society for Atmospheric Environment
• /
• v.34 no.5
• /
• pp.668-676
• /
• 2018

This study has developed a technique to divide the aerosol optical depth of the entire aerosol (${\tau}_{total}$) into the dust optical depth (${\tau}_D$) and the pollution particle optical depth (${\tau}_P$) using the AERONET sun/sky radiometer data provided in Version 3. This method was applied to the analysis of AERONET data observed from 2006 to 2016 in Beijing, China, Seoul and Gosan, Korea and Osaka, Japan and the aerosol optical depth trends of different types of atmospheric aerosols in Northeast Asia were analyzed. The annual variation of ${\tau}_{total}$ showed a tendency to decrease except for Seoul where observation data were limited. However, ${\tau}_D$ tended to decrease when ${\tau}_{total}$ were separated as ${\tau}_D$ and ${\tau}_P$, but ${\tau}_P$ tended to increase except for Osaka. This is because the concentration of airborne aerosols, represented by Asian dust in Northeast Asia, is decreased in both mass concentration and optical concentration. However, even though the mass concentration of pollution particles generated by human activity tends to decrease, Which means that the optical concentration represented as aerosol optical depth is increasing in Northeast Asia.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2009.10a
• /
• pp.477-479
• /
• 2009

• Korean Journal of Remote Sensing
• /
• v.32 no.3
• /
• pp.245-251
• /
• 2016

We present linear particle depolarization ratio at 440, 675, 870, and 1020 nm retrieved from measurements with an AERONET sun/sky radiometer at the source region of Asian dust, Dunhuang. The linear particle depolarization ratios are retrieved at the two receptor sites (Gosan and Osaka). The highest linear particle depolarization ratio of 0.34 at 1020 nm is retrieved from nearly pure Asian dust. The linear particle depolarization ratio decreased as the volume concentration of fine-mode particle increased. We can confirm that the ratio of Asian dust is changed by the value of the linear particle depolarization ratio retrieved by AERONET data.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.305-307
• /
• 2006

A multi-spectral photometer was set up as an NASA/AERONET site at Kinki University campus in Higashi-Osaka in 2002 for measuring urban aerosols. In addition, the SPM-613D (Kimoto Electric) commenced measurement of suspended particles matter (SPM) as $PM_{10}$ and $PM_{2.5}$ on March 15, 2004 at the same AERONET site. The obtained results revealed that the poor air quality of the Higashi-Osaka site is due not only to anthropogenic particles from local emissions, such as diesel vehicles and chemical industries, but also to dust particles brought from continental desert areas by large scale climatic conditions. To understand the characteristics of background atmosphere over Higashi-Osaka, we examined the relationship between $PM_{2.5}$ concentration and aerosol optical thickness (AOT) at a wavelength of 0.87 μm based on AERONET data for background atmosphere (AOT<0.2). We obtained a linear regression line between AOT and $PM_{2.5}$ concentration. Using the linear relationships between AOT and $PM_{2.5}$, we show ground-level concentrations of $PM_{2.5}$ of background atmosphere from Terra/MODIS satellite measurements.

• Korean Journal of Remote Sensing
• /
• v.36 no.2_1
• /
• pp.93-101
• /
• 2020

For the first time in Korea, aerosol type was separated as PD (Pure dust), DDM (Dust Dominant Mixed), PDM (Pollution Dominant Mixed), NA (Non-Absorbing), WA (Weakly Absorbing), MA (Moderately Absorbing), and SA (Strongly Absorbing) using depolarization ratio and single-scattering albedo based on AERONET sunphotometer data. Then, seasonal and annual occurrence frequency and AOD variation are analyzed. The proportion of pollution aerosols (NA, WA, MA, SA combined) was 58.9, 46.2, 59.5, and 67.1% at Anmyeon, Gosan, Gwangju, Seoul, respectively, with Seoul being the highest and the lowest at Gosan. Annual rate changestended to increase NA and decrease PD and DDM. The AOD by type showed the highest NA at all sites. In addition, the ratio of NA and AOD continued to increase.

• Korean Journal of Remote Sensing
• /
• v.24 no.4
• /
• pp.369-379
• /
• 2008

The aerosol retrieval algorithm for the Moderate Resolution Imaging Spectroradiometer (MODIS) measurements was updated recently. This paper reports on the comparison and validation of two latest versions (Collection 4 and 5, shortly C004 and C005) of the MODIS aerosol product over northeast Asian region. The differences between the aerosol optical thickness (AOT) from the C004 and C005 retrieval algorithms and the correlation with ground based AERONET sunphotometer observations are investigated. Over the study region, spatially averaged annual mean AOT retrieved from C005 algorithm $(AOT_{C005})$ is about 0.035 AOT (5%) less than the C004 counterparts. The linear correlations between MODIS and AERONET AOT also are R=0.89 (slope=0.86) for the C004 and R=0.95 (slope=1.00) for the C005. Moreover, the magnitude of the mean error in $AOT_{C005}$, difference between MODIS AOT and AERONET AOT, is 40% less than that in $AOT_{C004}$.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2002.04a
• /
• pp.127-128
• /
• 2002

대기 중 에어러솔이 지구의 복사수지에 미치는 영향을 파악하기 위한 연구들은 여러 각도에서 수행되고 있다. 2001년 봄철에 진행된 ACE-Asia 뿐만 아니라, ACE, ACE2, TARFOX, INDOEX 등등의 여러 집중 측정연구들이 수행되었다. 그러나 에어러솔 관측자료의 시공간적 한계는 여전히 남아있으며, 위성관측을 통한 에어러솔의 분석도, 다양한 지표면 상태 및 에어러솔의 특성에 대한 불완전한 가정 등으로 인해 충분한 정보를 제공하지 못하고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2001.11a
• /
• pp.283-284
• /
• 2001

라이다를 이용한 지구환경 감시 기술이 발전하고 대기 중 에어러솔에 대한 전지구적인 관측자료의 필요성이 증가하고 있다. 이와 동시에 관측결과의 신뢰성을 높이는데 필수적인 에어러솔에 대한 기본 정보, 특히 S-ratio(extinction to backscattering ratio)에 대한 데이터 베이스가 요구되고 있다. 특히, 2004년 발사 예정인 위성탑재 라이다 ESSP3(Earth System Science Pathfinder 3)와 같이 전 지구를 관측대상으로 하는 경우에는 전지구적인 S-ratio 자료가 특별히 요구된다. (중략)