Jae-Hyun Lim

PollyNET: a network of multiwavelength polarization Raman lidars

PollyNET is a growing global network of automatized multiwavelength polarization Raman lidars of type Polly (Althausen et al., 2009). The goal of this network is to conduct advanced remote measurements of aerosol profiles and clouds by the same type of instrument. Since 2006 this network assists the controlling and adjustment activities of Polly systems. A central facility receives the data from the Polly measurements. The observational data are displayed in terms of quicklooks at http://polly:tropos.de in near real time. In this way, the network serves as a central information platform for inquisitive scientists. PollyNET comprises permanent stations at Leipzig (Germany), Kuopio (Finland), Evora (Portugal), Baengnyeong Island (South Korea), Stockholm (Sweden), and Warsaw (Poland). Non-permanent stations have been used during several field experiments under both urban and very remote conditions - like the Amazon rainforest. These non-permanent stations were lasting from several weeks up to one year and have been located in Brazil, India, China, South Africa, Chile, and also aboard the German research vessels Polarstern and Meteor across the Atlantic. Within PollyNET the interaction and knowledge exchange is encouraged between the Polly operators. This includes maintenance support in system calibration procedures and distribution of latest hardware and software improvements. This presentation introduces the PollyNET. Main features of the Polly systems will be presented as well as recent instrumental developments. Some measurement highlights achieved within PollyNET are depicted.

Characteristics of PM Chemical Component during Haze Episode and Asian Dust at Gwang-ju

The aerosol characteristics between haze episode and Asian dust event were identified in January and March, 2013 in Gwang-ju of Korea to investigate the metal elements, ionic concentrations and carbonaceous particles of and . In the haze episode, the concentrations were increased 1~3.2 times of ionic species and 1.6~2.7 of metal elements. Especially, the concentration of , and consists of 50 percent in ionic species during haze episode that was higher than Asian dust event. This suggests that secondary aerosols from anthropogenic air pollution were mainly contributed by haze episode. During the Asian dust event, increase of metal concentrations was higher than haze episode because of remarkable increase of Ti, K and Fe originated from soil. The concentrations of carbonaceous particles were increased 2.5 times during haze episode, and 2.4 times of OC and 2.1 times of EC during Asian dust event in . However, these aerosol mass concentration does not affect the OC/EC ratio. The average equivalence ratios of cations/anions in were 0.99 in haze episodes and 0.94 during non-event day. The neutralization factor of was higher than that of . Futhermore, aerosol was aged due to atmospheric stagnation that might be affected by the haze episode.

Analysis of the Recent Trend of National Background PM 10 Concentrations over Korea, China, and Japan

The goal of this research is to examine the recent decade-long (2000~2014) trends of national background concentrations over China, Japan, and Korea. Based on the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project, which is three-party collaboration project among three countries, we investigated the long-term trends of national background PM10 concentrations in three countries over the recent 15 years, including the 2008 Beijing Olympic Game period. In accordance with the agreement among three countries, a total of 8 national background sites: three national background monitoring sites in China (2 sites in Dalian, and 1 in Xiamen), three sites in Korea (Ganghwa, Gosan, and Taean), and two sites in Japan (Oki and Rishiri), were chosen for the trend analysis. The results showed that Chinese background concentration recorded the highest level overall. However, the rapid declining recent trends of annual median (50-percentile) values were surprisingly detected since 2006 or 2007 in every site in China, with the most rapidly decreasing rate (-18.6±10.3%/year) over 2006~2007, and the second most rapidly decreasing rate (-18.0±1.5%/year) over 2007~2008. Based on the previous statistical literature, we concluded that this declining trends were due to the emission reduction of PM10 concentrations in China for 2008 Beijing Olympic Game. In Korea, Ganghwa was also showing the decreasing trends over the recent years since 2006, which is also well accorded with the decreasing period of Chinese background concentrations. Taean also implied some impact of Beijing Olympic Game, showing small but detectable decreasing trends, while Gosan showed the increasing tendencies probably due to the near-urban influences. However, since 2012, most sites in both China and Korea showed strong increasing trends, undoubtedly implying the increasement of both emission in 한·중·일 PM10 국가 배경농도 최근 경향 분석 361 J. Korean Soc. Atmos. Environ., Vol. 32, No. 4, 2016 1. 서 론 대기오염물질 배경농도란 대상 지역에서의 자체 인 위적 오염 발생원의 영향을 배제하여 자연적 배출량만 을 고려한 농도 수준으로서, 대상 지역의 자체 인위적 배출량을 최소화하였을 때 기대할 수 있는 대기오염물 질의 농도를 말한다 (Nopmongcol et al., 2016; EPA, 2014). 이때 대상 지역을 특정 지역 (혹은 국가)으로 특 정할 경우에 해당하는 지역 (국가) 배경농도는 인위적 오염물질이 아닌 자연적으로 배출되는 배출량뿐만 아 니라 장거리 수송되어 오는 농도까지 고려하는 농도이 므로, 풍상측 지역에서의 자연적 및 인위적 배출량의 영향을 모두 고려하는 개념으로 정의한다 (EPA, 2014; McKendry, 2006). 따라서 어느 지역 (국가)에서의 오염 물질 농도 감축을 위한 계획을 수립하는 것은 해당 지 역의 인위적인 활동으로 인해 발생하는 대기오염물질 의 기여도를 줄이는 것이 목표이므로, 예컨대 우리나 라의 PM10 농도의 감축을 위한 계획을 수립하고 결과 를 평가할 경우, PM10 배경농도를 파악하는 것은 국내 의 현실적인 PM10 규제 목표를 설정하고 평가할 때 중 요한 기준이 될 수 있다. 전 세계적으로 배경농도 분석에 대한 연구는 다양한 물질에 대하여 활발히 수행되어졌다. 한반도에서도 Rd, CFC, SO2, NO, O3, 미세먼지 등 여러 물질에 대한 배 경농도 측정 및 분석 또한 현재 수행되고 있으나 (Ko et al., 2014; Kang et al., 2012; Kim et al., 2001; Park et al., 1994; Kim et al., 1992), 특정 지점에서 단기 측정 값을 분석한 경우가 많은 편이라 한 지점에서 10년 이 상의 장기간의 추세에 대한 연구는 부족한 실정이다. 우리나라는 지정학적으로 중국 산둥 반도와 약 400 km 정도밖에 되지 않아, 동북아시아 지역의 가장 큰 오염물질 배출지역인 중국의 풍하측에 자리 잡고 있으 므로 편서풍을 타고 대륙으로부터 불어오는 황사와 같 은 자연배출량뿐만 아니라 중국에서 배출되는 인위적 인 배출량의 영향을 크게 받고 있어 이에 대한 영향 연구는 자주 보고되었다 (Choi et al., 2014; Lee et al., 2014; Park et al., 2012). 따라서 국내의 배출 규제와 목 표 수준을 논의하기 위해서는 국내 자체 배출량 규제 뿐만 아니라 국가 간 장거리 이동에 의한 월경성 대기 오염물질의 영향을 필수적으로 논의하여야 하므로 주 변 국가를 포함한 동북아시아 국가 배경농도에 대한 이해가 매우 필요하였다. 이에 따라 1990년대 이후 현 재까지 한·중·일 3국 정부 간 협의 하에 대기오염물 질 공동연구체계인 Long-range Transboundary Air Pollutants in Northeast Asia 사업 (이하 ‘LTP 사업’으로 명 명)이 발주되어 대기오염물질의 장거리 이동에 관한 국가 간 공동연구가 매우 오랫동안 진행되어 왔다. 특 히 대기오염물질의 장거리 이동에 관한 한·중·일 협 력 연구 중 대기오염물질들의 배출원-수용지 관계 (Source-Receptor Relationship)에 대한 모델링 연구는 3국 간 LTP 사업의 주요 이슈로 평가되고 있으며 (NIER, 2012a), 이와 연관된 측정 분석적 연구 또한 각 국가 배경농도 측정 지점들이 협의되어 국가별 배경농 도의 측정 분석적 연구가 병행되어 왔다. 본 연구에서 는 동북아시아 LTP 사업을 통해 수집된 한·중·일 국 가별 배경농도 측정소에서 2000년~2014년 측정된 미 세먼지 배경농도를 분석하여 그 경향성 및 계절적 특 성 등을 다양하게 분석하였다.

Investigation of aerosol optical properties for remote sensing through DRAGON (distributed regional aerosol gridded observation networks) campaign in Korea

Aerosols in the atmosphere, including dust and pollutants, scatters/absorbs solar radiation and change the microphysics of clouds, thus influencing the Earth’s energy budget, climate, air quality, visibility, agriculture and water circulation. Pollutants have also been reported to threaten the human health. The present research collaborated with the U.S. NASA and the U.S. Aerosol Robotic Network (AERONET) is to study the aerosol characteristics in East Asia and improve the long-distance transportation monitoring technology by analyzing the observations of aerosol characteristics in East Asia during Distributed Regional Aerosol Gridded Observation Networks (DRAGON) Campaign (March 2012-May 2012). The sun photometers that measure the aerosol optical characteristics were placed evenly throughout the Korean Peninsula and concentrated in Seoul and the metropolitan area. Observation data are obtained from the DRAGON campaign and the first year (2012) observation data (aerosol optical depth and aerosol spatial distribution) are analyzed. Sun photometer observations, including aerosol optical depth (AOD), are utilized to validate satellite observations from Geostationary Ocean Color Imager (GOCI) and Moderate Resolution Imaging Spectroradiometer (MODIS). Additional analysis is performed associated with the Northeast Asia, the Korean Peninsula in particular, to determine the spatial distribution of the aerosol.