19 July 2017  |  NASA

NASA and South Korea used research aircraft for an intensive study in and around the Seoul metropolitan area in 2016 to address the country’s poor air quality and lay the groundwork for next-generation pollution-monitoring satellites. Credits: NASA

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For six weeks in the summer of 2016 scientists from the United States and the Republic of Korea intensively studied air pollution over the Korean peninsula. Their mission: to diagnose the complex causes of the country’s poor air quality and in so doing lay the groundwork for next-generation pollution monitoring from space that both nations plan to launch in the next few years.

Initial scientific results from the joint NASA-Korean field campaign released today identified several strategies to reduce ozone and particulate matter levels in the Seoul metropolitan area and rural sections of the country. Seoul is one of the world’s five most-populated urban areas.

High concentrations of nitrogen dioxide (red and yellow) were observed over Seoul on June 9, 2016, by the Geo-TASO instrument flying on a NASA aircraft; lower concentrations (green and blue) were measured in outlying areas. The instrument simulates views that will be collected by a future air-quality satellite.

Credits: NASA/Laura Judd

Scientists from NASA and South Korea’s National Institute of Environmental Research (NIER) presented findings from the Korea-United States Air Quality study (KORUS-AQ) to representatives of the Ministry of Environment at a scientific briefing in Seoul. The analysis will inform South Korean policymakers developing air quality strategies and identifying specific emission sources.

The 2016 KORUS-AQ field experiment targeted May and June, a time of year when local sources of pollution typically dominate South Korea’s air quality. During these months pollution from East Asia and China travels less frequently over the Korean peninsula due to weather conditions. The scientists collected data from space, sea, land, and air. Airborne sampling was accomplished using two instrumented aircraft from NASA and one from Hanseo University, Seosan.

Reducing ozone pollution and harmful fine particles in the air could be achieved by cutting emissions of nitrogen oxides and volatile organic compounds, the study found. Ozone at ground level is formed by chemical reactions between these gases in the presence of sunlight. These same gases also played a dominant role in the chemical formation of fine particulate matter, accounting for roughly half of the observed concentration. Overall, more than three-quarters of the particulate matter measured during the study was formed by secondary chemical reactions rather than being directly emitted from smokestacks or tailpipes.

“It’s an encouraging result to see there is a clear overlap in the sources that need to be targeted to improve both fine particle and ozone pollution,” said James Crawford, lead U.S. KORUS-AQ scientist from NASA’s Langley Research Center in Hampton, Virginia.

Emissions from cars and trucks are one of the major sources of nitrogen oxides, according to the study, and industrial solvents, particularly toluene, were identified as the dominant volatile organic compounds contributing to the formation of ozone and particulate matter.

Key sets of detailed measurements collected during KORUS-AQ of air chemistry and pollution over Seoul, from the surface to a height of 28,000 feet, are also being analyzed by NASA and Korean scientists working on new space missions that will for the first time measure air pollution hourly from geostationary orbit more than 22,000 miles away. These Earth-observing satellites will use reflected sunlight to detect certain pollutants throughout the atmosphere reaching miles above the surface. Determining how much of a target pollutant is at ground level where people live and breathe is a continuing challenge. Analysis of the KORUS-AQ data sets will help scientists learn how to better tease out these details from space.

NASA and South Korea are both preparing air quality satellite missions for launch to geostationary orbits within the next five years. First will be the NIER Geostationary Environment Monitoring Spectrometer (GEMS), followed by NASA’s Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument. TEMPO will make accurate hourly daytime measurements of tropospheric pollutants – ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, and aerosols – over the United States, Canada and Mexico. GEMS will provide similar data over East Asia.

Link To 미 NASA가 280억원 써 가며 한국 미세먼지 연구한 까닭은

지난해 5월2일~6월12일. 서울 방이동의 올림픽공원에는 대기오염물질과 농도를 측정하는 국내 주요장비가 총출동했다. 하늘에선 미 항공우주국(NASA)의 연구용 항공기 ‘DC-8’가 공원 상공을 지그재그로 샅샅이 훑었다. 우주에선 한국의 천리안위성, 미국 등의 MODIS, VIRS, MOPITT, OMI 위성 관측장비가 올림픽공원 지점의 오염물질 관측값을 전송했다. 지상·하늘·우주에서의 입체적 연구조사가 이뤄진 이유는 단 한 가지, 미세먼지와 오존 생성과정을 밝히기 위해서였다.

한국 정부와 미 항공우주국(NASA)이 합동으로 수행한 ‘한·미 협력 국내 대기질 공동 조사(KORUS-AQ)’결과 일부가 19일 공개됐다. 환경부와 국립환경원, NASA는 조사기간 동안 한국에서 발생한 초미세먼지(PM2.5)의 52%는 국내에서 생성된 것이라고 설명했다. 나머지 중에서 34%는 중국내륙에서, 9%는 북한에서 생겨난 것으로 조사됐다. 국내 대기에서 초미세먼지 2차 생성과 고농도 오존 발생에 큰 영향을 주는 물질로는 휘발성유기화합물과 질소산화물이 지목됐다. 두 화학물질을 줄이려는 노력만 해도 미세먼지·오존 완화에 도움이 될 것이라는 얘기다.

Thank you to SK for sharing this story with us @ ZG! 

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9/11/17 4ZG