High-resolution mapping of SO2 using airborne observations from the GeoTASO instrument during the KORUS-AQ field study: PCA-based vertical column retrievals

Heesung Chong; Seoyoung Lee; Jhoon Kim; Ukkyo Jeong; Can Li; Nickolay A. Krotkov; Caroline R. Nowlan; Jassim A. Al-Saadi; Scott J. Janz; Matthew G. Kowalewski; Myoung Hwan Ahn; Mina Kang; Joanna Joiner; David P. Haffner; Lu Hu; Patricia Castellanos; L. Gregory Huey; Myungje Choi; Chul H. Song; Kyung Man Han; Ja Ho Koo

doi:10.1016/j.rse.2020.111725

High-resolution mapping of SO₂ using airborne observations from the GeoTASO instrument during the KORUS-AQ field study: PCA-based vertical column retrievals

Heesung Chong, Seoyoung Lee, Jhoon Kim, Ukkyo Jeong, Can Li, Nickolay A. Krotkov, Caroline R. Nowlan, Jassim A. Al-Saadi, Scott J. Janz, Matthew G. Kowalewski, Myoung Hwan Ahn, Mina Kang, Joanna Joiner, David P. Haffner, Lu Hu, Patricia Castellanos, L. Gregory Huey, Myungje Choi, Chul H. Song, Kyung Man HanJa Ho Koo

Chemistry

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is an airborne hyperspectral spectrometer measuring backscattered solar radiation in the ultraviolet (290–400 nm) and visible (415–695 nm) wavelength regions. This paper presents high-resolution sulfur dioxide (SO₂) maps over the Korean Peninsula, produced by SO₂ retrievals from GeoTASO measurements during the Korea–United States Air Quality Field Study (KORUS-AQ) from May to June 2016. The highly sensitive GeoTASO instrument with a spatial resolution of ~250 m × 250 m can detect point emission sources of SO₂ within its fields of view, even without merging multiple overlapping observations. To retrieve SO₂ vertical columns from the GeoTASO measurements, we apply an algorithm based on principal component analysis (PCA), which is effective in suppressing noise and biases in SO₂ retrievals. The retrievals successfully capture SO₂ plumes and various point sources such as power plants, a petrochemical complex, and a steel mill, located in South Chungcheong Province, some of which are not detected by a ground-based in situ measurement network. Spatial distributions of SO₂ from GeoTASO observations in source areas are consistent with those from the Stack Tele-Monitoring System reports and airborne in situ SO₂ measurements. Comparisons of SO₂ retrievals from GeoTASO and existing satellite sensors demonstrate the significance of high-resolution SO₂ observations, by indicating that GeoTASO detects small SO₂ emission sources that are not precisely resolved by single overpasses of satellites. To assess future geostationary SO₂ observations having a higher spatial resolution, we upscale the GeoTASO SO₂ retrievals to a spatial resolution of the Geostationary Environment Monitoring Spectrometer (GEMS). Since the upscaled GeoTASO retrievals also detect SO₂ plumes clearly, we expect from GEMS to identify even small SO₂ emission sources over Asia.

Original language	English
Article number	111725
Journal	Remote Sensing of Environment
Volume	241
DOIs	https://doi.org/10.1016/j.rse.2020.111725
State	Published - May 2020

Funding

This subject was supported by Korea Ministry of Environment (MOE) as the Public Technology Program based on Environmental Policy ( 2017000160001 ). We thank all members of the KORUS-AQ science team for their contributions to the field study and the data processing (doi:10.5067/Suborbital/KORUSAQ/DATA01). We thank NIER, all principal investigators, and their staff of AirKorea for establishing and maintaining the AirKorea stations used in this investigation. We would like to acknowledge all staff involved in the Stack TMS reports for operating the whole system and the free use of the data. We also thank the principal investigators of the Anmyon AERONET site, Je Gyu Ryu and Sang-Ok Han, and all staff for establishing and maintaining the monitoring site during the KORUS-AQ period. We acknowledge the free use of the OMSO2, OMSO2e, OMPS_NPP_NMSO2_PCA_L2, OMLER, and ERA5 datasets. A URL address where each of the data is available is stated in references below. This subject was supported by Korea Ministry of Environment (MOE) as the Public Technology Program based on Environmental Policy (2017000160001). We thank all members of the KORUS-AQ science team for their contributions to the field study and the data processing (doi:10.5067/Suborbital/KORUSAQ/DATA01). We thank NIER, all principal investigators, and their staff of AirKorea for establishing and maintaining the AirKorea stations used in this investigation. We would like to acknowledge all staff involved in the Stack TMS reports for operating the whole system and the free use of the data. We also thank the principal investigators of the Anmyon AERONET site, Je Gyu Ryu and Sang-Ok Han, and all staff for establishing and maintaining the monitoring site during the KORUS-AQ period. We acknowledge the free use of the OMSO2, OMSO2e, OMPS_NPP_NMSO2_PCA_L2, OMLER, and ERA5 datasets. A URL address where each of the data is available is stated in references below.

Funders	Funder number
Ministry of Education	2017000160001
Ministry of Environment, Turkey
National Environmental Research Institute	OMPS_NPP_NMSO2_PCA_L2

Keywords

Airborne remote sensing
GEMS
GeoTASO
KORUS-AQ
PCA technique
SO

Access to Document

10.1016/j.rse.2020.111725

Cite this

Chong, H., Lee, S., Kim, J., Jeong, U., Li, C., Krotkov, N. A., Nowlan, C. R., Al-Saadi, J. A., Janz, S. J., Kowalewski, M. G., Ahn, M. H., Kang, M., Joiner, J., Haffner, D. P., Hu, L., Castellanos, P., Huey, L. G., Choi, M., Song, C. H., ... Koo, J. H. (2020). High-resolution mapping of SO₂ using airborne observations from the GeoTASO instrument during the KORUS-AQ field study: PCA-based vertical column retrievals. Remote Sensing of Environment, 241, Article 111725. https://doi.org/10.1016/j.rse.2020.111725

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title = "High-resolution mapping of SO2 using airborne observations from the GeoTASO instrument during the KORUS-AQ field study: PCA-based vertical column retrievals",

abstract = "The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is an airborne hyperspectral spectrometer measuring backscattered solar radiation in the ultraviolet (290–400 nm) and visible (415–695 nm) wavelength regions. This paper presents high-resolution sulfur dioxide (SO2) maps over the Korean Peninsula, produced by SO2 retrievals from GeoTASO measurements during the Korea–United States Air Quality Field Study (KORUS-AQ) from May to June 2016. The highly sensitive GeoTASO instrument with a spatial resolution of ~250 m × 250 m can detect point emission sources of SO2 within its fields of view, even without merging multiple overlapping observations. To retrieve SO2 vertical columns from the GeoTASO measurements, we apply an algorithm based on principal component analysis (PCA), which is effective in suppressing noise and biases in SO2 retrievals. The retrievals successfully capture SO2 plumes and various point sources such as power plants, a petrochemical complex, and a steel mill, located in South Chungcheong Province, some of which are not detected by a ground-based in situ measurement network. Spatial distributions of SO2 from GeoTASO observations in source areas are consistent with those from the Stack Tele-Monitoring System reports and airborne in situ SO2 measurements. Comparisons of SO2 retrievals from GeoTASO and existing satellite sensors demonstrate the significance of high-resolution SO2 observations, by indicating that GeoTASO detects small SO2 emission sources that are not precisely resolved by single overpasses of satellites. To assess future geostationary SO2 observations having a higher spatial resolution, we upscale the GeoTASO SO2 retrievals to a spatial resolution of the Geostationary Environment Monitoring Spectrometer (GEMS). Since the upscaled GeoTASO retrievals also detect SO2 plumes clearly, we expect from GEMS to identify even small SO2 emission sources over Asia.",

keywords = "Airborne remote sensing, GEMS, GeoTASO, KORUS-AQ, PCA technique, SO",

author = "Heesung Chong and Seoyoung Lee and Jhoon Kim and Ukkyo Jeong and Can Li and Krotkov, {Nickolay A.} and Nowlan, {Caroline R.} and Al-Saadi, {Jassim A.} and Janz, {Scott J.} and Kowalewski, {Matthew G.} and Ahn, {Myoung Hwan} and Mina Kang and Joanna Joiner and Haffner, {David P.} and Lu Hu and Patricia Castellanos and Huey, {L. Gregory} and Myungje Choi and Song, {Chul H.} and Han, {Kyung Man} and Koo, {Ja Ho}",

note = "Publisher Copyright: {\textcopyright} 2020",

year = "2020",

month = may,

doi = "10.1016/j.rse.2020.111725",

language = "English",

volume = "241",

journal = "Remote Sensing of Environment",

issn = "0034-4257",

publisher = "Elsevier Inc.",

}

Chong, H, Lee, S, Kim, J, Jeong, U, Li, C, Krotkov, NA, Nowlan, CR, Al-Saadi, JA, Janz, SJ, Kowalewski, MG, Ahn, MH, Kang, M, Joiner, J, Haffner, DP, Hu, L, Castellanos, P, Huey, LG, Choi, M, Song, CH, Han, KM & Koo, JH 2020, 'High-resolution mapping of SO₂ using airborne observations from the GeoTASO instrument during the KORUS-AQ field study: PCA-based vertical column retrievals', Remote Sensing of Environment, vol. 241, 111725. https://doi.org/10.1016/j.rse.2020.111725

TY - JOUR

T1 - High-resolution mapping of SO2 using airborne observations from the GeoTASO instrument during the KORUS-AQ field study

T2 - PCA-based vertical column retrievals

AU - Chong, Heesung

AU - Lee, Seoyoung

AU - Kim, Jhoon

AU - Jeong, Ukkyo

AU - Li, Can

AU - Krotkov, Nickolay A.

AU - Nowlan, Caroline R.

AU - Al-Saadi, Jassim A.

AU - Janz, Scott J.

AU - Kowalewski, Matthew G.

AU - Ahn, Myoung Hwan

AU - Kang, Mina

AU - Joiner, Joanna

AU - Haffner, David P.

AU - Hu, Lu

AU - Castellanos, Patricia

AU - Huey, L. Gregory

AU - Choi, Myungje

AU - Song, Chul H.

AU - Han, Kyung Man

AU - Koo, Ja Ho

PY - 2020/5

Y1 - 2020/5

N2 - The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is an airborne hyperspectral spectrometer measuring backscattered solar radiation in the ultraviolet (290–400 nm) and visible (415–695 nm) wavelength regions. This paper presents high-resolution sulfur dioxide (SO2) maps over the Korean Peninsula, produced by SO2 retrievals from GeoTASO measurements during the Korea–United States Air Quality Field Study (KORUS-AQ) from May to June 2016. The highly sensitive GeoTASO instrument with a spatial resolution of ~250 m × 250 m can detect point emission sources of SO2 within its fields of view, even without merging multiple overlapping observations. To retrieve SO2 vertical columns from the GeoTASO measurements, we apply an algorithm based on principal component analysis (PCA), which is effective in suppressing noise and biases in SO2 retrievals. The retrievals successfully capture SO2 plumes and various point sources such as power plants, a petrochemical complex, and a steel mill, located in South Chungcheong Province, some of which are not detected by a ground-based in situ measurement network. Spatial distributions of SO2 from GeoTASO observations in source areas are consistent with those from the Stack Tele-Monitoring System reports and airborne in situ SO2 measurements. Comparisons of SO2 retrievals from GeoTASO and existing satellite sensors demonstrate the significance of high-resolution SO2 observations, by indicating that GeoTASO detects small SO2 emission sources that are not precisely resolved by single overpasses of satellites. To assess future geostationary SO2 observations having a higher spatial resolution, we upscale the GeoTASO SO2 retrievals to a spatial resolution of the Geostationary Environment Monitoring Spectrometer (GEMS). Since the upscaled GeoTASO retrievals also detect SO2 plumes clearly, we expect from GEMS to identify even small SO2 emission sources over Asia.

AB - The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is an airborne hyperspectral spectrometer measuring backscattered solar radiation in the ultraviolet (290–400 nm) and visible (415–695 nm) wavelength regions. This paper presents high-resolution sulfur dioxide (SO2) maps over the Korean Peninsula, produced by SO2 retrievals from GeoTASO measurements during the Korea–United States Air Quality Field Study (KORUS-AQ) from May to June 2016. The highly sensitive GeoTASO instrument with a spatial resolution of ~250 m × 250 m can detect point emission sources of SO2 within its fields of view, even without merging multiple overlapping observations. To retrieve SO2 vertical columns from the GeoTASO measurements, we apply an algorithm based on principal component analysis (PCA), which is effective in suppressing noise and biases in SO2 retrievals. The retrievals successfully capture SO2 plumes and various point sources such as power plants, a petrochemical complex, and a steel mill, located in South Chungcheong Province, some of which are not detected by a ground-based in situ measurement network. Spatial distributions of SO2 from GeoTASO observations in source areas are consistent with those from the Stack Tele-Monitoring System reports and airborne in situ SO2 measurements. Comparisons of SO2 retrievals from GeoTASO and existing satellite sensors demonstrate the significance of high-resolution SO2 observations, by indicating that GeoTASO detects small SO2 emission sources that are not precisely resolved by single overpasses of satellites. To assess future geostationary SO2 observations having a higher spatial resolution, we upscale the GeoTASO SO2 retrievals to a spatial resolution of the Geostationary Environment Monitoring Spectrometer (GEMS). Since the upscaled GeoTASO retrievals also detect SO2 plumes clearly, we expect from GEMS to identify even small SO2 emission sources over Asia.

KW - Airborne remote sensing

KW - GEMS

KW - GeoTASO

KW - KORUS-AQ

KW - PCA technique

KW - SO

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U2 - 10.1016/j.rse.2020.111725

DO - 10.1016/j.rse.2020.111725

M3 - Article

AN - SCOPUS:85081017883

SN - 0034-4257

VL - 241

JO - Remote Sensing of Environment

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