{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T22:15:09Z","timestamp":1768342509013,"version":"3.49.0"},"reference-count":42,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2023,7,20]],"date-time":"2023-07-20T00:00:00Z","timestamp":1689811200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Institute of Environment Research (NIER)","award":["NIER-2023-01-01-023"],"award-info":[{"award-number":["NIER-2023-01-01-023"]}]},{"name":"Ministry of Environment (MOE) of the Republic of Korea","award":["NIER-2023-01-01-023"],"award-info":[{"award-number":["NIER-2023-01-01-023"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The regional and global scale of aerosols in the atmosphere can be quantified using the aerosol optical depth (AOD) retrieved from satellite observations. To obtain reliable satellite AODs, conducting consistent validations and refining retrieval algorithms are crucial. AODs and \u00c5ngstr\u00f6m exponents (AEs) measured with the aerosol robotic network (AERONET) are considered as the ground truth for satellite validations. AERONET AEs are used to collocate the wavelength of the AERONET AODs to those of the satellite AODs when there is a discordancy in their wavelengths. However, numerous validation studies have proposed different strategies by applying the AERONET AODs and AEs, and spatiotemporal collocation criteria. This study examined the impact of the wavelength and spatial collocation radius variations by comparing AODs at 550 nm derived from the geostationary ocean color imager (GOCI) with those obtained from the AERONET for the year 2016. The estimated AERONET AODs at 550 nm varied from 5.18% to 11.73% depending on the selection of AOD and AE, and the spatial collocation radii from 0 to 40 km, respectively. The longer the collocation radius and the higher the AODs, the greater the variability observed in the validation results. Overall, the selection of the spatial collocation radius had a stronger impact on the variability in the validation results obtained compared to the selection of the wavelength. The variability was also found in seasonal analysis. Therefore, it is recommended to carefully select the data wavelength and spatial collocation radius, consider seasonal effects, and provide this information when validating satellite AODs using AERONET.<\/jats:p>","DOI":"10.3390\/rs15143621","type":"journal-article","created":{"date-parts":[[2023,7,21]],"date-time":"2023-07-21T01:58:38Z","timestamp":1689904718000},"page":"3621","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Spectral and Spatial Dependencies in the Validation of Satellite-Based Aerosol Optical Depth from the Geostationary Ocean Color Imager Using the Aerosol Robotic Network"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6437-9123","authenticated-orcid":false,"given":"Mijeong","family":"Kim","sequence":"first","affiliation":[{"name":"Environmental Satellite Center, National Institute of Environmental Research, Incheon 22689, Republic of Korea"}]},{"given":"Kyunghwa","family":"Lee","sequence":"additional","affiliation":[{"name":"Environmental Satellite Center, National Institute of Environmental Research, Incheon 22689, Republic of Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2488-2840","authenticated-orcid":false,"given":"Myungje","family":"Choi","sequence":"additional","affiliation":[{"name":"Goddard Earth Sciences Technology and Research (GESTAR) II, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"Climate and Radiation Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1132","DOI":"10.1001\/jama.287.9.1132","article-title":"Lung Cancer, Cardiopulmonary Mortality, and Long-Term Exposure to Fine Particulate Air Pollution","volume":"287","author":"Pope","year":"2002","journal-title":"JAMA"},{"key":"ref_2","unstructured":"Parry, M., Canziani, O., Palutikof, J., Van der Linden, P., and Hanson, C. (2007). Climate Change 2007-Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Fourth Assessment Report of the IPCC, Cambridge University Press."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2457","DOI":"10.1002\/2013JD020188","article-title":"Assessment of OMI near-UV aerosol optical depth over land","volume":"119","author":"Ahn","year":"2014","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2229","DOI":"10.1175\/1520-0477(1999)080<2229:RSOTAF>2.0.CO;2","article-title":"Remote Sensing of Tropospheric Aerosols from Space: Past, Present, and Future","volume":"80","author":"King","year":"1999","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5699","DOI":"10.5194\/acp-18-5699-2018","article-title":"The Ozone Monitoring Instrument: Overview of 14 years in space","volume":"18","author":"Levelt","year":"2018","journal-title":"Atmos. Chem. Phys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2989","DOI":"10.5194\/amt-6-2989-2013","article-title":"The Collection 6 MODIS aerosol products over land and ocean","volume":"6","author":"Levy","year":"2013","journal-title":"Atmos. Meas. Tech."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1077","DOI":"10.1016\/j.rse.2009.12.021","article-title":"Algorithm for retrieval of aerosol optical properties over the ocean from the Geostationary Ocean Color Imager","volume":"114","author":"Lee","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"E1","DOI":"10.1175\/BAMS-D-18-0013.1","article-title":"New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)","volume":"101","author":"Kim","year":"2020","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0034-4257(98)00031-5","article-title":"AERONET\u2014A federated instrument network and data archive for aerosol characterization","volume":"66","author":"Holben","year":"1998","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"31333","DOI":"10.1029\/1999JD900923","article-title":"Wavelength dependence of the optical depth of biomass burning, urban, and desert dust aerosols","volume":"104","author":"Eck","year":"1999","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1175\/JAS3385.1","article-title":"The MODIS aerosol algorithm, products, and validation","volume":"62","author":"Remer","year":"2005","journal-title":"J. Atmos. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"13965","DOI":"10.1002\/2014JD022453","article-title":"MODIS Collection 6 aerosol products: Comparison between Aqua\u2019s e-Deep Blue, Dark Target, and \u201cmerged\u201d data sets, and usage recommendations","volume":"119","author":"Sayer","year":"2014","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"557","DOI":"10.5194\/acp-11-557-2011","article-title":"An analysis of the collection 5 MODIS over-ocean aerosol optical depth product for its implication in aerosol assimilation","volume":"11","author":"Shi","year":"2011","journal-title":"Atmos. Chem. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2823","DOI":"10.5194\/amt-4-2823-2011","article-title":"A critical examination of spatial biases between MODIS and MISR aerosol products\u2013application for potential AERONET deployment","volume":"4","author":"Shi","year":"2011","journal-title":"Atmos. Meas. Tech."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8889","DOI":"10.5194\/acp-12-8889-2012","article-title":"Estimating marine aerosol particle volume and number from Maritime Aerosol Network data","volume":"12","author":"Sayer","year":"2012","journal-title":"Atmos. Chem. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1761","DOI":"10.5194\/amt-5-1761-2012","article-title":"Global and regional evaluation of over-land spectral aerosol optical depth retrievals from SeaWiFS","volume":"5","author":"Sayer","year":"2012","journal-title":"Atmos. Meas. Tech."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Park, S.S., Kim, S.-W., Song, C.-K., Park, J.-U., and Bae, K.-H. (2020). Spatio-temporal variability of aerosol optical depth, total ozone and NO2 over East Asia: Strategy for the validation to the GEMS Scientific Products. Remote Sens., 12.","DOI":"10.3390\/rs12142256"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"593","DOI":"10.5194\/acp-14-593-2014","article-title":"Comparing ECMWF AOD with AERONET observations at visible and UV wavelengths","volume":"14","author":"Cesnulyte","year":"2014","journal-title":"Atmos. Chem. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2907","DOI":"10.5194\/acp-13-2907-2013","article-title":"Observationally-constrained estimates of global fine-mode AOD","volume":"13","author":"Lee","year":"2013","journal-title":"Atmos. Chem. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"8006","DOI":"10.1029\/2001GL013206","article-title":"A spatio-temporal approach for global validation and analysis of MODIS aerosol products","volume":"29","author":"Ichoku","year":"2002","journal-title":"Geophys. Res. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"D13","DOI":"10.1029\/2002JD002366","article-title":"MODIS observation of aerosols and estimation of aerosol radiative forcing over southern Africa during SAFARI 2000: MODIS observation of aerosols during Safari 2000","volume":"108","author":"Ichoku","year":"2003","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_22","first-page":"D10","article-title":"Quantitative evaluation and intercomparison of morning and afternoon Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol measurements from Terra and Aqua","volume":"110","author":"Ichoku","year":"2005","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"10399","DOI":"10.5194\/acp-10-10399-2010","article-title":"Global evaluation of the Collection 5 MODIS dark-target aerosol products over land","volume":"10","author":"Levy","year":"2010","journal-title":"Atmos. Chem. Phys."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"913","DOI":"10.5194\/amt-5-913-2012","article-title":"Multi-sensor Aerosol Products Sampling System (MAPSS)","volume":"5","author":"Petrenko","year":"2012","journal-title":"Atmos. Meas. Tech."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"7864","DOI":"10.1002\/jgrd.50600","article-title":"Validation and uncertainty estimates for MODIS Collection 6 \u201cDeep Blue\u201d aerosol data: Deep blue collection 6 validation","volume":"118","author":"Sayer","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"D10","DOI":"10.1029\/2004JD004706","article-title":"Multiangle Imaging Spectroradiometer (MISR) global aerosol optical depth validation based on 2 years of coincident Aerosol Robotic Network (AERONET) observations","volume":"110","author":"Kahn","year":"2005","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"D23209","DOI":"10.1029\/2010JD014601","article-title":"Multiangle Imaging SpectroRadiometer global aerosol product assessment by comparison with the Aerosol Robotic Network","volume":"115","author":"Kahn","year":"2010","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"7139","DOI":"10.1002\/2016JD024834","article-title":"Validation and expected error estimation of Suomi-NPP VIIRS aerosol optical thickness and \u00c5ngstr\u00f6m exponent with AERONET: Validation of VIIRS Aerosol Products","volume":"121","author":"Huang","year":"2016","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4619","DOI":"10.5194\/amt-12-4619-2019","article-title":"Validation, comparison, and integration of GOCI, AHI, MODIS, MISR, and VIIRS aerosol optical depth over East Asia during the 2016 KORUS-AQ campaign","volume":"12","author":"Choi","year":"2019","journal-title":"Atmos. Meas. Tech."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"e2020EA001290","DOI":"10.1029\/2020EA001290","article-title":"How Long Is Too Long? Variogram Analysis of AERONET Data to Aid Aerosol Validation and Intercomparison Studies","volume":"7","author":"Sayer","year":"2020","journal-title":"Earth Space Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"00163","DOI":"10.1525\/elementa.2020.00163","article-title":"The Korea\u2013United States Air Quality (KORUS-AQ) field study","volume":"9","author":"Crawford","year":"2021","journal-title":"Elem. Sci. Anth."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"169","DOI":"10.5194\/amt-12-169-2019","article-title":"Advancements in the Aerosol Robotic Network (AERONET) Version 3 database\u2013Automated near-real-time quality control algorithm with improved cloud screening for Sun photometer aerosol optical depth (AOD) measurements","volume":"12","author":"Giles","year":"2019","journal-title":"Atmos. Meas. Tech."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"655","DOI":"10.5194\/acp-18-655-2018","article-title":"An overview of mesoscale aerosol processes, comparisons, and validation studies from DRAGON networks","volume":"18","author":"Holben","year":"2018","journal-title":"Atmos. Chem. Phys."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.5194\/gmd-13-1055-2020","article-title":"Development of Korean Air Quality Prediction System version 1 (KAQPS v1) with focuses on practical issues","volume":"13","author":"Lee","year":"2020","journal-title":"Geosci. Model Dev."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3375","DOI":"10.5194\/amt-13-3375-2020","article-title":"The AERONET Version 3 aerosol retrieval algorithm, associated uncertainties and comparisons to Version 2","volume":"13","author":"Sinyuk","year":"2020","journal-title":"Atmos. Meas. Tech."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"117530","DOI":"10.1016\/j.atmosenv.2020.117530","article-title":"Influence of cloud, fog, and high relative humidity during pollution transport events in South Korea: Aerosol properties and PM2.5 variability","volume":"232","author":"Eck","year":"2020","journal-title":"Atmos. Environ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1377","DOI":"10.5194\/amt-9-1377-2016","article-title":"GOCI Yonsei Aerosol Retrieval (YAER) algorithm and validation during the DRAGON-NE Asia 2012 campaign","volume":"9","author":"Choi","year":"2016","journal-title":"Atmos. Meas. Tech."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"385","DOI":"10.5194\/amt-11-385-2018","article-title":"GOCI Yonsei aerosol retrieval version 2 products: An improved algorithm and error analysis with uncertainty estimation from 5-year validation over East Asia","volume":"11","author":"Choi","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_39","first-page":"156","article-title":"On the Atmospheric Transmission of Sun Radiation and on Dust in the Air","volume":"11","year":"1929","journal-title":"Geogr. Ann."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.atmosres.2016.06.006","article-title":"Wavelength dependence of \u00c5ngstr\u00f6m exponent and single scattering albedo observed by skyradiometer in Seoul, Korea","volume":"181","author":"Koo","year":"2016","journal-title":"Atmos. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"D07207","DOI":"10.1029\/2005JD006328","article-title":"Angstrom exponent and bimodal aerosol size distributions","volume":"111","author":"Schuster","year":"2006","journal-title":"J. Geophys. Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"4559","DOI":"10.1029\/2002JD002975","article-title":"Spectral discrimination of coarse and fine mode optical depth","volume":"108","author":"Eck","year":"2003","journal-title":"J. Geophys. Res. Atmos."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/14\/3621\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:15:56Z","timestamp":1760127356000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/14\/3621"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,7,20]]},"references-count":42,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["rs15143621"],"URL":"https:\/\/doi.org\/10.3390\/rs15143621","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,7,20]]}}}