{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T03:05:12Z","timestamp":1769915112950,"version":"3.49.0"},"reference-count":82,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2023,7,7]],"date-time":"2023-07-07T00:00:00Z","timestamp":1688688000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["2020R1A5A1019649"],"award-info":[{"award-number":["2020R1A5A1019649"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["20210002920012002"],"award-info":[{"award-number":["20210002920012002"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Institute for Information and Communications Technology Planning &amp; Evaluation","award":["2020R1A5A1019649"],"award-info":[{"award-number":["2020R1A5A1019649"]}]},{"name":"Institute for Information and Communications Technology Planning &amp; Evaluation","award":["20210002920012002"],"award-info":[{"award-number":["20210002920012002"]}]},{"name":"SungKyunKwan University and the BK21 FOUR (Graduate School Innovation)","award":["2020R1A5A1019649"],"award-info":[{"award-number":["2020R1A5A1019649"]}]},{"name":"SungKyunKwan University and the BK21 FOUR (Graduate School Innovation)","award":["20210002920012002"],"award-info":[{"award-number":["20210002920012002"]}]},{"name":"Ministry of Education (MOE, Korea)","award":["2020R1A5A1019649"],"award-info":[{"award-number":["2020R1A5A1019649"]}]},{"name":"Ministry of Education (MOE, Korea)","award":["20210002920012002"],"award-info":[{"award-number":["20210002920012002"]}]},{"name":"National Research Foundation of Korea (NRF)","award":["2020R1A5A1019649"],"award-info":[{"award-number":["2020R1A5A1019649"]}]},{"name":"National Research Foundation of Korea (NRF)","award":["20210002920012002"],"award-info":[{"award-number":["20210002920012002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Stringent global regulations aim to reduce nitrogen dioxide (NO2) emissions from maritime shipping. However, the lack of a global monitoring system makes compliance verification challenging. To address this issue, we propose a systematic approach to monitor shipping emissions using unsupervised clustering techniques on spatio-temporal georeferenced data, specifically NO2 measurements obtained from the TROPOspheric Monitoring Instrument (TROPOMI) on board the Copernicus Sentinel-5 Precursor satellite. Our method involves partitioning spatio-temporally resolved measurements based on the similarity of NO2 column levels. We demonstrate the reproducibility of our approach through rigorous testing and validation using data collected from multiple regions and time periods. Our approach improves the spatial correlation coefficients between NO2 column clusters and shipping traffic frequency. Additionally, we identify a temporal correlation between NO2 column levels along shipping routes and the global container throughput index. We expect that our approach may serve as a prototype for a tool to identify anthropogenic maritime emissions, distinguishing them from background sources.<\/jats:p>","DOI":"10.3390\/rs15133453","type":"journal-article","created":{"date-parts":[[2023,7,10]],"date-time":"2023-07-10T00:47:35Z","timestamp":1688950055000},"page":"3453","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Systematic Approach to Identify Shipping Emissions Using Spatio-Temporally Resolved TROPOMI Data"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5554-5057","authenticated-orcid":false,"given":"Juhuhn","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7342-2090","authenticated-orcid":false,"given":"Michael T. M.","family":"Emmerich","sequence":"additional","affiliation":[{"name":"Leiden Institute of Applied Computer Science, Leiden University, 2333 CA Leiden, The Netherlands"}]},{"given":"Robert","family":"Voors","sequence":"additional","affiliation":[{"name":"Airbus Netherlands, 2333 CS Leiden, The Netherlands"}]},{"given":"Barend","family":"Ording","sequence":"additional","affiliation":[{"name":"Airbus Netherlands, 2333 CS Leiden, The Netherlands"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5255-4425","authenticated-orcid":false,"given":"Jong-Seok","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2063","DOI":"10.1016\/S1352-2310(99)00460-4","article-title":"Atmospheric chemistry of VOCs and NOx","volume":"34","author":"Atkinson","year":"2000","journal-title":"Atmos. Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.envpol.2007.06.012","article-title":"Human health effects of air pollution","volume":"151","author":"Kampa","year":"2008","journal-title":"Environ. Pollut."},{"key":"ref_3","unstructured":"United States Environmental Protection Agency (2023, July 04). Nitrogen Dioxide (NO2) Pollution, Available online: https:\/\/www.epa.gov\/no2-pollution."},{"key":"ref_4","first-page":"73","article-title":"Exposure to nitrogen dioxide (NO2) and respiratory disease risk","volume":"13","author":"Chauhan","year":"1998","journal-title":"Rev. Environ. Health"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4440","DOI":"10.1021\/cr500487s","article-title":"Multiphase Chemistry at the Atmosphere\u2013Biosphere Interface Influencing Climate and Public Health in the Anthropocene","volume":"115","author":"Shiraiwa","year":"2015","journal-title":"Chem. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1126\/science.278.5339.823","article-title":"Emissions from Ships","volume":"278","author":"Corbett","year":"1997","journal-title":"Science"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2004JD005619","article-title":"Emissions from international shipping: 1. The last 50 years","volume":"110","author":"Eyring","year":"2005","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"8512","DOI":"10.1021\/es071686z","article-title":"Mortality from ship emissions: A global assessment","volume":"41","author":"Corbett","year":"2007","journal-title":"Environ. Sci. Technol."},{"key":"ref_9","unstructured":"International Maritime Organization (2023, June 21). International Maritime Organization: Feb 2019 Supplement: MARPOL Annex VI & NTC 2008 (IC664E), Available online: https:\/\/wwwcdn.imo.org\/localresources\/en\/publications\/Documents\/Supplements\/English\/QQC664E_022019.pdf."},{"key":"ref_10","unstructured":"British Broadcasting Corporation (2023, June 21). Shipping Industry Faces Calls to Clean Up Emissions. Available online: https:\/\/www.bbc.com\/news\/business-43696900."},{"key":"ref_11","unstructured":"Gerretsen, I. (2023, June 21). Shipping Is One of the Dirtiest Industries. Now It\u2019s Trying to Clean Up Its Act. Available online: https:\/\/edition.cnn.com\/2019\/10\/03\/business\/global-shipping-climate-crisis-intl\/index.html."},{"key":"ref_12","unstructured":"Palmer, C. (2023, June 21). Cruise Industry Faces Choppy Seas as It Tries to Clean Up Its Act On Climate. Available online: https:\/\/www.reuters.com\/business\/sustainable-business\/cruise-industry-faces-choppy-seas-it-tries-clean-up-its-act-climate-2022-07-27\/."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.rse.2011.09.027","article-title":"TROPOMI on the ESA Sentinel-5 Precursor: A GMES mission for global observations of the atmospheric composition for climate, air quality and ozone layer applications","volume":"120","author":"Veefkind","year":"2012","journal-title":"Remote. Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"124037","DOI":"10.1088\/1748-9326\/abc445","article-title":"Detection of NO2 pollution plumes from individual ships with the TROPOMI\/S5P satellite sensor","volume":"15","author":"Georgoulias","year":"2020","journal-title":"Environ. Res. Lett."},{"key":"ref_15","first-page":"183","article-title":"Proposed IMO Regulations for the Prevention of Air Pollution from Ships","volume":"26","author":"Okamura","year":"1995","journal-title":"J. Marit. Law Commer."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"7615","DOI":"10.1038\/ncomms8615","article-title":"Spatial and temporal changes in cumulative human impacts on the world\u2019s ocean","volume":"6","author":"Halpern","year":"2015","journal-title":"Nat. Commun."},{"key":"ref_17","unstructured":"Institute of Shipping Economics and Logistics (2023, June 21). RWI\/ISL Container Throughput Input Index: Revival of Global Trade. Available online: https:\/\/www.isl.org\/en\/containerindex."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.5194\/amt-5-1085-2012","article-title":"Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms","volume":"5","author":"Berg","year":"2012","journal-title":"Atmos. Meas. Tech."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1777","DOI":"10.5194\/amt-6-1777-2013","article-title":"Measurements of air pollution emission factors for marine transportation in SECA","volume":"6","author":"Lagler","year":"2013","journal-title":"Atmos. Meas. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"149","DOI":"10.5194\/amt-7-149-2014","article-title":"Mobile measurements of ship emissions in two harbour areas in Finland","volume":"7","author":"Pirjola","year":"2014","journal-title":"Atmos. Meas. Tech."},{"key":"ref_21","first-page":"2597","article-title":"Field test of available methods to measure remotely SOx and NOx emissions from ships","volume":"7","author":"Gast","year":"2013","journal-title":"Atmos. Meas. Tech. Discuss."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"L23110","DOI":"10.1029\/2004GL020822","article-title":"Satellite measurements of NO2 from international shipping emissions","volume":"31","author":"Richter","year":"2004","journal-title":"Geophys. Res. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"074007","DOI":"10.1088\/1748-9326\/10\/7\/074007","article-title":"Ships going slow in reducing their NOx emissions: Changes in 2005\u20132012 ship exhaust inferred from satellite measurements over Europe","volume":"10","author":"Boersma","year":"2015","journal-title":"Environ. Res. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.5194\/amt-15-1415-2022","article-title":"Improved monitoring of shipping NO2 with TROPOMI: Decreasing NOx emissions in European seas during the COVID-19 pandemic","volume":"15","author":"Riess","year":"2022","journal-title":"Atmos. Meas. Tech."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"234","DOI":"10.2307\/143141","article-title":"A Computer Movie Simulating Urban Growth in the Detroit Region","volume":"46","author":"Tobler","year":"1970","journal-title":"Econ. Geogr."},{"key":"ref_26","unstructured":"Wright, J.D. (2015). International Encyclopedia of the Social & Behavioral Sciences, Elsevier. [2nd ed.]."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.5194\/amt-4-1805-2011","article-title":"Influence of low spatial resolution a priori data on tropospheric NO2 satellite retrievals","volume":"4","author":"Heckel","year":"2011","journal-title":"Atmos. Meas. Tech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"6679","DOI":"10.5194\/amt-11-6679-2018","article-title":"A physics-based approach to oversample multi-satellite, multispecies observations to a common grid","volume":"11","author":"Sun","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5650","DOI":"10.1021\/acs.est.7b01356","article-title":"Formaldehyde (HCHO) As a Hazardous Air Pollutant: Mapping Surface Air Concentrations from Satellite and Inferring Cancer Risks in the United States","volume":"51","author":"Zhu","year":"2017","journal-title":"Environ. Sci. Technol."},{"key":"ref_30","first-page":"1","article-title":"Nitrogen Oxide Emissions from U.S. Oil and Gas Production: Recent Trends and Source Attribution","volume":"41","author":"Dix","year":"2019","journal-title":"Geophys. Res. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"12594","DOI":"10.1021\/acs.est.9b04488","article-title":"Enhanced Capabilities of TROPOMI NO2: Estimating NOx from North American Cities and Power Plants","volume":"53","author":"Goldberg","year":"2019","journal-title":"Environ. Sci. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"e2020EF001665","DOI":"10.1029\/2020EF001665","article-title":"TROPOMI NO2 in the United States: A detailed look at the annual averages, weekly cycles, effects of temperature, and correlation with surface NO2 concentrations","volume":"9","author":"Goldberg","year":"2021","journal-title":"Earth\u2019s Future"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1038\/s41586-021-04229-0","article-title":"Global fine-scale changes in ambient NO2 during COVID-19 lockdowns","volume":"601","author":"Cooper","year":"2022","journal-title":"Nature"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3269","DOI":"10.1002\/2017JD028009","article-title":"First Top-Down Estimates of Anthropogenic NOx Emissions Using High-Resolution Airborne Remote Sensing Observations","volume":"123","author":"Souri","year":"2018","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Kurchaba, S., van Vliet, J., Meulman, J.J., Verbeek, F.J., and Veenman, C.J. (2021, January 2\u20135). Improving Evaluation of NO2 Emission from Ships Using Spatial Association on TROPOMI Satellite Data. Proceedings of the 29th International Conference on Advances in Geographic Information Systems, 2021\u2014SIGSPATIAL \u201921, New York, NY, USA.","DOI":"10.1145\/3474717.3484213"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Kurchaba, S., van Vliet, J., Verbeek, F.J., Meulman, J.J., and Veenman, C.J. (2022). Supervised Segmentation of NO2 Plumes from Individual Ships Using TROPOMI Satellite Data. Remote. Sens., 14.","DOI":"10.3390\/rs14225809"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1023\/A:1007452223027","article-title":"Machine Learning for the Detection of Oil Spills in Satellite Radar Images","volume":"30","author":"Kubat","year":"1998","journal-title":"Mach. Learn."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Kuhn, M., and Johnson, K. (2013). Applied Predictive Modeling, Springer.","DOI":"10.1007\/978-1-4614-6849-3"},{"key":"ref_39","unstructured":"United States Environmental Protection Agency (2023, June 21). Nitrogen Oxides (NOx): Why and How They Are Controlled; EPA-456\/F-99-006R, Available online: https:\/\/www3.epa.gov\/ttn\/catc\/cica\/files\/fnoxdoc.pdf."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1007\/s10098-014-0793-9","article-title":"The pollutant emissions from diesel-engine vehicles and exhaust aftertreatment systems","volume":"17","author":"Keskin","year":"2015","journal-title":"Clean Technol. Environ. Policy"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1175\/1520-0469(1999)056<0151:TGOMEG>2.0.CO;2","article-title":"The Global Ozone Monitoring Experiment (GOME): Mission Concept and First Scientific Results","volume":"56","author":"Burrows","year":"1999","journal-title":"J. Atmos. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.1109\/TGRS.2006.872333","article-title":"The ozone monitoring instrument","volume":"44","author":"Levelt","year":"2006","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_43","unstructured":"van Geffen, J.H.G.M., Eskes, H.J., Boersma, K.F., and Veefkind, J.P. (2022). TROPOMI ATBD of the Total and Tropospheric NO2 Data Products, Royal Netherlands Meteorological Institute. Technical Report."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Platt, U., and Perner, D. (1983). Measurements of Atmospheric Trace Gases by Long Path Differential UV\/Visible Absorption Spectroscopy, Springer.","DOI":"10.1007\/978-3-540-39552-2_13"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"6041","DOI":"10.1364\/AO.35.006041","article-title":"Numerical analysis and estimation of the statistical error of differential optical absorption spectroscopy measurements with least-squares methods","volume":"35","author":"Stutz","year":"1996","journal-title":"Appl. Opt."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Platt, U., and Stutz, J. (2008). Differential Optical Absorption Spectroscopy: Principles and Applications, Springer. Physics of Earth and Space Environments.","DOI":"10.1007\/978-3-540-75776-4_6"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1109\/38.56302","article-title":"NetCDF: An interface for scientific data access","volume":"10","author":"Rew","year":"1990","journal-title":"IEEE Comput. Graph. Appl."},{"key":"ref_48","unstructured":"Eskes, H., van Geffen, J., Boersma, F., Eichmann, K.U., Apituley, A., Pedergnana, M., Sneep, M., Veefkind, J.P., and Loyola, D. (2023, June 21). Sentinel-5 Precursor\/TROPOMI Level 2 Product User Manual Nitrogendioxide. Available online: https:\/\/sentinel.esa.int\/documents\/247904\/2474726\/Sentinel-5P-Level-2-Product-User-Manual-Nitrogen-Dioxide.pdf."},{"key":"ref_49","unstructured":"Natural Earth Data (2023, June 21). Free Vector and Raster Map Data at 1:10m, 1:50m, and 1:110m Scales [data set]. Available online: https:\/\/www.naturalearthdata.com\/."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1109\/TPAMI.1987.4767941","article-title":"Image Analysis Using Mathematical Morphology","volume":"PAMI-9","author":"Haralick","year":"1987","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_51","first-page":"19","article-title":"An Introduction to Spatial Econometrics","volume":"123","author":"LeSage","year":"2008","journal-title":"Rev. Econ. Ind."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"LeSage, J.P., and Pace, R.K. (2009). Introduction to Spatial Econometrics, Chapman & Hall\/CRC.","DOI":"10.1201\/9781420064254"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"3833","DOI":"10.5194\/amt-10-3833-2017","article-title":"Airborne DOAS retrievals of methane, carbon dioxide, and water vapor concentrations at high spatial resolution: Application to AVIRIS-NG","volume":"10","author":"Thorpe","year":"2017","journal-title":"Atmos. Meas. Tech."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1111\/j.1538-4632.1992.tb00261.x","article-title":"The Analysis of Spatial Association by Use of Distance Statistics","volume":"24","author":"Getis","year":"1992","journal-title":"Geogr. Anal."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1111\/j.1538-4632.1995.tb00338.x","article-title":"Local Indicators of Spatial Association\u2014LISA","volume":"27","author":"Anselin","year":"1995","journal-title":"Geogr. Anal."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"5941","DOI":"10.5194\/amt-11-5941-2018","article-title":"Nitrogen dioxide and formaldehyde measurements from the GEOstationary Coastal and Air Pollution Events (GEO-CAPE) Airborne Simulator over Houston, Texas","volume":"11","author":"Nowlan","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"6113","DOI":"10.5194\/amt-13-6113-2020","article-title":"Evaluating Sentinel-5P TROPOMI tropospheric NO2 column densities with airborne and Pandora spectrometers near New York City and Long Island Sound","volume":"13","author":"Judd","year":"2020","journal-title":"Atmos. Meas. Tech."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Motulsky, H.J., and Brown, R.E. (2006). Detecting outliers when fitting data with nonlinear regression\u2014A new method based on robust nonlinear regression and the false discovery rate. BMC Bioinform., 7.","DOI":"10.1186\/1471-2105-7-123"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1111\/j.1538-4632.1995.tb00912.x","article-title":"Local Spatial Autocorrelation Statistics: Distributional Issues and an Application","volume":"27","author":"Ord","year":"1995","journal-title":"Geogr. Anal."},{"key":"ref_60","unstructured":"ArcGIS (2023, June 21). How Generate Spatial Weights Matrix Works. Available online: https:\/\/pro.arcgis.com\/en\/pro-app\/latest\/tool-reference\/spatial-statistics\/how-generate-spatial-weights-matrix-spatial-statis.htm."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/S0167-7152(96)00140-X","article-title":"Sparse spatial autoregressions","volume":"33","author":"Pace","year":"1997","journal-title":"Stat. Probab. Lett."},{"key":"ref_62","unstructured":"Shapiro, L.G., and Stockman, G.C. (2001). Computer Vision, Prentice Hall."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"246","DOI":"10.2478\/IJNAOE-2013-0130","article-title":"Determination of an economical shipping route considering the effects of sea state for lower fuel consumption","volume":"5","author":"Roh","year":"2013","journal-title":"Int. J. Nav. Archit. Ocean. Eng."},{"key":"ref_64","first-page":"801","article-title":"Sur la division des corps materiels en parties","volume":"4","author":"Steinhaus","year":"1956","journal-title":"Bull. Acad. Pol. Sci."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1109\/TIT.1982.1056489","article-title":"Least squares quantization in PCM. Bell Telephone Laboratories Paper. Published in journal much later: Lloyd, S.P.: Least squares quantization in PCM","volume":"28","author":"Lloyd","year":"1982","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_66","first-page":"281","article-title":"Some methods for classification and analysis of multivariate observations","volume":"Volume 1","author":"MacQueen","year":"1967","journal-title":"Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1145\/331499.331504","article-title":"Data clustering: A review","volume":"31","author":"Jain","year":"1999","journal-title":"ACM Comput. Surv."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1109\/T-C.1973.223640","article-title":"Clustering Using a Similarity Measure Based on Shared Near Neighbors","volume":"C-22","author":"Jarvis","year":"1973","journal-title":"IEEE Trans. Comput."},{"key":"ref_69","unstructured":"Arthur, D., and Vassilvitskii, S. (2007, January 7\u20139). K-means++: The advantages of careful seeding. Proceedings of the Eighteenth Annual ACM-SIAM Symposium on Discrete Algorithms, New Orleans, LO, USA."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1007\/BF02289263","article-title":"Who belongs in the family?","volume":"18","author":"Thorndike","year":"1953","journal-title":"Psychometrika"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1002\/jae.2740","article-title":"Measuring global economic activity","volume":"36","author":"Hamilton","year":"2019","journal-title":"J. Appl. Econom."},{"key":"ref_72","first-page":"100108","article-title":"World economic growth and seaborne trade volume: Quantifying the relationship","volume":"4","author":"Michail","year":"2020","journal-title":"Transp. Res. Interdiscip. Perspect."},{"key":"ref_73","unstructured":"United Nations Conference on Trade and Development (2023, June 21). COVID-19 and Maritime Transport: Impact and Responses, Available online: https:\/\/unctad.org\/webflyer\/covid-19-and-maritime-transport-impact-and-responses."},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Verschuur, J., Koks, E.E., and Hall, J.W. (2021). Global economic impacts of COVID-19 lockdown measures stand out in high-frequency shipping data. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0248818"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1080\/03088839.2021.1876937","article-title":"Forecasting COVID-19 impact on RWI\/ISL container throughput index by using SARIMA models","volume":"48","author":"Koyuncu","year":"2021","journal-title":"Marit. Policy Manag."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"5","DOI":"10.2307\/1928754","article-title":"General Considerations and Assumptions","volume":"1","author":"Persons","year":"1919","journal-title":"Rev. Econ. Stat."},{"key":"ref_77","unstructured":"Copernicus Atmosphere Monitoring Service (2023, June 21). CAMS Global Reanalysis (EAC4), Available online: https:\/\/www.ecmwf.int\/en\/forecasts\/dataset\/cams-global-reanalysis."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.5194\/acp-3-1285-2003","article-title":"Averaging kernels for DOAS total-column satellite retrievals","volume":"3","author":"Eskes","year":"2003","journal-title":"Atmos. Chem. Phys."},{"key":"ref_79","unstructured":"Richter, A., Hilboll, A., and Burrows, J.P. (May, January 27). Improving satellite retrievals of large tropospheric NO2 columns. Proceedings of the Geophysical Research Abstracts, EGU General Assembly 2014, Vienna, Austria."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"759","DOI":"10.5194\/amt-10-759-2017","article-title":"Structural uncertainty in air mass factor calculation for NO2 and HCHO satellite retrievals","volume":"10","author":"Lorente","year":"2017","journal-title":"Atmos. Meas. Tech."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"3457","DOI":"10.1029\/1998JD100040","article-title":"Global nitrogen and sulfur inventories for oceangoing ships","volume":"104","author":"Corbett","year":"1999","journal-title":"J. Geophys. Res."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"481","DOI":"10.5194\/amt-14-481-2021","article-title":"Ground-based validation of the Copernicus Sentinel-5P TROPOMI NO2 measurements with the NDACC ZSL-DOAS, MAX-DOAS and Pandonia global networks","volume":"14","author":"Verhoelst","year":"2021","journal-title":"Atmos. Meas. Tech."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/13\/3453\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:08:37Z","timestamp":1760126917000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/13\/3453"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,7,7]]},"references-count":82,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["rs15133453"],"URL":"https:\/\/doi.org\/10.3390\/rs15133453","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,7,7]]}}}