{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T18:55:17Z","timestamp":1791226517558,"version":"4.1.0"},"reference-count":36,"publisher":"Optica Publishing Group","issue":"29","license":[{"start":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T00:00:00Z","timestamp":1790899200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/doi.org\/10.1364\/OA_License_v2#VOR"},{"start":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T00:00:00Z","timestamp":1790899200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/opg.optica.org\/policies\/opg-tdm-policy.json"}],"funder":[{"name":"Meteorological Research\n\t\t\t\t\t\tInstitute","id":[{"id":"https:\/\/ror.org\/031gqrq04","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":["opg.optica.org"],"crossmark-restriction":false},"short-container-title":["Appl. Opt."],"published-print":{"date-parts":[[2026,10,10]]},"abstract":"<jats:p>\n                    We present a three-wavelength differential absorption lidar (DIAL)\n\t\t\t\t\tmethod for the simultaneous retrieval of tropospheric ozone (O\n                    <jats:sub>3<\/jats:sub>\n                    ) and sulfur dioxide (\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    ). The system employs a single Nd:YAG\n\t\t\t\t\tlaser and a carbon dioxide (\n                    <jats:italic>CO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    ) Raman cell to generate three\n\t\t\t\t\tultraviolet laser wavelengths at 276, 287, and 299\u00a0nm. The\n\t\t\t\t\tnumber densities of O\n                    <jats:sub>3<\/jats:sub>\n                    and\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    are simultaneously retrieved by\n\t\t\t\t\tanalytically solving coupled DIAL equations using the three-wavelength\n\t\t\t\t\tobservation data. In contrast to conventional two-wavelength analyses\n\t\t\t\t\tthat are sensitive to the choice of wavelength pairs, the proposed\n\t\t\t\t\tthree-wavelength approach yields consistent retrieval results\n\t\t\t\t\tregardless of the wavelength combinations in the case where absorption\n\t\t\t\t\tcross sections are known. Spectrum factor calculations demonstrate\n\t\t\t\t\tthat the three wavelengths generated by stimulated Raman scattering\n\t\t\t\t\t(SRS) in\n                    <jats:italic>CO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    comprise one of the most suitable\n\t\t\t\t\twavelength sets for accurate differential absorption measurements\n\t\t\t\t\tusing Nd:YAG laser harmonics. Although the system is not optimized for\n\t\t\t\t\troutine monitoring of background\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    at typical environmental pollution\n\t\t\t\t\tlevels, it detected volcanic\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    at concentrations much lower than the\n\t\t\t\t\thuman odor threshold. Lidar observations in Tsukuba successfully\n\t\t\t\t\tdetected\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    plumes transported from Mt. Asama and\n\t\t\t\t\tMt. Oyama (Miyake Island), Japan. Thus, the proposed three-wavelength\n\t\t\t\t\tDIAL method provides increased measurement capability to the existing O\n                    <jats:sub>3<\/jats:sub>\n                    DIAL system by extending its\n\t\t\t\t\tapplication to the simultaneous observation of tropospheric O\n                    <jats:sub>3<\/jats:sub>\n                    and advected volcanic\n                    <jats:italic>SO<\/jats:italic>\n                    <jats:sub>2<\/jats:sub>\n                    over the height range of\n\t\t\t\t\t0.4\u20134\u00a0km without additional laser sources.\n                  <\/jats:p>","DOI":"10.1364\/ao.606751","type":"journal-article","created":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T13:00:09Z","timestamp":1789477209000},"page":"10128","update-policy":"https:\/\/doi.org\/10.1364\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Simultaneous observation of tropospheric O\n                    <sub>3<\/sub>\n                    and\u00a0volcanic SO\n                    <sub>2<\/sub>\n                    using a three-wavelength differential absorption lidar based on a Nd:YAG laser and\u00a0a\u00a0CO\n                    <sub>2<\/sub>\n                    Raman cell"],"prefix":"10.1364","volume":"65","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8430-0937","authenticated-orcid":true,"given":"Masahisa","family":"Nakazato","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/031gqrq04","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomohiro","family":"Nagai","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/031gqrq04","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8916-2695","authenticated-orcid":true,"given":"Tetsu","family":"Sakai","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/031gqrq04","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Osamu","family":"Uchino","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/031gqrq04","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"285","published-online":{"date-parts":[[2026,10,2]]},"reference":[{"key":"ao-65-29-10128-R1","doi-asserted-by":"publisher","first-page":"347","DOI":"10.1364\/OL.8.000347","type":"journal-article","volume":"8","author":"Uchino","year":"1983","journal-title":"Opt. Lett."},{"key":"ao-65-29-10128-R2","doi-asserted-by":"publisher","first-page":"2628","DOI":"10.1364\/AO.30.002628","type":"journal-article","volume":"30","author":"Grant","year":"1991","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R3","doi-asserted-by":"publisher","first-page":"3145","DOI":"10.1063\/1.1144769","type":"journal-article","volume":"65","author":"Kempfer","year":"1994","journal-title":"Rev. Sci. Instrum."},{"key":"ao-65-29-10128-R4","doi-asserted-by":"publisher","first-page":"832","DOI":"10.1175\/1520-0426(1989)006<0832:DTOMUA>2.0.CO;2","type":"journal-article","volume":"6","author":"Ancellet","year":"1989","journal-title":"J. Atmos. Oceanic\n\t\t\t\t\tTechnol."},{"key":"ao-65-29-10128-R5","doi-asserted-by":"publisher","first-page":"7045","DOI":"10.1364\/AO.33.007045","type":"journal-article","volume":"33","author":"Sunesson","year":"1994","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R6","doi-asserted-by":"publisher","first-page":"5509","DOI":"10.1364\/AO.37.005509","type":"journal-article","volume":"37","author":"Ancellet","year":"1998","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R7","type":"journal-article","article-title":"A new DIAL\n\t\t\t\t\tbased on a N2 Raman converter for ozone monitoring: design\n\t\t\t\t\tand application during the ESCOMPTE Campaign","volume-title":"Quadrennial Ozone Symposium (QOS)","author":"Simeonov","year":"2004"},{"key":"ao-65-29-10128-R8","doi-asserted-by":"publisher","first-page":"2269","DOI":"10.1364\/AO.46.002269","type":"journal-article","volume":"46","author":"Nakazato","year":"2007","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R9","doi-asserted-by":"publisher","first-page":"512","DOI":"10.1364\/AO.48.000512","type":"journal-article","volume":"48","author":"Machol","year":"2009","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R10","doi-asserted-by":"publisher","first-page":"4181","DOI":"10.1364\/AO.20.004181","type":"journal-article","volume":"20","author":"Fredriksson","year":"1981","journal-title":"Appl.\n\t\t\t\t\tOpt."},{"key":"ao-65-29-10128-R11","doi-asserted-by":"publisher","first-page":"722","DOI":"10.1364\/AO.23.000722","type":"journal-article","volume":"23","author":"Egeb\u00e4ck","year":"1984","journal-title":"Appl.\n\t\t\t\t\tOpt."},{"key":"ao-65-29-10128-R12","doi-asserted-by":"publisher","first-page":"4330","DOI":"10.1364\/AO.26.004330","type":"journal-article","volume":"26","author":"Edner","year":"1987","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R13","doi-asserted-by":"publisher","first-page":"419","DOI":"10.1007\/s003400050525","type":"journal-article","volume":"67","author":"Weibring","year":"1998","journal-title":"Appl.\n\t\t\t\t\tPhys. B"},{"key":"ao-65-29-10128-R14","doi-asserted-by":"publisher","first-page":"949","DOI":"10.1364\/AO.40.000949","type":"journal-article","volume":"40","author":"Fujii","year":"2001","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R15","doi-asserted-by":"publisher","first-page":"524","DOI":"10.1364\/AO.41.000524","type":"journal-article","volume":"41","author":"Fujii","year":"2002","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R16","doi-asserted-by":"publisher","first-page":"3583","DOI":"10.1364\/AO.42.003583","type":"journal-article","volume":"42","author":"Weibring","year":"2003","journal-title":"Appl.\n\t\t\t\t\tOpt."},{"key":"ao-65-29-10128-R17","doi-asserted-by":"publisher","first-page":"175","DOI":"10.1029\/91GL02793","type":"journal-article","volume":"19","author":"Hoff","year":"1992","journal-title":"Geophys. Res. Lett."},{"key":"ao-65-29-10128-R18","doi-asserted-by":"publisher","first-page":"18827","DOI":"10.1029\/94JD01515","type":"journal-article","volume":"99","author":"Edner","year":"1994","journal-title":"J. Geophys. Res."},{"key":"ao-65-29-10128-R19","doi-asserted-by":"publisher","first-page":"245","DOI":"10.1016\/S0143-8166(01)00098-7","type":"journal-article","volume":"37","author":"Svanberg","year":"2002","journal-title":"Opt. Lasers Eng."},{"key":"ao-65-29-10128-R20","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1016\/S0143-8166(01)00084-7","type":"journal-article","volume":"37","author":"Weibring","year":"2002","journal-title":"Opt. Lasers Eng."},{"key":"ao-65-29-10128-R21","doi-asserted-by":"publisher","first-page":"227","DOI":"10.1117\/12.466783","type":"journal-article","volume":"4891","author":"Kinoshita","year":"2003","journal-title":"Proc. SPIE"},{"key":"ao-65-29-10128-R22","doi-asserted-by":"publisher","first-page":"7073","DOI":"10.1016\/j.atmosenv.2004.01.061","type":"journal-article","volume":"38","author":"Seino","year":"2004","journal-title":"Atmos.\n\t\t\t\t\tEnviron."},{"key":"ao-65-29-10128-R23","doi-asserted-by":"publisher","first-page":"3541","DOI":"10.1364\/AO.24.003541","type":"journal-article","volume":"24","author":"Warren","year":"1985","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R24","doi-asserted-by":"publisher","first-page":"2827","DOI":"10.1364\/AO.24.002827","type":"journal-article","volume":"24","author":"Browell","year":"1985","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R25","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1002\/0471643173","volume-title":"Elastic Lidar","author":"Kovalev","year":"2004"},{"key":"ao-65-29-10128-R26","first-page":"19","article-title":"Chapter 2.\n\t\t\t\t\tMethodology","volume-title":"Instrument Development for\n\t\t\t\t\tAtmospheric Research and Monitoring","author":"AncelletBosenberg","year":"1997"},{"key":"ao-65-29-10128-R27","doi-asserted-by":"publisher","first-page":"25599","DOI":"10.1029\/94JD02187","type":"journal-article","volume":"99","author":"Vandaele","year":"1994","journal-title":"J. Geophys. Res."},{"key":"ao-65-29-10128-R28","doi-asserted-by":"publisher","first-page":"14501","DOI":"10.1029\/JD091iD13p14501","type":"journal-article","volume":"91","author":"Molina","year":"1986","journal-title":"J. Geophys. Res."},{"key":"ao-65-29-10128-R31","doi-asserted-by":"publisher","first-page":"605","DOI":"10.2151\/jmsj1965.72.4_605","type":"journal-article","volume":"72","author":"Fujimoto","year":"1994","journal-title":"J. Meteorol. Soc. Jpn."},{"key":"ao-65-29-10128-R32","doi-asserted-by":"publisher","first-page":"6225","DOI":"10.1364\/AO.38.006225","type":"journal-article","volume":"38","author":"Godin","year":"1999","journal-title":"Appl. Opt."},{"key":"ao-65-29-10128-R33","first-page":"35","type":"journal-article","volume":"64","author":"Ito","year":"2004","journal-title":"J. Aerol. Obs."},{"key":"ao-65-29-10128-R34","doi-asserted-by":"publisher","first-page":"1248","DOI":"10.1175\/2007JAMC1644.1","type":"journal-article","volume":"47","author":"Tsunematsu","year":"2008","journal-title":"J. Appl. Meteorol. Climatol."},{"key":"ao-65-29-10128-R35","volume-title":"Workbook of Atmospheric Dispersion\n\t\t\t\t\tEstimates","author":"Turner","year":"1970"},{"key":"ao-65-29-10128-R36","doi-asserted-by":"publisher","first-page":"371","DOI":"10.1016\/S0030-3992(01)00041-X","type":"journal-article","volume":"33","author":"Fiorani","year":"2001","journal-title":"Opt. Laser Technol."},{"key":"ao-65-29-10128-R39","doi-asserted-by":"publisher","first-page":"141","DOI":"10.1117\/1.602068","type":"journal-article","volume":"38","author":"Fukuchi","year":"1999","journal-title":"Opt. Eng."},{"key":"ao-65-29-10128-R40","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1117\/1.1347999","type":"journal-article","volume":"40","author":"Fukuchi","year":"2001","journal-title":"Opt. Eng."}],"container-title":["Applied Optics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/opg.optica.org\/viewmedia.cfm?URI=ao-65-29-10128&seq=0","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T18:34:55Z","timestamp":1791225295000},"score":1,"resource":{"primary":{"URL":"https:\/\/opg.optica.org\/abstract.cfm?URI=ao-65-29-10128"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,2]]},"references-count":36,"journal-issue":{"issue":"29","published-online":{"date-parts":[[2026]]},"published-print":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.1364\/ao.606751","relation":{},"ISSN":["1559-128X","2155-3165"],"issn-type":[{"value":"1559-128X","type":"print"},{"value":"2155-3165","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,2]]},"assertion":[{"value":"Optica Publishing Group","name":"publisher","label":"This article is maintained by"},{"value":"https:\/\/doi.org\/10.1364\/AO.606751","name":"articlelink","label":"Crossref DOI link to publisher maintained version"},{"value":"research-article","name":"content_type","label":"Article type"},{"value":"Screened by Similarity Check","name":"cross_check","label":"Similarity check"},{"value":"Yes","order":0,"name":"peer_reviewed","label":"Peer reviewed","group":{"name":"peer_review","label":"Peer review"}},{"value":"Single blind","order":1,"name":"review_process","label":"Review process","group":{"name":"peer_review","label":"Peer review"}},{"value":"25 May 2026","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"15 September 2026","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2 October 2026","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}},{"value":"\u00a9 2026 Optica Publishing Group. All rights, including\n\t\t\t\t\tfor text and data mining (TDM), Artificial Intelligence (AI) training,\n\t\t\t\t\tand similar technologies, are reserved.","name":"copyright","label":"Copyright"}]}}