{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T21:06:23Z","timestamp":1791839183743,"version":"4.3.4"},"reference-count":59,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5506","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[2001,2,9]]},"abstract":"<jats:p>The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution levels were observed over the entire northern Indian Ocean toward the Intertropical Convergence Zone at about 6\u00b0S. We show that agricultural burning and especially biofuel use enhance carbon monoxide concentrations. Fossil fuel combustion and biomass burning cause a high aerosol loading. The growing pollution in this region gives rise to extensive air quality degradation with local, regional, and global implications, including a reduction of the oxidizing power of the atmosphere.<\/jats:p>","DOI":"10.1126\/science.1057103","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T09:47:44Z","timestamp":1027763264000},"page":"1031-1036","source":"Crossref","is-referenced-by-count":641,"title":["The Indian Ocean Experiment: Widespread Air Pollution from South and Southeast Asia"],"prefix":"10.1126","volume":"291","author":[{"given":"J.","family":"Lelieveld","sequence":"first","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P. J.","family":"Crutzen","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."},{"name":"Center for Atmospheric Sciences, Scripps Institution of Oceanography, La Jolla, CA 92093\u20134922, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"V.","family":"Ramanathan","sequence":"additional","affiliation":[{"name":"Center for Atmospheric Sciences, Scripps Institution of Oceanography, La Jolla, CA 92093\u20134922, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M. O.","family":"Andreae","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C. A. M.","family":"Brenninkmeijer","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T.","family":"Campos","sequence":"additional","affiliation":[{"name":"National Center for Atmospheric Research, Boulder, CO 80303, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G. R.","family":"Cass","sequence":"additional","affiliation":[{"name":"School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332\u20130340, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. R.","family":"Dickerson","sequence":"additional","affiliation":[{"name":"Department of Meteorology, University of Maryland, College Park, MD 20742, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H.","family":"Fischer","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. A.","family":"de Gouw","sequence":"additional","affiliation":[{"name":"Utrecht University, 3584 CC Utrecht, Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Hansel","sequence":"additional","affiliation":[{"name":"University of Innsbruck, A-6020 Innsbruck, Austria."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Jefferson","sequence":"additional","affiliation":[{"name":"Climate Monitoring and Diagnostics Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80303, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Kley","sequence":"additional","affiliation":[{"name":"Research Centre Ju\u0308lich, ICG-2, D-52428, Ju\u0308lich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. T. J.","family":"de Laat","sequence":"additional","affiliation":[{"name":"Utrecht University, 3584 CC Utrecht, Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Lal","sequence":"additional","affiliation":[{"name":"Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, India."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M. G.","family":"Lawrence","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. M.","family":"Lobert","sequence":"additional","affiliation":[{"name":"Center for Atmospheric Sciences, Scripps Institution of Oceanography, La Jolla, CA 92093\u20134922, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"O. L.","family":"Mayol-Bracero","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. P.","family":"Mitra","sequence":"additional","affiliation":[{"name":"National Physical Laboratory, New Delhi 110 012, India."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T.","family":"Novakov","sequence":"additional","affiliation":[{"name":"Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. J.","family":"Oltmans","sequence":"additional","affiliation":[{"name":"Climate Monitoring and Diagnostics Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80303, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. A.","family":"Prather","sequence":"additional","affiliation":[{"name":"University of California, Riverside, CA 92521\u20130403, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T.","family":"Reiner","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H.","family":"Rodhe","sequence":"additional","affiliation":[{"name":"Department of Meteorology, Stockholm University, S-10691 Stockholm, Sweden."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H. A.","family":"Scheeren","sequence":"additional","affiliation":[{"name":"Utrecht University, 3584 CC Utrecht, Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Sikka","sequence":"additional","affiliation":[{"name":"40 Mausam Vihar, New Delhi 110051, India."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Williams","sequence":"additional","affiliation":[{"name":"Max-Planck-Institute for Chemistry, Post Office Box 3060, D-55020 Mainz, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","unstructured":"J. T. Houghton et al. Eds. Climate Change 1995: The Science of Climate Change (Cambridge Univ. Press Cambridge 1996)."},{"key":"e_1_3_1_3_2","unstructured":"G. Marland et al. Global Regional and National CO 2 Emissions (Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Oak Ridge TN 1999) (available at )."},{"key":"e_1_3_1_4_2","doi-asserted-by":"crossref","first-page":"2671","DOI":"10.1029\/97GL02800","volume":"24","author":"Elliot S.","year":"1997","unstructured":"Elliot S., et al., Geophys. Res. Lett. 24, 2671 (1997).","journal-title":"Geophys. Res. Lett."},{"key":"e_1_3_1_5_2","doi-asserted-by":"crossref","first-page":"1553","DOI":"10.1016\/S1352-2310(96)00236-1","volume":"31","author":"Arndt R. L.","year":"1997","unstructured":"Arndt R. L., Carmichael G. R., Streets D. G., Bhatti N., Atmos. Environ. 31, 1553 (1997).","journal-title":"Atmos. Environ."},{"key":"e_1_3_1_6_2","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1029\/1999GL900068","volume":"26","author":"Chameides W. L.","year":"1999","unstructured":"Chameides W. L., et al., Geophys. Res. Lett. 26, 867 (1999).","journal-title":"Geophys. Res. Lett."},{"key":"e_1_3_1_7_2","first-page":"711","volume":"29","author":"Hall D. O.","year":"1994","unstructured":"Hall D. O., Rosillo-Calle F., Woods J., Chemosphere 29, 711 (1994).","journal-title":"Chemosphere"},{"key":"e_1_3_1_8_2","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1016\/0360-5442(94)90053-1","volume":"19","author":"Sathaye J.","year":"1994","unstructured":"Sathaye J., Tyler S., Goldman N., Energy 19, 573 (1994).","journal-title":"Energy"},{"key":"e_1_3_1_9_2","unstructured":"V. Ramanathan et al. Indian Ocean Experiment (INDOEX) (C 4 publication #162 University of California San Diego CA 1996) (available at )."},{"key":"e_1_3_1_10_2","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1007\/BF01029689","volume":"64","author":"Krishnamurti T. N.","year":"1997","unstructured":"Krishnamurti T. N., Jha B., Rasch P. J., Ramanathan V., Meteorol. Atmos. Phys. 64, 123 (1997);","journal-title":"Meteorol. Atmos. Phys."},{"key":"e_1_3_1_10_3","unstructured":". For a review of the monsoon meteorology and the role of El Ni\u00f1o see"},{"key":"e_1_3_1_10_4","doi-asserted-by":"publisher","DOI":"10.1029\/97JC02719"},{"key":"e_1_3_1_11_2","unstructured":"Computer simulations with an interactive chemistry GCM have been performed at T63 resolution (1.8\u00b0 latitude and longitude). The chemistry GCM has been described by G. J. Roelofs and J. Lelieveld [ Tellus 49B 38 (1997)] and E. Roeckner et al. [ J. Clim. 12 3004 (1999)]. To represent actual meteorology we assimilated analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF) as described by A. T. J. de Laat et al. (35). The T63 resolution model version has been evaluated by A. S. Kentarchos G. J. Roelofs and J. Lelieveld [ J. Atmos. Sci. 57 2824 (2000)]. The chemistry scheme includes a representation of higher hydrocarbons as described by G. J. Roelofs and J. Lelieveld [ J. Geophys. Res. 105 22697 (2000)]."},{"key":"#cr-split#-e_1_3_1_12_2.1","unstructured":"Aerosol sampling as used at KCO the R\/V Brown and the C-130 aircraft and associated chemical analysis techniques are described by C. Leck and C. Persson [ Tellus 48B 272 (1996)]"},{"key":"#cr-split#-e_1_3_1_12_2.2","unstructured":"T. Novakov D. A. Hegg and P. V. Hobbs [ J. Geophys. Res. 102 30023 (1997)]"},{"key":"#cr-split#-e_1_3_1_12_2.3","unstructured":"L. S. Hughes et al. [ Environ. Sci. Technol. 32 1153 (1998)]"},{"key":"#cr-split#-e_1_3_1_12_2.4","unstructured":"M. O. Andreae et al. [ Tellus 52B 1066 (2000)]"},{"key":"#cr-split#-e_1_3_1_12_2.5","unstructured":"and H. Maring et al. [ J. Geophys. Res. 105 14677 (2000)]. Single-particle analysis was performed by aerosol time-of-flight spectrometry as described by P. J. Silva and K. A. Prather [ Environ. Sci. Technol. 31 3074 (1997)] and E. E. Gard et al. [ Science 279 1184 (1998)]. Aerosol measurements on the Citation aircraft were performed according to F. Schr\u00f6der and J. Str\u00f6m [ Atmos. Res. 44 333 (1997)]. On KCO and the C-130 aircraft aerosol optical properties were measured according to T. L. Anderson et al. [ J. Geophys. Res. 104 26793 (1999)] and P. J. Sheridan and J. A. Ogren [ J. Geophys. Res. 104 16793 (1999)]. At KCO four cascade impactors were operated simultaneously each with six stages (size ranges). The number of cascade impactor substrates analyzed resulting in Fig. 2 was 192."},{"key":"e_1_3_1_13_2","unstructured":"According to a review by J. Heintzenberg [ Tellus 41B 149 (1989)] in North America and Europe urban fine aerosols typically contain 28% sulfate 31% organics 9% BC 8% ammonium 6% nitrate and 18% other material (mean mass = 32 \u03bcg\/m 3 ); suburban aerosols contain 37% sulfate 24% organics 5% BC 11% ammonium 4% nitrate and 19% other material (mean mass = 15 \u03bcg\/m 3 ); and remote continental aerosols contain 22% sulfate 11% organics 3% BC 7% ammonium 3% nitrate and 56% other material (mean mass = 4.8 \u03bcg\/m 3 ). Additional data on different aerosol types consistent with this review are presented by J. H. Seinfeld and S. N. Pandis [ Atmospheric Chemistry and Physics (Wiley New York 1998)]."},{"key":"e_1_3_1_14_2","doi-asserted-by":"crossref","unstructured":"A. S. Ackerman et al. Science 288 1042 (2000).","DOI":"10.1126\/science.288.5468.1042"},{"key":"e_1_3_1_15_2","doi-asserted-by":"publisher","DOI":"10.1038\/35011039"},{"key":"e_1_3_1_15_3","unstructured":"; V. Ramanathan unpublished data."},{"key":"e_1_3_1_16_2","doi-asserted-by":"crossref","first-page":"22137","DOI":"10.1029\/1999JD900187","volume":"104","author":"Cooke W. F.","year":"1999","unstructured":"Cooke W. F., et al., J. Geophys. Res. 104, 22137 (1999);","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_16_3","unstructured":". The BC\/total carbon and organic carbon\/BC ratios observed during INDOEX much resemble those in urban Japan and Korea ["},{"key":"e_1_3_1_16_4","doi-asserted-by":"publisher","DOI":"10.1029\/2000GL011759"},{"key":"e_1_3_1_16_5","unstructured":"]. These ratios were nearly constant over the Indian Ocean whereas total carbon and BC were highly correlated ( r 2 = 0.81) providing strong indications of the primary nature of the INDOEX aerosol carbon."},{"key":"e_1_3_1_17_2","unstructured":"J. G. J. Olivier et al. Description of EDGAR Version 2 (RIVM Report 771060002 National Institute for Public Health and Environment Bilthoven Netherlands 1996) (available at ). An update is presented by J. A. van Aardenne et al. ( Global Biogeochem. Cycles in press. The EDGAR estimates of Asian CO emissions from biofuel combustion are about 20% lower compared with the inventory by D. G. Streets and S. T. Waldhoff [ Energy 24 841 (1999)]."},{"key":"e_1_3_1_18_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.250.4988.1669"},{"key":"e_1_3_1_19_2","doi-asserted-by":"crossref","first-page":"941","DOI":"10.1016\/S0301-4215(97)00090-6","volume":"25","author":"Srivastava L.","year":"1997","unstructured":"Srivastava L., Energy Policy 25, 941 (1997).","journal-title":"Energy Policy"},{"key":"e_1_3_1_20_2","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1016\/S0360-5442(98)00033-4","volume":"23","author":"Streets D. G.","year":"1998","unstructured":"Streets D. G., Waldhoff S. T., Energy 23, 1029 (1998).","journal-title":"Energy"},{"key":"e_1_3_1_21_2","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/S0301-4215(96)00105-X","volume":"25","author":"Ravindranath N. H.","year":"1997","unstructured":"Ravindranath N. H., Ramakrishna J., Energy Policy 25, 63 (1997).","journal-title":"Energy Policy"},{"key":"e_1_3_1_22_2","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/S0961-9534(97)10059-9","volume":"14","author":"Sinha C. S.","year":"1998","unstructured":"Sinha C. S., Sinha S., Joshi V., Biomass Bioenergy 14, 489 (1998).","journal-title":"Biomass Bioenergy"},{"key":"e_1_3_1_23_2","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/S0961-9534(99)00056-2","volume":"17","author":"Mahapartra A. K.","year":"1999","unstructured":"Mahapartra A. K., Mitchell C. P., Biomass Bioenergy 17, 291 (1999).","journal-title":"Biomass Bioenergy"},{"key":"e_1_3_1_24_2","unstructured":"The \u0394CH 3 CN\/\u0394CO molar ratio refers to the enhancement of these gases compared with background air. The lowest concentrations of CH 3 CN (140 pptv) and CO (50 ppbv) observed south of the ITCZ have been used as background values (pptv is parts per trillion by volume or pmol\/mol; ppbv is parts per billion by volume or nmol\/mol). CH 3 CN\/CO from biomass burning varies according to the fuel type and the burning temperature. The measurements by J. M. Lobert et al. [in Global Biomass Burning: Atmospheric Climatic and Biospheric Implications J. S. Levine Ed. (MIT Press Cambridge MA 1991) pp. 289\u2013304] and by R. Holzinger et al. [ Geophys. Res. Lett. 26 1161 (1999)] indicate a mean range of 0.13 to 0.25%."},{"key":"#cr-split#-e_1_3_1_25_2.1","unstructured":"The instrumentation on board the Citation aircraft has been described by J. Lelieveld et al. [ J. Geophys. Res. 104 8201 (1999)]. On the Citation C-130 aircraft and the R\/V Brown CH 3 CN and CH 3 C(O)CH 3 have been measured by proton-transfer-reaction mass spectrometry as described by W. Lindinger A. Hansel and A. Jordan [ Int. J. Mass Spectrom Ion Proc. 173 191 (1998)]. On the C-130 aircraft these gases and SO 2 were also measured by chemical ionization mass spectrometry. On the Citation aircraft CO was measured by tunable diode laser spectrometry (TDLAS) as described by F. G. Wienhold et al. [ Appl. Phys. B67 411 (1998)]"},{"key":"#cr-split#-e_1_3_1_25_2.2","unstructured":"on the R\/V Brown CO was measured by by TDLAS as described by H. Fischer et al. [ J. Geophys. Res. 102 23559 (1997)]."},{"key":"e_1_3_1_26_2","unstructured":"The source analysis of measured pollution has been supported by back-trajectory calculations. The trajectory model uses high-resolution ECMWF-analyzed meteorological data as described by M. P. Scheele P. C. Siegmund and P. F. J. van Velthoven [ Meteorol. Appl. 3 267 (1996)]."},{"key":"e_1_3_1_27_2","unstructured":"The measurements refer to nine 600-liter canister samples three collected south and six north of the ITCZ analyzed according to the method of C. A. M. Brenninkmeijer ["},{"key":"e_1_3_1_27_3","doi-asserted-by":"crossref","first-page":"10595","DOI":"10.1029\/93JD00587","volume":"98","author":"Brenninkmeijer C. A. M.","year":"1993","unstructured":"Brenninkmeijer C. A. M., J. Geophys. Res. 98, 10595 (1993);","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_27_4","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/S1465-9972(99)00018-5","volume":"1","author":"Brenninkmeijer C. A. M.","year":"1999","unstructured":"Brenninkmeijer C. A. M., et al., Chemosphere Global. Change Sci. 1, 33 (1999);","journal-title":"Chemosphere Global. Change Sci."},{"key":"e_1_3_1_27_5","unstructured":"]. 14 CO can result from biomass burning and the oxidation of natural hydrocarbons. Forest emissions of hydrocarbons however are small whereas hydrocarbon oxidation is minimal during winter."},{"key":"e_1_3_1_28_2","unstructured":"We observed a mean molar enhancement of CH 3 Cl relative to CO of 1.98 \u00d7 10 \u22123 in the marine BL a strong indication of biomass burning emissions; see"},{"key":"e_1_3_1_28_3","doi-asserted-by":"crossref","first-page":"8429","DOI":"10.1029\/1998JD100084","volume":"104","author":"Keene W. C.","year":"1999","unstructured":"Keene W. C., et al., J. Geophys. Res. 104, 8429 (1999);","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_28_4","doi-asserted-by":"crossref","first-page":"8373","DOI":"10.1029\/1998JD100077","volume":"104","author":"Lobert J. M.","year":"1999","unstructured":"Lobert J. M., et al., J. Geophys. Res. 104, 8373 (1999);","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_28_5","unstructured":". We found high correlations ( r 2 = 0.9) of CH 3 Cl with CO CH 3 CN C 2 H 2 and C 6 H 6 all products from incomplete (biomass) combustion."},{"key":"#cr-split#-e_1_3_1_29_2.1","unstructured":"On the R\/V Brown and on the C-130 aircraft CO was measured according to R. R. Dickerson and A. C. Delany [ J. Atmos. Oceanic Technol. 5 424 (1988)]"},{"key":"#cr-split#-e_1_3_1_29_2.2","unstructured":"on KCO CO was measured according to M. Cogan and J. M. Lobert [ Proceedings of the 43rd Annual ISA Analysis Division Symposium vol. 31 (Instrument Society of America Research Triangle Park NC 1998) pp. 229-234. See also (24)."},{"key":"e_1_3_1_30_2","unstructured":"Ozone measurements were performed from balloons with Electrochemical Concentration Cell sondes coupled to V\u00e4is\u00e4l\u00e4 radiosondes on KCO as described by W. D. Komhyr et al. [ J. Geophys. Res. 100 9231 (1995)] and on the R\/V Brown as described by D. Kley et al. [ Q. J. R. Met. Soc. 123 2009 (1997)]."},{"key":"e_1_3_1_31_2","first-page":"931","volume":"76","author":"Venkata Ramana M.","year":"1999","unstructured":"Venkata Ramana M., et al., Curr. Sci. 76, 931 (1999).","journal-title":"Curr. Sci."},{"key":"e_1_3_1_32_2","unstructured":"O. P. Madan et al. Meteorological Analysis During INDOEX Intensive Field Phase\u20141999 (Centre for Atmospheric Sciences New Delhi India 1999)."},{"key":"e_1_3_1_33_2","unstructured":"NO as measured from the Citation aircraft was generally below the detection limit of 40 pptv. On the R\/V Brown NO was generally below 10 pptv (T. P. Carsey R. R. Dickerson M. L. Farmer unpublished data)."},{"key":"e_1_3_1_34_2","doi-asserted-by":"crossref","first-page":"18981","DOI":"10.1029\/97JD01078","volume":"102","author":"Rhoads K. P.","year":"1997","unstructured":"Rhoads K. P., et al., J. Geophys. Res. 102, 18981 (1997).","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_35_2","doi-asserted-by":"crossref","first-page":"18907","DOI":"10.1029\/98JD01566","volume":"103","author":"Lal S.","year":"1998","unstructured":"Lal S., Naja M., Jayaraman A., J. Geophys. Res. 103, 18907 (1998).","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_36_2","doi-asserted-by":"crossref","first-page":"13881","DOI":"10.1029\/1999JD900176","volume":"104","author":"de Laat A. T. J.","year":"1999","unstructured":"de Laat A. T. J., et al., J. Geophys. Res. 104, 13881 (1999).","journal-title":"J. Geophys. Res."},{"key":"e_1_3_1_37_2","first-page":"931","volume":"76","author":"Naja M.","year":"1999","unstructured":"Naja M., et al., Curr. Sci. 76, 931 (1999).","journal-title":"Curr. Sci."},{"key":"e_1_3_1_38_2","doi-asserted-by":"publisher","DOI":"10.1029\/1998JD100004"},{"key":"e_1_3_1_39_2","doi-asserted-by":"crossref","first-page":"123","DOI":"10.3402\/tellusb.v51i1.16264","volume":"51","author":"Crutzen P. J.","year":"1999","unstructured":"Crutzen P. J., Lawrence M. G., P\u00f6schl U., Tellus 51AB, 123 (1999);","journal-title":"Tellus"},{"key":"e_1_3_1_39_3","unstructured":". Primary OH production occurs through O 3 photodissociation by solar shortwave radiation in the presence of water vapor [the reaction O( 1 D) + H 2 O \u2192 2OH]. After the initial loss of OH through its reaction with a pollutant gas e.g. CO a peroxy radical (e.g. HO 2 ) is formed which can react with NO yielding NO 2 and regenerating OH. NO 2 subsequently photodissociates and forms O 3 ."},{"key":"e_1_3_1_40_2","unstructured":"The Asian emissions of CO nonmethane hydrocarbons (NMHC) NO x and SO 2 will strongly depend on the fuel mix used (coal oil and biofuels) and the efficiency of industrial and traffic emissions. Two-stroke engines for example which are widely used in India burn at relatively low temperatures so that NO x emissions are limited and CO and NMHC emissions are large. The Intergovernmental Panel on Climate Change [ Emission Scenarios (Cambridge Univ. Press Cambridge 2000)] estimates that CO 2 CO NO x SO 2 and NMHC emissions in Organization for Economic Cooperation and Development countries will change from 2000 to 2020 by 2 to 24% \u221214 to 27% \u221213 to 30% \u221260 to \u221249% and \u22128 to 5% respectively (hence partly reductions) whereas in Asia these emissions will grow by 41 to 104% 7 to 34% 50 to 81% 15 to 114% and 9 to 89% respectively."},{"key":"e_1_3_1_41_2","unstructured":"We are grateful for the support by many funding agencies notably the NSF the Department of Energy NASA the National Oceanic and Atmospheric Administration the Indian Space Research Organization the European Union the Max-Planck-Gesellschaft the French Centre National d'Etudes Spatiales the Netherlands Supercomputing Facility and the Netherlands Organization for Scientific Research. We thank J. Olivier for his help with emission estimates (16 39)."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.1057103","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,9]],"date-time":"2024-01-09T23:02:25Z","timestamp":1704841345000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.1057103"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2001,2,9]]},"references-count":59,"journal-issue":{"issue":"5506","published-print":{"date-parts":[[2001,2,9]]}},"alternative-id":["10.1126\/science.1057103"],"URL":"https:\/\/doi.org\/10.1126\/science.1057103","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2001,2,9]]}}}