This article is about the Indian Ocean brown cloud. For China, see Air pollution in China.
The Indian Ocean brown cloud or Asian brown cloud is a layer of air pollution that recurrently covers parts of South Asia, namely the northern Indian Ocean, India, and Pakistan.[1][2] Viewed from satellite photos, the cloud appears as a giant brown stain hanging in the air over much of the Indian subcontinent and the Indian Ocean every year between October and February, possibly also during earlier and later months. The term was coined in reports from the UNEP Indian Ocean Experiment (INDOEX). It was found to originate mostly due to farmers burning stubble in Punjab and to lesser extent Haryana and Uttar Pradesh. The debilitating air quality in Delhi is also due to the stubble burning in Punjab.[3]
Atmospheric brown cloud over ChinaA brown-cloud storm over Asia
The term atmospheric brown cloud is used for a more generic context not specific to the Asian region.[4]
The Asian brown cloud is created by a range of airborne particles and pollutants from combustion (e.g., woodfires, cars, and factories), biomass burning[5] and industrial processes with incomplete burning.[6] The cloud is associated with the winter monsoon (October/November to February/March) during which there is no rain to wash pollutants from the air.[7]
Observationsedit
This pollution layer was observed during the Indian Ocean Experiment (INDOEX) intensive field observation in 1999 and described in the UNEP impact assessment study published 2002.[3] Scientists in India claimed that the Asian Brown cloud is not something specific to Asia.[8] Subsequently, when the United Nations Environment Programme (UNEP) organized a follow-up international project, the subject of study was renamed the Atmospheric Brown Cloud with focus on Asia.
The cloud was also reported by NASA in 2004[9] and 2007.[10]
Although aerosol particles are generally associated with a global cooling effect, recent studies have shown that they can actually have a warming effect in certain regions such as the Himalayas.[11]
Impactsedit
Health problemsedit
One major impact is on health. A 2002 study indicated nearly two million people die each year, in Asia alone, from conditions related to the brown cloud.[12]
Regional weatheredit
A second assessment study was published in 2008.[13] It highlighted regional concerns regarding:
Changes of rainfall patterns with the Asian monsoon, as well as a delaying of the start of the Asian monsoon, by several weeks.[14][15] The observed weakening Indian monsoon and in China northern drought and southern flooding is influenced by the clouds.
Increase in rainfall over the AustralianTop End and Kimberley regions. A CSIRO study has found that by displacing the thermal equator southwards via cooling of the air over East Asia, the monsoon which brings most of the rain to these regions has been intensified and displaced southward.[16]
Retreat of the Hindu Kush-Himalayan glaciers and snow packs. The cause is attributed to rising air temperatures that are more pronounced in elevated regions, a combined warming effect of greenhouse gases and the Asian Brown Cloud. Also deposition of black carbon decreases the reflection and exacerbates the retreat. Asian glacial melting could lead to water shortages and floods for the hundreds of millions of people who live downstream.
Decrease of crop harvests. Elevated concentrations of surface ozone are likely to affect crop yields negatively. The impact is crop specific.
Cyclone intensity in Arabian Seaedit
A 2011 study found that pollution is making Arabian Sea cyclones more intense as the atmospheric brown clouds has been producing weakening wind patterns which prevent wind shear patterns that historically have prohibited cyclones in the Arabian Sea from becoming major storms. This phenomenon was found responsible for the formation of stronger storms in 2007 and 2010 that were the first recorded storms to enter the Gulf of Oman.[17][18]
Global warming and dimmingedit
The 2008 report also addressed the global concern of warming and concluded that the brown clouds have masked 20 to 80 percent of greenhouse gas forcing in the past century. The report suggested that air pollution regulations can have large amplifying effects on global warming.[clarification needed]
Another major impact is on the polar ice caps. Black carbon (soot) in the Asian Brown Cloud may be reflecting sunlight and dimming Earth below but it is warming other places by absorbing incoming radiation and warming the atmosphere and whatever it touches.[19] Black carbon is three times more effective than carbon dioxide—the most common greenhouse gas—at melting polar ice and snow.[20] Black carbon in snow causes about three times the temperature change as carbon dioxide in the atmosphere. On snow—even at concentrations below five parts per billion–dark carbon triggers melting, and may be responsible for as much as 94 percent of Arctic warming.[21]
^Srinivasan (10 September 2002). (PDF). Current Science. 83 (5): 586–592. Archived from the original (PDF) on 5 November 2004.
^Ramanathan, Veerabhadran; Crutzen, P. J.; Lelieveld, J.; Mitra, A. P.; Althausen, D.; Anderson, J.; Andreae, M. O.; Cantrell, W.; et al. (2001). "Indian Ocean experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze". Journal of Geophysical Research. 106 (D22): 28371–28398. Bibcode:2001JGR...10628371R. doi:10.1029/2001JD900133.
^ abRamanathan, Veerabhadran et al. (2002) The Asian brown cloud climate and other environmental impacts: impact study June 5, 2004, at the Wayback Machine Center for Clouds, Chemistry and Climate, United Nations Environment Programme, Nairobi Kenya, ISBN92-807-2240-9, accessed 8 December 2008
^Haag, Amanda Leigh (2007). "The even darker side of brown clouds". Nature Reports Climate Change. 1 (709): 52–53. doi:10.1038/climate.2007.41.
^Gustafsson, Örjan; Kruså, Martin; Zencak, Zdenek; Sheesley, R. J.; Granat, Lennart; Engström, Erik; Praveen, P. S.; Rao, P. S. P.; Leck, Caroline; Rodhe, Henning; et al. (2009). "Brown Clouds over South Asia: Biomass or Fossil Fuel Combustion?". Science. 323 (5913): 495–498. Bibcode:2009Sci...323..495G. doi:10.1126/science.1164857. PMID 19164746. S2CID 44712883.
^Taylor, David (1 January 2003). . Environmental Health Perspectives. 111 (1): A21–A22. doi:10.1289/ehp.111-a21a. PMC1241333. Archived from the original on 2006-08-28.
^Petit, C. W. (2003) "A darkening sky: A smoky shroud over Asia blocks both sun and rain" U.S. News & World Report (17 March 2003), 134(8): pp. 46-8
^Pandve, Harshal T. (2008). "The Asian Brown Cloud". Indian Journal of Occupational and Environmental Medicine. 12 (2): 93–5. doi:10.4103/0019-5278.43269. PMC2796752. PMID 20040987.
^NASA Eyes Effects of a Giant 'Brown Cloud' Worldwide (2004)
^Global Aerosol System 2000-2007 (NASA Earth Observatory)
^Ramanathan, Veerabhadran; Ramana, MV; Roberts, G; Kim, D; Corrigan, C; Chung, C; Winker, D (2 August 2007). "Warming trends in Asia amplified by brown cloud solar absorption". Nature. 448 (7153): 575–578. Bibcode:2007Natur.448..575R. doi:10.1038/nature06019. PMID 17671499. S2CID 4420513.
^Ahmad, K. (2002). "Pollution cloud over south Asia is increasing ill health". Lancet. 360 (9332): 549. doi:10.1016/S0140-6736(02)09762-3. PMID 12241664. S2CID 35909421.
^"Archived copy" (PDF). Archived from the original on 2008-11-18. Retrieved 2008-11-18.{{cite web}}: CS1 maint: archived copy as title (link) CS1 maint: bot: original URL status unknown (link)
^Paper reporting the delaying of the monsoon being caused by brown cloud[permanent dead link]
^Rotstayn, Leon; Cai, Wenju; Dix, Martin R.; Farquhar, Graham D.; Feng, Yan; Ginoux, Paul; Herzog, Michael; Ito, Akinori; et al. (2 May 2007). . Journal of Geophysical Research. 112 (D09202): D09202. Bibcode:2007JGRD..11209202R. doi:10.1029/2006JD007712. hdl:2027.42/94749. Archived from the original on 2007-09-30.
^"Link Between Air Pollution and Cyclone Intensity in Arabian Sea". National Science Foundation. 2011-11-02. Retrieved 2011-11-07.
^Evan, Amato T.; Kossin, James P.; Chung, Chul; Ramanathan, V. (2011-11-03). "Arabian Sea tropical cyclones intensified by emissions of black carbon and other aerosols". Nature. 479 (7371): 94–97. Bibcode:2011Natur.479...94E. doi:10.1038/nature10552. PMID 22051678. S2CID 4423931.
^Biello, David (August 1, 2007). "Brown Haze from Cooking Fires Cooking EarthToo.The brown haze over Asia warms the atmosphere just as much as greenhouse gases". Scientific American.
^Biello, David (June 8, 2007). "Impure as the Driven Snow: Smut is a bigger problem than greenhouse gases in polar meltdown". Scientific American.
^Boswell, Randy (October 19, 2009). . Canwest News Service. Archived from the original on February 6, 2010.
Further readingedit
Ramanathan, V.; Crutzen, P. J. (2003). "New Directions: Atmospheric Brown "Clouds"". Atmospheric Environment. 37 (28): 4033–4035. Bibcode:2003AtmEn..37.4033R. doi:10.1016/S1352-2310(03)00536-3.
Silva-Send, Nilmini (2007) Preventing regional air pollution in Asia : the potential role of the European Convention on Long Range Transboundary Air Pollution in Asian regionsUniversity of Kiel, Kiel, Germany, OCLC 262737812
External linksedit
, from WebArchive
December 15, 2023
asian, brown, cloud, this, article, about, indian, ocean, brown, cloud, china, pollution, china, indian, ocean, brown, cloud, layer, pollution, that, recurrently, covers, parts, south, asia, namely, northern, indian, ocean, india, pakistan, viewed, from, satel. This article is about the Indian Ocean brown cloud For China see Air pollution in China The Indian Ocean brown cloud or Asian brown cloud is a layer of air pollution that recurrently covers parts of South Asia namely the northern Indian Ocean India and Pakistan 1 2 Viewed from satellite photos the cloud appears as a giant brown stain hanging in the air over much of the Indian subcontinent and the Indian Ocean every year between October and February possibly also during earlier and later months The term was coined in reports from the UNEP Indian Ocean Experiment INDOEX It was found to originate mostly due to farmers burning stubble in Punjab and to lesser extent Haryana and Uttar Pradesh The debilitating air quality in Delhi is also due to the stubble burning in Punjab 3 Atmospheric brown cloud over ChinaA brown cloud storm over AsiaThe term atmospheric brown cloud is used for a more generic context not specific to the Asian region 4 Contents 1 Causes 2 Observations 3 Impacts 3 1 Health problems 3 2 Regional weather 3 3 Cyclone intensity in Arabian Sea 3 4 Global warming and dimming 4 See also 5 References 6 Further reading 7 External linksCauses editThe Asian brown cloud is created by a range of airborne particles and pollutants from combustion e g woodfires cars and factories biomass burning 5 and industrial processes with incomplete burning 6 The cloud is associated with the winter monsoon October November to February March during which there is no rain to wash pollutants from the air 7 Observations editThis pollution layer was observed during the Indian Ocean Experiment INDOEX intensive field observation in 1999 and described in the UNEP impact assessment study published 2002 3 Scientists in India claimed that the Asian Brown cloud is not something specific to Asia 8 Subsequently when the United Nations Environment Programme UNEP organized a follow up international project the subject of study was renamed the Atmospheric Brown Cloud with focus on Asia The cloud was also reported by NASA in 2004 9 and 2007 10 Although aerosol particles are generally associated with a global cooling effect recent studies have shown that they can actually have a warming effect in certain regions such as the Himalayas 11 Impacts editHealth problems edit One major impact is on health A 2002 study indicated nearly two million people die each year in Asia alone from conditions related to the brown cloud 12 Regional weather edit A second assessment study was published in 2008 13 It highlighted regional concerns regarding Changes of rainfall patterns with the Asian monsoon as well as a delaying of the start of the Asian monsoon by several weeks 14 15 The observed weakening Indian monsoon and in China northern drought and southern flooding is influenced by the clouds Increase in rainfall over the Australian Top End and Kimberley regions A CSIRO study has found that by displacing the thermal equator southwards via cooling of the air over East Asia the monsoon which brings most of the rain to these regions has been intensified and displaced southward 16 Retreat of the Hindu Kush Himalayan glaciers and snow packs The cause is attributed to rising air temperatures that are more pronounced in elevated regions a combined warming effect of greenhouse gases and the Asian Brown Cloud Also deposition of black carbon decreases the reflection and exacerbates the retreat Asian glacial melting could lead to water shortages and floods for the hundreds of millions of people who live downstream Decrease of crop harvests Elevated concentrations of surface ozone are likely to affect crop yields negatively The impact is crop specific Cyclone intensity in Arabian Sea edit A 2011 study found that pollution is making Arabian Sea cyclones more intense as the atmospheric brown clouds has been producing weakening wind patterns which prevent wind shear patterns that historically have prohibited cyclones in the Arabian Sea from becoming major storms This phenomenon was found responsible for the formation of stronger storms in 2007 and 2010 that were the first recorded storms to enter the Gulf of Oman 17 18 Global warming and dimming edit The 2008 report also addressed the global concern of warming and concluded that the brown clouds have masked 20 to 80 percent of greenhouse gas forcing in the past century The report suggested that air pollution regulations can have large amplifying effects on global warming clarification needed Another major impact is on the polar ice caps Black carbon soot in the Asian Brown Cloud may be reflecting sunlight and dimming Earth below but it is warming other places by absorbing incoming radiation and warming the atmosphere and whatever it touches 19 Black carbon is three times more effective than carbon dioxide the most common greenhouse gas at melting polar ice and snow 20 Black carbon in snow causes about three times the temperature change as carbon dioxide in the atmosphere On snow even at concentrations below five parts per billion dark carbon triggers melting and may be responsible for as much as 94 percent of Arctic warming 21 See also edit nbsp Global warming portal nbsp Environment portalAsian Dust Arctic haze Air pollution in India Chemical Equator 1997 2006 2009 2013 Southeast Asian hazeReferences edit Srinivasan 10 September 2002 Asian Brown Cloud fact and fantasy PDF Current Science 83 5 586 592 Archived from the original PDF on 5 November 2004 Ramanathan Veerabhadran Crutzen P J Lelieveld J Mitra A P Althausen D Anderson J Andreae M O Cantrell W et al 2001 Indian Ocean experiment An integrated analysis of the climate forcing and effects of the great Indo Asian haze Journal of Geophysical Research 106 D22 28371 28398 Bibcode 2001JGR 10628371R doi 10 1029 2001JD900133 a b Ramanathan Veerabhadran et al 2002 The Asian brown cloud climate and other environmental impacts impact study Archived June 5 2004 at the Wayback Machine Center for Clouds Chemistry and Climate United Nations Environment Programme Nairobi Kenya ISBN 92 807 2240 9 accessed 8 December 2008 Haag Amanda Leigh 2007 The even darker side of brown clouds Nature Reports Climate Change 1 709 52 53 doi 10 1038 climate 2007 41 Gustafsson Orjan Krusa Martin Zencak Zdenek Sheesley R J Granat Lennart Engstrom Erik Praveen P S Rao P S P Leck Caroline Rodhe Henning et al 2009 Brown Clouds over South Asia Biomass or Fossil Fuel Combustion Science 323 5913 495 498 Bibcode 2009Sci 323 495G doi 10 1126 science 1164857 PMID 19164746 S2CID 44712883 Taylor David 1 January 2003 The ABCs of Haze Environmental Health Perspectives 111 1 A21 A22 doi 10 1289 ehp 111 a21a PMC 1241333 Archived from the original on 2006 08 28 Petit C W 2003 A darkening sky A smoky shroud over Asia blocks both sun and rain U S News amp World Report 17 March 2003 134 8 pp 46 8 Pandve Harshal T 2008 The Asian Brown Cloud Indian Journal of Occupational and Environmental Medicine 12 2 93 5 doi 10 4103 0019 5278 43269 PMC 2796752 PMID 20040987 NASA Eyes Effects of a Giant Brown Cloud Worldwide 2004 Global Aerosol System 2000 2007 NASA Earth Observatory Ramanathan Veerabhadran Ramana MV Roberts G Kim D Corrigan C Chung C Winker D 2 August 2007 Warming trends in Asia amplified by brown cloud solar absorption Nature 448 7153 575 578 Bibcode 2007Natur 448 575R doi 10 1038 nature06019 PMID 17671499 S2CID 4420513 Ahmad K 2002 Pollution cloud over south Asia is increasing ill health Lancet 360 9332 549 doi 10 1016 S0140 6736 02 09762 3 PMID 12241664 S2CID 35909421 Archived copy PDF Archived from the original on 2008 11 18 Retrieved 2008 11 18 a href Template Cite web html title Template Cite web cite web a CS1 maint archived copy as title link CS1 maint bot original URL status unknown link Brown cloud delaying monsoon Paper reporting the delaying of the monsoon being caused by brown cloud permanent dead link Rotstayn Leon Cai Wenju Dix Martin R Farquhar Graham D Feng Yan Ginoux Paul Herzog Michael Ito Akinori et al 2 May 2007 Have Australian rainfall and cloudiness increased due to the remote effects of Asian anthropogenic aerosols Journal of Geophysical Research 112 D09202 D09202 Bibcode 2007JGRD 11209202R doi 10 1029 2006JD007712 hdl 2027 42 94749 Archived from the original on 2007 09 30 Link Between Air Pollution and Cyclone Intensity in Arabian Sea National Science Foundation 2011 11 02 Retrieved 2011 11 07 Evan Amato T Kossin James P Chung Chul Ramanathan V 2011 11 03 Arabian Sea tropical cyclones intensified by emissions of black carbon and other aerosols Nature 479 7371 94 97 Bibcode 2011Natur 479 94E doi 10 1038 nature10552 PMID 22051678 S2CID 4423931 Biello David August 1 2007 Brown Haze from Cooking Fires Cooking EarthToo The brown haze over Asia warms the atmosphere just as much as greenhouse gases Scientific American Biello David June 8 2007 Impure as the Driven Snow Smut is a bigger problem than greenhouse gases in polar meltdown Scientific American Boswell Randy October 19 2009 Burning crops darken Arctic sky speed polar melt Canwest News Service Archived from the original on February 6 2010 Further reading editRamanathan V Crutzen P J 2003 New Directions Atmospheric Brown Clouds Atmospheric Environment 37 28 4033 4035 Bibcode 2003AtmEn 37 4033R doi 10 1016 S1352 2310 03 00536 3 Silva Send Nilmini 2007 Preventing regional air pollution in Asia the potential role of the European Convention on Long Range Transboundary Air Pollution in Asian regions University of Kiel Kiel Germany OCLC 262737812External links editBray Marianne 2002 Asian Brown Cloud poses global threat CNN from WebArchive Retrieved from https en wikipedia org w index php title Asian brown cloud amp oldid 1186856668, wikipedia, wiki, book, books, library,
