Elevated aerosol layer over South Asia worsens the Indian droughts

Droughts have become more severe and recurrent over the Indian sub-continent during the second half of the twentieth century, leading to more severe hydro-climatic and socio-economic impacts over one of the most densely populated parts of the world. So far, droughts have mostly been connected to cir...

Descripción completa

Detalles Bibliográficos
Autores principales: Fadnavis, Suvarna, Sabin, T. P., Roy, Chaitri, Rowlinson, Matthew, Rap, Alexandru, Vernier, Jean-Paul, Sioris, Christopher E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6635485/
https://www.ncbi.nlm.nih.gov/pubmed/31311972
http://dx.doi.org/10.1038/s41598-019-46704-9
_version_ 1783435891304300544
author Fadnavis, Suvarna
Sabin, T. P.
Roy, Chaitri
Rowlinson, Matthew
Rap, Alexandru
Vernier, Jean-Paul
Sioris, Christopher E.
author_facet Fadnavis, Suvarna
Sabin, T. P.
Roy, Chaitri
Rowlinson, Matthew
Rap, Alexandru
Vernier, Jean-Paul
Sioris, Christopher E.
author_sort Fadnavis, Suvarna
collection PubMed
description Droughts have become more severe and recurrent over the Indian sub-continent during the second half of the twentieth century, leading to more severe hydro-climatic and socio-economic impacts over one of the most densely populated parts of the world. So far, droughts have mostly been connected to circulation changes concomitant with the abnormal warming over the Pacific Ocean, prevalently known as “El Niño”. Here, exploiting observational data sets and a series of dedicated sensitivity experiments, we show that the severity of droughts during El Niño is amplified (17%) by changes in aerosols. The model experiments simulate the transport of boundary layer aerosols from South Asian countries to higher altitudes (12–18 km) where they form the Asian Tropopause Aerosol Layer (ATAL) (~ 60–120°E, 20–40°N). During El Niño, the anomalous overturning circulation from the East Asian region further enriches the thickness of aerosol layers in the ATAL over the northern part of South Asia. The anomalous aerosol loading in the ATAL reduces insolation over the monsoon region, thereby exacerbating the severity of drought by further weakening the monsoon circulation. Future increases in industrial emissions from both East and South Asia will lead to a wider and thicker elevated aerosol layer in the upper troposphere, potentially amplifying the severity of droughts.
format Online
Article
Text
id pubmed-6635485
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-66354852019-07-24 Elevated aerosol layer over South Asia worsens the Indian droughts Fadnavis, Suvarna Sabin, T. P. Roy, Chaitri Rowlinson, Matthew Rap, Alexandru Vernier, Jean-Paul Sioris, Christopher E. Sci Rep Article Droughts have become more severe and recurrent over the Indian sub-continent during the second half of the twentieth century, leading to more severe hydro-climatic and socio-economic impacts over one of the most densely populated parts of the world. So far, droughts have mostly been connected to circulation changes concomitant with the abnormal warming over the Pacific Ocean, prevalently known as “El Niño”. Here, exploiting observational data sets and a series of dedicated sensitivity experiments, we show that the severity of droughts during El Niño is amplified (17%) by changes in aerosols. The model experiments simulate the transport of boundary layer aerosols from South Asian countries to higher altitudes (12–18 km) where they form the Asian Tropopause Aerosol Layer (ATAL) (~ 60–120°E, 20–40°N). During El Niño, the anomalous overturning circulation from the East Asian region further enriches the thickness of aerosol layers in the ATAL over the northern part of South Asia. The anomalous aerosol loading in the ATAL reduces insolation over the monsoon region, thereby exacerbating the severity of drought by further weakening the monsoon circulation. Future increases in industrial emissions from both East and South Asia will lead to a wider and thicker elevated aerosol layer in the upper troposphere, potentially amplifying the severity of droughts. Nature Publishing Group UK 2019-07-16 /pmc/articles/PMC6635485/ /pubmed/31311972 http://dx.doi.org/10.1038/s41598-019-46704-9 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Fadnavis, Suvarna
Sabin, T. P.
Roy, Chaitri
Rowlinson, Matthew
Rap, Alexandru
Vernier, Jean-Paul
Sioris, Christopher E.
Elevated aerosol layer over South Asia worsens the Indian droughts
title Elevated aerosol layer over South Asia worsens the Indian droughts
title_full Elevated aerosol layer over South Asia worsens the Indian droughts
title_fullStr Elevated aerosol layer over South Asia worsens the Indian droughts
title_full_unstemmed Elevated aerosol layer over South Asia worsens the Indian droughts
title_short Elevated aerosol layer over South Asia worsens the Indian droughts
title_sort elevated aerosol layer over south asia worsens the indian droughts
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6635485/
https://www.ncbi.nlm.nih.gov/pubmed/31311972
http://dx.doi.org/10.1038/s41598-019-46704-9
work_keys_str_mv AT fadnavissuvarna elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT sabintp elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT roychaitri elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT rowlinsonmatthew elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT rapalexandru elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT vernierjeanpaul elevatedaerosollayeroversouthasiaworsenstheindiandroughts
AT siorischristophere elevatedaerosollayeroversouthasiaworsenstheindiandroughts