The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes

Convective transport plays a key role in aerosol enhancement in the upper troposphere and lower stratosphere (UTLS) over the Asian monsoon region where low-level convective instability persists throughout the year. We use the state-of-the-art ECHAM6–HAMMOZ global chemistry–climate model to investiga...

Full description

Bibliographic Details
Published in:Atmospheric Chemistry and Physics
Main Authors: Fadnavis, Suvarna, Müller, Rolf, Kalita, Gayatry, Rowlinson, Matthew, Rap, Alexandru, Li, Jui-Lin Frank, Gasparini, Blaž, Laakso, Anton
Format: Text
Language:English
Published: 2019
Subjects:
Online Access:https://doi.org/10.5194/acp-19-9989-2019
https://www.atmos-chem-phys.net/19/9989/2019/
id ftcopernicus:oai:publications.copernicus.org:acp74213
record_format openpolar
spelling ftcopernicus:oai:publications.copernicus.org:acp74213 2023-05-15T14:59:05+02:00 The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes Fadnavis, Suvarna Müller, Rolf Kalita, Gayatry Rowlinson, Matthew Rap, Alexandru Li, Jui-Lin Frank Gasparini, Blaž Laakso, Anton 2019-08-09 application/pdf https://doi.org/10.5194/acp-19-9989-2019 https://www.atmos-chem-phys.net/19/9989/2019/ eng eng doi:10.5194/acp-19-9989-2019 https://www.atmos-chem-phys.net/19/9989/2019/ eISSN: 1680-7324 Text 2019 ftcopernicus https://doi.org/10.5194/acp-19-9989-2019 2019-12-24T09:48:44Z Convective transport plays a key role in aerosol enhancement in the upper troposphere and lower stratosphere (UTLS) over the Asian monsoon region where low-level convective instability persists throughout the year. We use the state-of-the-art ECHAM6–HAMMOZ global chemistry–climate model to investigate the seasonal transport of anthropogenic Asian sulfate aerosols and their impact on the UTLS. Sensitivity simulations for SO 2 emission perturbation over India (48 % increase) and China (70 % decrease) are performed based on the Ozone Monitoring Instrument (OMI) satellite-observed trend, rising over India by ∼4.8 % per year and decreasing over China by ∼7.0 % per year during 2006–2017. The enhanced Indian emissions result in an increase in aerosol optical depth (AOD) loading in the UTLS by 0.61 to 4.17 % over India. These aerosols are transported to the Arctic during all seasons by the lower branch of the Brewer–Dobson circulation enhancing AOD by 0.017 % to 4.8 %. Interestingly, a reduction in SO 2 emission over China inhibits the transport of Indian sulfate aerosols to the Arctic in summer-monsoon and post-monsoon seasons due to subsidence over northern India. The region of sulfate aerosol enhancement shows significant warming in the UTLS over northern India, south China ( 0.2±0.15 to 0.8±0.72 K) and the Arctic ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">1</mn><mo>±</mo><mn mathvariant="normal">0.62</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="51pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6b8d82df5c23f66fffe20f5420b1c3f8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-19-9989-2019-ie00001.svg" width="51pt" height="10pt" src="acp-19-9989-2019-ie00001.png"/></svg:svg> to 1.6±1.07 K). The estimated seasonal mean direct radiative forcing at the top of the atmosphere (TOA) induced by the increase in Indian SO 2 emission is − 0.2 to − 1.5 W m −2 over northern India. The Chinese SO 2 emission reduction leads to a positive radiative forcing of ∼0.6 to 6 W m −2 over China. The decrease in vertical velocity and the associated enhanced stability of the upper troposphere in response to increased Indian SO 2 emissions will likely decrease rainfall over India. Text Arctic Copernicus Publications: E-Journals Arctic Indian Atmospheric Chemistry and Physics 19 15 9989 10008
institution Open Polar
collection Copernicus Publications: E-Journals
op_collection_id ftcopernicus
language English
description Convective transport plays a key role in aerosol enhancement in the upper troposphere and lower stratosphere (UTLS) over the Asian monsoon region where low-level convective instability persists throughout the year. We use the state-of-the-art ECHAM6–HAMMOZ global chemistry–climate model to investigate the seasonal transport of anthropogenic Asian sulfate aerosols and their impact on the UTLS. Sensitivity simulations for SO 2 emission perturbation over India (48 % increase) and China (70 % decrease) are performed based on the Ozone Monitoring Instrument (OMI) satellite-observed trend, rising over India by ∼4.8 % per year and decreasing over China by ∼7.0 % per year during 2006–2017. The enhanced Indian emissions result in an increase in aerosol optical depth (AOD) loading in the UTLS by 0.61 to 4.17 % over India. These aerosols are transported to the Arctic during all seasons by the lower branch of the Brewer–Dobson circulation enhancing AOD by 0.017 % to 4.8 %. Interestingly, a reduction in SO 2 emission over China inhibits the transport of Indian sulfate aerosols to the Arctic in summer-monsoon and post-monsoon seasons due to subsidence over northern India. The region of sulfate aerosol enhancement shows significant warming in the UTLS over northern India, south China ( 0.2±0.15 to 0.8±0.72 K) and the Arctic ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">1</mn><mo>±</mo><mn mathvariant="normal">0.62</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="51pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6b8d82df5c23f66fffe20f5420b1c3f8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-19-9989-2019-ie00001.svg" width="51pt" height="10pt" src="acp-19-9989-2019-ie00001.png"/></svg:svg> to 1.6±1.07 K). The estimated seasonal mean direct radiative forcing at the top of the atmosphere (TOA) induced by the increase in Indian SO 2 emission is − 0.2 to − 1.5 W m −2 over northern India. The Chinese SO 2 emission reduction leads to a positive radiative forcing of ∼0.6 to 6 W m −2 over China. The decrease in vertical velocity and the associated enhanced stability of the upper troposphere in response to increased Indian SO 2 emissions will likely decrease rainfall over India.
format Text
author Fadnavis, Suvarna
Müller, Rolf
Kalita, Gayatry
Rowlinson, Matthew
Rap, Alexandru
Li, Jui-Lin Frank
Gasparini, Blaž
Laakso, Anton
spellingShingle Fadnavis, Suvarna
Müller, Rolf
Kalita, Gayatry
Rowlinson, Matthew
Rap, Alexandru
Li, Jui-Lin Frank
Gasparini, Blaž
Laakso, Anton
The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
author_facet Fadnavis, Suvarna
Müller, Rolf
Kalita, Gayatry
Rowlinson, Matthew
Rap, Alexandru
Li, Jui-Lin Frank
Gasparini, Blaž
Laakso, Anton
author_sort Fadnavis, Suvarna
title The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
title_short The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
title_full The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
title_fullStr The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
title_full_unstemmed The impact of recent changes in Asian anthropogenic emissions of SO2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
title_sort impact of recent changes in asian anthropogenic emissions of so2 on sulfate loading in the upper troposphere and lower stratosphere and the associated radiative changes
publishDate 2019
url https://doi.org/10.5194/acp-19-9989-2019
https://www.atmos-chem-phys.net/19/9989/2019/
geographic Arctic
Indian
geographic_facet Arctic
Indian
genre Arctic
genre_facet Arctic
op_source eISSN: 1680-7324
op_relation doi:10.5194/acp-19-9989-2019
https://www.atmos-chem-phys.net/19/9989/2019/
op_doi https://doi.org/10.5194/acp-19-9989-2019
container_title Atmospheric Chemistry and Physics
container_volume 19
container_issue 15
container_start_page 9989
op_container_end_page 10008
_version_ 1766331217394794496