Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases
<p>Black carbon (BC) aerosols emitted from natural and anthropogenic sources induce positive radiative forcing and global warming, which in turn significantly affect the Asian summer monsoon (ASM). However, many aspects of the BC effect on the ASM remain elusive and largely inconsistent among...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-10-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/20/11823/2020/acp-20-11823-2020.pdf |
| _version_ | 1830518589238542336 |
|---|---|
| author | X. Xie X. Xie G. Myhre X. Liu X. Liu X. Li Z. Shi H. Wang A. Kirkevåg J.-F. Lamarque D. Shindell T. Takemura Y. Liu |
| author_facet | X. Xie X. Xie G. Myhre X. Liu X. Liu X. Li Z. Shi H. Wang A. Kirkevåg J.-F. Lamarque D. Shindell T. Takemura Y. Liu |
| author_sort | X. Xie |
| collection | DOAJ |
| description | <p>Black carbon (BC) aerosols emitted from natural and anthropogenic sources
induce positive radiative forcing and global warming,
which in turn significantly affect the Asian summer monsoon (ASM).
However, many aspects of the BC effect on the ASM remain elusive
and largely inconsistent among previous studies, which is strongly dependent on
different low-level thermal feedbacks over the Asian continent and the surrounding ocean.
This study examines the response of the ASM to BC forcing in comparison with
the effect of doubled greenhouse gases (GHGs) by analyzing the Precipitation Driver
Response Model Intercomparison Project (PDRMIP) simulations
under an extremely high BC level (10 times modern global BC emissions or concentrations,
labeled <span class="inline-formula">BC</span><span class="inline-formula">×</span>10) from nine global climate models (GCMs).
The results show that although BC and GHGs both enhance the ASM precipitation minus evaporation (<span class="inline-formula"><i>P</i>−<i>E</i></span>; a 13.6 % increase for BC forcing and 12.1 % for GHGs from the nine-model ensemble, respectively),
there exists a much larger uncertainty in changes in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> induced by BC than by GHGs.
The summer <span class="inline-formula"><i>P</i>−<i>E</i></span> is increased by 7.7 % to 15.3 % due to these two forcings
over three subregions, including East Asian, South Asian and western North Pacific monsoon regions.
Further analysis of moisture budget reveals distinct mechanisms controlling the increases in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> induced by BC and GHGs.
The change in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> by BC is dominated by the dynamic effect due to the enhanced large-scale monsoon circulation,
whereas the GHG-induced change is dominated by the thermodynamic effect through increasing atmospheric water vapor.
Radiative forcing of BC significantly increases the upper-level atmospheric temperature
over the Asian region to enhance the upper-level meridional land–sea thermal gradient (MLOTG),
resulting in a northward shift of the upper-level subtropical westerly jet
and an enhancement of the low-level monsoon circulation,
whereas radiative forcing of GHGs significantly increases the tropical upper-level temperature,
which reduces the upper-level MLOTG and suppresses the low-level monsoonal circulation.
Hence, our results indicate a different mechanism of BC climate effects
under the extremely high BC level: that BC forcing significantly
enhances the upper-level atmospheric temperature over the Asian region,
determining ASM changes, instead of low-level thermal feedbacks as indicated by previous studies.</p> |
| first_indexed | 2024-12-22T04:22:23Z |
| format | Article |
| id | doaj.art-39bda60486dd4d0f85ec393f6a25ad6d |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-22T04:22:23Z |
| publishDate | 2020-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-39bda60486dd4d0f85ec393f6a25ad6d2022-12-21T18:39:14ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242020-10-0120118231183910.5194/acp-20-11823-2020Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gasesX. Xie0X. Xie1G. Myhre2X. Liu3X. Liu4X. Li5Z. Shi6H. Wang7A. Kirkevåg8J.-F. Lamarque9D. Shindell10T. Takemura11Y. Liu12SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, ChinaCAS Center for Excellence in Quaternary Science and Global Change, Xi'an, ChinaCenter for International Climate and Environmental Research, Oslo, NorwaySKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, ChinaCollege of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, ChinaSKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, ChinaSKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, ChinaSchool of Tourism and Hospitality Management, Shaanxi Radio and TV University, Xi'an, ChinaNorwegian Meteorological Institute, Oslo, NorwayNational Center for Atmospheric Research, Boulder, USANicholas School of the Environment, Duke University, Durham, USAClimate Change Science Section, Kyushu University, Fukuoka, JapanEnvironmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA<p>Black carbon (BC) aerosols emitted from natural and anthropogenic sources induce positive radiative forcing and global warming, which in turn significantly affect the Asian summer monsoon (ASM). However, many aspects of the BC effect on the ASM remain elusive and largely inconsistent among previous studies, which is strongly dependent on different low-level thermal feedbacks over the Asian continent and the surrounding ocean. This study examines the response of the ASM to BC forcing in comparison with the effect of doubled greenhouse gases (GHGs) by analyzing the Precipitation Driver Response Model Intercomparison Project (PDRMIP) simulations under an extremely high BC level (10 times modern global BC emissions or concentrations, labeled <span class="inline-formula">BC</span><span class="inline-formula">×</span>10) from nine global climate models (GCMs). The results show that although BC and GHGs both enhance the ASM precipitation minus evaporation (<span class="inline-formula"><i>P</i>−<i>E</i></span>; a 13.6 % increase for BC forcing and 12.1 % for GHGs from the nine-model ensemble, respectively), there exists a much larger uncertainty in changes in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> induced by BC than by GHGs. The summer <span class="inline-formula"><i>P</i>−<i>E</i></span> is increased by 7.7 % to 15.3 % due to these two forcings over three subregions, including East Asian, South Asian and western North Pacific monsoon regions. Further analysis of moisture budget reveals distinct mechanisms controlling the increases in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> induced by BC and GHGs. The change in ASM <span class="inline-formula"><i>P</i>−<i>E</i></span> by BC is dominated by the dynamic effect due to the enhanced large-scale monsoon circulation, whereas the GHG-induced change is dominated by the thermodynamic effect through increasing atmospheric water vapor. Radiative forcing of BC significantly increases the upper-level atmospheric temperature over the Asian region to enhance the upper-level meridional land–sea thermal gradient (MLOTG), resulting in a northward shift of the upper-level subtropical westerly jet and an enhancement of the low-level monsoon circulation, whereas radiative forcing of GHGs significantly increases the tropical upper-level temperature, which reduces the upper-level MLOTG and suppresses the low-level monsoonal circulation. Hence, our results indicate a different mechanism of BC climate effects under the extremely high BC level: that BC forcing significantly enhances the upper-level atmospheric temperature over the Asian region, determining ASM changes, instead of low-level thermal feedbacks as indicated by previous studies.</p>https://acp.copernicus.org/articles/20/11823/2020/acp-20-11823-2020.pdf |
| spellingShingle | X. Xie X. Xie G. Myhre X. Liu X. Liu X. Li Z. Shi H. Wang A. Kirkevåg J.-F. Lamarque D. Shindell T. Takemura Y. Liu Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases Atmospheric Chemistry and Physics |
| title | Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases |
| title_full | Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases |
| title_fullStr | Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases |
| title_full_unstemmed | Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases |
| title_short | Distinct responses of Asian summer monsoon to black carbon aerosols and greenhouse gases |
| title_sort | distinct responses of asian summer monsoon to black carbon aerosols and greenhouse gases |
| url | https://acp.copernicus.org/articles/20/11823/2020/acp-20-11823-2020.pdf |
| work_keys_str_mv | AT xxie distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT xxie distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT gmyhre distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT xliu distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT xliu distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT xli distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT zshi distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT hwang distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT akirkevag distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT jflamarque distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT dshindell distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT ttakemura distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases AT yliu distinctresponsesofasiansummermonsoontoblackcarbonaerosolsandgreenhousegases |