Impact of Chinese Urbanization and Aerosol Emissions on the East Asian Summer MonsoonSource: Journal of Climate:;2016:;volume( 030 ):;issue: 003::page 1019DOI: 10.1175/JCLI-D-15-0593.1Publisher: American Meteorological Society
Abstract: AbstractImpacts of urbanization and anthropogenic aerosols in China on the East Asian summer monsoon (EASM) are investigated using version 5.1 of the Community Atmosphere Model (CAM5.1) by comparing simulations with and without incorporating urban land cover and/or anthropogenic aerosol emissions. Results show that the increase of urban land cover causes large surface warming and an urban frictional drag, both leading to a northeasterly wind anomaly in the lower troposphere over eastern China (EC). This weakens the southerly winds associated with the EASM and causes a convergence anomaly in southern China (SC) with increased ascent, latent heating, and cloudiness. The enhanced latent heating reinforces surface convergence and upper-level divergence over SC, leading to more northward advection in the upper level into northern China (NC) and descending between 30° and 50°N over East Asia. Cloudiness reduction, adiabatic heating, and warm advection over NC all enhance the urban heating there, together causing anomalous tropospheric warming at those latitudes over East Asia. Anthropogenic aerosols cause widespread cooling at the surface and in the troposphere over EC, which decreases the summer land?ocean thermal contrast, leading to a weakened EASM circulation with reduced moisture transport to NC. This results in wetter and drier conditions over SC and NC, respectively. When both the urbanization and anthropogenic aerosols are included in the model, aerosols? cooling is partially offset by the urban heating, and their joint effect on the circulation is dominated by the aerosols? effect with a reduced magnitude. In the combined experiment, surface and tropospheric temperatures are also altered by the decrease (increase) in cloudiness over NC (SC) with most of the cooling confined to SC, which further weakens the EASM circulation.
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contributor author | Jiang, Zhihong;Huo, Fei;Ma, Hongyun;Song, Jie;Dai, Aiguo | |
date accessioned | 2018-01-03T11:00:03Z | |
date available | 2018-01-03T11:00:03Z | |
date copyright | 11/2/2016 12:00:00 AM | |
date issued | 2016 | |
identifier other | jcli-d-15-0593.1.pdf | |
identifier uri | http://138.201.223.254:8080/yetl1/handle/yetl/4245871 | |
description abstract | AbstractImpacts of urbanization and anthropogenic aerosols in China on the East Asian summer monsoon (EASM) are investigated using version 5.1 of the Community Atmosphere Model (CAM5.1) by comparing simulations with and without incorporating urban land cover and/or anthropogenic aerosol emissions. Results show that the increase of urban land cover causes large surface warming and an urban frictional drag, both leading to a northeasterly wind anomaly in the lower troposphere over eastern China (EC). This weakens the southerly winds associated with the EASM and causes a convergence anomaly in southern China (SC) with increased ascent, latent heating, and cloudiness. The enhanced latent heating reinforces surface convergence and upper-level divergence over SC, leading to more northward advection in the upper level into northern China (NC) and descending between 30° and 50°N over East Asia. Cloudiness reduction, adiabatic heating, and warm advection over NC all enhance the urban heating there, together causing anomalous tropospheric warming at those latitudes over East Asia. Anthropogenic aerosols cause widespread cooling at the surface and in the troposphere over EC, which decreases the summer land?ocean thermal contrast, leading to a weakened EASM circulation with reduced moisture transport to NC. This results in wetter and drier conditions over SC and NC, respectively. When both the urbanization and anthropogenic aerosols are included in the model, aerosols? cooling is partially offset by the urban heating, and their joint effect on the circulation is dominated by the aerosols? effect with a reduced magnitude. In the combined experiment, surface and tropospheric temperatures are also altered by the decrease (increase) in cloudiness over NC (SC) with most of the cooling confined to SC, which further weakens the EASM circulation. | |
publisher | American Meteorological Society | |
title | Impact of Chinese Urbanization and Aerosol Emissions on the East Asian Summer Monsoon | |
type | Journal Paper | |
journal volume | 30 | |
journal issue | 3 | |
journal title | Journal of Climate | |
identifier doi | 10.1175/JCLI-D-15-0593.1 | |
journal fristpage | 1019 | |
journal lastpage | 1039 | |
tree | Journal of Climate:;2016:;volume( 030 ):;issue: 003 | |
contenttype | Fulltext |