JpGU-AGU Joint Meeting 2017

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[EE] Oral

A (Atmospheric and Hydrospheric Sciences) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS07] [EE] Aerosol impacts on air quality and climate

Mon. May 22, 2017 10:45 AM - 12:15 PM 101 (International Conference Hall 1F)

convener:Kyu-Myong Kim(NASA Goddard Space Flight Center), Teppei J Yasunari(Faculty of Engineering, Hokkaido University), Mian Chin(NASA Goddard Space Flight Center), Toshihiko Takemura(Research Institute for Applied Mechanics, Kyushu University), Chairperson:Mian Chin(NASA/Goddard Space Flight Center), Chairperson:Teppei Yasunari(Faculty of Engineering, Hokkaido University), Chairperson:Toshihiko Takemura(Research Institute for Applied Mechanics, Kyushu University), Chairperson:Kyu-Myong Kim(NASA/Goddard Space Flight Center)

10:45 AM - 11:00 AM

[AAS07-07] Increases in wintertime aerosol concentrations and severe haze days in eastern China over the past decades: Roles of variations in meteorological parameters and anthropogenic emissions

★Invited papers

*Hong Liao1, Yang Yang2, Ke Li3 (1.School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, China , 2.Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA, 3.Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China)

Keywords:air quality, aerosol, climate change, severe haze, eastern China

The increases in wintertime aerosol concentrations and severe haze days in eastern China over the past decades were quantified by using observed atmospheric visibility, observed PM2.5 concentrations, simulated PM2.5 concentrations from the Goddard Earth-Observing System (GEOS) chemical transport model (GEOS-Chem), as well as simulated climate change from 15 CMIP5 climate models. Observed winter haze days (defined as days with atmospheric visibility less than 10 km and relative humidity less than 80%) averaged over eastern China (105–122.5°E, 20–45°N) increased from 21 days in 1980 to 42 days in 2014. Averaged over eastern China, simulated wintertime surface-layer PM2.5 concentrations from the GEOS-Chem model exhibited an increasing trend of 10.5 (±6.2) μg m-3 decade-1 over eastern China in the past decades, in which the changes in anthropogenic emissions and in climate contributed 87% and 17%, respectively. Observed severe haze days (defined as days with observed PM2.5 >150 μg m-3) occurred mainly over Northern China. Conducive weather conditions, such as reduced surface winter northerlies, weakened northwesterlies in the midtroposphere, and enhanced thermal stability of the lower atmosphere, were an important ingredient of severe haze episodes. Results from the 15 CMIP5 models showed that the frequency of weather conditions conducive to severe haze events in northern China increased substantially under greenhouse warming.