@article{453ff391fe5d426fade4d1d52b1b9df8,
title = "The Impact of the Aerosol Direct Radiative Forcing on Deep Convection and Air Quality in the Pearl River Delta Region",
abstract = "Literature has reported the remarkable aerosol impact on low-level cloud by direct radiative forcing (DRF). Impacts on middle-upper troposphere cloud are not yet fully understood, even though this knowledge is important for regions with a large spatial heterogeneity of emissions and aerosol concentration. We assess the aerosol DRF and its cloud response in June (with strong convection) in Pearl River Delta region for 2008–2012 at cloud-resolving scale using an air quality-climate coupled model. Aerosols suppress deep convection by increasing atmospheric stability leading to less evaporation from the ground. The relative humidity is reduced in middle-upper troposphere due to induced reduction in both evaporation from the ground and upward motion. The cloud reduction offsets 20% of the aerosol DRF. The weaker vertical mixing further increases surface aerosol concentration by up to 2.90 μg/m3. These findings indicate the aerosol DRF impact on deep convection and in turn regional air quality.",
keywords = "aerosol, air quality, direct radiative forcing, feedback",
author = "Z. Liu and Yim, {Steve H.L.} and C. Wang and Lau, {N. C.}",
note = "Funding Information: This work is jointly supported by the Early Career Scheme of Research Grants Council of Hong Kong (grant CUHK24301415), the National Key Basic Research Program of China (grant 2015CB954103), the Improvement on Competitiveness in Hiring New Faculties Fund (2013/2014) of The Chinese University of Hong Kong (grant 4930059), and the Vice-Chancellor{\textquoteright}s Discretionary Fund of The Chinese University of Hong Kong (grant 4930744). We thank the two anon ymous reviewers for their constructive comments and suggestions. The authors thank the MIT Greater China Fund for Innovation 2015 for facilitating the collaboration between the CUHK and MIT research teams. We would also like to thank Prof. Kai Wang from NCSU for helping with model configuration of the 2005 carbon bond mechanism and the Information Technology Services Centre (ITSC) at CUHK for technical support. The ERA-Interim data are available from European Centre for Medium-Range Weather Forecasts (http://apps.ecmwf.int/datasets/data/ interim-full-moda/levtype=sfc/). The downward SW radiation is available from the World Radiation Data Center (http://wrdc.mgo.rssi.ru/). The Level-3 Moderate Resolution Imaging Spectroradiometer MYD08 monthly cloud product (collection 6) is provided by the Land Processes Distributed Active Archive Center (LP DAAC) managed by NASA (ftp://ladsweb.nascom. nasa.gov/allData/6/MYD08_M3). The L2B radar reflectivity and cloud mask products (2B-GEOPROF) are provided by CloudSat Data Processing Center (ftp:// ftp.cloudsat.cira.colostate.edu). The in situ meteorology and air-quality observations are provided by Hong Kong Observatory (http://www.hko.gov.hk/ cis/climat_e.htm) and Hong Kong Environmental Protection Department (https://cd.epic.epd.gov.hk/EPICDI/air/ station/?lang=en). Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = may,
day = "16",
doi = "10.1029/2018GL077517",
language = "English (US)",
volume = "45",
pages = "4410--4418",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "9",
}