Premium
Impact of Southeast Asian smoke on aerosol properties in Southwest China: First comparison of model simulations with satellite and ground observations
Author(s) -
Zhu Jun,
Xia Xiangao,
Wang Jun,
Zhang Jinqiang,
Wiedinmyer Christine,
Fisher Jenny A.,
Keller Christoph A.
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd025793
Subject(s) - aerosol , china , environmental science , chemical transport model , sun photometer , biomass burning , satellite , climatology , smoke , peninsula , atmospheric sciences , range (aeronautics) , meteorology , geography , geology , materials science , archaeology , aerospace engineering , engineering , composite material
Smoke aerosols have been observed in Southwest China as a result of long‐range transport from surrounding areas in March and April. The processes driving this transport and the resultant impact on regional aerosol optical properties are studied here through a combined use of the Goddard Earth Observing System (GEOS)‐Chem chemistry transport model in conjunction with satellite and the first‐ever ground‐based observations in the Southwest China. The potential biomass burning source regions as well as their respective contributions to aerosol loading in Southwest China are quantified. Compared to Sun photometer observations of aerosol optical depth (AOD) at 550 nm at eight stations in the study region (10–28°N, 90–115°E, comprising Northeast India, Indo‐China Peninsula, and Southwest and South China), the AOD simulated by GEOS‐Chem (nested grid with 0.5° × 0.667° resolution) by using the Fire Inventory from National Center for Atmospheric Research shows an average bias of −0.17 during January 2012 to May 2013. However, during the biomass burning months (March–April), the simulated AOD is much improved with a bias of −0.04. Model sensitivity experiments show that biomass burning in Burma and Northeast India is the largest contributor to smoke AOD (~88%) and total AOD (~57%) over Kunming, an urban site in Southwest China. Case studies on 21–23 March 2013 show that the smoke layer in Northeast India and North Burma can extend from the surface to 4 km and then be transported to Southwest China by prevailing westerly airflow. Model‐simulated AOD and vertical distribution of aerosols are respectively in good agreement with satellite measurements from Moderate Resolution Imaging Spectroradiometer and Cloud‐Aerosol Lidar with Orthogonal Polarization.