Simulation of direct radiative forcing of aerosols and their effects on East Asian climate using an interactive AGCM-aerosol coupled system

Abstract

International audienceAn interactive system coupling the Beijing Climate Center atmospheric general circulation model (BCC_AGCM2. 0. 1) and the Canadian Aerosol Module (CAM) with updated aerosol emission sources was developed to investigate the global distributions of optical properties and direct radiative forcing (DRF) of typical aerosols and their impacts on East Asian climate. The simulated total aerosol optical depth (AOD), single scattering albedo, and asymmetry parameter were generally consistent with the ground-based measurements. Under all-sky conditions, the simulated global annual mean DRF at the top of the atmosphere was -2. 03 W m-2 for all aerosols including sulfate, organic carbon (OC), black carbon (BC), dust, and sea salt; the global annual mean DRF was -0. 23 W m-2 for sulfate, BC, and OC aerosols. The sulfate, BC, and OC aerosols led to decreases of 0. 58° and 0. 14 mm day-1 in the JJA means of surface temperature and precipitation rate in East Asia. The differences of land-sea surface temperature and surface pressure were reduced in East Asian monsoon region due to these aerosols, thus leading to the weakening of East Asian summer monsoon. Atmospheric dynamic and thermodynamic were affected due to the three types of aerosol, and the southward motion between 15°N and 30°N in lower troposphere was increased, which slowed down the northward transport of moist air carried by the East Asian summer monsoon, and moreover decreased the summer monsoon precipitation in south and east China. © 2011 Springer-Verlag

Tempo-spatial characteristics of sub-daily temperature trends in mainland China

“…The long-term change in surface solar radiation over mainland China was attributed to global and regional changes of aerosol properties in the early 1990s (Qian et al 2007). However Shi et al (2008) also noted changes in Chinese radiation instrumentation in the early 1990s, and Zhang et al (2012) in a modelling study derive overall negative direct radiative forcing, and resultant coolness, over eastern Asia given recent (after 2000) anthropogenic aerosol emissions.…”

Simultaneous reductions in emissions of black carbon and co-emitted species will weaken the aerosol net cooling effect

“…We use the aerosol-climate atmosphere-only model BCC_AGCM2.0.1_CUACE/Aero developed by Zhang et al (2012a), and improved by Jing and Zhang (2013), Zhang et al (2014), and Z. L. in this study. The aerosol direct, semi-direct, and indirect effects (albedo and lifetime indirect effects on stratiform clouds) have been included in BCC_AGCM2.0.1_CUACE/Aero.…”

“…The aerosol direct, semi-direct, and indirect effects (albedo and lifetime indirect effects on stratiform clouds) have been included in BCC_AGCM2.0.1_CUACE/Aero. The model has been used to study the impact of aerosol direct radiative effect on East Asian climate (Zhang et al, 2012a), direct radiative forcing of anthropogenic aerosols (Bond et al, 2013;Myhre et al, 2013a), climate response to the presence of BC in cloud droplets , effect of non-spherical dust aerosol on its direct radiative forcing (Wang et al, 2013b), anthropogenic aerosol indirect effect (Z. L. , and direct effect of dust aerosol on arid and semi-arid regions .…”

Application and evaluation of a new radiation code under McICA scheme in BCC_AGCM2.0.1

“…Experiments were designed to reveal (a) the differences in simulated climate between the two configurations and (b) the impact of changing subgrid cloud structures on simulated climate within the new configuration. For all the following experiments, the sea surface temperature (SST) data are from the global Hadley Centre Sea Ice and Sea Surface Temperature (HadISST) data set (Rayner et al, 2003) for years up to 1981 and the Reynolds et al (2002) for years after 1981; the greenhouse gases are set the same by using the current values; aerosols are produced by a coupled aerosol model (named CAM) that is described in detail in Zhang et al (2012). All of the experiments are integrated from September 1979 to December 1990, and the results of the last 10 years are used for analysis.…”