Climate Response due to Black Carbon Aerosols and Black-Carbon-induced SST Effects in MIROC5.0

Abstract:

This study used the Models for Interdisciplinary Research on Climate, MIROC5.0, one member of the Coupled Model Intercomparison Project (CMIP5), to investigate the effects of black carbon (BC) aerosols on atmospheric circulations and climate including intricate feedback mechanism. The simulations with and without BC were conducted and the difference between these two runs is the corresponding response due to BC. Both atmosphere-ocean coupled general circulation model simulation (CGCM with full ocean) and the fixed SST runs (AGCM with prescribed sea surface temperature and sea ice temperature) were used to study the effects from ocean boundary conditions. The regional effects due to BC may be much larger than models have assumed (Andreae and Ramanathan, 2013; Bond et al., 2013). There are many studies used simplified mixed-layer ocean under prescribed surface heat flux to estimate the climate effect of BC (Kim et al., 2014), however these ocean-atmosphere coupled processes act on seasonal and annual time scales more real than non-ocean-atmosphere coupled models. Our results showed that the comprehensively sea-air interaction amplified the heating effect of black carbon aerosols; the presence of BC affected climate not only at local source areas but also at remote regions due to changes on energy transport processes and atmospheric circulations; we also discussed how the feedback of SST induced by BC affected on the distribution and magnitudes of climate response such as temperature, precipitation and cloud coverage between CGCM and AGCM runs.