Sensitivity experiments of impacts of large-scale urbanization in East China on East Asian winter monsoon

By using the global atmospheric general circulation model CAM4.0 including an urban canopy parameterization scheme, the possible impacts of large-scale urbanization in East China on East Asian winter monsoon was investigated via idealized numerical experiments. Results suggest that large-scale urbanization can cause a significant warming effect in both surface temperature and air temperature near the surface over most areas of East China. Meanwhile, large-scale urbanization also alters the surface energy balance, causing evident increases in net surface long-wave radiation and sensible heat flux as well as intensified surface thermal heating to the atmosphere. Forced by the surface thermal heating anomalies induced by the large-scale urban expansion, East Asian winter monsoon circulation exhibits distinct changes. Overall, the extensive urbanization over East China will weaken East Asian winter monsoon, but intensify winter monsoon in northeast China.