资源环境科技发展态势分析平台

Using the Goddard Earth Observing System (GEOS)-Chem model driven by GEOS-4 assimilated meteorological data, the potential influence of two La Nina Modoki events on aerosol concentrations over eastern China is explored. The results indicate that the impact of La Nina Modoki on aerosol concentrations differs between strong and moderate events. During the mature phase of the strong event of 1998/1999, an anomalous dipole pattern is observed over eastern China, i.e., with increased aerosol concentrations in the south and reduced concentrations in the north. The dipole pattern in the moderate event of 2000/2001 is reversed, with reduced aerosol concentrations in the south and increased concentrations in north China. Additionally, decreased aerosol concentrations are seen in spring of the decaying phase for the 1998/1999 event, while in the decaying spring of the 2000/2001 event, the dipole is reversed relative to the mature phase. During the decaying summer, aerosol concentrations are found to increase over eastern China in the 1998/1999 event but not in the 2000/2001 event. These anomalous aerosol concentrations are mainly caused by changes in circulation associated with the two La Nina Modoki events. In contrast, the role of wet deposition is observed to be limited during the lifespan of these two events. It is also found that the potential influence of the two La Nina Modoki events on aerosol concentrations can be up to 20% of the climatological mean. This suggests that La Nina Modoki has an important role in determining the distribution of aerosol concentrations over eastern China.