Mechanism on how the spring arctic sea ice impacts the East Asian summer monsoon

TittelMechanism on how the spring arctic sea ice impacts the East Asian summer monsoon
PublikasjonstypeJournal Article
ForfattereGuo, D, Gao, Y, Bethke, I, Gong, D, Johannessen, OM, Wang, H
TidsskriftTheoretical and Applied Climatology

Observational analysis and purposely designed coupled atmosphere–ocean (AOGCM) and atmosphere-only (AGCM) model simulations are used together to investigate a new mechanism describing how spring Arctic sea ice impacts the East Asian summer monsoon (EASM). Consistent with previous studies, analysis of observational data from 1979 to 2009 show that spring Arctic sea ice is significantly linked to the EASM on inter-annual timescales. Results of a multivariate Empirical Orthogonal Function analysis reveal that sea surface temperature (SST) changes in the North Pacific play a mediating role for the inter-seasonal connection between spring Arctic sea ice and the EASM. Large-scale atmospheric circulation and precipitation changes are consistent with the SST changes. The mechanism found in the observational data is confirmed by the numerical experiments and can be described as follows: spring Arctic sea ice anomalies cause atmospheric circulation anomalies, which, in turn, cause SST anomalies in the North Pacific. The SST anomalies can persist into summer and then impact the summer monsoon circulation and precipitation over East Asia. The mediating role of SST changes is highlighted by the result that only the AOGCM, but not the AGCM, reproduces the observed sea ice-EASM linkage.

Refereed DesignationRefereed
Forfatterens adresse


guo_etal_2012_mechanism_on_how_the_spring_arctic_sea_ice_impacts_the_east_asian_summer_monsoon.pdf3.79 MB