Summary of Abstract Submission

Abstract Submission No. IO50-05-0001PresentationOral



1 Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India


This abstract summarizes the delayed impact of the Indian Ocean Dipole Mode (IODM) on the East Asian Summer Monsoon (EASM) in particular over the Korea-Japan sector. Analysis suggests that the impact of IODM is more on the EASM rather than on the South Asian Summer Monsoon. Results reveal that the peak positive phase of the dipole during autumn could suppress the following summer monsoon activity over East Asia three seasons later, in particular over the Korea-Japan sector, South China and the adjacent West Pacific region. Composite and correlation analysis suggests that the autumn positive phase of the dipole could induce heavy snow over Eastern Eurasia, just north of the Korea-Japan peninsula, during the following winter and spring seasons. This could increase the temperature gradient conducive to transport cold and dry air towards East Asia during the following summer. The anomalous northerly winds due to heavy snow displace the North Pacific Subtropical High eastwards, resulting in a weak low-level jet. This could inhibit moisture supply from the Pacific leading to subdued rainfall activity. The footprints of the IODM for delayed response, three seasons later, could be carried by the snow distribution over Eastern Eurasia or through the Sea Surface Temperatures through the Indonesian Through-Flow Sector. Furthermore partial correlation analysis suggests that the IODM has more impact than ENSO on the EASM. A positive dipole prevailed over the Indian Ocean during autumn (SON) 2007, excessive snow during winter (January) 2008 over China and just north of Korea-Japan was also reported. The North Pacific Subtropical High weakened during summer (JJA) 2008 resulting in a severe drought over Korea-Japan during summer 2008. Exactly opposite conditions prevailed during SON 2010 JJA 2011, leading to unusual heavy rains over Korea-Japan during JJA 2011. Though a one-to-one correspondence cannot be claimed, such type of information could serve as useful guidelines for planners, managers to adopt suitable strategies.