Dr. Tianjun Zhou
LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing

Changes of East Asian summer monsoon: Past, Present and Future

Time and place
Wed 27 Feb 2013, 14.00
Room C609, Arrhenius Laboratory, 6th floor

(This event has taken place)


Summer monsoon affects billions of peoples’ livelihoods over East Asia. The East Asian summer monsoon (EASM) has been weakening in the last halve of the 20th century and led to shortage of water resource in North China. Understanding the reasons of EASM weakening has been a challenge of monsoon study community. The proposed mechanisms range from global warming to anthropogenic aerosols. In this seminar, based on both data diagnosis and numerical modeling, the author will show evidences that the weakening EASM in the last halve of the 20th century is regional manifestation of global monsoon (GM) change, which was driven by the tropical lobe of Pacific Decadal Oscillation (PDO). The PDO-driven natural variation of EASM overwhelms the impact of global warming. The weakening tendency of GM is only a phenomena starting from the 1950s, the early century (1901-1955) witnessed an upward trend. Both proxy data and numerical modeling show that the recent weakening of EASM is not unprecedented in the past millennium. Future changes of EASM projected by CMIP5 models under RCP4.5 scenario indicate an enhanced monsoon circulation and increased precipitation.