Nishida Prize

Yu Kosaka


Research on mechanisms of tropical atmosphere-ocean interactions and teleconnection patterns related to climate variability and extreme weather

A list of five major papers

  • Kosaka, Y., and S.-P. Xie, 2016: The tropical Pacific as a key pacemaker of the variable rates of global warming. Nature Geoscience, 9, 669-673.
  • Kosaka, Y., and S.-P. Xie, 2013: Recent global-warming hiatus tied to equatorial Pacific surface cooling. Nature, 501, 403-407.
  • Kosaka, Y., S.-P. Xie, N.-C. Lau, and G. A. Vecchi, 2013: Origin of seasonal predictability for summer climate over the Northwestern Pacific. Proceedings of the National Academy of Sciences of the United States of America, 110, 7574- 7579.
  • Kosaka, Y., and H. Nakamura, 2010: Mechanisms of meridional teleconnection observed between a summer monsoon system and a subtropical anticyclone. Part I: The Pacific-Japan pattern. J. Climate, 23, 5085-5108.
  • Kosaka, Y., H. Nakamura, M. Watanabe, and M. Kimoto, 2009: Analysis on the dynamics of a wave-like teleconnection pattern along the summertime Asian jet based on a reanalysis dataset and climate model simulations. J. Meteorological Society of Japan, 87, 561-580.

Major achievements

Yu Kosaka has made world-leading research results on atmospheric circulation changes associated with tropical ocean-atmosphere variability and its relationship with global warming through active international joint research. First, “the pacemaker experiment” with an atmosphere-ocean coupled model was developed which constrains the natural variation of the tropical Pacific Ocean to the observed history while the anthropogenic radiative forcing by greenhouse gas increase is prescribed. She found that the remote effects of the tropical Pacific variability caused acceleration and deceleration of the observed global mean temperature rise. This novel technique has become the world standard now, and it is included in the protocol of the sixth Coupled Model Intercomparison Project. She also serves as the lead author of the IPCC 6th Assessment Report. Additionally, she clarified the dynamical characteristics of atmospheric circulation variability called “the PJ pattern”, which brings about abnormal weather in summertime East Asia, and its modulations under the global warming. She further showed its coupling with a tropical Indo-Pacific Ocean variability. These achievements, especially her contribution to the fusion of the research fields of natural climate variability and global warming, are highly appreciated both domestically and internationally.