Nishida Prize

Yoshio Kawatani

Commendation

Studies on atmospheric gravity waves and quasi-biennial oscillations and changes in stratospheric circulation associated with climate change

A list of five major papers

  • Kawatani, Y., M. Takahashi, K. Sato, S. P. Alexander, and T. Tsuda, 2009: Global distribution of atmospheric waves in the equatorial upper troposphere and lower stratosphere: AGCM simulation of sources and propagation, J. Geophys. Res, 114, D01102, doi:10.1029/2008JD010374.
  • Kawatani, Y., K. Sato, T. J. Dunkerton, S. Watanabe, S. Miyahara, and M. Takahashi, 2010a: The roles of equatorial trapped waves and internal inertia-gravity waves in driving the quasi-biennial oscillation. Part I: Zonal mean wave forcing, J. Atmos. Sci., 67, 963-980.
  • Kawatani, Y., K. Sato, T. J. Dunkerton, S. Watanabe, S. Miyahara, and M. Takahashi, 2010b: The roles of equatorial trapped waves and internal inertia-gravity waves in driving the quasi-biennial oscillation. Part II: Three-dimensional distribution of wave forcing, J. Atmos. Sci., 67, 981-997.
  • Kawatani, Y., K. Hamilton and S. Watanabe, 2011: The Quasi-biennial oscillation in a double CO2 climate, J. Atmos. Sci., 68, 265-283.
  • Kawatani, Y. and K. Hamilton, 2013: Weakened stratospheric Quasibiennial Oscillation driven by increased tropical mean upwelling, Nature, 497, 478-481, doi:10.1038/nature12140.

Major achievements

Yoshio Kawatani has effectively combined high-resolution climate model experiments, observation data from meteorological stations and satellites, and analysis of global atmospheric reanalysis data, and has published cutting-edge results in publications such as Nature, on the mechanism of the “Quasi-2-year oscillation (QBO)” of equatorial stratospheric east-west winds involving atmospheric gravity waves of tropospheric origin that have been largely unexplained, as well as on the modulations accompanying global warming. Atmospheric gravity waves can only be expressed explicitly by high-resolution atmospheric models. First, he estimated the three-dimensional propagation of the atmospheric gravity wave which caused the QBO from the atmospheric model experiment of the highest resolution in the world in those days, which was developed by his supervisors, and obtained new knowledge on the excitation source. Furthermore, by analyzing the experimental results of other high-resolution models, he reversed the academic prediction that the QBO cycle would increase and weaken as a result of future warming. Moreover, the identification of the weakening of the QBO from meteorological station data is an important climatological and climatological achievement as evidence of the progress of warming. Dr. Kawatani has already been honored twice by the Japan Meteorological Society and has been active in international committees.

Nominator

Masaaki Takahashi