Evolving perspectives on abrupt seasonal changes of the general circulation
Professor Duzheng YE (Tu-cheng YEH) was decades ahead of his time in proposing a model experiment to investigate whether abrupt seasonal changes of the general circulation can arise through circulation feedbacks alone, unrelated to underlying inhomogeneities at the lower boundary. Here, we introduce Professor YEH's ideas during the 1950s and 1960s on the general circulation and summarize the results and suggestions of Yeh et al. (1959) on abrupt seasonal changes. We then review recent advances in understanding abrupt seasonal changes arising from model experiments like those proposed by Yeh et al. (1959). The model experiments show that circulation feedbacks can indeed give rise to abrupt seasonal transitions. In these transitions, large-scale eddies that originate in midlatitudes and interact with the zonal mean flow and meridional overturning circulations in the tropics play central roles.
© 2017 Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag GmbH Germany. Received 29 March 2017; revised 21 June 2017; accepted 28 June 2017. First Online: 17 August 2017. J. H. LU is indebted to Professor YEH's mentoring over more than two decades. Both authors acknowledge the Organization Committee of Professor YEH's Centenary Symposium for the invitation to the symposium. J. H. LU is grateful for the support from the LASG during his visit to the lab. J. H. LU is supported by the National Nature Science Foundation of China (Grant No. 4157060636) and the Hundred Talents Program of Sun Yat-sen University.