Ho-Hsuan Wei will work with Kris Karnauskas and others at CIRES to better understand the dynamics of variability within the Intertropical Convergence Zone (ITCZ). In particular, Ho-Hsuan will focus on the annual cycle of the ITCZ and its relation to the ocean energy transport.
The ITCZ is a zonally-elongated band of deep convective clouds in the tropics, which migrates seasonally with a more northward (southward) position in boreal (austral) summer. Understanding these tropical rainbands, which deliver water to regions strongly dependent on agriculture, is a major challenge for the climate sciences. While recent theoretical advances based on energetic constraints have provide important insight on understanding the response of the ITCZ position, it is shown that the relation between the ITCZ position and energetic quantities is more complicated under subseasonal timescales due to the changes in the Hadley circulation vertical structure. Also, the partition between the ocean and atmospheric energy transports can lead to different responses of the ITCZ position under energetic framework. By prescribing both fixed and seasonally varying ocean energy transport data and analyzing with a coupled atmosphere-ocean model, Ho-Hsuan aims to extend understanding of the annual cycle of the Hadley cells and the ITCZ.