SLS Seminar: Brian Green (MIT)
"The damping of ITCZ shifts by the ocean circulation through its coupling to the trade winds"
Global-scale rain bands in the tropics, known as the intertropical convergence zone (ITCZ), are sensitive to the atmosphere’s energy balance and reside in the hemisphere most strongly heated by radiation and surface heat fluxes. Coupled to the atmosphere above by the trade winds that feed the ITCZ, the tropical ocean circulation is capable of transporting large amounts of energy across the equator, strongly affecting the energy balance and the position of the ITCZ. Using a coupled atmosphere-ocean general circulation model, we show how the coupling of the trade winds to the ocean’s subtropical cells results in a robust damping of northsouth ITCZ shifts by up to a factor of four on interannual and longer timescales. This damping effect can be quantified using a simple model of the atmosphere’s hemispheric energy balance that accounts for the structure of the inter-hemispheric system. Implications of these results for past and future changes in tropical rainfall will be discussed.
About the Speaker
Brian Green's interests lie in ocean dynamics, their role in climate, and the use of numerical techniques to model them. He was lead author on a recent study which showed interaction between ocean circulation and the trade winds damps movement of the ITCZ (Inter Tropical Convergence Zone) to transport heat across the equator. Green's PhD advisor is John Marshall.
About the Series
The Atmosphere, Ocean and Climate Sack Lunch Seminar Series is an informal seminar series within PAOC that focuses on more specialized topics than the PAOC Colloquium. Seminar topics include all research concerning the science of atmosphere, ocean and climate. The seminars usually take place on Wednesdays from 12-1pm in 54-915. The presentations are either given by an invited speaker or by a member of PAOC and can focus on new research or discussion of a paper of particular interest.