GAFD Seminar: Ruth Geen (University of Birmingham)

Wednesday, 11 November 2026 at 12:30

Is it a Monsoon? Dynamical Regime Analyses of Climate Models

Event details

Title: Is it a Monsoon? Dynamical Regime Analyses of Climate Models 

Abstract: “Global monsoon” describes the global movement of the intertropical convergence zone north and south across the equator throughout the year. This concept of the monsoon as a global system has been studied widely using a hierarchy of models, including aquaplanet simulations, in which an Earth-like simulation is run for an entirely water covered planet. This seminar will review the insights gathered from this approach, and ask ’is the aquaplanet monsoon truly comparable to Earth’s global and regional monsoon systems’. Using a novel regime analysis tool, NEMI, across a model hierarchy, we interrogate the upper-level momentum budget of the regional Hadley cells. We show that a summertime ‘angular momentum conserving’ regime is seen broadly across much of the global tropics, consistent with the aquaplanet perspective. However, a closer look at the South Asian monsoon reveals a strong role for stationary vs transient waves, counter to results from aquaplanet simulations.

Organiser

Mathematics and Statistics

Location

Laver 320