Role of ITCZ Shifts on Barotropic Instability: The Effects of Moisture and Implications for Tropical Cyclones

Student Seminar Series

Department of Atmospheric & Oceanic Sciences

presents

a talk by

Eric Bembenek
PhD candidate

Role of ITCZ Shifts on Barotropic Instability: The Effects of Moisture and Implications for Tropical Cyclones

The Intertropical Convergence Zone (ITCZ) is a barotropically unstable region and an important generator of tropical cyclones (TCs). The ITCZ is seen to shift poleward during northern hemisphere summer and asymmetries between the hemispheres in their respective global warming signatures imply a further shift to the north. Dynamics of both the ITCZ and the TCs it generates are strongly influenced by precipitation through the release of latent heat. Here we consider the role of moisture on TC genesis and the latitudinal position of the ITCZ. To this end, we use a shallow water model with a prescribed heating function and parameterized precipitation. Both the heating function and the precipitation are modelled as mass sinks, the difference being that the precipitation mass sink is determined by the dynamics of the flow. We evaluate the energetics of the system and TC genesis as a function of the latitudinal position of the prescribed heating and a parameter controlling the strength of precipitation-related latent heat release.

Wednesday Oct 09/ 2.30 PM/ Room 934 Burnside Hall